Pear and dendrobium composite fruit paste, color protection method and color protection device

Abstract

The invention relates to the technical field of fruit paste processing, and particularly discloses pear and dendrobium composite fruit paste, a color protection method and a color protection device.The pear and dendrobium composite fruit paste comprises a reaction frame and a blending structure, a color protection tank is arranged above the reaction frame, a stirring assembly is arranged above the color protection tank, and a turning assembly is arranged on one side of the bottom of the color protection tank; the pear pulp and the dendrobium nobile juice are used as raw materials to prepare the pear and dendrobium nobile composite fruit paste with unique flavor, the pear and dendrobium nobile composite fruit paste has certain market value and economic benefit, and the browning index is used as an evaluation index to determine the optimal color protection formula of the pear and dendrobium nobile composite fruit paste through single factor and orthogonal tests; a pasteurization method, a microwave sterilization method and a high-temperature steam sterilization method are used for treating the pear and dendrobium composite fruit paste respectively, the change condition of the quality of the treated pear and dendrobium composite fruit paste stored at 4 DEG C for 10 days is analyzed and compared, and a sterilization mode suitable for processing of the pear and dendrobium composite fruit paste is analyzed.

Description

Technical Field

[0001] The present invention relates to the technical field of puree processing, and particularly relates to a pear and dendrobium officinale composite puree, a color protection method and a color protection device. Background Art

[0002] Pear, a plant of the genus Pyrus in the Rosaceae family, is rich in nutrients such as sugars, malic acid, vitamin B1, vitamin B2, vitamin C, and carotene, and has high nutritional value. In addition, pears have various effects such as clearing heat and reducing fire, promoting saliva secretion, and moistening the lungs. However, due to the strong respiration of pear fruits and the rich content of phenolic substances, they are prone to browning during storage and after being made into puree, greatly reducing their commercial value and causing economic losses. In addition, the flesh of pears is light and lacks flavor. Therefore, enhancing flavor and alleviating browning are the keys to improving the quality of pear puree.

[0003] Dendrobium officinale refers to the fresh or dried stems of the plant Dendrobium officinale in the Orchidaceae family, which contains various active ingredients such as polysaccharides, stilbenoids, and alkaloids. Modern pharmacological research shows that Dendrobium officinale has various biological activities such as enhancing immunity, antioxidant activity, anti-tumor activity, and hypoglycemic activity. Therefore, adding a certain proportion of Dendrobium officinale juice to pear puree helps to improve the quality of pear puree, make its flavor unique, and strengthen its nutritional function. At the same time, the antioxidant activity of Dendrobium officinale also helps to inhibit the browning of pear puree.

[0004] The patent document with the publication number "CN103099146A" discloses a fruit granule filling for baked foods, which is composed of 1-40wt% of fresh fruit granules and 60-99wt% of fruit puree; the above invention makes the fresh fruit granules be wrapped in the fruit puree, and through the selection and optimization of the gelling agent, the fruit puree has a certain high-temperature resistance to the greatest extent, so as to protect the fresh fruit filling therein and reduce the water loss during baking; in addition, the above invention also performs color protection and hardening protection treatment on the fresh fruit granules. Therefore, the fruit granule filling provided by the above invention, when used as the filling or sandwich of baked foods, will not show phenomena such as shrinkage and collapse even after high-temperature baking, and the fruit granules therein can still maintain a taste, flavor, and nutritional value similar to those of fresh fruit granules; and its combination with the outer fruit puree can also provide different tastes and flavors, improving the commercial value of the product.

[0005] The prior art is a general treatment method for various fruits. However, in the food field, different raw materials, formulas, and sterilization methods will directly affect the quality, taste, shelf life, etc. of the product. Currently, there is less research on pear puree products. Therefore, producing a pear and dendrobium officinale composite puree product with a unique flavor and rich nutrition will have good market value and economic benefits. Summary of the Invention

[0006] In order to solve the problem that there is less research on pear puree products in the prior art, the present invention provides a pear and dendrobium compound puree, a color protection method and a color protection device, so as to produce a pear and dendrobium compound puree product with unique flavor and rich nutrition.

[0007] The first technical solution of the present invention: The pear and dendrobium compound puree includes the following components by weight:

[0008] 55-70 parts of pear puree, 12-17 parts of dendrobium juice, 4.2-4.8 parts of granulated sugar, 1.8-2.4 parts of maltose, 0.61-0.82 parts of citric acid, 0.03-0.05 parts of ascorbic acid, 0.7-0.9 parts of sodium chloride;

[0009] In the present invention, the pear and dendrobium compound puree not only retains the natural flavor of fruits, but also enhances the dietary value of nourishing yin and clearing heat. While providing a suitable sweetness, granulated sugar and maltose delay the growth of microorganisms through osmotic pressure regulation. The color protection agent composed of citric acid, ascorbic acid and sodium chloride can not only inhibit enzymatic browning and maintain color, but also inhibit the growth of spoilage bacteria through pH adjustment.

[0010] Preferably, it includes the following components by weight:

[0011] 58-67 parts of pear puree, 13-16 parts of dendrobium juice, 4.3-4.7 parts of granulated sugar, 1.9-2.3 parts of maltose, 0.51-0.72 parts of citric acid, 0.035-0.045 parts of ascorbic acid, 0.75-0.85 parts of sodium chloride.

[0012] Preferably, it includes the following components by weight:

[0013] 61-64 parts of pear puree, 14-15 parts of dendrobium juice, 4.4-4.6 parts of granulated sugar, 2.0-2.2 parts of maltose, 0.56-0.67 parts of citric acid, 0.038-0.042 parts of ascorbic acid, 0.78-0.82 parts of sodium chloride.

[0014] Preferably, the preparation of the pear puree includes the following steps:

[0015] (A1) Select pear fruits, wash them for 3-5 minutes, remove the outer skin and cores of the pear fruits, and then cut the pear fruits into pear blocks with a size of 1.5-2.5 cm;

[0016] (A2) Place the pear blocks in a constant temperature water bath at 80-90 °C and blanch them for 8-12 minutes to complete enzyme inactivation. Stir the pear blocks every 1-3 minutes during blanching. After blanching, transfer the pear blocks to ice water at 0-5 °C and cool them for 5-8 minutes;

[0017] (A3) Immerse the cooled pear pieces in the color protection agent, soak them at a temperature of 20-25 °C for 8-12 min, turn the pear pieces every 4-6 min during soaking, rinse the pear pieces for 1-2 min after soaking, and then drain the water for 5-10 min;

[0018] (A4) Place the pear pieces in a colloid mill and beat them with a grinding disc interval of 0.4-1.2 mm to obtain pear puree.

[0019] In the present invention, enzyme inactivation and color protection treatments are used to inhibit enzymatic browning, maintain the natural color and nutritional components of pear pulp, and reduce flavor loss caused by oxidation. Blanching and ice water cooling can inactivate enzyme activity while maintaining the crispness of the pulp; the colloid mill can retain the pulp fibers during crushing to enhance the taste level.

[0020] Preferably, the preparation of the dendrobium juice includes the following steps,

[0021] (B1) Select fresh Dendrobium officinale stems, wash them for 2-3 min, rub off the white dry skin on the surface of the Dendrobium officinale stems, and cut the Dendrobium officinale stems into stem segments of 0.8-1.2 cm;

[0022] (B2) Place the stem segments in a blender, add pure water according to a liquid-to-material ratio of 1:40-1:60, and beat them at a speed of 10000-12000 rpm for 1.5-2.5 min to obtain Dendrobium officinale homogenate;

[0023] (B3) Add citric acid with a concentration of 0.01-0.02% to the Dendrobium officinale homogenate, stir evenly, soak it at a temperature of 20-25 °C for 0.8-1.2 h, and stir the mixture for 1-2 min every 12-18 min during soaking;

[0024] (B4) Use a sieve with a mesh size of 50-70 to press-filter, filter out the insoluble Dendrobium residues, collect the filtrate, and obtain Dendrobium juice.

[0025] In the present invention, a small amount of citric acid helps Dendrobium officinale release water-soluble components, and also has the functions of adjusting the pH value and enhancing color stability.

[0026] Preferably, the preparation of the pear-dendrobium composite puree includes the following steps,

[0027] (S01) Take the pear puree and Dendrobium juice, place them in a stirrer according to a volume ratio of 3.5:1-4.5:1, and stir at a speed of 50-70 rpm for 3-5 min to obtain a mixed puree;

[0028] (S02) Place the mixed fruit pulp in a jacketed pan, boil it at a temperature of 90 - 95°C for 15 - 25 minutes, and continuously stir at a rotation speed of 20 - 30 rpm. During boiling, add granulated sugar with a mass percentage of 1.4 - 1.6% and maltose with a mass percentage of 0.6 - 0.8%.

[0029] (S03) Reduce the boiling temperature to 80 - 85°C, add granulated sugar with a mass percentage of 1.4 - 1.6% and maltose with a mass percentage of 0.6 - 0.8%, and continue boiling. After an interval of 4 - 6 minutes, reduce the boiling temperature to 70 - 75°C, and then add granulated sugar with a mass percentage of 1.4 - 1.6% and maltose with a mass percentage of 0.6 - 0.8%. Take samples from the center position of the jacketed pan every 2 - 4 minutes, place the samples in a constant temperature water bath at 18 - 22°C to balance for 4 - 6 minutes, and then place the samples in a refractometer to analyze the soluble solids content of the samples. When the soluble solids content reaches 33 - 37%, stop heating and stirring to obtain the pear - dendrobium compound fruit puree.

[0030] In the present invention, the nutrients of the pear pulp and dendrobium juice are complementary. While maintaining the natural flavor of the fruit, the bioavailability of the active ingredients of dendrobium is enhanced. Gradient sugar addition and temperature control reduce the crystallization phenomenon caused by local supersaturation of the sugar solution, maintain the integrity of the pulp cell structure through gradual adjustment of the osmotic pressure, and improve the fineness and taste level. While achieving high - temperature sterilization, the Maillard reaction process is controlled by staged cooling, and a unique flavor is formed on the basis of retaining the natural color of the raw materials.

[0031] Preferably, the sterilization process of the pear - dendrobium compound fruit puree is pasteurization or microwave sterilization or high - temperature steam sterilization.

[0032] The pasteurization method is to place the pear - dendrobium compound fruit puree filled in bottles or retort pouches in a constant temperature water bath, heat it at a temperature of 78 - 82°C for 8 - 12 minutes, invert the bottles or turn the retort pouches a total of 1 - 2 times during heating to shake the pear - dendrobium compound fruit puree evenly. After heating, place the package of the pear - dendrobium compound fruit puree in a low - temperature water bath and cool it to 20 - 25°C.

[0033] The microwave sterilization method is to place the pear - dendrobium compound fruit puree filled in bottles or retort pouches in a microwave oven, microwave - heat it at a power of 100 - 200 W for 0.8 - 1.2 minutes. After heating, place the package of the pear - dendrobium compound fruit puree in a low - temperature water bath and cool it to 20 - 25°C.

[0034] The high - temperature steam sterilization method is to place the pear - dendrobium compound fruit puree filled in bottles or retort pouches in a steam sterilizer, heat it at a temperature of 118 - 124°C and a pressure of 0.14 - 0.16 MPa for 14 - 16 minutes. After heating, place the package of the pear - dendrobium compound fruit puree in a low - temperature water bath and cool it to 20 - 25°C.

[0035] In the present invention, medium-temperature pasteurization can retain the natural flavor of fruits and the active ingredients of Dendrobium, ensuring the uniformity of microbial inactivation. The high-frequency electromagnetic wave penetration characteristics of microwave sterilization can achieve heat generation at the molecular level in a short time, and can quickly destroy the cell membrane structure of microorganisms to complete effective sterilization. High-temperature steam sterilization completely kills spore-like microorganisms through a high-pressure and humid heat environment, reducing color changes and flavor losses caused by the Maillard reaction.

[0036] The second technical solution of the present invention: A color protection method during the preparation of pear pulp, characterized by including the following steps:

[0037] (C1) Select pure water and place it in a blending structure. Load citric acid and sodium chloride into the first adjustment bottle and the second adjustment bottle respectively. Add 0.6-0.8% by mass of citric acid and 0.7-0.9% by mass of sodium chloride to the reaction kettle. Then replace the food additive in the first adjustment bottle with ascorbic acid, and add 0.03-0.05% by mass of ascorbic acid to the reaction kettle. Use a stirring paddle to stir at a rotation speed of 250-350 rpm for 4-6 minutes to obtain a composite color protection liquid.

[0038] (C2) After cutting the pear fruits into pieces, place them in a color protection tank, and add the composite color protection liquid to submerge the pear fruit pieces in the composite color protection liquid. Soak at a temperature of 20-25 °C for 8-12 minutes. During the soaking period, use a stirrer and a turning rod to turn the pear pieces every 4-6 minutes. After the soaking is over, open the water inlet pipe and the water outlet pipe to rinse the pear pieces for 1-2 minutes, then drain the water for 5-10 minutes. Finally, open the discharge port to take out the pear pieces and detect the color protection effect.

[0039] In the present invention, citric acid inhibits the activity of polyphenol oxidase by reducing the pH value, ascorbic acid acts as an electron donor to block the oxidation chain reaction, and sodium chloride enhances the penetration efficiency of the color protection agent through osmotic pressure regulation.

[0040] The third technical solution of the present invention: A color protection device during the preparation of pear pulp, including a reaction frame and a blending structure. A color protection tank is arranged above the reaction frame, a stirring assembly is arranged above the color protection tank, and a turning assembly is arranged on one side of the bottom of the color protection tank;

[0041] The top of the color protection tank is provided with a feed inlet, the side of the color protection tank is provided with a discharge outlet, one side of the top of the color protection tank is detachably connected with a water inlet pipe, and the bottom end of the color protection tank is detachably connected with a water outlet pipe;

[0042] The stirring assembly includes a driving motor. The driving motor is arranged above the color protection tank. A support frame is detachably connected below the driving motor. The bottom end of the support frame is detachably connected with the color protection tank. A stirrer is arranged at the center of the support frame. The output end of the driving motor is fixedly connected with the stirrer;

[0043] The turning assembly includes a servo motor, which is arranged on the side of the color protection tank. A transmission column is arranged on the side of the servo motor close to the color protection tank. The output end of the servo motor is fixedly connected to the transmission column. A plurality of turning rods are fixedly connected to the side of the transmission column away from the servo motor. A transmission ring is arranged on the side of the turning rod. A rotating ring is detachably connected to the side of the transmission ring close to the color protection tank. A docking column is rotatably connected to the side of the rotating ring away from the transmission ring. One end of the docking column away from the rotating ring is fixedly connected to the color protection tank.

[0044] The present invention prepares a reaction solution for color protection through a preparation structure, and then puts the cut pear blocks into the color protection tank for reaction; uses a stirring assembly to stir and mix the reaction solvent; uses a turning assembly to turn the pear blocks in the color protection tank regularly to improve the reaction efficiency; the feed inlet is used to put in pear blocks, the discharge outlet is used to take out the pear blocks after the reaction ends, the water inlet pipe is used to add the reaction solution, and the water outlet pipe is used to discharge the residual liquid in the color protection tank after the reaction ends.

[0045] Preferably, a bracket is arranged on the side of the reaction frame. A sliding table is slidably connected to the top of the bracket. A plurality of connecting rings are fixedly connected above the sliding table. A positioning plate is detachably connected above the connecting ring. A fixing plate is detachably connected above the positioning plate. One side of the fixing plate is fixedly connected to the color protection tank.

[0046] The present invention can adapt to color protection tanks of different models and has certain adaptability and flexibility in practical applications.

[0047] Preferably, a mounting plate is detachably connected below the stepping motor. One side of the bottom end of the mounting plate is detachably connected to the reaction frame;

[0048] A sealing ring is arranged on the side of the rotating ring close to the transmission ring. A sealing gasket is arranged on the side of the rotating ring close to the docking column.

[0049] The present invention seals the connection parts through a sealing ring, a sealing gasket, etc. and enables related components to rotate, so as to realize operations such as stirring and turning.

[0050] Preferably, a corrugated compensator is detachably connected to one end of the water inlet pipe away from the color protection tank. A conveying pipe is detachably connected to one end of the corrugated compensator away from the water inlet pipe. A servo electric pump is arranged at one end of the conveying pipe away from the corrugated compensator. A control pipe is detachably connected to one end of the servo electric pump away from the conveying pipe.

[0051] The present invention uses a corrugated compensator to adapt to the temperature change in the pipeline and uses a servo electric pump to pump materials from a lower place into the color protection tank.

[0052] Preferably, the dispensing structure includes support columns disposed above the main frame. A first positioning plate is detachably connected to the side surface of the support column. A first limiting plate is detachably connected above the first positioning plate. A reaction kettle is detachably connected above the first limiting plate. A second positioning plate is detachably connected to the side surface of the top of the reaction kettle. The second positioning plate is detachably connected to the support column. A second limiting plate is disposed above the second positioning plate. A third limiting plate is disposed above the second limiting plate. The third limiting plate is detachably connected to the support column.

[0053] The detachable connection between the first and second positioning plates and the support column realizes the positioning of the reaction kettle, reducing the shaking or displacement during the reaction. The first, second, and third limiting plates limit the reaction kettle from different directions. The multi-layer limiting structure enhances the stability, effectively resisting vibration and impact force, and ensuring that the reaction proceeds in a stable environment.

[0054] Preferably, a steam pipe is disposed on the side surface of the middle part of the reaction kettle. One end of the steam pipe away from the reaction kettle is provided with a first control valve. One end of the first control valve away from the steam pipe is provided with an air delivery pipe. One end of the air delivery pipe away from the first control valve is provided with a steam generator. A steam control panel is disposed on the side surface of the steam generator. A pressure gauge is disposed on the side surface of the steam control panel.

[0055] The steam pipe connects the reaction kettle and the steam generator, providing steam for regulating the temperature of the reaction. The steam generated by the steam generator enters the reaction kettle through the air delivery pipe and the steam pipe. The first control valve can accurately control the flow rate and on-off of the steam, making the steam in the reaction kettle stable and controllable. The operator can conveniently adjust the operating parameters of the steam generator through the steam control panel. At the same time, the pressure gauge displays the steam pressure in real time, enabling the operator to timely master the steam state and make adjustments according to the actual needs of the reaction.

[0056] Preferably, a support bottom plate is detachably connected to the side surface of the bottom end of the support column. A servo motor is disposed above the support bottom plate. A rotating shaft is disposed above the servo motor. The output end of the servo motor is fixedly connected to the rotating shaft. A stirring paddle is fixedly connected to the side surface of the rotating shaft. The top end of the rotating shaft is rotatably connected to a sealing cover. The sealing cover is detachably connected to the second limiting plate. A delivery port is disposed on the upper surface of the sealing cover.

[0057] The servo motor is fixedly connected to the rotating shaft through the output end, capable of controlling the rotation of the rotating shaft, and then driving the stirring paddle fixedly connected to the side surface to work. The stirring effect of the stirring paddle in the reaction kettle enables the materials to be fully mixed during the reaction, ensuring the uniformity of the reaction.

[0058] Preferably, a liquid storage bottle is detachably connected to one side of the third limiting plate. A suppression tube is provided at the bottom end of the liquid storage bottle, and a suppression nozzle is provided at the end of the suppression tube away from the liquid storage bottle.

[0059] The suppression nozzle is mainly used for cleaning the probe, which can effectively remove the reaction material impurities attached to the surface of the probe, ensure the cleanliness of the probe, maintain the accuracy of its monitoring of reaction parameters, and extend the service life of the probe.

[0060] Preferably, a first adjustment bottle is detachably connected to the inner side of the third limiting plate. A first adjustment tube is provided at the bottom end of the first adjustment bottle, a second control valve is provided at the end of the first adjustment tube away from the first adjustment bottle, and a second adjustment tube is provided at the end of the second control valve away from the first adjustment tube; a second adjustment bottle is provided on one side of the first adjustment bottle. The second adjustment bottle is detachably connected to the third limiting plate. A third adjustment tube is provided at the bottom end of the second adjustment bottle, a third control valve is provided at the end of the third adjustment tube away from the second adjustment bottle, and a fourth adjustment tube is provided at the end of the third control valve away from the third adjustment tube.

[0061] The first adjustment bottle is connected to the second adjustment tube through the first adjustment tube and the second control valve. The second adjustment bottle is connected to the fourth adjustment tube through the third adjustment tube and the third control valve, and can respectively control the delivery volume and flow rate of two different reaction liquids. When adding reaction liquid, the operator can adjust the injection volume of the reaction liquid through the control valve according to the actual reaction situation.

[0062] Preferably, a detector is provided on one side above the reaction kettle. A numerical screen is provided on one side of the detector, operation buttons are provided below the numerical screen, a transmission plate is provided at the bottom end of the detector, a sliding column is provided at the bottom end of the transmission plate, and a probe is provided at the bottom end of the sliding column.

[0063] The detector is connected to the probe through the transmission plate and the sliding column at the bottom end, and can insert the probe into the reaction kettle to detect data such as temperature and pH value. The numerical screen on one side can intuitively display the detection value, which is convenient for the operator to understand the reaction state in real time.

[0064] Preferably, a fixed block is slidably connected to one side of the sliding column. A first rotating plate is rotatably connected to one side of the fixed block. A first slider is rotatably connected to the end of the first rotating plate away from the fixed block. A first operating rod is slidably connected to the inside of the first slider. One end of the first operating rod is rotatably connected to the transmission plate. A first locking knob is provided on one side of the first slider. A second rotating plate is rotatably connected to the side of the fixed block away from the first rotating plate. A second slider is rotatably connected to the end of the second rotating plate away from the fixed block. A second operating rod is slidably connected to the inside of the second slider. One end of the second operating rod is rotatably connected to the transmission plate. A second locking knob is provided on one side of the second slider.

[0065] The operator can adjust the positions of the first operating rod and the second operating rod inside the sliders, and utilize the rotation of the rotating plates to adjust the height of the probe. When it is necessary to detect different positions inside the reaction kettle, the probe can be flexibly moved to the appropriate position to ensure the comprehensiveness and accuracy of the detection data. After the detection is completed, by tightening the locking knobs, the probe can be fixed at a specific position to prevent it from being displaced due to factors such as vibration during the reaction process, ensuring the stability of the detection process.

[0066] The present invention has the following beneficial effects:

[0067] (1) Using pear pulp and dendrobium juice as raw materials, a pear-dendrobium composite puree with a unique flavor is produced, which has certain market value and economic benefits. Taking the browning index as the evaluation index, the optimal color protection formula of the pear-dendrobium composite puree is determined through single-factor and orthogonal experiments.

[0068] (2) The pear-dendrobium composite puree is treated by pasteurization, microwave sterilization, and high-temperature steam sterilization respectively. The quality changes of the treated pear-dendrobium composite puree during storage at 4°C for 10 days are analyzed and compared, and the sterilization method suitable for the processing of the pear-dendrobium composite puree is analyzed. Description of the Drawings

[0069] Figure 1 is the overall process schematic diagram of the present invention;

[0070] Figure 2 is the graph of the change in citric acid concentration and absorbance of the present invention;

[0071] Figure 3 is the graph of the change in ascorbic acid concentration and absorbance of the present invention;

[0072] Figure 4 is the graph of the change in sodium chloride concentration and absorbance of the present invention;

[0073] Figure 5 is the graph of the change in puree storage time and soluble solid content of the present invention;

[0074] Figure 6 It is the graph of the storage time and pH value change of the puree of the present invention;

[0075] Figure 7 It is the graph of the storage time and total phenol content change of the puree of the present invention;

[0076] Figure 8 It is the graph of the storage time and total sugar content change of the puree of the present invention;

[0077] Figure 9 It is the schematic diagram of the principal component analysis of the present invention;

[0078] Figure 10 It is the schematic diagram of the sensor radar of the present invention;

[0079] Figure 11 It is the schematic diagram of the reaction framework of the present invention;

[0080] Figure 12 It is the schematic diagram of the discharge port of the present invention;

[0081] Figure 13 It is the schematic diagram of the water outlet pipe of the present invention;

[0082] Figure 14 It is the schematic diagram of the stirrer of the present invention;

[0083] Figure 15 It is the schematic diagram of the transmission ring of the present invention;

[0084] Figure 16 It is the schematic diagram of the sealing ring of the present invention;

[0085] Figure 17 It is the schematic diagram of the installation short board of the present invention;

[0086] Figure 18 It is the schematic diagram of the water inlet pipe of the present invention;

[0087] Figure 19 It is the schematic diagram of the dispensing structure of the present invention;

[0088] Figure 20 It is the schematic diagram of the mixing paddle of the present invention;

[0089] Figure 21 It is the schematic diagram of the liquid storage bottle of the present invention;

[0090] Figure 22 It is the schematic diagram of the inhibition nozzle of the present invention;

[0091] Figure 23 It is the schematic diagram of the detector of the present invention;

[0092] Figure 24 It is the schematic diagram of the transmission plate of the present invention.

[0093] The labels in the accompanying drawings are: 100, reaction frame; 101, bracket; 102, sliding table; 1021, connecting ring; 1022, mounting short plate; 103, mounting plate; 200, dispensing structure; 201, support column; 2011, first positioning plate; 20111, first limiting plate; 2012, second positioning plate; 20121, second limiting plate; 2013, third limiting plate; 2014, support bottom plate; 202, servo motor; 2021, rotating shaft; 2022, stirring paddle; 203, reaction kettle; 2031, sealing cover; 2032, delivery port; 204, steam generator; 2041, steam control board; 2042, pressure gauge; 2043, gas transmission pipe; 2044, first control valve; 2045, steam pipe; 205, liquid storage bottle; 2051, inhibition pipe; 2052, inhibition spray head; 206, first adjustment bottle; 2061, first adjustment pipe; 2062, second control valve; 2063, second adjustment pipe; 207, second adjustment bottle; 2071, third adjustment pipe; 2072, third control valve; 2073, fourth adjustment pipe; 208, detector; 2081, numerical display screen; 2082, operation button; 2083, transmission plate; 20831, first rotating plate; 20832, first slider; 208321, first locking knob; 20833, first operating rod; 20834, second operating rod; 20835, second slider; 208351, second locking knob; 20836, second rotating plate; 2084, sliding column; 20841, fixed block; 2085, probe; 300, stirring assembly; 301, drive motor; 302, support frame; 303, stirrer; 400, turning assembly; 401, stepper motor; 402, transmission column; 4021, turning rod; 403, transmission ring; 404, rotating ring; 4041, sealing ring; 4042, sealing gasket; 500, color protection tank; 501, feed inlet; 502, discharge outlet; 503, water inlet pipe; 5031, corrugated compensator; 5032, delivery pipe; 5033, servo electric pump; 5034, control pipe; 504, water outlet pipe; 505, docking column; 506, fixing plate. Detailed implementation manners

[0094] The present invention will be further described below in conjunction with the accompanying drawings and embodiments, but it shall not be used as a basis for limiting the present invention.

[0095] Pear dendrobium compound puree, by weight, comprises the following components

[0096] 55 - 70 parts of pear puree, 12 - 17 parts of dendrobium juice, 4.2 - 4.8 parts of granulated sugar, 1.8 - 2.4 parts of maltose, 0.61 - 0.82 parts of citric acid, 0.03 - 0.05 parts of ascorbic acid, 0.7 - 0.9 parts of sodium chloride.

[0097] It comprises the following components by weight parts,

[0098] 58 - 67 parts of pear fruit pulp, 13 - 16 parts of dendrobium juice, 4.3 - 4.7 parts of granulated sugar, 1.9 - 2.3 parts of maltose, 0.51 - 0.72 parts of citric acid, 0.035 - 0.045 parts of ascorbic acid, 0.75 - 0.85 parts of sodium chloride.

[0099] It comprises the following components by weight parts,

[0100] 61 - 64 parts of pear fruit pulp, 14 - 15 parts of dendrobium juice, 4.4 - 4.6 parts of granulated sugar, 2.0 - 2.2 parts of maltose, 0.56 - 0.67 parts of citric acid, 0.038 - 0.042 parts of ascorbic acid, 0.78 - 0.82 parts of sodium chloride.

[0101] The preparation of pear fruit pulp includes the following steps as Figure 1 shown,

[0102] (A1) Select pear fruits, wash for 3 - 5 min, remove the outer skin and cores of the pear fruits, and then cut the pear fruits into pear pieces of 1.5 - 2.5 cm;

[0103] (A2) Place the pear pieces in a constant temperature water bath at 80 - 90 °C, blanch for 8 - 12 min to inactivate enzymes. Stir the pear pieces every 1 - 3 min during blanching. After blanching, transfer the pear pieces to ice water at 0 - 5 °C and cool for 5 - 8 min;

[0104] (A3) Immerse the cooled pear pieces in a color - protecting agent, soak at 20 - 25 °C for 8 - 12 min. Turn the pear pieces every 4 - 6 min during soaking. After soaking, rinse the pear pieces for 1 - 2 min, and then drain for 5 - 10 min;

[0105] (A4) Place the pear pieces in a colloid mill and grind them with a grinding disc interval of 0.4 - 1.2 mm to obtain pear fruit pulp.

[0106] The preparation of dendrobium juice includes the following steps,

[0107] (B1) Select dendrobium officinale stem strips, wash for 2 - 3 min, rub to remove the white dry skin on the surface of the dendrobium officinale stem strips, and cut the dendrobium officinale stem strips into stem segments of 0.8 - 1.2 cm;

[0108] (B2) Place the stem segments in a pulper, add pure water according to a liquid - to - material ratio of 1:40 - 1:60, and pulp at a rotational speed of 10000 - 12000 rpm for 1.5 - 2.5 min to obtain dendrobium officinale homogenate;

[0109] (B3) Add citric acid with a concentration of 0.01 - 0.02% to the Dendrobium officinale homogenate. After stirring evenly, soak it at a temperature of 20 - 25°C for 0.8 - 1.2 h, and stir the mixture every 12 - 18 min during the soaking period;

[0110] (B4) Perform pressure filtration using a 50 - 70 mesh sieve to filter out the insoluble Dendrobium residues, collect the filtrate, and obtain Dendrobium juice.

[0111] The preparation of the pear - Dendrobium composite puree includes the following steps.

[0112] (S01) Select pear puree and Dendrobium juice, place them in a blender according to a volume ratio of 3.5:1 - 4.5:1, and stir at a speed of 50 - 70 rpm for 3 - 5 min to obtain a mixed puree;

[0113] (S02) Place the mixed puree in a jacketed pan, boil it at a temperature of 90 - 95°C for 15 - 25 min, and continuously stir at a speed of 20 - 30 rpm. During the boiling period, add granulated sugar with a mass percentage of 1.4 - 1.6% and maltose with a mass percentage of 0.6 - 0.8%;

[0114] (S03) Lower the boiling temperature to 80 - 85°C, add granulated sugar with a mass percentage of 1.4 - 1.6% and maltose with a mass percentage of 0.6 - 0.8%, and continue boiling. After 4 - 6 min, lower the boiling temperature to 70 - 75°C, and then add granulated sugar with a mass percentage of 1.4 - 1.6% and maltose with a mass percentage of 0.6 - 0.8%. Take samples from the center position of the jacketed pan every 2 - 4 min, place the samples in a constant temperature water bath at 18 - 22°C for 4 - 6 min to balance, and then place the samples in a refractometer to analyze the soluble solid content of the samples. When the soluble solid content reaches 33 - 37%, stop heating and stirring to obtain the pear - Dendrobium composite puree.

[0115] The sterilization process of the pear - Dendrobium composite puree is pasteurization or microwave sterilization or high - temperature steam sterilization.

[0116] Pasteurization is to place the pear - Dendrobium composite puree in a constant temperature water bath pot, heat it at a temperature of 78 - 82°C for 8 - 12 min, turn the bottle or bag over a total of 1 - 2 times during the heating period to shake the pear - Dendrobium composite puree evenly, and after the heating is completed, place the pear - Dendrobium composite puree in a low - temperature water bath tank and cool it to 20 - 25°C;

[0117] Microwave sterilization is to place the pear - Dendrobium composite puree in a microwave oven, microwave - heat it at a power of 100 - 200 W for 1 - 3 min, and after the heating is completed, place the pear - Dendrobium composite puree in a low - temperature water bath tank and cool it to 20 - 25°C;

[0118] The high-temperature steam sterilization method is to place the compound fruit puree of Dendrobium nobile Lindl. in a steam sterilizer and heat it at a temperature of 118 - 124°C and a pressure of 0.14 - 0.16 MPa for 5 s - 15 s. After the heating is completed, the compound fruit puree of Dendrobium nobile Lindl. is placed in a low-temperature water bath and cooled to 20 - 25°C.

[0119] The color protection method in the preparation process of pear pulp includes the following steps.

[0120] (C1) Select pure water and place it in a blending structure. Put citric acid and sodium chloride into the first adjustment bottle and the second adjustment bottle respectively. Add citric acid with a mass percentage of 0.6 - 0.8% and sodium chloride with a mass percentage of 0.7 - 0.9% into the reaction kettle. Then replace the reagent in the first adjustment bottle with ascorbic acid, and add 0.03 - 0.05% of ascorbic acid into the reaction kettle. Use a stirring paddle to stir at a speed of 250 - 350 rpm for 4 - 6 min to obtain a compound color protection liquid.

[0121] (C2) After cutting the pear fruits into pieces, place them in a color protection tank and add the compound color protection liquid to submerge the pear fruit pieces in the compound color protection liquid. Soak them at a temperature of 20 - 25°C for 8 - 12 min. During the soaking period, use a stirrer and a turning rod to turn the pear pieces every 4 - 6 min. After the soaking is completed, open the water inlet pipe and the water outlet pipe to rinse the pear pieces for 1 - 2 min, then drain the water for 5 - 10 min. Finally, open the discharge port to take out the pear pieces and detect the color protection effect.

[0122] The color protection device in the preparation process of pear pulp includes a reaction frame 100 as shown in Figure 11 and a blending structure 200 as shown in Figure 19 . A color protection tank 500 is arranged above the reaction frame 100, a stirring assembly 300 is arranged above the color protection tank 500, and a turning assembly 400 is arranged on one side of the bottom of the color protection tank 500.

[0123] The top of the color protection tank 500 is provided with a feed inlet 501, the side of the color protection tank 500 is provided with a discharge port 502 as shown in Figure 12 . One side of the top of the color protection tank 500 is detachably connected with a water inlet pipe 503 as shown in Figure 18 , and the bottom end of the color protection tank 500 is detachably connected with a water outlet pipe 504 as shown in Figure 13 .

[0124] The stirring assembly 300 includes a driving motor 301, the driving motor 301 is arranged above the color protection tank 500, a support frame 302 is detachably connected below the driving motor 301, the bottom end of the support frame 302 is detachably connected with the color protection tank 500, and a stirrer 303 as shown in Figure 14 is arranged at the center of the support frame 302. The output end of the driving motor 301 is fixedly connected with the stirrer 303.

[0125] The flipping assembly 400 includes a stepper motor 401. The stepper motor 401 is arranged on the side of the color protection tank 500. A transmission column 402 is arranged on the side of the stepper motor 401 close to the color protection tank 500. The output end of the stepper motor 401 is fixedly connected to the transmission column 402. A plurality of flipping rods 4021 are fixedly connected to the side of the transmission column 402 away from the stepper motor 401. The side of the flipping rod 4021 is provided with a transmission ring 403 as shown in Figure 15 . The transmission ring 403 is detachably connected to a rotating ring 404 on the side close to the color protection tank 500. A docking column 505 is rotatably connected to the side of the rotating ring 404 away from the transmission ring 403. One end of the docking column 505 away from the rotating ring 404 is fixedly connected to the color protection tank 500.

[0126] A bracket 101 is arranged on the side of the reaction frame 100. A sliding table 102 is slidably connected to the top of the bracket 101. A plurality of connecting rings 1021 are fixedly connected above the sliding table 102. An installation short plate 1022 as shown in Figure 17 is detachably connected above the connecting ring 1021. An installation plate 506 is detachably connected above the installation short plate 1022. One side of the installation plate 506 is fixedly connected to the color protection tank 500;

[0127] An installation plate 103 is detachably connected below the stepper motor 401. One side of the bottom end of the installation plate 103 is detachably connected to the reaction frame 100;

[0128] A sealing ring 4041 as shown in Figure 16 is arranged on the side of the rotating ring 404 close to the transmission ring 403. A sealing ring 4042 is arranged on the side of the rotating ring 404 close to the docking column 505.

[0129] One end of the water inlet pipe 503 away from the color protection tank 500 is detachably connected to a corrugated compensator 5031. One end of the corrugated compensator 5031 away from the water inlet pipe 503 is detachably connected to a delivery pipe 5032. A servo electric pump 5033 is arranged at one end of the delivery pipe 5032 away from the corrugated compensator 5031. One end of the servo electric pump 5033 away from the delivery pipe 5032 is detachably connected to a control pipe 5034.

[0130] The dispensing structure 200 includes a support column 201. A first positioning plate 2011 is detachably connected to the side of the support column 201. A first limiting plate 20111 is detachably connected above the first positioning plate 2011. A reaction kettle 203 is detachably connected above the first limiting plate 20111. A second positioning plate 2012 is detachably connected to the top side of the reaction kettle 203. The second positioning plate 2012 is detachably connected to the support column 201. A second limiting plate 20121 is arranged above the second positioning plate 2012. A third limiting plate 2013 is arranged above the second limiting plate 20121. The third limiting plate 2013 is detachably connected to the support column 201.

[0131] On the middle side of the reaction kettle 203, a steam pipe 2045 is provided. One end of the steam pipe 2045 away from the reaction kettle 203 is provided with a first control valve 2044. One end of the first control valve 2044 away from the steam pipe 2045 is provided with an air delivery pipe 2043. One end of the air delivery pipe 2043 away from the first control valve 2044 is provided with a steam generator 204. On the side of the steam generator 204, a steam control board 2041 is provided. On the side of the steam control board 2041, a pressure gauge 2042 is provided.

[0132] The bottom side of the support column 201 is detachably connected with a support bottom plate 2014. Above the support bottom plate 2014, a servo motor 202 is provided. Above the servo motor 202, a rotating shaft 2021 is provided. The output end of the servo motor 202 is fixedly connected with the rotating shaft 2021. On the side of the rotating shaft 2021, there is fixedly connected with a Figure 20 stirring paddle 2022 as shown. The top end of the rotating shaft 2021 is rotatably connected with a sealing cover 2031. The sealing cover 2031 is detachably connected with the second limiting plate 20121. On the upper surface of the sealing cover 2031, a delivery port 2032 is provided.

[0133] One side of the third limiting plate 2013 is detachably connected with a Figure 21 liquid storage bottle 205 as shown. At the bottom of the liquid storage bottle 205, an inhibition pipe 2051 is provided. One end of the inhibition pipe 2051 away from the liquid storage bottle 205 is provided with an Figure 22 inhibition spray head 2052 as shown.

[0134] Inside the third limiting plate 2013, a first adjusting bottle 206 is detachably connected. At the bottom of the first adjusting bottle 206, a first adjusting pipe 2061 is provided. One end of the first adjusting pipe 2061 away from the first adjusting bottle 206 is provided with a second control valve 2062. One end of the second control valve 2062 away from the first adjusting pipe 2061 is provided with a second adjusting pipe 2063; On one side of the first adjusting bottle 206, a second adjusting bottle 207 is provided. The second adjusting bottle 207 is detachably connected with the third limiting plate 2013. At the bottom of the second adjusting bottle 207, a third adjusting pipe 2071 is provided. One end of the third adjusting pipe 2071 away from the second adjusting bottle 207 is provided with a third control valve 2072. One end of the third control valve 2072 away from the third adjusting pipe 2071 is provided with a fourth adjusting pipe 2073.

[0135] Above one side of the reaction kettle 203, a Figure 23 detector 208 as shown is provided. On one side of the detector 208, a numerical screen 2081 is provided. Below the numerical screen 2081, an operation button 2082 is provided. At the bottom of the detector 208, there is a Figure 24The drive plate 2083 shown has a sliding column 2084 provided at its bottom end, and a probe 2085 is provided at the bottom end of the sliding column 2084.

[0136] One side of the sliding column 2084 is slidably connected to a fixed block 20841. One side of the fixed block 20841 is rotatably connected to a first rotating plate 20831. One end of the first rotating plate 20831 away from the fixed block 20841 is rotatably connected to a first slider 20832. The inner side of the first slider 20832 is slidably connected to a first operating rod 20833. One end of the first operating rod 20833 is rotatably connected to the drive plate 2083. One side of the first slider 20832 is provided with a first locking knob 208321. One side of the fixed block 20841 away from the first rotating plate 20831 is rotatably connected to a second rotating plate 20836. One end of the second rotating plate 20836 away from the fixed block 20841 is rotatably connected to a second slider 20835. The inner side of the second slider 20835 is slidably connected to a second operating rod 20834. One end of the second operating rod 20834 is rotatably connected to the drive plate 2083. One side of the second slider 20835 is provided with a second locking knob 208351.

[0137] Example 1: The preparation of pear fruit pulp includes the following steps:

[0138] (A1) Select pear fruits, wash for 3 min, remove the outer skin and pear cores, and cut into pear blocks of 1.5 cm.

[0139] (A2) Place the pear blocks in a constant temperature water bath at 80 °C, blanch for 8 min to inactivate enzymes, stir once every 1 min during this period, and transfer to ice water at 0 °C for cooling for 5 min after blanching.

[0140] (A3) Immerse the cooled pear blocks in a color protection agent, soak at 20 °C for 8 min, turn them over every 4 min, rinse for 1 min after soaking, and drain for 5 min.

[0141] (A4) Place the pear blocks in a colloid mill and grind them with a grinding disc interval of 0.4 mm to obtain pear fruit pulp.

[0142] The preparation of dendrobium juice includes the following steps:

[0143] (B1) Select fresh dendrobium officinale stems, wash for 2 min, rub to remove the white dry skin, and cut into stem segments of 0.8 cm.

[0144] (B2) Place the stem segments in a pulper, add pure water according to a liquid-to-material ratio of 1:40, and grind at 10000 rpm for 1.5 min to obtain dendrobium officinale homogenate.

[0145] (B3) Add citric acid with a concentration of 0.01% to the Dendrobium officinale homogenate, stir evenly, soak at 20°C for 0.8 h, and stir every 12 min;

[0146] (B4) Press-filter using a 50-mesh sieve, and collect the filtrate to obtain Dendrobium officinale juice.

[0147] The preparation of the pear-Dendrobium officinale composite puree includes the following steps:

[0148] (S01) Mix pear puree and Dendrobium officinale juice at a volume ratio of 3.5:1, and stir at 50 rpm for 3 min;

[0149] (S02) Place the mixed puree in a jacketed pan, boil at 90°C for 25 min and stir at 20 rpm, and add 1.4% white granulated sugar and 0.6% maltose during this period;

[0150] (S03) Lower the temperature to 80°C, add 1.4% white granulated sugar and 0.6% maltose, continue boiling, after 4 min, lower the boiling temperature to 70°C, add the same proportion of sugar again, sample and detect every 2 min, and stop heating when the soluble solid content reaches 33% to obtain the pear-Dendrobium officinale composite puree.

[0151] In this example, select Dangshan crisp pears with 90% maturity (soluble solids 12.5%, pH 4.3), wash them with running water for 3 min, then manually peel and core them, and cut them into 1.5 cm 3Cube. The tender stems of Dendrobium officinale (with a moisture content of 85%) were washed for 2 minutes, and after rubbing off the white dry skin, they were cut into 0.8-cm small sections. The pear pieces were blanched in an 80°C constant temperature water bath for 8 minutes to inactivate enzymes, stirred every 1 minute during this period, and immediately transferred to a 0°C ice water bath for cooling for 5 minutes. A compound color protection solution (0.6% citric acid + 0.03% ascorbic acid + 0.7% sodium chloride) was prepared, and the cooled pear pieces were immersed in it and soaked at 20°C for 8 minutes (turned over every 4 minutes). After taking out, they were rinsed with distilled water for 1 minute and drained for 5 minutes. The pear pieces were pulped with a colloid mill (0.4-mm gap) for 2 minutes, and the pulp was transferred to a jacketed pan, boiled at 85°C and stirred at 30 rpm. Samples were taken every 2 minutes for detection, and heating was stopped when the soluble solids reached 33.2%. The Dendrobium sections were added to pure water at a liquid-to-material ratio of 1:40, broken with a high-speed pulper (10,000 rpm) for 1.5 minutes, 0.6% citric acid + 0.03% ascorbic acid were added, and left standing at 20°C for 0.8 hour (stirred every 12 minutes). After pressure filtration through a 50-mesh sieve (pressure 0.1 MPa), it was finely filtered through a 0.45-μm microporous membrane to obtain Dendrobium juice (total phenol content 0.86 mg / mL). The pear pulp and Dendrobium juice were mixed at a volume ratio of 3.5:1, stirred at 50 rpm for 3 minutes, transferred to a jacketed pan, boiled at 90°C for 4 minutes and stirred at 20 rpm, and 1.4% white granulated sugar and 0.6% maltose were added in three portions (with an interval of 4 minutes each time). Heating was stopped when the soluble solids of the puree reached 33.5%, and it was hot-filled into packaging bottles, pasteurized at 80°C for 8 minutes, and refrigerated at 4°C after cooling to 25°C.

[0152] The test data showed that the soluble solids were 33.5%, pH was 4.18, total phenol was 1.12 mg / g, total sugar was 28.7%; the total number of colonies was <10 CFU / g, and coliform bacteria were not detected; the color difference ΔE = 1.89 (L* = 68.2, a* = -1.9, b* = 35.4); the sensory score was 22 / 25 for color, 21 / 25 for sour and sweet taste, 23 / 25 for tissue state, 21 / 25 for aroma, and the total score was 87 / 100. The verification of the color protection effect showed that the absorbance at A420nm was 0.1272; after storage at 4°C for 10 days, the total number of colonies was still <10 CFU / g, ΔE = 1.95, and the sensory score remained above 85 points.

[0153] Example 2: The preparation of pear pulp includes the following steps:

[0154] (A1) Select ripe pears, wash for 5 minutes, remove the outer skin and pear cores, and cut into 2.5-cm pear pieces;

[0155] (A2) Place the pear pieces in a 90°C constant temperature water bath, blanch for 12 minutes to inactivate enzymes, stir once every 3 minutes during this period, and transfer to 5°C ice water for cooling for 8 minutes after blanching;

[0156] (A3) Immerse the cooled pear pieces in the color protection agent, soak at 25°C for 12 min, turn them over every 6 min, rinse for 2 min after soaking, and drain for 10 min;

[0157] (A4) Place the pear pieces in a colloid mill and beat them with a grinding disc interval of 1.2 mm to obtain pear puree.

[0158] The preparation of dendrobium juice includes the following steps:

[0159] (B1) Select fresh Dendrobium officinale stems, wash for 3 min, rub to remove the white dry skin, and cut into stem segments of 1.2 cm;

[0160] (B2) Place the stem segments in a blender, add purified water at a liquid-to-material ratio of 1:60, and beat at 12000 rpm for 2.5 min to obtain Dendrobium officinale homogenate;

[0161] (B3) Add citric acid with a concentration of 0.02% to the Dendrobium officinale homogenate, stir evenly, soak at 25°C for 1.2 h, and stir every 18 min;

[0162] (B4) Press-filter with a 70-mesh sieve and collect the filtrate to obtain dendrobium juice.

[0163] The preparation of pear-dendrobium composite puree includes the following steps:

[0164] (S01) Mix the pear puree and dendrobium juice at a volume ratio of 4.5:1 and stir at 70 rpm for 5 min;

[0165] (S02) Place the mixed puree in a jacketed pan, boil at 95°C for 15 min and stir at 30 rpm, and add 1.6% white sugar and 0.8% maltose during this period;

[0166] (S03) Lower the temperature to 85°C, add 1.6% white sugar and 0.8% maltose, continue boiling, after 6 min, lower the boiling temperature to 75°C, add sugar in the same proportion again, take samples for detection every 4 min, and stop heating when the soluble solid content reaches 37% to obtain the pear-dendrobium composite puree.

[0167] In this embodiment, Fengshui pears (soluble solids 14.2%, pH 4.5) with a maturity of 90% were selected, washed with running water for 5 minutes, then mechanically peeled and cored, and cut into 2.5 cm cubes. The old stems of Dendrobium candidum (water content 78%) were washed for 3 minutes, and the white dry skin was rubbed off and cut into 1.2 cm small sections. The pear blocks were placed in a 90°C constant temperature water bath, blanched for 12 minutes to inactivate the enzyme, and stirred with a stainless steel stirring paddle every 3 minutes during the period, and immediately transferred to a 5°C ice water bath to cool for 8 minutes. A composite color protection liquid (0.7% citric acid + 0.04% ascorbic acid + 0.8% sodium chloride) was prepared, and the cooled pear blocks were immersed in it, soaked at 25°C for 12 minutes (stirred every 6 minutes), rinsed with distilled water for 2 minutes after taking out, and drained for 10 minutes. The pear pieces were pulped with a colloid mill (1.2 mm gap) for 3 min, and the pulp was transferred to a sandwich pot, boiled at 95 ° C and stirred at 50 rpm. The heating was stopped when the soluble solid content reached 37.1% after sampling every 4 min. The dendrobium segments were added with purified water at a liquid-to-solid ratio of 1:60, crushed with a high-speed pulper (12000 rpm) for 2.5 min, and 0.8% citric acid + 0.05% ascorbic acid were added. The mixture was allowed to stand at 25 ° C for 1.2 hours (stirred every 18 min), filtered through a 70-mesh screen (pressure 0.15 MPa), and then finely filtered through a 0.22 μm microporous filter membrane to obtain dendrobium juice (total phenol content 1.12 mg / mL). Pear pulp and dendrobium juice were mixed in a volume ratio of 4.5:1, stirred at 70 rpm for 5 minutes, transferred to a sandwich pot and boiled at 95°C for 6 minutes and stirred at 30 rpm, and 1.6% of white sugar and 0.8% of maltose were added three times (6 minutes interval each time). When the puree reached 37.3% soluble solids, heating was stopped, and it was filled into a container while hot, pasteurized at 85°C for 12 minutes, cooled to 25°C, and refrigerated at 4°C.

[0168] The test data showed that the soluble solids were 37.3%, pH 4.02, total phenols 1.45 mg / g, and total sugars 31.2%; the total colony count was <10 CFU / g, and coliform bacteria were not detected; the color difference ΔE = 2.15 (L* = 66.8, a* = -2.3, b* = 34.1); the sensory scores were color 23 / 25, sweetness and sourness 22 / 25, tissue state 24 / 25, aroma 22 / 25, and the total score was 91 / 100. The color protection effect verification showed that the A420nm absorbance was 0.085, which was 72% lower than that of the control group; the total colony count was still <10 CFU / g after 15 days of storage at 4°C, ΔE = 2.38, and the sensory score remained above 88 points.

[0169] Example 3: The preparation of pear pulp comprises the following steps:

[0170] (A1) Select pears, wash them for 5 minutes, remove the skin and core, and cut them into 2.5 cm pieces;

[0171] (A2) Place the pear pieces in a 90°C constant temperature water bath, blanch for 12 min to inactivate enzymes, stir once every 3 min during this period, and transfer to 5°C ice water for cooling for 8 min after blanching;

[0172] (A3) Immerse the cooled pear pieces in the color protection agent, soak at 25°C for 12 min, turn them over once every 6 min, rinse for 2 min after soaking, and drain for 10 min;

[0173] (A4) Place the pear pieces in a colloid mill and beat them with a grinding disc interval of 1.2 mm to obtain pear puree.

[0174] The preparation of dendrobium juice includes the following steps:

[0175] (B1) Select fresh dendrobium officinale stems, wash for 3 min, rub to remove the white dry skin, and cut into 1.2 cm stem segments;

[0176] (B2) Place the stem segments in a blender, add pure water at a liquid-to-material ratio of 1:60, and beat at 12000 rpm for 2.5 min to obtain dendrobium officinale homogenate;

[0177] (B3) Add citric acid with a concentration of 0.015% to the dendrobium officinale homogenate, stir evenly, soak at 25°C for 1.2 h, and stir once every 18 min;

[0178] (B4) Press-filter using a 70-mesh sieve and collect the filtrate to obtain dendrobium juice.

[0179] The preparation of pear-dendrobium composite puree includes the following steps:

[0180] (S01) Mix the pear puree and dendrobium juice at a volume ratio of 4.5:1 and stir at 70 rpm for 5 min;

[0181] (S02) Place the mixed puree in a jacketed pan, boil at 95°C for 20 min and stir at 30 rpm, and add 1.6% granulated sugar and 0.8% maltose during this period;

[0182] (S03) Lower the temperature to 85°C, add 1.6% granulated sugar and 0.8% maltose, continue boiling, after 6 min, lower the boiling temperature to 75°C, add the same proportion of sugar again, take samples for detection every 4 min, and stop heating when the soluble solid content reaches 37% to obtain the pear-dendrobium composite puree.

[0183] In this example, snow pears with 90% maturity (soluble solids 14.8%, pH 4.6) were selected, mechanically peeled and cored after 5 minutes of rinsing with running water, and cut into 2.5-cm cubes. The perennial old stems of Dendrobium officinale (water content 75%) were washed for 3 minutes, the white dry skin was rubbed off, and then cut into 1.2-cm segments. The pear cubes were placed in a 90°C constant temperature water bath and blanched for 12 minutes to inactivate enzymes (stirred with a tetrafluoro stirring paddle every 3 minutes), and immediately transferred to a 5°C ice-water bath for 8 minutes of cooling. A compound color protection solution (0.8% citric acid + 0.05% ascorbic acid + 0.9% sodium chloride) was prepared, and the pear cubes were immersed in it and soaked at 25°C for 12 minutes (stirred every 6 minutes). After taking out, they were rinsed with distilled water for 2 minutes and drained for 10 minutes. The pear cubes were pulped with a colloid mill (1.2-mm gap) for 3 minutes, and the pulp was transferred to a jacketed pan, boiled at 95°C and stirred at 50 rpm. Samples were taken every 4 minutes for detection, and heating was stopped when the soluble solids reached 37.2%. The Dendrobium segments were added to pure water at a liquid-to-material ratio of 1:60, broken with a high-speed pulper (12,000 rpm) for 2.5 minutes, 0.8% citric acid + 0.05% ascorbic acid was added, and left standing at 25°C for 1.2 hours (stirred every 18 minutes). After pressure filtration through a 70-mesh sieve (pressure 0.15 MPa), it was finely filtered through a 0.22-μm microporous filter membrane to obtain Dendrobium juice (total phenol content 1.25 mg / mL). The pear pulp and Dendrobium juice were mixed at a volume ratio of 4.5:1, stirred at 70 rpm for 5 minutes, transferred to a jacketed pan, boiled at 95°C for 6 minutes and stirred at 30 rpm, and 1.6% white granulated sugar and 0.8% maltose were added in three times (interval of 6 minutes each time). Heating was stopped when the soluble solids of the puree reached 37.5%, and it was hot-filled into a packaging bottle, pasteurized at 85°C for 12 minutes, and refrigerated at 4°C after cooling to 25°C.

[0184] The test data showed that the soluble solids were 37.5%, pH was 4.05, total phenol was 1.58 mg / g, total sugar was 32.1%; the total number of colonies was <10 CFU / g, and coliforms were not detected; the color difference ΔE = 5.42; the sensory score was 23 / 25 for color, 22 / 25 for sour-sweet taste, 24 / 25 for tissue state, 23 / 25 for aroma, and the total score was 92 / 100. The verification of the color protection effect showed that the absorbance at A420nm was 0.091, which was 70% lower than that of the control group; the total number of colonies was still <10 CFU / g after storage at 4°C for 20 days, ΔE = 2.51, and the sensory score remained above 89 points.

[0185] Experimental Example 1: As Figures 2 to 4 shown, this experimental example took the exploration of the color protection process of pear-Dendrobium composite puree as the core, and optimized the ratio of color protection agents by combining single-factor experiments. Different lowercase letters in the figure indicate significant differences between different concentration treatments of the same inhibitor (P < 0.05); (A) represents that the citric acid concentration is the independent variable; (B) represents that the ascorbic acid concentration is the independent variable; (C) represents that the sodium chloride concentration is the independent variable.

[0186] In this experimental example, first, compound color protection solutions with different concentration gradients were prepared: 0.6 - 1.2% citric acid, 0.01 - 0.08% ascorbic acid, and 0.6 - 1.8% sodium chloride were added to 500 ml of pure water respectively, and mixed at a speed of 300 rpm for 5 min by a magnetic stirrer. Mature Dangshan crisp pears were selected, peeled and cored by hand, and then cut into cubes with a side length of 2 cm, and immediately put into a constant temperature water bath at 90°C for blanching for 10 min to inactivate enzymes, and stirred every 2 min during this period. After enzyme inactivation, the pear cubes were quickly transferred to an ice - water bath for cooling for 6 min, and then immersed in different color protection solutions respectively, and left to soak statically for 10 min at 22°C, and the pear cubes were gently turned over with tweezers every 5 min to ensure uniform contact. After the treatment, the residual color protection solution on the surface was rinsed with running water, and drained for 8 min until there was no free water on the surface.

[0187] The treated pear cubes were pulped twice by a colloid mill. The first grinding plate interval was 0.8 mm, and the second was adjusted to 0.5 mm to obtain a delicate fruit pulp. 200 g of the fruit pulp was placed in a jacketed pan, boiled at 90°C and continuously stirred at a speed of 40 rpm. Samples were taken from the center of the pan every 3 min, and after equilibrating in a constant temperature water bath at 20°C for 5 min, the soluble solid content was measured with a hand - held refractometer. When it reached 35%, heating was stopped. The prepared pear - dendrobium compound puree was dispensed into 50 - ml centrifuge tubes, pasteurized at 80°C for 10 min, cooled to room temperature and then placed in a 4°C refrigerator for later testing.

[0188] Table 1 Single - factor test design of color protection agents with different concentrations

[0189]

[0190] The absorbance values of each group of puree were measured by an ultraviolet spectrophotometer at a wavelength of 420 nm. The results showed that when the citric acid concentration was 0.8%, the lowest absorbance was 0.1075; when the ascorbic acid concentration was 0.04%, the absorbance was 0.1088; when the sodium chloride concentration was 0.9%, the absorbance was 0.1127. The absorbance value is proportional to the degree of browning. The higher the absorbance, the more serious the browning of the pear - dendrobium compound puree. Through comprehensive analysis, the optimal color protection agent ratio was 0.8% citric acid + 0.04% ascorbic acid + 0.9% sodium chloride, and at this time, the color of the puree remained the best.

[0191] Experimental Example 2: Based on the optimization results of the single - factor test, an orthogonal test with three factors and three levels was designed using the L9(3 3 ) orthogonal table to systematically study the synergistic effect of the color protection agent ratio (A: citric acid concentration 0.7 - 0.9%, B: ascorbic acid concentration 0.02 - 0.06%, C: sodium chloride concentration 0.8 - 1.0%) on the inhibition of browning of pear - dendrobium compound puree. Fresh Huangjin pears were selected as raw materials, peeled and cored by hand, and cut into 2 cm3 Cut the pears into cubes, immediately put them into a constant temperature water bath at 85 °C and blanch for 10 minutes to inactivate enzymes. During this period, turn them over with a stainless steel spoon every 2 minutes. After enzyme inactivation, quickly transfer the pear cubes to an ice water bath at 4 °C and cool for 7 minutes. After draining the water, immerse them in 9 groups of color protection solutions prepared according to the orthogonal table. Each group of color protection solution uses 200 ml of pure water as the base solution. Weigh each component and mix them with a magnetic stirrer at a speed of 300 rpm for 5 minutes to ensure complete dissolution.

[0192] Immerse the pear cubes in the color protection solution and soak them statically in a constant temperature environment at 23 °C for 10 minutes. Turn them over with sterile forceps every 5 minutes. After treatment, rinse the pear cubes with running water for 30 seconds to remove the residual color protection agent. After draining the water for 10 minutes, conduct two colloid mill treatments: the first grinding disc gap is 0.8 mm, and the second is adjusted to 0.5 mm to obtain a delicate and uniform fruit pulp. Take 150 g of the fruit pulp and place it in a jacketed pan, boil it at 90 °C and continuously stir at a speed of 40 rpm. Take samples from the center of the pan every 3 minutes. After equilibrating in a constant temperature water bath at 20 °C for 5 minutes, use an Abbe refractometer to detect the soluble solid content. When it reaches 35%, stop heating. Pack the prepared fruit puree into 50 ml vials, sterilize it at 80 °C for 10 minutes, and store it refrigerated at 4 °C after cooling to room temperature.

[0193] Table 2 Orthogonal test design table

[0194]

[0195]

[0196] Table 3 Orthogonal test results

[0197]

[0198] Use a UV-visible spectrophotometer to measure the absorbance values of each group of fruit puree at a wavelength of 420 nm. Determine the primary and secondary factors through range analysis: the concentration of citric acid (R = 0.028) has the greatest impact on anti-browning, followed by ascorbic acid (R = 0.014), and sodium chloride has the least impact (R = 0.006). The verification experiment of the optimal combination A1B2C1 (0.7% citric acid + 0.04% ascorbic acid + 0.8% sodium chloride) shows that the absorbance value of the fruit puree is only 0.072, which is further reduced by 9.1% compared with the optimal group in the orthogonal test (0.079 in experiment number 1). It is found in actual operation that the color protection solution needs to be prepared and used immediately and stored away from light. The temperature of the colloid mill during pulping should be controlled below 30 °C. The end point of boiling needs to be strictly monitored for changes in the refractive index to ensure that the soluble solids meet the standards and avoid excessive browning.

[0199] Experimental Example 3: The purpose of this experimental example is to measure the browning degree. First, take 5.00 g of the prepared compound puree sample of pear and Dendrobium officinale and place it in a 50 mL centrifuge tube. Add 15.0 mL of ethanol with a volume fraction of 95%, and use a vortex mixer to oscillate at the maximum speed (2500 rpm) for 10 min to fully mix the pulp and ethanol. Place the centrifuge tube in a refrigerated centrifuge, set the rotation speed to 4000 r / min, and centrifuge for 10 min at room temperature. After the centrifuge completely stops, take out the centrifuge tube, and use a pipette to aspirate the upper clear liquid into a quartz cuvette.

[0200] Turn on the ultraviolet-visible spectrophotometer and preheat it for 30 min. Use 95% ethanol as a blank control for baseline correction. Place the cuvette in the sample cell and measure the absorbance value of the supernatant at a wavelength of 420 nm. Each sample is measured in parallel 3 times and the average value is taken. The browning degree is expressed by the absorbance value, and the larger the value, the deeper the browning degree.

[0201] Experimental Example 4: The purpose of this experimental example is to measure the color difference of the puree. First, take the sterilized compound puree of pear and Dendrobium officinale and the untreated fresh puree as the control group, and conduct colorimetric analysis respectively. Before the experiment, turn on the bench-top spectrophotometer (model: X-Rite SP62) and preheat it for 30 min, and calibrate it with a standard white board to ensure that the instrument is in a stable state. Take 50 g of the puree sample and place it in a high-speed homogenizer, and homogenize it at a speed of 12000 rpm for 2 min to make the pulp particle distribution uniform. Carefully inject the homogenized puree into the quartz cuvette supporting the instrument, avoid generating bubbles, clean the outer wall of the cuvette with lens paper, and then put it into the sample chamber.

[0202] Set the instrument parameters as follows: D65 standard light source, 10° field of view angle, and measurement aperture of 8 mm. Each group of samples is measured in parallel 5 times, and the values of L* (brightness), a* (red-green axis), and b* (yellow-blue axis) are recorded, and the average value is taken as the colorimetric index of this group. The puree of the control group (L0* = 68.52, a0* = -2.15, b0* = 35.87) is measured under the same conditions. Use ΔE to reflect the change degree of the color between the sterilized group and the control group. The calculation of ΔE adopts the formula:

[0203]

[0204] Among them, L* represents brightness, and the larger the L* value, the higher the brightness; a* > 0 indicates that the object is reddish, a* < 0 indicates that the object is greenish; b* > 0 indicates that the object is yellowish, b* < 0 indicates that the object is bluish. L0 * 、a0 * 、b0 * values respectively represent the brightness, redness, and yellowness of the untreated group.

[0205] For example, if the puree of a certain sterilized group is measured to have L* = 65.38, a* = -1.89, b* = 32.45, then

[0206] ΔE = √[(65.38 - 68.52) 2 + (-1.89 + 2.15) 2 + (32.45 - 35.87) 2 = √[(-3.14) 2 + (0.26) 2 + (-3.42) 2 = √

[0207] (9.86 + 0.07 + 11.69) = √21.62 ≈ 4.65。

[0208] Experimental Example 5: The purpose of this experimental example is to analyze the physicochemical indexes and aroma of the compound puree of Dendrobium brymerianum and pear. First, take the freshly prepared compound puree of Dendrobium brymerianum and pear and conduct multi-dimensional quality inspections:

[0209] Content of soluble solids: Use an ATAGO PAL-1 handheld refractometer. First, calibrate it to 0.0% with distilled water. Drop 3 drops of the puree on the surface of the prism, close the cover plate, and then read the value. Measure in parallel 3 times and take the average value.

[0210] pH value: Pour the puree into a 50 mL beaker, mix it evenly with a magnetic stirrer at a speed of 200 rpm for 3 min. Use a Mettler-Toledo SevenCompact pH meter, immerse the electrode in the sample and let it stand for 30 s, and record the value after the reading is stable.

[0211] Total phenol content: Adopt the Folin-Ciocalteu method. Weigh accurately the gallic acid standard product and prepare a standard solution with a concentration of 0.01 - 0.1 mg / mL. Take 1 mL of the supernatant of the puree and add 5 mL of Folin-Ciocalteu reagent and 4 mL of 7.5% sodium carbonate solution. React in the dark for 2 hours, then measure the absorbance at a wavelength of 765 nm, and calculate the total phenol content (calculated as gallic acid) according to the standard curve.

[0212] Total sugar content: Phenol-sulfuric acid method. Take 0.5 mL of the diluted puree solution, add 1 mL of 5% phenol solution and 5 mL of concentrated sulfuric acid. Heat in a boiling water bath for 15 min, then cool to room temperature, measure the absorbance at a wavelength of 490 nm, and draw a standard curve with glucose as the standard product.

[0213] Weigh out another 20 g of the puree and dispense it into 50 mL centrifuge tubes, with 3 parallel samples in each group. Seal the tubes with aluminum foil sealing film and let them stand at room temperature for 30 min. Use a PEN3 type electronic nose (Airsense, Germany) for measurement. Set the parameters as follows: sampling time 1 s / group, sensor cleaning time 100 s (cleaning flow rate 400 mL / min), injection time 5 s, injection flow rate 400 mL / min, and analysis sampling time 100 s. Insert the injection needle vertically into the headspace of the centrifuge tube and draw 1000 μL of headspace gas into the detection chamber of the electronic nose. Clean the system with pure air for 3 min before testing each sample, and the data acquisition period is 69 - 71 s. The electronic nose is equipped with 10 metal oxide semiconductor sensors, which are sensitive to substances such as aromatic hydrocarbons, nitrogen oxides, and sulfides respectively.

[0214] Table 4 Performance of the 10 sensors of the electronic nose

[0215] Sensor number Sensor code Sensitive substance 1 W1C Aromatic hydrocarbon compound 2 W5S Nitrogen oxide compound 3 W3C Ammonia, aromatic molecule 4 W6S Hydride 5 W5C Olefin, aromatic, polar molecule 6 W1S Alkane 7 W1W Sulfur compound 8 W2S Alcohol, partial aromatic compound 9 W2W Aromatic hydrocarbon compound, sulfur-containing organic compound 10 W3S Alkane and aliphatic

[0216] In this experimental example, the data was processed by principal component analysis (PCA) and linear discriminant analysis (LDA) to evaluate the aroma differences between different treatment groups.

[0217] Experimental Example 6: The purpose of this experimental example was to evaluate the sensory properties of the pear dendrobium composite puree. Seven selected sensory evaluators (aged 20 - 45 years old, without olfactory or gustatory disorders) were recruited for this experiment. They received 2 pre - trainings before the experiment to ensure that they understood the scoring criteria. During the formal evaluation, the puree samples stored in the refrigerator were restored to room temperature (20 ± 2 °C) and dispensed into white disposable plastic cups (20 g / cup), with random three - digit numbers marked on the cup body. The evaluation environment was kept quiet and clean, with 4000K color temperature lighting to avoid odor interference.

[0218] The evaluators tasted 3 groups of samples in sequence, with each group containing sterilized puree and control puree. Rinse the mouth with mineral water before tasting, and leave a 3 - minute interval between each sample. The evaluation form used a 100 - point sub - item scoring system:

[0219] Observe the color and luster of the puree. A score of 16 - 25 points requires a uniform pink color with a sense of transparency. Samples with a score lower than 8 points have a dull color or show browning.

[0220] Take 5 g of the puree and place it on the tongue to feel the balance of sour and sweet. A score of 16 - 25 points requires a coordinated sour - sweet ratio. Samples that are too sour (pH < 3.8) or too sweet (soluble solids > 38%) are both judged to have a low score.

[0221] Stir the puree. A score of 16 - 25 points requires no obvious granularity, moderate viscosity (about 1500 - 2000 mPa·s), and a uniform texture without stratification.

[0222] Sniff the cup mouth 3 times. Between 16 - 25 minutes, it should have both the fruity aroma of pears and the fresh scent of dendrobium, without any cooking smell or off - odor.

[0223] Table 5 Sensory Evaluation Table

[0224] Item Evaluation criterion Color and luster (25 points) Dull color, light pink, without luster (1 - 7) With luster, pink (8 - 15) Bright pink color (16 - 25) Sweet and sour taste (25 points) Too sour or too sweet (1 - 7) Light sour or sweet taste (8 - 15) Sour with a touch of sweetness, suitable taste (16 - 25) Texture state (25 points) The puree has visible particles and uneven texture (1 - 7) The puree is delicate and slightly uneven in texture (8 - 15) The puree is delicate and uniform in texture (16 - 25) Aroma (25 points) Without the aroma of pear fruit (1 - 7) With a faint aroma of pear fruit and no other aroma (8 - 15) With a fresh mixed fruit aroma (16 - 25)

[0225] Data processing was carried out using SPSS 26.0 software. The average score and standard deviation of each index were calculated, and the differences between groups were compared through one - way analysis of variance (ANOVA). The results showed that the total sensory score of the puree with the optimal color - protection formula (A1B2C1) was 89.3 ± 3.1, significantly higher than that of the control group (78.5 ± 4.2). Among them, the scores of color (22.1 ± 1.8) and aroma (21.7 ± 2.3) increased particularly significantly.

[0226] Experimental Example 7: The purpose of this experimental example was to detect the microbial indicators of the pear - dendrobium composite puree. According to the GB4789.2 - 2022 standard, the total number of colonies of the pear - dendrobium composite puree after color - protection and sterilization was determined. Before the experiment, the ultra - clean workbench was turned on and run for 30 minutes, and the workbench surface and pipette were wiped with 75% ethanol to ensure a sterile operating environment. 5.00 g of the puree sample was placed in a 50 mL sterile homogenization bag, and 45 mL of sterile physiological saline (0.85% NaCl) was added. It was homogenized with a beating homogenizer at 200 times / min for 1 minute to prepare a 1:10 (10 -1 ) sample homogenate.

[0227] Using the 10 - fold serial dilution method, dilutions from 10 -2 to 10 -6 were prepared in sequence. 1 mL of the homogenate of each dilution was injected into a sterile petri dish, and immediately 15 mL of PCA medium (plate count agar) at about 45 °C was poured in and gently rotated and mixed. After the medium solidified, it was inverted and placed in an incubator at 36 ± 1 °C for 48 ± 2 hours.

[0228] After the incubation, plates with colony counts between 30 - 300 CFU were selected for counting. If two consecutive dilution - degree plates met the counting requirements, the formula was used: Total number of colonies (CFU / g) = (colony count of the first dilution degree × dilution multiple + colony count of the second dilution degree × dilution multiple) / 2. For example, if the colony count on the 10 -4 plate was 256 and the colony count on the 10 -5 plate was 28, then the calculation was (256 × 10 4 +28 × 10 5 ) / 2 = (2.56 × 10 6 +2.8 × 10 6 ) / 2 = 2.68 × 10 6 CFU / g.

[0229] Experimental Example 8: The objective of this experimental example was to explore the effect of sterilization methods on the color difference of the compound puree of Dendrobium officinale and pears. Three sterilization processes were used to treat the samples:

[0230] Pasteurization group: The puree was placed in a constant temperature water bath and heated at 78 °C for 10 min, with gentle stirring every 2 min during the process;

[0231] Microwave sterilization group: The puree was divided and filled into high-temperature resistant containers and treated with a 2450 MHz microwave oven at a power of 150 W for 1 min;

[0232] High-temperature steam sterilization group: A high-pressure sterilizer was used to sterilize at 121 °C and 0.15 MPa for 15 s;

[0233] The control group was fresh puree without sterilization. All the treated purees were quickly cooled to 25 °C and stored refrigerated at 4 °C.

[0234] The color difference was measured using a CM-700d spectrophotometer (Konica Minolta). Under the conditions of D65 light source and a 10° field angle of view, the samples stored for 0, 2, 4, 6, 8, and 10 days were detected for L* (brightness), a* (red-green value), and b* (yellow-blue value). The calculation formula for ΔE is:

[0235] ΔE = √[(L* - L0*)2 + (a* - a0*)2 + (b* - b0*)2], where L0* = 30.21, a0* = 15.98, and b0* = 29.37 are the initial values of the control group.

[0236] The experimental results showed that ΔE of the high-temperature steam sterilization group was 5.55 (P < 0.05), which was significantly higher than that of other groups. This was because high temperature promoted the oxidation of phenolic substances to form melanin.

[0237] ΔE of the pasteurization group was between 0.11 and 1.99, and ΔE of the microwave sterilization group was between 0.16 and 1.79, both lower than the visually distinguishable threshold of ΔE = 2; while ΔE of the high-temperature steam group continuously > 5.09, and the color difference value reached a peak of 6.16 on the 2nd day.

[0238] The a value of the high-temperature steam group increased from the initial 20.50 to 21.94 (P < 0.05), indicating an enhanced red tone, which was consistent with the phenomenon that high temperature promoted the isomerization of carotenoids; at the same time, the L value decreased by 2.13, indicating a significant loss of brightness.

[0239] Table 6 Changes in color difference of the compound puree of Dendrobium officinale and pears under different treatments during storage

[0240]

[0241]

[0242] In actual operation, it was found that after high-temperature steam sterilization, it was necessary to quickly cool to 4°C to inhibit subsequent browning. However, even so, its ΔE was still significantly higher than that of other groups.

[0243] Experimental Example 9: As Figure 5 、 Figure 6 shown, the purpose of this experimental example was to study the effects of different sterilization processes on the quality stability of the compound puree of Dendrobium officinale and pears. First, freshly prepared compound puree of Dendrobium officinale and pears was selected and treated with three sterilization processes:

[0244] Pasteurization: The puree was placed in a constant temperature water bath at 78°C and heated for 10 min, with uniform stirring every 2 min during this period.

[0245] Microwave sterilization: The puree was dispensed into polypropylene containers (50 g per portion) and irradiated with a 2450 MHz microwave oven at a power of 150 W for 3 min.

[0246] High-temperature steam sterilization: A high-pressure sterilizer was used to treat it at 121°C and 0.15 MPa for 10 s. The control group was fresh puree without sterilization. All treated samples were quickly cooled to 25°C and stored refrigerated at 4°C. Samples were taken for testing at 0, 2, 4, 6, 8, and 10 days respectively.

[0247] Determination of soluble solids content: An ATAGO PAL-10S hand-held refractometer was used. Before each determination, it was calibrated to 0.0% with distilled water. 3 drops of the puree were dropped on the surface of the prism, and the value was read after closing the cover plate. The average value was taken after parallel determination 5 times. The results showed that the initial soluble solids content was 36.0% for all groups (P > 0.05). After 10 days of storage, the retention rate of the high-temperature steam group reached 99.2% (35.8%), which was significantly higher than that of other groups (P < 0.05). This may be because high temperature promoted the degradation of polysaccharides such as cellulose and starch in the puree, generating soluble oligosaccharides, thus maintaining a relatively high solids content.

[0248] pH value determination: The puree was poured into a 50 mL beaker, mixed evenly at a speed of 200 rpm with a magnetic stirrer for 3 min, and a Mettler-Toledo SevenExcellence pH meter was used. The electrode was immersed in the sample and left standing for 30 seconds, and the reading was recorded after it stabilized. The results showed that the initial pH values of the pasteurization group and the microwave sterilization group decreased from 4.23 of the control group to 4.12 and 4.15 respectively (P < 0.05), which was related to the inactivation of pectin methylesterase by high temperature, resulting in the release of free pectic acid; while the pH value of the high-temperature steam group did not change significantly (P > 0.05). During storage, the pH values of all groups continued to decrease and dropped to 3.98, 4.02, and 4.05 respectively on the 10th day. This may be due to the production of organic acids (such as lactic acid and acetic acid) by the metabolism of residual microorganisms.

[0249] Experiments show that although high-temperature steam sterilization can better retain soluble solids, it will lead to a decrease in pH stability. In actual production, the sterilization method can be selected according to the product positioning: if the pursuit is to retain nutrition, microwave sterilization is recommended; if the shelf life needs to be extended, pasteurization combined with cold chain transportation can be adopted.

[0250] Experimental Example 10: As Figure 7 shown, the purpose of this experimental example is to study the effects of different sterilization processes on the total phenol content of pear dendrobium composite puree. First, freshly prepared pear dendrobium composite puree (total phenol content 1.46 ± 0.05 mg / g) was selected and treated with three sterilization processes:

[0251] Pasteurization group: The puree was placed in a constant temperature water bath at 78°C and heated for 10 min, with gentle stirring every 2 min during this period;

[0252] Microwave sterilization group: The puree was dispensed into high-temperature resistant containers (50 g per portion) and irradiated with a 2450 MHz microwave oven at a power of 150 W for 2 min;

[0253] High-temperature steam sterilization group: Treated with a high-pressure sterilizer at 121°C and 0.15 MPa for 15 s. The control group was fresh puree without sterilization. All treated samples were quickly cooled to 25°C and stored refrigerated at 4°C, and samples were taken for testing at 0, 2, 4, 6, 8, and 10 days respectively.

[0254] The total phenol content was determined by the Folin-Ciocalteu method: 0.5 g of puree was precisely weighed, 5 mL of 80% ethanol by volume was added, vortex mixed for 2 min and then ultrasonically extracted for 30 min (power 200 W, temperature 40°C). The extract was centrifuged at 4000 r / min for 10 min, 1 mL of the supernatant was taken and added to 5 mL of Folin-Ciocalteu reagent (pre-diluted 10 times) and 4 mL of 7.5% sodium carbonate solution, and the absorbance was measured at a wavelength of 765 nm after reacting in the dark for 2 hours. Using gallic acid as the standard product to draw a standard curve (R 2 = 0.9987), and the total phenol content (mg GAE / g) was calculated.

[0255] The experimental results showed that the high-temperature steam sterilization group (1.40 ± 0.03 mg / g) was significantly higher than the pasteurization group (1.14 ± 0.02 mg / g) and the microwave sterilization group (1.17 ± 0.04 mg / g) (P < 0.05), which may be due to the high temperature promoting the destruction of the cell wall structure and releasing more bound phenols.

[0256] The total phenol content of all groups decreased with time. The retention rate of the high-temperature steam group was the highest on the 10th day (91.1%), and the pasteurization group decreased the fastest (losing 30.1%). This was consistent with the result that the ΔE value of the high-temperature steam sterilization group was continuously > 5.09. It was speculated that the Maillard reaction induced by high temperature generated melanoidins with antioxidant activity, partially offsetting the loss of phenols.

[0257] The total phenol content was significantly negatively correlated with ΔE (r = -0.87, P < 0.01), indicating that the higher the degree of browning, the more phenolic substances were retained.

[0258] Experimental Example 11: As Figure 8 shown, the goal of this experiment was to explore the effect of different sterilization processes on the total sugar content of pear dendrobium composite puree, and the phenol-sulfuric acid method was used to systematically analyze the change law of sugar content during sterilization treatment and storage. Freshly prepared pear dendrobium composite puree (total sugar content 29.33 ± 0.56%) was selected for the experiment, and three sterilization treatments were carried out respectively:

[0259] Pasteurization group: The puree was placed in a constant temperature water bath at 78°C and heated for 10 min, with gentle stirring every 2 min during this period;

[0260] Microwave sterilization group: The puree was dispensed into polypropylene containers (50 g / serving) and irradiated with a 2450 MHz microwave oven at a power of 150 W for 2 min;

[0261] High-temperature steam sterilization group: A high-pressure sterilizer was used to treat it at 121°C and 0.15 MPa for 5 s. The control group was fresh puree without sterilization. All treated samples were quickly cooled to 25°C and stored at 4°C. Samples were taken for detection at 0, 2, 4, 6, 8, and 10 days respectively.

[0262] The steps for determining the total sugar content were as follows: Weigh 0.5 g of puree into a 50 mL centrifuge tube, add 5 mL of ultrapure water, vortex mix for 30 seconds, and then ultrasonically extract for 20 min (power 150 W, temperature 40°C). The extract was centrifuged at 4000 r / min for 10 min, and 0.5 mL of the supernatant was taken and added to 1 mL of 5% phenol solution and 5 mL of concentrated sulfuric acid. After boiling water bath for 15 min, it was cooled to room temperature, and the absorbance was measured at a wavelength of 490 nm. Using glucose as the standard product to draw a standard curve (R 2 = 0.9992), calculate the total sugar content (%).

[0263] The experimental results showed that the high-temperature steam sterilization group (30.39 ± 0.41%) was significantly higher than other groups (P < 0.05), which was because high temperature promoted the hydrolysis of macromolecular substances such as protopectin and cellulose into soluble monosaccharides.

[0264] The total sugar content of all groups decreased with time. The retention rate of the high-temperature steam group was the lowest (93.4%) on the 10th day, while the retention rate of the pasteurization group was the highest (98.2%). This was related to the intensified browning reaction caused by the increase in the dissolved oxygen concentration in the high-temperature steam sterilization group (measured by a dissolved oxygen meter as 8.2 mg / L, significantly higher than 4.5 - 5.0 mg / L of other groups). The oxidation of phenols consumed reducing sugars while generating brown substances.

[0265] The total sugar content was significantly negatively correlated with the ΔE value (r = -0.89, P < 0.01), indicating that the darker the color, the more sugar was lost.

[0266] Experimental Example 12: As Figure 9 , Figure 10 shown, in this experiment, an electronic nose technology system was used to analyze the effects of different sterilization processes on the aroma components of pear dendrobium compound puree. Freshly prepared puree (non-sterilized group) and puree samples treated by pasteurization (78 °C / 10 min), microwave sterilization (2450 MHz / 150 W / 1 min), and high-temperature steam sterilization (121 °C / 0.15 MPa / 15 min) were selected, with 3 parallel samples in each group. The samples were dispensed into 50 mL headspace vials (20 g / vial), sealed with aluminum foil, and left standing at room temperature for 30 min for aroma enrichment.

[0267] A PEN3 type electronic nose (Airsense, Germany) was used for determination. The parameter settings were: sampling time 1 s / group, sensor self-cleaning time 100 s (flow rate 400 mL / min), injection time 5 s, injection flow rate 400 mL / min, and analysis sampling time 100 s. The data acquisition period was 69 - 71 s, and principal component analysis (PCA) was performed using WinMuster software. The sensor array consisted of 10 metal oxide semiconductor sensors. Among them, W1W was sensitive to sulfides, and W5S responded to nitrogen oxides.

[0268] The experimental results showed that the contribution rate of PC1 was 86.9%, the contribution rate of PC2 was 6.5%, and the cumulative interpretation of the aroma information was 93.4%. The non-sterilized group was closely clustered with the pasteurization and microwave groups on the PCA graph, while the high-temperature steam group deviated significantly, indicating that its aroma profile had changed significantly.

[0269] For the high-temperature steam group, the signal value of the W1W sensor increased from 2.35 ± 0.12 at the baseline to 3.56 ± 0.21 (P < 0.05), with an increase of 51.7%. This was mainly attributed to the high temperature promoting the decomposition of sulfur-containing amino acids to generate volatile sulfides (such as dimethyl sulfide). The signal value of W5S increased from 1.89 ± 0.08 to 2.64 ± 0.15 (P < 0.05), which might be related to the Maillard reaction induced by high temperature to produce nitrogen-containing heterocyclic compounds.

[0270] The puree in the high-temperature steam group showed a stronger caramel aroma, which was consistent with the increasing trends of sulfides and nitrogen compounds detected by the electronic nose.

[0271] Experimental Example 13: This experimental example systematically studied the effects of different sterilization processes on the microbial safety and sensory quality of pear dendrobium compound puree. Fresh puree was selected and divided into four groups: an unsterilized group, a pasteurization group (78°C / 10 min), a microwave sterilization group (2450 MHz / 150 W / 1 min), and a high-temperature steam sterilization group (121°C / 0.15 MPa / 15 min). Each group of samples was dispensed into 50 mL sterile vials (20 g / vial) and stored refrigerated at 4°C. Samples were taken for testing at 0, 2, 4, 6, 8, and 10 days respectively.

[0272] The determination of total colony count was carried out according to the GB4789.2-2022 standard: 5 g of puree was added to 45 mL of physiological saline, homogenized by tapping for 1 min and then serially diluted to 10 -6 , 1 mL of the dilution was poured onto PCA medium and cultured at 36°C for 48 hours.

[0273] Table 7 Changes in total colony count and sensory properties of pear dendrobium compound puree under different treatments during storage

[0274] Processing conditions Time / d Total number of colonies / (CFU / g) Sensory evaluation / points Untreated 0 <![CDATA[13.33±5.78 Abc > 76 Pasteurization 0 ND 79 2 ND — 4 ND — 6 <![CDATA[6.67±11.55 cd > — 8 <![CDATA[16.67±5.78 b > — 10 <![CDATA[26.67±5.78 a > — Microwave sterilization 0 ND 74 2 ND — 4 <![CDATA[3.33±5.78 d > — 6 <![CDATA[6.67±5.78 cd > — 8 <![CDATA[13.33±11.55 bc > — 10 <![CDATA[16.67±5.78 b > — High-temperature steam sterilization 0 ND 81 2 ND — 4 ND — 6 ND — 8 ND — 10 ND —

[0275] Note: Different capital letters indicate significant differences among the three at the initial time (P < 0.05); different lowercase letters indicate significant differences among the different storage times of these three treatments (P < 0.05). ND indicates that the microbial count is below the detection limit (<1 CFU / g); — indicates not detected.

[0276] The results showed that: the initial total colony count of the unsterilized group was 13.33 ± 5.78 CFU / g; none were detected initially in the three sterilization groups (ND), meeting the enterprise standard of QCPADL0001-2015 (≤1500 CFU / g); during storage, the total colony count of the pasteurization group rose to 26.67 ± 5.78 CFU / g on the 10th day, the microwave group rose to 16.67 ± 5.78 CFU / g, and none were detected in the high-temperature steam group throughout.

[0277] Sensory evaluation was carried out by 7 trained evaluators according to the criteria in Table 4: the unsterilized group scored 76 points and had a slight fermented odor; the high-temperature steam group scored 81 points, with a uniform pink color, a balanced sweet and sour taste, and a prominent dendrobium aroma; the microwave group scored the lowest (74 points) due to a slight cooked taste.

[0278] The embodiments of the present invention are given for purposes of illustration and description. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. Pear Dendrobium composite puree, characterized by: Comprising the following components by weight parts, 55 - 70 parts of pear fruit pulp, 12 - 17 parts of dendrobium juice, 4.2 - 4.8 parts of granulated sugar, 1.8 - 2.4 parts of maltose, 0.61 - 0.82 parts of citric acid, 0.03 - 0.05 parts of ascorbic acid, 0.7 - 0.9 parts of sodium chloride; The preparation of the pear - dendrobium composite puree comprises the following steps, (S01) Select pear fruit pulp and dendrobium juice, and place them in a stirrer according to a volume ratio of 3.5:1 - 4.5:1, and stir at a speed of 50 - 70 rpm for 3 - 5 min to obtain a mixed fruit pulp; (S02) Place the mixed fruit pulp in a jacketed pan, boil it at a temperature of 90 - 95 °C for 15 - 25 min, and continuously stir at a speed of 20 - 30 rpm. During boiling, add granulated sugar with a mass percentage of 1.4 - 1.6% and maltose with a mass percentage of 0.6 - 0.8%; (S03) Lower the boiling temperature to 80 - 85 °C, add granulated sugar with a mass percentage of 1.4 - 1.6% and maltose with a mass percentage of 0.6 - 0.8%, and continue boiling; after an interval of 4 - 6 min, lower the boiling temperature to 70 - 75 °C, and then add granulated sugar with a mass percentage of 1.4 - 1.6% and maltose with a mass percentage of 0.6 - 0.8%; Take samples from the center position of the jacketed pan every 2 - 4 min, place the samples in a constant temperature water bath at 18 - 22 °C to balance for 4 - 6 min, then place the samples in a refractometer to analyze the soluble solids content of the samples. When the soluble solids content reaches 33 - 37%, stop heating and stirring to obtain the pear - dendrobium composite puree.

2. The pear dendrobium composite puree according to claim 1, characterized in that: The preparation of the pear fruit pulp comprises the following steps, (A1) Select pear fruits, wash them for 3 - 5 min, remove the outer skin and cores of the pear fruits, and then cut the pear fruits into pear blocks with a size of 1.5 - 2.5 cm; (A2) Place the pear blocks in a constant temperature water bath at 80 - 90 °C, blanch them for 8 - 12 min to inactivate enzymes. Stir the pear blocks every 1 - 3 min during blanching. After blanching, transfer the pear blocks to ice water at 0 - 5 °C and cool for 5 - 8 min; (A3) Immerse the cooled pear blocks in a color - protecting agent, soak them at a temperature of 20 - 25 °C for 8 - 12 min, turn the pear blocks every 4 - 6 min during soaking. After soaking, rinse the pear blocks for 1 - 2 min, and then drain water for 5 - 10 min; (A4) Place the pear blocks in a colloid mill and beat them with a grinding disc interval of 0.4 - 1.2 mm to obtain pear fruit pulp.

3. The pear dendrobium composite puree according to claim 1, wherein: The preparation of the dendrobium juice comprises the following steps, (B1) Select dendrobium officinale stems, wash them for 2 - 3 min, rub to remove the white dry skin on the surface of the dendrobium officinale stems, and cut the dendrobium officinale stems into stem segments with a size of 0.8 - 1.2 cm; (B2) Place the stem segments in a pulper, add pure water according to a liquid - to - solid ratio of 1:40 - 1:60, and beat at a speed of 10000 - 12000 rpm for 1.5 - 2.5 min to obtain dendrobium officinale homogenate; (B3) Add citric acid with a concentration of 0.01 - 0.02% to the dendrobium officinale homogenate, stir evenly, and soak at a temperature of 20 - 25 °C for 0.8 - 1.2 h. Stir the mixture every 12 - 18 min during soaking; Perform pressure filtration using a 50 - 70 mesh sieve to filter out insoluble Dendrobium residues, collect the filtrate, and obtain Dendrobium juice.

4. The compound puree of Dendrobium nobile Lindl. and pear according to claim 1, characterized in that: The sterilization process of the pear - Dendrobium compound puree is pasteurization or microwave sterilization or high - temperature steam sterilization. The pasteurization method is to place the pear - Dendrobium compound puree in a constant - temperature water bath, heat it at a temperature of 78 - 82 °C for 8 - 12 min, invert the bottle or turn the bag a total of 1 - 2 times during heating to shake the pear - Dendrobium compound puree evenly. After heating, place the pear - Dendrobium compound puree in a low - temperature water bath and cool it to 20 - 25 °C. The microwave sterilization method is to place the pear - Dendrobium compound puree in a microwave oven and heat it with a power of 100 - 200 W for 1 - 3 min. After heating, place the pear - Dendrobium compound puree in a low - temperature water bath and cool it to 20 - 25 °C. The high - temperature steam sterilization method is to place the pear - Dendrobium compound puree in a steam sterilizer, heat it at a temperature of 118 - 124 °C and a pressure of 0.14 - 0.16 MPa for 5 - 15 s. After heating, place the pear - Dendrobium compound puree in a low - temperature water bath and cool it to 20 - 25 °C.

5. The pear dendrobium composite puree according to claim 1, characterized in that: The color - protection method in the preparation process of the pear puree includes the following steps. (C1) Select pure water and place it in a reaction kettle. Load citric acid and sodium chloride into the first adjusting bottle and the second adjusting bottle respectively. Add 0.6 - 0.8% citric acid and 0.7 - 0.9% sodium chloride by mass percentage to the reaction kettle. Then replace the reagent in the first adjusting bottle with ascorbic acid and add 0.03 - 0.05% ascorbic acid to the reaction kettle. Use a stirring paddle to stir at a speed of 250 - 350 rpm for 4 - 6 min to obtain a compound color - protection liquid. (C2) After cutting the pears into pieces, place them in a color - protection tank and add the compound color - protection liquid to submerge the pear pieces in the compound color - protection liquid. Soak them at a temperature of 20 - 25 °C for 8 - 12 min. During soaking, use a stirrer and a turning rod to turn the pear pieces every 4 - 6 min. After soaking, open the water inlet pipe and the water outlet pipe to rinse the pear pieces for 1 - 2 min, then drain for 5 - 10 min. Finally, open the discharge port to take out the pear pieces and detect the color - protection effect.

6. The pear dendrobium composite puree according to claim 1, characterized in that: The color - protection device in the preparation process of the pear puree includes a reaction frame (100) and a dispensing structure (200). Above the reaction frame (100), there is a color - protection tank (500). Above the color - protection tank (500), there is a stirring assembly (300). On one side of the bottom of the color - protection tank (500), there is a turning assembly (400). The top of the color - protection tank (500) is provided with a feed inlet (501). The side of the color - protection tank (500) is provided with a discharge outlet (502). One side of the top of the color - protection tank (500) is detachably connected with a water inlet pipe (503). The bottom end of the color - protection tank (500) is detachably connected with a water outlet pipe (504). The stirring assembly (300) includes a driving motor (301). The driving motor (301) is arranged above the color protection tank (500). A support frame (302) is detachably connected below the driving motor (301). The bottom end of the support frame (302) is detachably connected to the color protection tank (500). A stirrer (303) is arranged at the center of the support frame (302). The output end of the driving motor (301) is fixedly connected to the stirrer (303). The turning assembly (400) includes a stepping motor (401). The stepping motor (401) is arranged on the side of the color protection tank (500). A transmission column (402) is arranged on the side of the stepping motor (401) close to the color protection tank (500). The output end of the stepping motor (401) is fixedly connected to the transmission column (402). A plurality of turning rods (4021) are fixedly connected to the side of the transmission column (402) far from the stepping motor (401). A transmission ring (403) is arranged on the side of the turning rod (4021). A rotating ring (404) is detachably connected to the side of the transmission ring (403) close to the color protection tank (500). A docking column (505) is rotatably connected to the side of the rotating ring (404) far from the transmission ring (403). One end of the docking column (505) far from the rotating ring (404) is fixedly connected to the color protection tank (500).

7. The pear dendrobium composite puree according to claim 6, wherein: A bracket (101) is arranged on the side of the reaction frame (100). A sliding table (102) is slidably connected to the top end of the bracket (101). A plurality of connecting rings (1021) are fixedly connected above the sliding table (102). An installation short plate (1022) is detachably connected above the connecting ring (1021). A fixing plate (506) is detachably connected above the installation short plate (1022). One side of the fixing plate (506) is fixedly connected to the color protection tank (500). An installation plate (103) is detachably connected below the stepping motor (401). One side of the bottom end of the installation plate (103) is detachably connected to the reaction frame (100). A sealing ring (4041) is arranged on the side of the rotating ring (404) close to the transmission ring (403). A sealing ring (4042) is arranged on the side of the rotating ring (404) close to the docking column (505).

8. The pyrrosia pear compound puree according to claim 6, characterized in that: One end of the water inlet pipe (503) far from the color protection tank (500) is detachably connected to a corrugated compensator (5031). One end of the corrugated compensator (5031) far from the water inlet pipe (503) is detachably connected to a conveying pipe (5032). A servo electric pump (5033) is arranged at the end of the conveying pipe (5032) far from the corrugated compensator (5031). One end of the servo electric pump (5033) far from the conveying pipe (5032) is detachably connected to a control pipe (5034).

9. The pear dendrobium composite puree according to claim 6, wherein: The blending structure (200) includes a support column (201). A first positioning plate (2011) is detachably connected to the side surface of the support column (201). A first limiting plate (20111) is detachably connected above the first positioning plate (2011). A reaction kettle (203) is detachably connected above the first limiting plate (20111). A second positioning plate (2012) is detachably connected to the top side surface of the reaction kettle (203). The second positioning plate (2012) is detachably connected to the support column (201). A second limiting plate (20121) is provided above the second positioning plate (2012). A third limiting plate (2013) is provided above the second limiting plate (20121). The third limiting plate (2013) is detachably connected to the support column (201).

10. The pear dendrobium composite puree according to claim 9, characterized in that: A steam pipe (2045) is provided on the middle side surface of the reaction kettle (203). One end of the steam pipe (2045) away from the reaction kettle (203) is provided with a first control valve (2044). One end of the first control valve (2044) away from the steam pipe (2045) is provided with an air delivery pipe (2043). One end of the air delivery pipe (2043) away from the first control valve (2044) is provided with a steam generator (204). A steam control board (2041) is provided on the side surface of the steam generator (204). A pressure gauge (2042) is provided on the side surface of the steam control board (2041).

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