Preparation process of preserved polygonatum odoratum

Abstract

The present invention discloses a production process of preserved polygonatum odoratum, specifically, fresh polygonatum odoratum is used as a raw material, the fresh polygonatum odoratum is washed clean, and then the washed polygonatum odoratum is subjected to the procedures including but not limited to cutting, steaming, sugaring and drying to obtain the preserved polygonatum odoratum, and the steaming time is 1.5-2 h; in the sugaring process, the steamed materials are placed in a sugar solution to be soaked for 3.5-4.5 h, and after soaking is finished, the materials are taken out to be soaked in hot water at the temperature of 50-70 DEG C for one time; the sugar solution is an aqueous solution of mixed sugar composed of white granulated sugar and erythritol according to the mass ratio of 1: 1, and the sugar content of the sugar solution is 35-40 w / w%; in the drying process, forced air drying is carried out for 4-5 h under the condition of 55-60 DEG C, and then natural cooling is carried out to the room temperature. The method disclosed by the invention is simple in process, and the prepared preserved polygonatum odoratum is warm yellow, full in appearance, soft in texture, soft and glutinous in mouth feel, suitable in sweetness, and not sticky to hands, and slightly has unique fragrance of polygonatum odoratum.

Description

Technical Field

[0001] The present invention relates to a method for making ready-to-eat foods, and specifically to a production process for preserved fruit of Polygonatum odoratum Mill. Background Art

[0002] Polygonatum odoratum Mill. is a perennial herb of the genus Polygonatum in the family Asparagaceae. The dried rhizome of Polygonatum odoratum Mill. is a traditional Chinese tonic medicinal material. It is sweet, slightly cold, and belongs to the lung and stomach meridians. Its main components are polysaccharides, steroidal saponins, flavonoids, glycosides, etc. It is listed as a top-grade medicine in "Shennong's Herbal Classic" and has various pharmacological effects such as strengthening the body resistance and tonifying, nourishing the lung yin, moistening the lungs and relieving cough, enhancing immunity, beautifying the skin, and delaying aging. At the same time, Polygonatum odoratum Mill. was included in the "List of Medicinal and Edible Homologous Substances" as early as 2002, which reflects its potential advantages as an auxiliary food therapy substance.

[0003] With the acceleration of people's living rhythm and the increasing attention to health, more and more people begin to seek portable and effective health foods, which has also given rise to a new trend of portable health preservation. Exploring the benefits of functional foods with medicinal and edible homology is closely related to portable health preservation in modern society. Polygonatum odoratum Mill. was included in the "List of Medicinal and Edible Homologous Substances" in 2002 and has potential advantages as an auxiliary food therapy substance. Taking it for a long time can remove facial dark spots, improve complexion, make the skin moist, and reduce wrinkles by regulating the balance of internal organs.

[0004] In ancient times, Polygonatum odoratum Mill. was mostly processed by scraping off the skin, soaking in honey water, and then steaming thoroughly. In modern times, it is mostly washed, cut into thick slices, and used raw, with a limited consumer group. The invention patent with publication number CN101433330A discloses a method for making ready-to-eat Polygonatum sibiricum Redoute or ready-to-eat Polygonatum odoratum Mill., which uses Polygonatum sibiricum Redoute or Polygonatum odoratum Mill. as raw materials and includes the processes of material selection, slicing, pickling, boiling, steaming, kneading, sugar coating, and packaging. The material selection process: fresh Polygonatum sibiricum Redoute or Polygonatum odoratum Mill. is washed and peeled, and dried Polygonatum sibiricum Redoute or dried Polygonatum odoratum Mill. is soaked and washed; the pickling process: pickled with a salt and wine mixture; the boiling process: put it in a solution of licorice and tangerine peel and boil for 5 - 8 minutes; the kneading process: put it in a basin and knead while it is hot after steaming; the sugar coating process: soak it in a sugar solution with a sugar content of 8% - 12% by weight; the sugar coating process: put it in a sugar solution and boil for 1 - 2 minutes and then soak until the moisture content of the raw material is 37% - 45% by weight. The sugar solution has a sugar content of 25% - 30% by weight and agar powder is added after boiling, and the weight ratio of agar powder to sugar solution is (8 - 12):10000. Although the ready-to-eat Polygonatum sibiricum Redoute made by the method of this invention can regulate blood sugar and blood lipids, the taste is not satisfactory, and honey needs to be added in the sugar coating and sugar coating processes to improve the taste of the finished product. On the other hand, the process of the method of this invention is relatively cumbersome. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a production process for polygonatum fruit preserves with simple processes, soft texture and sweet and glutinous taste of the finished product.

[0006] To solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A production process for polygonatum fruit preserves, characterized in that fresh polygonatum is used as raw material, and after being cleaned, it is prepared through processes including but not limited to slicing, steaming, sugaring and drying. Among them,

[0008] In the sugaring process, the steamed material is soaked in the sugar solution for 3.5 - 4.5 h. After the soaking is completed, the material is taken out and passed through hot water at 50 - 70 °C; the sugar solution is an aqueous solution of a mixed sugar composed of white granulated sugar and erythritol in a mass ratio of 1:1, and the sugar content of the sugar solution is 35 - 40 w / w%.

[0009] In the drying process, it is dried by blowing air at 55 - 60 °C for 4 - 5 h, and then naturally cooled to room temperature.

[0010] The applicant found in the experiment that the parameter selection in the steaming process, sugaring process and drying process has a great influence on the texture and taste of the obtained polygonatum fruit preserves. Specifically: if the steaming time is too long, the texture of the pulp tissue is soft but without a glutinous taste; if the steaming time is too short, the texture of the pulp tissue is hard and brittle, and there is mucus on the surface and it is sticky; using a mixed sugar composed of white granulated sugar and erythritol in a mass ratio of 1:1 as the sugar source and controlling the sugar content of the sugar solution to be 35 - 40 w / w%, the sugar solution forms a large osmotic pressure, which can effectively exchange the sugar in the sugar solution and the water in the polygonatum tissue, so that the obtained fruit preserves can obtain the desired sweetness while cooperating with the subsequent drying process to obtain a plump appearance; therefore, the above steaming process, sugaring process and drying process cooperate with each other, are closely related and act synergistically, so that the obtained polygonatum fruit preserves have a plump shape, a soft texture, a sweet and glutinous taste and a slightly unique fragrance of polygonatum.

[0011] When cleaning fresh polygonatum, wash the surface mud of the raw material with clean water, pull out the root whiskers, and scrape off the epidermis.

[0012] Furthermore, in the impregnation process, the temperature of the sugar solution is preferably 50 - 70 °C, more preferably 60 °C.

[0013] Furthermore, the slicing process is to cut the raw material into thin slices with a thickness of 0.5 - 0.7 cm, and more preferably to cut the raw material into thin slices with a thickness of 0.5 - 0.7 cm and a length of 4 - 6 cm.

[0014] In a preferred embodiment, the steaming time in the steaming process is 1.5 h; in the sugar-preserving process, the steamed material is soaked in a sugar solution at 60 °C for 3.5 h. After the soaking is completed, the material is taken out and rinsed in hot water at 60 °C; the sugar content of the sugar solution is 35 w / w%; in the drying process, the material that has completed the sugar-preserving process is dried by blowing air at 60 °C for 4.5 h, and then naturally cooled to room temperature.

[0015] Fresh polygonatum odoratum is accompanied by a large amount of mucus. In order to improve the sugar infiltration effect in the later stage and further improve the taste, it is preferred to perform a cold water soaking process after the slicing process and before the steaming process. Specifically, the sliced material is placed in water at 4 - 8 °C and soaked for 8 - 12 h to remove the excess mucus on the surface of the sliced material and prevent oxidation.

[0016] Furthermore, the production process described in the present invention further includes a packaging process after the drying process, preferably using vacuum packaging. After the packaging process, a sterilization process can also be included to extend the shelf life of the product, preferably using pasteurization.

[0017] Compared with the prior art, by controlling the parameters in the steaming process, sugar-preserving process and drying process, and cooperating with each other, the polygonatum odoratum fruit preserves obtained by the present invention have a plump appearance, a soft texture, a soft, glutinous, sweet taste with a unique fragrance of polygonatum odoratum. In addition, the method of the present invention has a simple process and is easy to industrialize. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is the standard curve of anhydrous glucose at 490 nm.

[0019] Figure 2 It is the standard curve of rutin at 508 nm.

[0020] Figure 3 It is the standard curve of dioscin at 533 nm.

[0021] Figure 4 It is the photo of the freshly sliced polygonatum odoratum after steaming for different times.

[0022] Figure 5 It is the curve of the influence of the mass fraction of the sugar solution on the sensory score of the polygonatum odoratum fruit preserves during sugar-preserving.

[0023] Figure 6 It is the curve of the influence of the temperature and time of the sugar solution on the sensory score of the polygonatum odoratum fruit preserves during sugar-preserving.

[0024] Figure 7 It is the curve of the influence of the drying temperature on the sensory score of the polygonatum odoratum fruit preserves. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] To better explain the technical solution of the present invention, the present invention will be further described in detail below in conjunction with embodiments, but the implementation manners of the present invention are not limited thereto.

[0026] Example 1

[0027] The production process of the polygonatum odoratum fruit preserves described in the present invention includes the following steps:

[0028] Raw material selection: Select fresh, plump polygonatum odoratum without insect eyes or lesions, with a size of 5 - 10 cm per section (the fresh rhizome of polygonatum odoratum Mill., a perennial herb of the genus Polygonatum in the family Asparagaceae, identified by a researcher from the Guangxi Institute of Botany) as the raw material.

[0029] Washing: Wash the sediment clean with clean water, pull out the rootlets on the surface of the polygonatum odoratum, and scrape off the epidermis with a small knife.

[0030] Slicing: Cut the polygonatum odoratum into thin slices with a length of 4 - 6 cm and a thickness of 0.5 - 0.7 cm.

[0031] Cold water soaking: Soak the sliced materials in cold water at 4 - 6 °C for 8 - 12 h to prevent oxidation and remove excess mucus. After soaking, take out and drain the water.

[0032] Steaming: The raw polygonatum odoratum has a strong raw taste. Appropriate pretreatment can improve the tissue structure of the pulp, soften the pulp, and is beneficial to subsequent sugar infiltration to improve the taste of the fruit preserves. Therefore, the steaming method is used for pretreatment of the polygonatum odoratum slices before sugar marinating. The steaming time is 1.5 - 2 h.

[0033] Sugar marinating: Use erythritol: white granulated sugar = 1:1 (mass ratio) and mix evenly as the sugar for sugar infiltration. The sugar content of the sugar solution is 35 - 40 w / w%. Place the steamed materials in the sugar solution and soak for 3.5 - 4.5 h. After soaking, take out the materials and pass them through hot water at 60 °C for 2 - 3 s to wash off the excess sugar on the surface of the polygonatum odoratum slices.

[0034] Drying: Dry under the condition of blowing air at 55 - 60 °C for 4 - 5 h, and then naturally cool to room temperature. Appropriate drying conditions can improve the taste of fruit preserve products, and controlling the water content is beneficial to the preservation of fruit preserve products. Waiting for the polygonatum odoratum fruit preserves to cool after drying can maintain the soft and glutinous feeling of the fruit preserves.

[0035] Packaging: Adopt vacuum packaging.

[0036] Sterilization: The packaged fruit preserves are pasteurized to achieve the purpose of inhibiting the growth of microorganisms and extending the shelf life of the product.

[0037] 1. Test method

[0038] 1.1 Single-factor experiment design for the process study of polygonatum fruit preserves

[0039] 1.1.1 Influence of steaming time of fresh polygonatum on the softness of polygonatum fruit preserves

[0040] Fresh polygonatum has an obvious raw taste and is accompanied by a large amount of mucus, which has a great impact on the sugar infiltration effect and taste in the later stage. In this experiment, the method of steaming was used for the pretreatment of polygonatum slices, and the influence of different steaming times on the softness of polygonatum fruit preserves was explored.

[0041] Single-factor experiments need to be controlled for polygonatum fruit preserve slices. Polygonatum slices of appropriate size and uniform thickness soaked in cold water overnight were selected as experimental materials. After draining the excess water from the polygonatum slices, 100 g of polygonatum slices were weighed for each portion. They were evenly spread on the steaming plate. When the water in the lower layer boiled and steamed, the pot lid was covered and steaming was started for 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, and 3 h respectively. Then, a sensory evaluation of the steamed polygonatum slices was carried out, and the optimal steaming time of fresh polygonatum slices was selected based on the softness and taste of the polygonatum slices.

[0042] 1.1.2 Influence of the mass fraction of sugar solution during impregnation on the quality of polygonatum fruit preserves. A mixed sugar of granulated sugar:erythritol = 1:1 (mass ratio) was used as the test sugar. Aqueous solutions with mass fractions of 20%, 25%, 30%, 35%, 40%, and 45% were respectively prepared as sugar solutions with a volume of 600 mL to explore the influence of different sugar solution mass fractions on the quality of polygonatum fruit preserves. Fresh polygonatum slices steamed for 1 h were fixed. 200 g of steamed polygonatum slices were impregnated in each 600 mL of sugar solution. The sugar impregnation temperature was 50 °C and the time was 2.5 h. After the sugar infiltration was completed, hot air drying was carried out at 70 °C for 4 h.

[0043] 1.1.3 Influence of sugar solution temperature and time during impregnation on the quality of polygonatum fruit preserves. A mixed syrup with a mass fraction of 40% was used as the sugar infiltration solution, and the remaining test conditions were the same as those in 1.2. The sugar impregnation temperatures were set at 30 °C, 40 °C, 50 °C, 60 °C, 70 °C, and 80 °C to explore the influence of different sugar impregnation temperatures and times on the quality of polygonatum fruit preserves.

[0044] 1.1.4 Influence of hot air drying temperature on the quality of polygonatum fruit preserves. Fixed conditions: Fresh polygonatum slices steamed for 1 h, and the sugar solution during impregnation had a mass fraction of 40% (a mixed sugar composed of granulated sugar:erythritol = 1:1 (mass ratio) was used as the test sugar), and soaked at 50 °C for 2.5 h. After the soaking was completed, equal amounts of polygonatum were subjected to hot air drying at 50 °C, 60 °C, 70 °C, and 80 °C for 4.5 h respectively to investigate the influence of different temperatures on the quality of polygonatum fruit preserves.

[0045] 1.2 Orthogonal experiment design for the process study of polygonatum fruit preserves

[0046] Based on the results of single-factor experiments, the production process of polygonatum fruit preserves was optimized using an orthogonal experiment. The influencing factors of the orthogonal experiment were determined to be the mass fraction of the sugar solution used for sugar impregnation (A), the sugar impregnation time of polygonatum fruit preserves (B), and the temperature of hot air drying (C), as shown in Table 1. Fresh polygonatum slices steamed for 1.0 h were fixed as the raw materials for making fruit preserves, the sugar used for sugar curing was fixed as erythritol:sucrose = 1:1, the sugar impregnation temperature was 60 °C, and hot air drying was carried out for 4.5 h.

[0047] Table 1 Orthogonal level table of polygonatum fruit preserves

[0048]

[0049] 1.3 Sensory evaluation of polygonatum fruit preserves

[0050] A fixed sensory evaluation panel consisting of 10 volunteers who had undergone sensory training in advance was used to conduct a sensory evaluation of polygonatum fruit preserves according to the quality evaluation form of polygonatum fruit preserves formulated based on the General Rules for the Quality of Candied Fruits (GB / T 10782-2021). The scoring rules are shown in Table 2.

[0051] Table 2 Sensory evaluation form of polygonatum fruit preserves

[0052]

[0053]

[0054] 1.4 Determination of the contents of crude polysaccharides, total saponins, and total flavonoids in polygonatum fruit preserves

[0055] 1.4.1 Determination of the content of crude polysaccharides in polygonatum fruit preserves: The method for determining the content of polysaccharides in polygonatum fruit preserves was carried out with reference to the method for determining the content of polysaccharides in polygonatum decoction pieces in Part I of the Pharmacopoeia of the People's Republic of China and the detection method of Luo Chunping et al. (Luo Chunping, Lu Youli, and Wang Xingxing. "Optimization of the Method for Rapid Determination of Polysaccharides by Phenol-Sulfuric Acid Method." Chemical Industry Management, Issue 3 (2021): 90–91, 94. https: / / doi.org / 10.19900 / j.cnki.ISSN1008-4800.2021.03.043.).

[0056] Preparation of reference substance solution and establishment of standard curve: Take an appropriate amount of anhydrous glucose, weigh it accurately, dissolve it in water to prepare a solution containing 0.6 mg of anhydrous glucose per 1 mL, and you will get the reference substance solution. Accurately measure 0, 1.0, 1.5, 2.0, 2.5, and 3.0 mL of the reference substance solution, respectively, place them in 50 mL volumetric flasks, and make up the volume with water. Mix well. Accurately measure 2 mL of each of the above solutions, place them in stoppered test tubes, add 1 mL of 4% phenol solution to each, mix well, quickly add 7.0 mL of sulfuric acid, shake well, incubate in a water bath at 40 °C for 30 minutes, take out, place in an ice-water bath for 5 minutes, take out, using the corresponding reagent as the blank, according to the ultraviolet-visible spectrophotometry (General Principles 0401), pipette 0.2 mL of the sample solution into a 96-well plate and measure the absorbance at a wavelength of 490 nm using a microplate reader. Using the absorbance as the ordinate and the concentration of anhydrous glucose in the reference substance as the abscissa, plot the standard curve. The regression curve obtained is: Y = 7.241X + 0.056 (R 2 = 0.9908), as Figure 1 shown, there is a linear relationship in the concentration range of 0 - 0.036 mg / mL.

[0057] Preparation of test sample solution: Cut the preserved fruit of Polygonatum odoratum into pieces, accurately weigh 1.0797 g of the cut preserved fruit of Polygonatum odoratum, first add a small amount of water to a mortar and grind it into a paste, then transfer it to a round-bottomed flask, add 100 mL of water, heat under reflux for 1 hour, repeat the extraction 2 times, filter with absorbent cotton, combine the filtrates, concentrate to an appropriate volume, transfer to a 100 mL volumetric flask, make up the volume with water, accurately measure 2 mL, add 10 mL of ethanol, stir and centrifuge, take the precipitate, dissolve it in water, place it in a 50 mL volumetric flask, and dilute to the mark, shake well. Accurately measure 1 mL, according to the method under the preparation of the standard curve, starting from "add 1 mL of 4% phenol solution", measure the absorbance according to the law, read the weight (mg) of anhydrous glucose in the test sample solution from the standard curve, and calculate to obtain the content of Polygonatum odoratum polysaccharide in the preserved fruit.

[0058] 1.4.2 Determination of total saponins and total flavonoids in Polygonatum odoratum: Refer to the methods for determining flavonoids and saponins by Huang Jinyue, Qiu Xueyan, etc. to establish the methods for determining the total saponins and total flavonoids in the preserved fruit of Polygonatum odoratum (Huang Jinyue, Cui Fuyan, Zheng Shijia, Jiang Jiaxin, Yang Jiaying, Wang Zhigang, Yu Chunmiao and Yang Bo. "Response surface optimization of the extraction methods of total saponins and total flavonoids from the rhizomes of Polygonatum sibiricum and their application in the comparison of component contents of Polygonatum sibiricum from different producing areas". Acta Chinese Medicine and Pharmacology 49, issue 9 (2021): 56–61. https: / / doi.org / 10.19664 / j.cnki.1002-2392.210212. Qiu Xueyan, Lin Houwen, Shen Liming, Liu Gaolin, Jin Guangzhu and Zhang Hengbi. "Effect of different color-developing agents on the determination of total saponins in Polygonatum odoratum". Pharmaceutical Care and Research, issue 2 (2006): 129–32.).

[0059] Preparation of the total flavonoid reference substance solution of Polygonatum odoratum: Precisely weigh 3.03 mg of rutin reference substance, and make up the volume to 10 mL in a volumetric flask with 60% ethanol solution to obtain a standard substance solution with a concentration of 0.303 mg / mL.

[0060] Establishment of the rutin standard curve: Take 0, 1.2, 1.5, 1.8, 2.1 mL of the standard substance solution in 10 mL graduated stoppered test tubes, add 0.3 mL of 5% sodium nitrite, and let stand for 6 min; then add 0.3 mL of 10% aluminum nitrate solution and let stand for 6 min. After making up the volume with 60% ethanol, take 5 mL of each solution with different concentrations and add 2 mL of 4% sodium hydroxide, shake well and let stand for 15 min. Take 0.2 mL of each diluted test sample solution in a 96-well plate and measure its absorbance at 508 nm using an enzyme-linked immunosorbent assay reader. With the rutin concentration as the abscissa and the absorbance as the ordinate, the regression curve is obtained: Y = 3.6656X + 0.0488 (R 2 = 0.9985), as Figure 2 shown, it shows a linear relationship in the concentration range of 0 - 0.06363 mg / mL.

[0061] Preparation of the total flavonoid test sample solution of Polygonatum odoratum preserved fruit: Weigh 10.45 g of the cut Polygonatum odoratum preserved fruit, add a small amount of 80% ethanol solution in a mortar and grind it into a paste. Transfer it to a 150 mL conical flask, add 60 mL of 80% ethanol solution and perform ultrasonic extraction for 0.5 h. Repeat the extraction 3 times. After the extraction, combine the filtrates, centrifuge and collect the supernatant. Concentrate it under reduced pressure until there is no alcohol smell, add an equal volume of ethyl acetate for extraction, repeat the extraction three times, combine the ethyl acetate parts, rotate and dry under reduced pressure. Dissolve the dried product with 60% ethanol solution and make up the volume to 10 mL in a graduated stoppered glass tube for standby. The total test sample solution of Polygonatum odoratum preserved fruit is obtained.

[0062] Determination of the total flavonoid content in the test sample solution: Precisely pipette 2 mL of the total flavonoid test sample solution into a 10 mL graduated stoppered test tube, and repeat the color development operation from "add 0.3 mL of 5% sodium nitrite". Before measuring with the enzyme-linked immunosorbent assay reader, pass the colored test sample solution through a 0.2 nm organic filter membrane. Measure its absorbance at 508 nm and calculate the total flavonoid content of Polygonatum odoratum.

[0063] 1.4.3 Preparation and standard curve establishment of the total saponin reference substance solution of Polygonatum odoratum:

[0064] Preparation of the dioscin reference substance solution: Precisely weigh 2.82 mg of dioscin reference substance, and prepare a 0.2 mg / mL reference substance solution with methanol and store it in a refrigerator at 4℃ for standby.

[0065] Establishment of the standard curve for dioscin: Accurately pipette 0, 0.4, 0.6, 0.8, and 1.0 mL of the dioscin reference substance solution into 10-mL stoppered graduated test tubes. Evaporate the methanol in a 60°C water bath until dry. Add 0.2 mL of 5% vanillin glacial acetic acid solution to the test tubes, cool in an ice bath for 2 min, then add 0.8 mL of perchloric acid, mix well, cover with a stopper, heat in a 60°C water bath for 18 min for color development. After the reaction, cool in an ice bath for 2 min, add glacial acetic acid to make up the volume to 10 mL, mix well. Then take 0.2 mL and transfer it to a 96-well plate, and measure the absorbance at 533 nm using a microplate reader. Taking the dioscin concentration as the abscissa and the absorbance as the ordinate, the regression curve is obtained: Y = 4.7693X + 0.0563 (R2 = 0.9926). As Figure 3 shown, it shows a linear relationship in the concentration range of 0 - 0.02 mg / mL.

[0066] Preparation of the test sample of total saponins from Polygonatum odoratum fruit preserves: Weigh 3.00170 g of Polygonatum odoratum fruit preserves, add a small amount of 80% ethanol, grind it into a paste in a mortar, then transfer it to a 150-mL conical flask, add 20 mL of 80% ethanol solution, and perform ultrasonic extraction for 0.5 h. Repeat this 3 times. Combine the filtrates, centrifuge, and take the supernatant. Rotavaporize under reduced pressure until there is no alcohol smell, add an equal volume of n-butanol for extraction, repeat the extraction 3 times. Combine the n-butanol parts and evaporate to dryness under reduced pressure. Dissolve the white precipitate with a small amount of methanol and transfer it to a 10-mL stoppered graduated glass tube, and make up the volume to the mark with methanol to obtain the test solution of total saponins from Polygonatum odoratum fruit preserves. Accurately pipette 1 mL of the test sample solution of saponins from Polygonatum odoratum fruit preserves into a 10-mL stoppered graduated glass tube and make up the volume to obtain the test sample solution 1 of total saponins from Polygonatum odoratum fruit preserves.

[0067] Determination of the content of total saponins in Polygonatum odoratum fruit preserves: Accurately pipette 2 mL of the test solution 1 of total saponins from Polygonatum odoratum fruit preserves into a 10-mL stoppered glass test tube, evaporate the methanol according to the method for establishing the standard curve of dioscin, add the corresponding color-developing solvent, after color development, take 0.2 mL of the color-developed solution and measure its absorbance at 533 nm in a 96-well plate, and calculate the content of total saponins in Polygonatum odoratum fruit preserves.

[0068] 1.5 Determination of the water content in Polygonatum odoratum fruit preserves

[0069] The determination method was formulated with reference to the first method for water content determination in 《GB 5009.3 - 2016》, and the water content of the Polygonatum odoratum fruit preserves obtained from the orthogonal experiment was determined according to the requirements of 《GB 14884 - 2016 National Food Safety Standard Preserves》. The determination results are shown in Table 4.

[0070] 1.6 Statistical analysis

[0071] In this experiment, WPS office and prism software were used for data sorting and analysis. P < 0.05 indicates that the difference is statistically significant, with a significant difference. P < 0.001 indicates that the difference is statistically significant, with an extremely significant difference.

[0072] 2 Results and analysis

[0073] 2.1 Single factor test analysis of the preparation of preserved polygonatum fruit

[0074] 2.1.1 Steaming time of Polygonatum odoratum preserved fruit: The best steaming time is 1.5h.

[0075] There is a lot of mucus and a distinct raw smell on the surface of fresh Polygonatum odoratum slices. They need to be pre-steamed before candied to remove the mucus and raw smell of Polygonatum odoratum. The effect of steaming time on the state of fresh Polygonatum odoratum slices is shown in Table 3. The color and morphology are shown in Table 3. Figure 4 From this table, we can see that as the steaming time increases, the mucus exudation on the surface of the radix odoratum slices is significantly improved, and the chewing taste changes from crisp to soft and glutinous. Fresh radix odoratum slices begin to taste sweet after steaming. The tissue structure of the radix odoratum slices also changes when the steaming time is too long. The texture of the tissue structure becomes soft, and there is obvious juice exudation, and the color becomes darker. The influence of steaming time on the state of radix odoratum slices changes. When the steaming time is 1.0h, the radix odoratum slices have better color, taste and suitable full flesh tissue structure. Therefore, 1.0h is selected as the condition for steaming radix odoratum in subsequent orthogonal experiments.

[0076] Table 3 Effect of pre-steaming time on fresh Polygonatum odoratum slices

[0077]

[0078]

[0079] 2.1.2 Effect of the mass fraction of soaking sugar solution on the quality of preserved Polygonatum odoratum fruit.

[0080] like Figure 5 As shown in the figure, it can be determined that the optimal soaking sugar solution mass fraction is 40%. As the sugar solution mass fraction gradually increases, the sensory score of the Polygonatum odoratum preserved fruit also increases. The sensory score is the highest when the sugar solution fraction is 40%. When the sugar solution concentration is low at 20-30%, the sugar solution cannot form a large osmotic pressure, and it is difficult to effectively exchange the sugar in the sugar solution with the water in the preserved fruit tissue, which affects the sweetness of the preserved fruit. After drying, the preserved fruit is not full in appearance, which affects the sensory score. The sugar solution concentration of 35-40% can effectively promote the exchange of water and sugar in the Polygonatum odoratum preserved fruit, thereby obtaining a higher sensory score. The score of the preserved fruit soaked in syrup with a mass fraction of 50% begins to decrease, which may be due to the excessive sugar content, which leads to excessive infiltration of sugar, making the Polygonatum odoratum preserved fruit sweeter. In addition, too concentrated infiltration syrup can easily make the texture of the Polygonatum odoratum preserved fruit hard and the taste worse.

[0081] 2.1.3 Effects of sugar-preserving temperature and time on the quality of Polygonatum odoratum preserved fruit.

[0082] Effects of sugar soaking temperature and time on the quality of preserved Polygonatum odoratum fruit Figure 6, it can be seen that within a certain range, the sugar infusion temperature is positively correlated with the sensory score of the polygonatum fruit preserves. For example, under the condition of soaking for 1.5 h, the sensory score shows an increasing trend after the temperature reaches 40 °C. Under the condition of soaking for 2.5 h, the sensory score of the polygonatum fruit preserves changes little with the temperature; under the soaking conditions of 3.5 h and 4.5 h, the sensory score trends are the same. The sensory score shows an upward trend between 50 °C and 70 °C and a relatively obvious downward trend after 70 °C. Therefore, it is considered that soaking for 4.5 h at 60 °C to 70 °C can obtain fruit preserve products with a higher sensory score.

[0083] 2.1.4 Influence of the air-blowing drying temperature and time on the sensory score of the polygonatum fruit preserves.

[0084] Fruit preserve products require an appropriate water content. If the water content is too high, it is easy for the fruit preserves to deteriorate and rot. If the water content is too low, it will affect the taste of the fruit preserves. It is known that Figure 7 , when the air-blowing drying time is fixed at 4.5 h, the sensory score increases with the increase of the drying temperature, and the best sensory score is obtained at 60 °C. When the drying temperature is 50 °C, due to the low temperature, the fruit preserves are not thoroughly dried and the water content is relatively large, so the sensory score is low. When the temperature is higher than 60 °C, the water content of the fruit preserves becomes even lower. Excessive sugar crystallization makes the fruit preserves hard and the taste deteriorates, so the sensory score decreases.

[0085] 2.2 Analysis of the results of the orthogonal experiment on the polygonatum fruit preserves

[0086] The results of the orthogonal experiment are shown in Table 4. It can be seen from this table that the primary and secondary factors affecting the sugar content of the polygonatum fruit preserves are the drying temperature (C), the sugar infusion time (B), and the mass fraction of the sugar alcohol in the sugar infusion (A). That is, the drying temperature and sugar infusion time of the polygonatum fruit preserves have the greatest influence on the sensory evaluation of the fruit preserves. The best production process for the polygonatum fruit preserves is A1B1C1. That is, the mass fraction of the sugar solution in the sugar pickling process is 35%, the sugar pickling soaking time is 3.5 h, and the air-blowing drying temperature is 60 °C, which are the best conditions for the production of the polygonatum fruit preserves. It can be known from the variance analysis of the test results in Table 5 that the mass fraction of the sugar alcohol in the sugar infusion and the sugar infusion time have no significant influence on the sensory score of the polygonatum fruit preserves (P > 0.05), and the air-blowing drying temperature of the polygonatum fruit preserves has a significant influence on the sensory score of the polygonatum fruit preserves (P = 0.04 < 0.05).

[0087] Table 4 Results of the orthogonal experiment for optimizing the technology of the polygonatum fruit preserves

[0088]

[0089]

[0090] Table 5 Variance analysis table

[0091]

[0092] Note: P < 0.05 indicates statistical significance.

[0093] 2.3 Quality evaluation of Polygonatum odoratum fruit preserves

[0094] The contents of polysaccharides, total saponins and total flavonoids in the fruit preserves prepared by the optimal production process (A1B1C1, that is, the mass fraction of sugar solution in the sugar-preserving process is 35%, the sugar-preserving soaking time is 3.5 h, and the air-blowing drying temperature is 60 °C) calculated from the standard curve are shown in Table 6 below.

[0095] Table 6 Contents of main components in Polygonatum odoratum fruit preserves prepared by the optimal process A1B1C1

[0096]

[0097] 3 Conclusion

[0098] In this experiment, the sensory evaluation was used as the main evaluation index for the development of Polygonatum odoratum fruit preserves, and the production process parameters of Polygonatum odoratum fruit preserves were optimized through single-factor and orthogonal experiments. Finally, it was determined that the best steaming time for the Polygonatum odoratum fruit preserves using the hot-assisted sugar infiltration method was 1.0 h, the sugar solution mass fraction was 35%, the sugar infiltration temperature was 60 °C, the sugar infiltration time was 3.5 h, and the air-blowing drying condition was drying at 60 °C for 4.5 h. The Polygonatum odoratum fruit preserves prepared under these process conditions showed a warm yellow color, a plump appearance, a soft and glutinous taste, an appropriate sweetness with a unique fragrance of Polygonatum odoratum, and did not stick to the hands. Moreover, the contents of polysaccharides and saponins in Polygonatum odoratum were rich.

[0099] Through the research on the immunomodulatory effect of crude polysaccharides from Polygonatum odoratum and the development of Polygonatum odoratum fruit preserves in this experiment, a theoretical basis was provided for the research and development of related drugs and foods of Polygonatum odoratum.

[0100] Example 2

[0101] Raw material selection: Select fresh, plump Polygonatum odoratum without insect eyes or lesions, with each section being 5 - 10 cm in size (the fresh rhizome of Polygonatum odoratum Mill., a perennial herb of the genus Polygonatum in the family Asparagaceae, identified by a researcher from the Guangxi Institute of Botany) as the raw material.

[0102] Washing: Wash the mud clean with clear water, pull out the root hairs on the surface of Polygonatum odoratum, and scrape off the epidermis with a small knife.

[0103] Slicing: Cut Polygonatum odoratum into thin slices with a length of 4 - 6 cm and a thickness of 0.5 - 0.7 cm.

[0104] Cold water soaking: Soak the sliced materials in cold water at 4 - 6 °C for 10 h to prevent oxidation and remove excess mucus, and then take them out and drain the water after soaking.

[0105] Steaming: The steaming time is 1.5 h.

[0106] Sugaring: Use erythritol: white granulated sugar = 1:1 (mass ratio) and mix evenly as the sugar for sugar infiltration. The sugar content of the sugar solution is 35 w / w%. Place the steamed material in the sugar solution at 65°C and soak for 4.5 h. After soaking, take out the material and pass it through 60°C hot water for 2 s to wash away the excess sugar on the surface of the polygonatum slices.

[0107] Drying: Dry under forced air at 55°C for 5 h, and then naturally cool to room temperature. After cooling to room temperature, use the same method as in Example 1 to detect its moisture content, which is 16.82%.

[0108] Packaging: Use vacuum packaging.

[0109] Sterilization: The packaged preserved fruits are pasteurized.

[0110] The polygonatum preserved fruits produced in this example are warm yellow in color, full in shape, soft and glutinous in taste, suitable in sweetness and slightly with the unique fragrance of polygonatum, and do not stick to hands. Use the same method as in Example 1 to detect the content of the main active ingredients in the obtained polygonatum preserved fruits, and the results are shown in Table 7 below.

[0111] Comparative Example 2-1

[0112] Repeat Example 2, except that in the drying process, dry under forced air at 50°C for 5 h, and then naturally cool to room temperature. After cooling to room temperature, use the same method as in Example 1 to detect its moisture content, which is 19.03%.

[0113] The polygonatum preserved fruits produced in this comparative example are warm yellow in color, full in shape, soft and glutinous in taste, suitable in sweetness and slightly with the unique fragrance of polygonatum, and do not stick to hands. Use the same method as in Example 1 to detect the content of the main active ingredients in the obtained polygonatum preserved fruits, and the results are shown in Table 7 below.

[0114] Comparative Example 2-2

[0115] Repeat Example 2, except that:

[0116] Sugaring: Use erythritol: white granulated sugar = 1:1 (mass ratio) and mix evenly as the sugar for sugar infiltration. The sugar content of the sugar solution is 40 w / w%. Place the steamed material in the sugar solution at 55°C and soak for 5.5 h. After soaking, take out the material and pass it through 60°C hot water for 2 s to wash away the excess sugar on the surface of the polygonatum slices.

[0117] Drying: Dry under forced air at 40°C for 4 h, and then naturally cool to room temperature. After cooling to room temperature, use the same method as in Example 1 to detect its moisture content, which is 23.40%.

[0118] Packaging: Use vacuum packaging.

[0119] Sterilization: The packaged preserved fruits are pasteurized.

[0120] The color of the polygonatum fruit preserves prepared in this comparative example is warm yellow, with a plump appearance, a soft and glutinous texture, a suitable sweetness, and a unique fragrance of polygonatum, and it does not stick to the hands. The content of the main active ingredients in the obtained polygonatum fruit preserves was detected by the same method as in Example 1, and the results are shown in Table 7 below.

[0121] Table 7 Content of main components in polygonatum fruit preserves

[0122]

Claims

1. A manufacturing process of polygonatum fruit preserves, characterized in that, Prepared from fresh polygonatum odoratum as raw material, after being cleaned, through processes including but not limited to slicing, steaming, sugaring and drying, wherein, In the steaming process, the steaming time is 1.5 - 2h; In the sugaring process, the steamed material is soaked in the sugar solution for 3.5 - 4.5h. After the soaking is completed, the material is taken out and passed through hot water at 50 - 70°C once; the sugar solution is an aqueous solution of a mixed sugar composed of white granulated sugar and erythritol in a mass ratio of 1:1, and the sugar content of the sugar solution is 35 - 40 w / w%; In the drying process, it is dried by blowing air at 55 - 60°C for 4 - 5h, and then naturally cooled to room temperature.

2. The manufacturing process according to claim 1, characterized in that, In the impregnation process, the temperature of the sugar solution is 50 - 70°C.

3. The manufacturing process according to claim 1, characterized in that, The slicing process is to cut the raw material into thin slices with a thickness of 0.5 - 0.7cm.

4. The manufacturing process according to claim 3, characterized in that, The slicing process is to cut the raw material into thin slices with a thickness of 0.5 - 0.7cm and a length of 4 - 6cm.

5. The production process according to any one of claims 1 - 4, characterized in that, In the steaming process, the steaming time is 1.5h; In the sugaring process, the steamed material is soaked in the sugar solution at 60°C for 3.5h. After the soaking is completed, the material is taken out and passed through hot water at 60°C once; the sugar content of the sugar solution is 35 w / w%; In the drying process, it is dried by blowing air at 60°C for 4.5h, and then naturally cooled to room temperature.

6. The manufacturing process according to any one of claims 1 to 4, characterized in that, A cold water soaking process is carried out after the slicing process and before the steaming process.

7. The manufacturing process according to claim 6, characterized in that, The cold water soaking process is to soak the sliced material in water at 4 - 8°C for 8 - 12h.

8. The manufacturing process according to any one of claims 1 to 4, characterized in that, A packaging process is also included after the drying process.

9. The manufacturing process according to claim 8, characterized in that, A sterilization process is also included after the packaging process.

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