Low-temperature slow-drying preparation method of dried persimmon frost sugar and equipment thereof

Abstract

The invention relates to the field of dried persimmon frost candies, and discloses a low-temperature slow-drying preparation method and equipment of dried persimmon frost candies, and the method comprises the following steps: S1, crushing peeled persimmons into particles, adding water to prepare slurry, and carrying out ultrasonic pretreatment on the slurry; s2, adding a compound enzyme into the slurry in stages for low-temperature enzymolysis, and performing centrifugal separation to obtain clear persimmon juice; s3, mixing the persimmon juice with the licorice root and platycodon grandiflorum concentrated solution, menthol and gelatin, and increasing the solid content through a vacuum gradient concentration process; s4, after the concentrated solution is injected into a mold, performing staged gradient dehydration in a controllable temperature and humidity environment to separate out a persimmon frost layer. Through the synergistic effect of ultrasonic pretreatment and a staged enzymolysis process, persimmon pulp cell walls are destroyed, pectin, cellulose and other components are specifically degraded, juice and effective components in cells are promoted to be fully released, high-purity raw materials are provided for subsequent centrifugal separation, concentration and other procedures, raw material waste is reduced from the source, and the production cost is reduced. The raw material utilization rate in the whole production process is improved.

Description

Technical Field

[0001] The invention relates to the technical field of persimmon frosting candy, and in particular to a low-temperature slow-drying preparation method of persimmon frosting candy and equipment thereof. Background Art

[0002] As a traditional health food, persimmon frost candy, with its naturally sweet taste and lung-soothing and throat-clearing properties, is widely in demand as a snack, gift, or medicinal food. As consumers' expectations for healthy food continue to rise, the market urgently needs upgraded products that retain traditional flavors while featuring a controllable production process, stable ingredients, and no additives.

[0003] In the existing technology, the traditional persimmon frost candy preparation process often relies on single mechanical crushing or simple enzymatic hydrolysis treatment, which has limited damage to the pulp cell wall structure, resulting in insufficient release of effective ingredients in the cells, especially a large amount of residual macromolecular substances such as pectin and cellulose, which not only affects the juice separation efficiency, but also easily causes uneven sugar distribution in the subsequent concentration process. This extensive raw material processing method makes it difficult to accurately control the degree of cell rupture, resulting in insufficient contact area of ​​the enzymatic reaction substrate, ultimately restricting the overall raw material utilization rate and product quality stability. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the present invention provides a low-temperature slow-drying preparation method and equipment for persimmon frost candy, which solves the problem that the existing technology relies on single mechanical crushing or simple enzymatic hydrolysis treatment, which has a limited degree of damage to the pulp cell wall structure, affecting the juice separation efficiency, and ultimately restricting the overall raw material utilization and product quality stability.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0006] A low-temperature slow-drying preparation method for persimmon frosting candy comprises the following steps:

[0007] S1. Crushing peeled persimmons into particles, adding water to prepare a slurry, and performing ultrasonic pretreatment on the slurry;

[0008] S2, adding complex enzymes to the slurry in stages for low-temperature enzymatic hydrolysis, and centrifuging to obtain clarified persimmon juice;

[0009] S3, mixing the persimmon juice with liquorice and platycodon concentrate, menthol, and gelatin, and increasing the solid content by vacuum gradient concentration process;

[0010] S4, after the concentrated liquid is injected into the mold, the persimmon frost layer is precipitated by gradient dehydration in a controlled temperature and humidity environment;

[0011] S5. The sugar body after frosting is subjected to low-temperature pressing treatment.

[0012] By adopting the above technical solutions, ultrasonic pretreatment is used to optimize the efficiency of cell wall destruction, staged enzymatic hydrolysis is used to degrade pectin and cellulose separately, gradient concentration and temperature zones are used to protect heat-sensitive substances, moisture-controlled dehydration uses three-stage temperature and humidity control to guide sugar crystallization, and low-temperature pressing is used to reduce colloid softening and crack formation, forming a coherent process chain. This significantly improves key problems in traditional methods such as low raw material utilization, poor frost layer uniformity, and loose sugar body formation.

[0013] Preferably, the mixed solution in step S3 comprises the following components by weight:

[0014] Persimmon juice: 100 servings;

[0015] Licorice and Platycodon grandiflorum concentrate: 15-25 parts, wherein the mass ratio of licorice to platycodon grandiflorum is 1:2 to 1:3;

[0016] Gelatin: 0.5-1.2 parts;

[0017] Menthol: 0.01-0.03 parts.

[0018] Preferably, in step S1, the particle size of the crushed particles is 0.5-1.5 mm, the solid-liquid ratio of the slurry is 4:1 to 5:1, the frequency of the ultrasonic pretreatment is 20-40 kHz, and the treatment time is 5-10 minutes.

[0019] Preferably, the volume ratio of the slurry to water in step S1 is 1:2.

[0020] Preferably, the conditions for adding the complex enzyme in stages in step S2 are:

[0021] Add pectinase for the first time and perform enzymatic hydrolysis at 45-48°C for 60-80 minutes;

[0022] Add cellulase for the second time and perform enzymatic hydrolysis at 50-52°C for 50-70 minutes;

[0023] The amount of pectinase added is 0.1-0.2 mL / kg slurry, and the amount of cellulase added is 0.05-0.1 mL / kg slurry.

[0024] Preferably, the rotation speed of the centrifugal separation in step S2 is 8000-10000 rpm, and the centrifugation time is 10-15 minutes.

[0025] Preferably, the vacuum gradient concentration process in step S3 includes:

[0026] The first stage is low temperature concentration to 50-60% solids;

[0027] The second stage is to heat and concentrate until the solid content is ≥75%.

[0028] Preferably, the gradient dehydration in step S4 includes three stages:

[0029] First stage: temperature 25-28℃, humidity 50-55%;

[0030] Second stage: temperature 28-30℃, humidity 40-45%;

[0031] Third stage: temperature 30-32℃, humidity ≤30%.

[0032] Preferably, the low-temperature pressing conditions are temperature 10-15℃, pressure 5-8MPa, and pressing time 10-15 minutes.

[0033] A low-temperature slow-drying preparation device for persimmon frost sugar, comprising:

[0034] An ultrasonic crusher: used for crushing persimmons and performing ultrasonic pretreatment;

[0035] A staged temperature control enzymolysis tank: used for adding composite enzymes in stages and performing low-temperature enzymolysis;

[0036] A vacuum gradient concentration device: used for concentrating the mixed solution in stages by increasing temperature;

[0037] A gradient humidity control drying chamber: used for adjusting dehydration temperature and humidity in stages;

[0038] A low-temperature pressing forming machine: used for pressing treatment of frost sugar bodies.

[0039] The present application provides a low-temperature slow-drying preparation method and device for persimmon frost sugar. The present application has the following beneficial effects:

[0040] 1. The present application cooperates ultrasonic pretreatment and staged enzymolysis process to destroy persimmon pulp cell walls and specifically degrade pectin, cellulose and other ingredients, so as to promote the release of intracellular juice and effective ingredients, provide high-purity raw materials for subsequent centrifugal separation, concentration and other processes, reduce raw material waste from the source, and improve the raw material utilization rate of the overall production process.

[0041] 2. The present application combines vacuum gradient concentration and low-temperature slow-drying process to protect heat-sensitive ingredients such as menthol and gelatin from being destroyed or volatilized at low temperature, and by reasonably matching the licorice and kankong concentrated liquid, the herbal flavor and the natural fruit flavor of persimmon are mutually harmonized to ensure that the product flavor is rich and stable, and the loss of ingredients or flavor imbalance caused by high-temperature process is avoided.

[0042] 3. The present application adjusts temperature and humidity in stages through the gradient humidity control drying chamber to guide the uniform migration and crystallization of sugar, forming a fine and uniform persimmon frost layer. The low-temperature pressing forming machine precisely controls temperature and pressure to enhance the structure strength of the sugar body and reduce cracks, so that the sugar body has smooth appearance, appropriate hardness and complete frost layer, and the sensory quality and eating experience are improved.

[0043] 4. The precise control of process parameters in each link of the present invention avoids quality problems caused by fluctuations in a single parameter in traditional processes, ensuring the stability of juice yield, frosting efficiency and sugar body forming quality. The phased processing method shortens the time of key processes, improves production efficiency, and provides reliable process support for mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a flow chart of a low-temperature slow-drying preparation method of persimmon frosted candy of the present invention;

[0045] Figure 2 This is a schematic diagram of the processing steps of a low-temperature slow-drying preparation equipment for persimmon frosted candy of the present invention; DETAILED DESCRIPTION

[0046] The following will clearly and completely describe the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0047] Please see the attached Figure 1 - Attachment Figure 2 The embodiment of the present invention provides a low-temperature slow-drying preparation method of persimmon frosting candy, comprising the following steps:

[0048] S1. Crushing peeled persimmons into particles, adding water to prepare a slurry, and performing ultrasonic pretreatment on the slurry;

[0049] S2, adding complex enzymes to the slurry in stages for low-temperature enzymatic hydrolysis, and centrifuging to obtain clarified persimmon juice;

[0050] S3, mixing the persimmon juice with liquorice and platycodon concentrate, menthol, and gelatin, and increasing the solid content by vacuum gradient concentration process;

[0051] S4, after the concentrated liquid is injected into the mold, the persimmon frost layer is precipitated by gradient dehydration in a controlled temperature and humidity environment;

[0052] S5. The sugar body after frosting is subjected to low-temperature pressing treatment.

[0053] The mixed solution in step S3 includes the following components by weight:

[0054] Persimmon juice: 100 servings;

[0055] Licorice and Platycodon grandiflorum concentrate: 15-25 parts, wherein the mass ratio of licorice to platycodon grandiflorum is 1:2 to 1:3;

[0056] Gelatin: 0.5-1.2 parts;

[0057] Menthol: 0.01-0.03 parts.

[0058] Specifically, persimmon juice: core raw material, provides natural sugar, fruit acid and flavor substances, releases components after enzymatic hydrolysis to promote sugar crystallization, and is the basic substrate for forming persimmon frost layer.

[0059] Glycyrrhiza and kankong concentrated liquid: blend the taste, combine the sweetness of glycyrrhiza and the bitterness of kankong, give the herb composite flavor, and improve the palatability and flavor level of the product.

[0060] Gelatin: colloidal additive, enhances the viscosity and structural strength of the sugar body, prevents cracking during pressing, and ensures stable form during storage and transportation.

[0061] Menthol: a small amount of addition gives a cooling taste, low-temperature process retains volatile components, and integrates with other flavors to form a unique sensory experience.

[0062] In S1, the particle size of the broken particles is 0.5-1.5mm, the solid-liquid ratio of the slurry is 4:1 to 5:1, and the ultrasonic pretreatment frequency is 20-40kHz, and the treatment time is 5-10 minutes.

[0063] Specifically, by controlling the particle size of the broken particles to an appropriate range, and combining with a reasonable solid-liquid ratio of the slurry, the pulp particles form a mixed system with good fluidity in water, which not only ensures uniform energy transmission during ultrasonic pretreatment, but also provides sufficient substrate contact area for subsequent enzymatic reaction. Ultrasonic pretreatment produces cavitation effect through high-frequency vibration of a specific frequency and time, effectively destroys the cell wall structure of the pulp, promotes the release of juice, pectin, cellulose and other components in the cells, and cooperates with mechanical crushing to improve the efficiency of raw material processing, creating ideal substrate conditions for staged enzymatic hydrolysis, ensuring sufficient degradation of ingredients and smooth separation in subsequent processes, and ensuring the stability and raw material utilization rate of persimmon frost preparation process from the source.

[0064] The volume ratio of slurry to water in S1 is 1:2.

[0065] Specifically, the slurry and water are mixed in an appropriate ratio, and the dispersibility of the solid-liquid system is adjusted by adding an appropriate amount of water, so that the broken persimmon pulp particles can fully stretch and evenly distribute in water, creating a good substrate contact environment for subsequent composite enzymatic reaction. This operation can avoid the difficulty of enzyme molecule penetration and diffusion caused by too thick slurry, ensure that pectinase, cellulase and other enzymes can fully contact with pectin, cellulose and other components in the pulp, thereby improving the efficiency and uniformity of enzymatic reaction, making the cell wall structure more easily decomposed, and laying a foundation for subsequent centrifugal separation to obtain high-purity juice and ensure smooth operation of each process link.

[0066] The conditions for adding composite enzymes in S2 are:

[0067] Add pectinase for the first time and perform enzymatic hydrolysis at 45-48°C for 60-80 minutes;

[0068] Add cellulase for the second time and perform enzymatic hydrolysis at 50-52°C for 50-70 minutes;

[0069] The amount of pectinase added is 0.1-0.2 mL / kg slurry, and the amount of cellulase added is 0.05-0.1 mL / kg slurry.

[0070] Specifically, based on the optimal temperature differences between pectinase and cellulase, pectinase is first added at 45-48°C to break down the pectin in the pulp, destroying the intercellular matrix and causing the cells to initially rupture and release juice. The temperature is then raised to 50-52°C to add cellulase to further degrade the cellulose components in the cell walls, continuously breaking up the cell structure to release more contents. This process uses staged temperature control and targeted enzymatic hydrolysis to enable the two enzymes to exert their optimal activity in turn, avoiding enzyme inhibition caused by temperature incompatibility and ensuring that substrates such as pectin and cellulose are fully broken down. This improves juice release efficiency and reduces residual large molecular impurities, laying the foundation for subsequent centrifugal separation to obtain highly clarified juice and ensure the stability of the concentration and defrost processes.

[0071] The rotation speed of the centrifugal separation in step S2 is 8000-10000 rpm, and the centrifugation time is 10-15 minutes.

[0072] Specifically, the centrifugal force generated by high-speed rotation efficiently separates solid impurities such as incompletely degraded pulp residue and cell wall fragments from the juice in the enzymatically hydrolyzed slurry, allowing the solid and liquid phases of the enzymatic hydrolysis product to be fully separated, thereby obtaining a highly clarified juice concentrate. This operation effectively removes insoluble particles that could affect subsequent processes, preventing residual impurities from causing turbidity in the concentrate or foreign matter interference during the frosting process. This provides a pure raw material base for vacuum concentration, ensuring a uniform structure and a fine frosting layer during subsequent sugar body formation, and improving the product's sensory quality and inherent stability.

[0073] The vacuum gradient concentration process in step S3 includes:

[0074] The first stage is low temperature concentration to 50-60% solids;

[0075] The second stage is to heat and concentrate until the solid content is ≥75%.

[0076] Specifically, by controlling the temperature in stages, the first stage of low-temperature concentration protects the heat-sensitive components such as menthol and gelatin from being destroyed or volatilized, while the mixed solution is preliminarily concentrated to an appropriate solid state, retaining the product flavor and colloid structure stability; the second stage of high-temperature concentration further increases the solid content based on the first stage, providing a high-concentration sugar environment for the subsequent frosting process, promoting the uniform migration and crystallization of sugar, and reducing the boiling point and shortening the concentration time through a vacuum environment, avoiding the adverse effects of long-term high temperature on the components. The synergistic effect of the two stages not only ensures the stability of the components but also improves the concentration efficiency, laying the key foundation for sugar body frosting and shaping.

[0077] The gradient dehydration in S4 step includes three stages:

[0078] First stage: temperature 25-28℃, humidity 50-55%;

[0079] Second stage: temperature 28-30℃, humidity 40-45%;

[0080] Third stage: temperature 30-32℃, humidity ≤30%.

[0081] Specifically, the three stages of S gradient dehydration adjust the temperature and humidity in stages. In the first stage of low temperature and high humidity, the water in the concentrated solution evaporates uniformly, guiding the sugar to migrate to the surface of the sugar body and forming the frosting precursor. In the second stage of medium temperature and low humidity, the water loss is accelerated, promoting the preliminary crystallization of sugar and forming the frost crystal nucleus. In the third stage of high temperature and low humidity, the frost crystal continues to grow and densify, finally forming a uniform and complete persimmon frost layer on the surface of the sugar body. At the same time, by gradually reducing the humidity, the water loss rate inside the sugar body is controlled to avoid cracking or uneven frost layer caused by sudden changes in temperature and humidity, providing a sugar body with stable structure and good frost layer adhesion for subsequent pressing, ensuring the appearance and quality of the product.

[0082] In S5 step, the low-temperature pressing conditions are temperature 10-15℃, pressure 5-8MPa, and pressing time 10-15 minutes.

[0083] Specifically, by inhibiting the softening of gelatin and other colloids in a low-temperature environment, the stability of the sugar body structure is maintained. At the same time, suitable pressure is used to densify the loose frosting sugar body, enhancing the internal bonding force. By ensuring sufficient pressing time, uniform pressure transmission is achieved, avoiding local stress concentration. This not only ensures the entry texture but also improves the resistance during transportation and storage, realizing the key quality solidification from frosting to shaped products.

[0084] A low-temperature slow-drying preparation equipment for persimmon frosting sugar, comprising:

[0085] Ultrasonic crusher: used for crushing persimmons and performing ultrasonic pretreatment;

[0086] Stage-controlled temperature enzymolysis tank: used for stage addition of composite enzymes and low-temperature enzymolysis;

[0087] Vacuum gradient concentration device: for concentrating mixed liquid in stages;

[0088] Gradient humidity control drying chamber: for adjusting dehydration temperature and humidity in stages;

[0089] Low-temperature press forming machine: for pressing treatment of bloom sugar;

[0090] Specifically, the ultrasonic crusher crushes persimmon pulp and performs ultrasonic pretreatment, destroys the cell wall by mechanical crushing and cavitation effect, promotes the release of juice, pectin and other ingredients, and provides efficient reaction substrates for subsequent enzymolysis;

[0091] The staged temperature control enzyme hydrolysis tank is added in stages according to the difference in the optimum temperature of pectinase and cellulase, first degrades pectin material, and then decomposes cell wall cellulose, to ensure that the substrate is fully enzymolyzed and obtain a high clarity base liquid;

[0092] The vacuum gradient concentration device concentrates the mixed liquid in stages, protects the heat-sensitive components such as menthol at low temperature, and rapidly increases the solid content at high temperature to provide a high-concentration sugar environment for bloom;

[0093] The gradient humidity control drying chamber adjusts the temperature and humidity in stages, guides the migration of sugar to the surface and crystallization, forms a uniform and complete persimmon frost layer, and controls the water loss rate of the sugar body to ensure the stability of the structure;

[0094] The low-temperature press forming machine applies appropriate pressure to the bloom sugar body in a low-temperature environment, inhibits the softening of the colloid and enhances the internal bonding force, so that the sugar body is densified, the surface is smooth, and the frost layer is complete and attached. Through precise process control, each device realizes efficient utilization of raw materials, stable retention of ingredients, and optimization of product quality in the low-temperature slow drying process, ensuring that the persimmon frost has a delicate taste, uniform frost layer, and good storage performance.

[0095] The following will be described in conjunction with specific examples:

[0096] Example 1

[0097] Raw material ratio (weight parts):

[0098] Persimmon juice: 100 parts

[0099] Licorice and kudzu vine concentrated liquid: 20 parts (licorice: kudzu vine = 1:2.5)

[0100] Gelatin: 0.8 parts

[0101] Menthol: 0.02 parts

[0102] Preparation process:

[0103] Slurry pretreatment (S1):

[0104] Peeled persimmons were crushed to a particle size of 1.0 mm, mixed with water at a solid-liquid ratio of 4.5:1 (persimmon particles: water) to make pulp, and then transferred to an ultrasonic device for treatment at a frequency of 20-40 kHz for 7 minutes.

[0105] Staged enzymatic hydrolysis (S2):

[0106] Stage 1: Add pectinase 0.15 mL / kg slurry at 46°C and perform enzymatic hydrolysis for 70 minutes;

[0107] The second stage: the temperature was raised to 51°C, 0.075 mL / kg of cellulase was added, and enzymatic hydrolysis was carried out for 60 minutes;

[0108] Centrifugation: Centrifuge at 8000-10000 rpm for 12 minutes to collect the clarified persimmon juice.

[0109] Mixed Concentration (S3):

[0110] Gelatin was swelled at 40℃ for 30 minutes in advance, menthol was dissolved in ethanol and then mixed with persimmon juice and liquorice and platycodon concentrate;

[0111] Vacuum gradient concentration: the first stage is concentrated at 55°C to 55% solids, and the second stage is concentrated at 65°C to 78% solids.

[0112] Gradient dehydration cream (S4):

[0113] Stage 1: 26°C, 52% humidity, dehydration for 12 hours;

[0114] Stage 2: 29°C, 42% humidity, dehydration for 8 hours;

[0115] The third stage: dehydration at 31°C and 25% humidity for 6 hours.

[0116] Low temperature pressing (S5):

[0117] Press at 12°C and 6 MPa pressure for 12 minutes, and then demould to obtain the finished product.

[0118] Example 2

[0119] This embodiment differs from the above-mentioned embodiment 1 in that:

[0120] Raw material ratio (parts by weight):

[0121] Licorice and Platycodon grandiflorum concentrate: 15 parts (Licorice: Platycodon grandiflorum = 1:2)

[0122] Gelatin: 1.2 parts

[0123] Menthol: 0.01 parts

[0124] Differences in preparation process:

[0125] Slurry pretreatment (S1):

[0126] Crushed particle size 0.5 mm, solid-liquid ratio 5:1, ultrasonic wave 40 kHz for 5 minutes. Staged enzymatic hydrolysis (S2):

[0127] First stage: 48°C pectinase 0.1 mL / kg slurry enzymatic hydrolysis for 60 minutes;

[0128] Second stage: 52°C cellulase 0.1 mL / kg slurry enzymatic hydrolysis for 50 minutes; centrifugal speed 10000 rpm, time 10 minutes.

[0129] Vacuum concentration (S3):

[0130] First stage concentrated to 50% solids, second stage concentrated to 75%.

[0131] Low-temperature pressing (S5):

[0132] Pressing at 10°C, 8 MPa pressure for 10 minutes.

[0133] Example Three

[0134] The difference between this example and the above-mentioned Example One is:

[0135] Raw material ratio (weight parts):

[0136] Glycyrrhiza and kankong concentrated liquid: 25 parts (Glycyrrhiza: Kankong = 1:3)

[0137] Gelatin: 0.5 parts

[0138] Menthol: 0.03 parts

[0139] Preparation process difference:

[0140] Vacuum concentration (S3):

[0141] First stage concentrated to 60% solids at 60°C, second stage concentrated to 80% at 70°C.

[0142] Gradient dehydration and cream separation (S4):

[0143] First stage: dehydration at 28°C, 50% humidity for 10 hours;

[0144] Second stage: dehydration at 30°C, 40% humidity for 8 hours;

[0145] Third stage: dehydration at 32°C, 20% humidity for 5 hours.

[0146] Low-temperature pressing (S5):

[0147] Pressing at 15°C, 5 MPa pressure for 15 minutes.

[0148] Comparative Example 1 (Omitting Ultrasonic Pretreatment)

[0149] This comparative example differs from Example 1 in that:

[0150] Differences in preparation process:

[0151] Slurry pretreatment (S1):

[0152] Peeled persimmons were crushed to 1.0 mm and pulped directly without ultrasonic pretreatment, with a solid-liquid ratio of 4.5:1.

[0153] The remaining steps are the same as the parameters in Example 1.

[0154] Comparative Example 2 (Combined Enzymolysis Stage)

[0155] This comparative example differs from Example 1 in that:

[0156] Differences in preparation process:

[0157] Staged enzymatic hydrolysis (S2):

[0158] At the same time, 0.15 mL / kg of pectinase and 0.075 mL / kg of cellulase were added to the slurry, and the enzymatic hydrolysis was carried out at a constant temperature of 50° C. for 130 minutes (combining the two-stage time) without adjusting the temperature gradient.

[0159] The remaining steps are the same as the parameters in Example 1.

[0160] Comparative Example 3 (Single Stage Concentration)

[0161] This comparative example differs from Example 1 in that:

[0162] Differences in preparation process:

[0163] Vacuum concentration (S3):

[0164] The gradient concentration was cancelled, and the temperature was directly raised to 65° C. and concentrated to 78% solid content in one step (omitting the first stage of low-temperature concentration).

[0165] The remaining steps are the same as the parameters in Example 1.

[0166] Table 1. Comparison of experimental results

[0167]

[0168]

[0169] Comparison project explanation:

[0170] Juice yield: The percentage of juice mass after enzymatic hydrolysis and centrifugation to the total mass of the pulp, reflecting the efficiency of raw material utilization, which is affected by pretreatment and enzymatic hydrolysis process.

[0171] Thickness of persimmon frost layer: average value measured by optical microscope, 0.2-0.3mm is optimal, affected by dehydration process and raw material uniformity.

[0172] Saccharimeter test value: Use a handheld saccharimeter to measure the soluble solids content, which reflects the sugar concentration and is related to the raw material ratio and concentration process.

[0173] Moisture content: Determined by loss on drying method, <10% can ensure the hardness and shelf life of the sugar, which is controlled by the dehydration process.

[0174] Sugar body crack rate: Statistical analysis of the proportion of cracked sugar bodies to measure molding stability, which is related to the uniformity of the concentrate and pressing parameters.

[0175] Microbial indicators: The total colony count (CFU / g) must comply with GB17399 standards and is affected by the cleanliness and moisture content of the raw materials.

[0176] Defrost time: the time from injection molding to the formation of a complete frost layer, which affects production efficiency and depends on the temperature and humidity gradient and sugar conditions.

[0177] Analysis and discussion of the differences in test parameters between the examples and the comparative examples:

[0178] The impact of ultrasonic pretreatment: The examples used ultrasonic pretreatment to break up the fruit pulp, significantly improving cell wall destruction efficiency and promoting the full release of juice and active ingredients. Comparative Example 1, which omitted this step, saw a significant decrease in juice yield, prolonged defrost time, and uneven frost thickness, demonstrating the crucial role of ultrasound in improving raw material utilization.

[0179] The difference between staged and combined enzymatic hydrolysis: In Example 1, the phased addition of pectinase and cellulase targeted the degradation of different cell wall components, resulting in high juice clarity and low sugar cracking. In Comparative Example 2, after combining the enzymatic hydrolysis stages, enzyme activity was limited, resulting in increased pectin residue, a significant increase in sugar cracking, and insufficient flavor release, demonstrating the necessity of staged, temperature-controlled enzymatic hydrolysis.

[0180] Comparison of gradient concentration and single concentration: Example 1 uses vacuum gradient concentration in stages to protect heat-sensitive ingredients and increase sugar concentration to prevent scorching. Comparative Example 3 uses single high-temperature concentration, which reduces the stability of colloids such as gelatin, increases the cracking rate of the sugar, and significantly loses menthol through volatilization, highlighting the importance of gradient concentration for ingredient retention and sugar formation.

[0181] The difference between gradient dehydration and constant humidity conditions: In Example 1, three-stage temperature and humidity control were used to guide the uniform migration and frosting of sugars, resulting in a dense and uniform frosting layer. In Comparative Example 2, which used constant temperature and humidity dehydration, the differences in sugar crystallization rates led to a mottled or uneven frosting layer, significantly reducing the yield rate. This demonstrates the effectiveness of staged humidity control in optimizing product appearance and stability.

[0182] Comparison of low-temperature pressing and traditional molding: In Example 1, low-temperature pressing inhibited colloid softening, enhanced sugar binding, and reduced cracking. In Comparative Example 3, where pressing parameters were not optimized, the sugar was loose and prone to cracking, with poor storage tolerance, demonstrating the necessity of low-temperature pressing for structural stability.

[0183] Synergistic Effects of Adjusting Excipient Ratios: The examples adjust the ratio of licorice and platycodon and the amount of gelatin to balance flavor and structure. For example, in Example 3, increasing the amount of licorice and platycodon enhances the sweetness and thickness of the frosting, while reducing the amount of gelatin requires a longer pressing time to maintain the structure, demonstrating the dynamic synergy between ratios and process parameters.

[0184] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A low-temperature slow-drying method for preparing persimmon frosting candy, characterized in that: The following steps are involved: S1. Crushing peeled persimmons into particles, adding water to prepare a slurry, and performing ultrasonic pretreatment on the slurry; S2, adding complex enzymes to the slurry in stages for low-temperature enzymatic hydrolysis, and centrifuging to obtain clarified persimmon juice; S3, mixing the persimmon juice with liquorice and platycodon concentrate, menthol, and gelatin, and increasing the solid content by vacuum gradient concentration process; S4, after the concentrated liquid is injected into the mold, the persimmon frost layer is precipitated by gradient dehydration in a controlled temperature and humidity environment; S5. The sugar body after frosting is subjected to low-temperature pressing treatment.

2. The low-temperature slow-drying preparation method of persimmon frosting candy according to claim 1, characterized in that: The mixed solution in step S3 comprises the following components by weight: Persimmon juice: 100 servings; Licorice and Platycodon grandiflorum concentrate: 15-25 parts, wherein the mass ratio of licorice to platycodon grandiflorum is 1:2 to 1:3; Gelatin: 0.5-1.2 parts; Menthol: 0.01-0.03 parts.

3. The low-temperature slow-drying preparation method of persimmon frosting candy according to claim 1, characterized in that: In the step S1, the particle size of the crushed particles is 0.5-1.5 mm, the solid-liquid ratio of the slurry is 4:1 to 5:1, the ultrasonic pretreatment frequency is 20-40 kHz, and the treatment time is 5-10 minutes.

4. The low-temperature slow-drying preparation method of persimmon frosting candy according to claim 1, characterized in that: The volume ratio of the slurry to water in step S1 is 1:

2.

5. The low-temperature slow-drying preparation method of persimmon frosting candy according to claim 1, characterized in that: The conditions for adding the complex enzyme in stages in step S2 are: Add pectinase for the first time and perform enzymatic hydrolysis at 45-48°C for 60-80 minutes; Add cellulase for the second time and perform enzymatic hydrolysis at 50-52°C for 50-70 minutes; The amount of pectinase added is 0.1-0.2 mL / kg slurry, and the amount of cellulase added is 0.05-0.1 mL / kg slurry.

6. The low-temperature slow-drying preparation method of persimmon frosting candy according to claim 1, characterized in that: The rotation speed of the centrifugal separation in the step S2 is 8000-10000 rpm, and the centrifugation time is 10-15 minutes.

7. The low-temperature slow-drying method for preparing persimmon frosting candy according to claim 1, characterized in that: The vacuum gradient concentration process in step S3 includes: The first stage is low temperature concentration to 50-60% solids; The second stage is to heat and concentrate until the solid content is ≥75%.

8. The low-temperature slow-drying method for preparing persimmon frosting candy according to claim 1, characterized in that: The gradient dehydration in step S4 includes three stages: Stage 1: temperature 25-28°C, humidity 50-55%; Stage 2: Temperature 28-30°C, humidity 40-45%; Stage 3: Temperature 30-32℃, humidity ≤30%.

9. The low-temperature slow-drying preparation method of persimmon frosting candy according to claim 1, characterized in that: In the step S5, the low-temperature pressing conditions are a temperature of 10-15° C., a pressure of 5-8 MPa, and a pressing time of 10-15 minutes.

10. The low-temperature slow-drying preparation equipment for persimmon frosted candy according to claim 1, used for the low-temperature slow-drying preparation method for persimmon frosted candy according to any one of claims 1 to 9, characterized in that: include: Ultrasonic crusher: used to crush persimmons and perform ultrasonic pretreatment; Staged temperature-controlled enzymatic hydrolysis tank: used for staged addition of compound enzymes and low-temperature enzymatic hydrolysis; Vacuum gradient concentration device: used to concentrate the mixed liquid by increasing the temperature in stages; Gradient humidity controlled drying chamber: used to adjust the dehydration temperature and humidity in stages; Low temperature pressing machine: used for pressing frosted sugar bodies.

Images