Method and system for predicting fruit cracking rate of frozen sleep litchis
By constructing a multi-parameter prediction model for lychee cracking rate, the problem of large fluctuations in cracking rate of dormant lychees was solved, achieving precise control and production efficiency optimization, and reducing energy consumption and processing losses.
Patent Information
- Application Number
- CN202511684666.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-17
- Publication Date
- 2026-02-13
AI Technical Summary
In existing frozen lychee technology, the fruit cracking rate fluctuates greatly, lacks quantitative basis, and the adjustment of freezing parameters depends on experience, resulting in high processing losses and difficulty in achieving quality stability and production efficiency optimization.
By acquiring the initial temperature, fruit diameter, pulp moisture content, peel thickness, and freezing dormancy solution temperature of lychees, a fruit cracking rate prediction model is constructed. Combined with peel maturity and pulp sugar content, the fruit cracking rate is calculated, providing quantitative guidance for optimizing process parameters.
It enables precise control of the cracking rate of frozen dormant lychees, reduces processing losses, lowers energy consumption, simplifies operating procedures, and improves production efficiency and quality stability.
Smart Images
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Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of fruit preservation, in particular to a method and system for predicting the cracking rate of frozen and dormant litchi. BACKGROUND
[0002] Litchi is a typical tropical fruit, which is mainly produced in summer in the south. The yield is large and the marketing period is concentrated. However, the postharvest physiological metabolism of litchi is extremely vigorous, the respiration intensity is much higher than that of apple, and problems such as peel browning, nutritional quality decline and flavor volatile are prone to occur, resulting in poor storage resistance, short shelf life, and thus limited transportation radius, making it difficult to achieve year-round supply of fresh fruit.
[0003] Quick freezing technology is an effective means to maintain the postharvest quality of litchi, which can maximize the maintenance of its original flavor, texture and nutrition. However, during the freezing process, cracking becomes a key problem that restricts the improvement of quality. The peel of litchi is thin and brittle, and the structure is low. During the freezing process, the internal ice crystal volume expands and stress concentrates, and when the peel cannot withstand the stress, it will crack. Moreover, when the coolant is much lower than the critical temperature that the peel can tolerate, the peel will also crack. Under the conventional freezing process, the cracking rate of litchi is generally between 8% and 15%, and for some varieties such as "Feixiaoshuo", it even exceeds 20%, resulting in high processing loss rate. Especially in the conventional slow air freezing process, the large ice crystals formed will seriously damage the cell structure of the fruit, not only aggravating the cracking, but also causing severe juice loss after thawing and significant reduction in commodity value, causing great economic losses to enterprises. However, we cannot blindly reduce the coolant temperature to make the peel brittle and aggravate the cracking.
[0004] At present, litchi is frozen and dormant by freezing technology, which greatly prolongs the preservation time of litchi and is a kind of litchi preservation technology. Frozen and dormant litchi refers to the process of quickly freezing litchi in a zero environment through a high thermal conductivity liquid to form uniform and fine ice crystals in the cells, so that the cells are in a dormant state, avoiding the problem of browning and corruption during storage. However, the control of the freezing process still highly depends on the experience of technical personnel, and there are problems of blind parameter adjustment and lack of quantitative basis. In traditional operation, the freezing temperature and cooling rate are often adjusted subjectively, and the quantitative correlation between process parameters and cracking rate has not been established, resulting in a fluctuation of 5% to 8% in the cracking rate of the same batch. In addition, existing researches are mostly about the influence of single factor such as temperature or ice crystal size on cracking, and there is a lack of systematic and multi-parameter coordinated prediction and control method.
[0005] Therefore, in view of the deficiencies in the prior art, it is necessary to provide a method and system for predicting the cracking rate of frozen and dormant litchi to solve the deficiencies in the prior art. SUMMARY
[0006] One of the purposes of the present application is to provide a method for predicting the cracking rate of frozen sleep litchi to avoid the shortcomings of the prior art. The method for predicting the cracking rate of frozen sleep litchi can predict the cracking rate based on the variety constant, pulp water content, peel maturity, pulp sugar content, frozen sleep liquid temperature, and frozen sleep time of litchi.
[0007] The above-mentioned purposes of the present application are achieved by the following technical measures: The present application provides a method for predicting the cracking rate of frozen sleep litchi, comprising the following steps: S1, obtaining the initial temperature of litchi, the average fruit diameter of litchi, the pulp water content, the average thickness of peel, and the frozen sleep liquid temperature of the frozen sleep liquid used during frozen sleep, and calculating the average center temperature of the pulp of litchi; S2, calculating the frozen sleep of litchi according to the average center temperature of the pulp obtained in S1 and the ice point empirical temperature of the pulp, and determining whether the frozen sleep is up to standard, when the frozen sleep is up to standard, entering S3; S3, obtaining the peel maturity and pulp sugar content of litchi; S4, constructing a cracking rate prediction model according to the frozen sleep liquid temperature, the peel maturity, the pulp sugar content, the average fruit diameter of litchi, the pulp water content, and the average thickness of peel, and calculating the cracking rate according to the cracking rate prediction model.
[0008] In the S2, the average center temperature of the pulp of litchi is calculated by formula (1); Formula (1); Wherein, t is the frozen sleep time, unit: min; T 中 is the average center temperature of the pulp, unit: ℃; T l is the frozen sleep liquid temperature, unit: ℃; T 初 is the initial temperature of litchi, unit: ℃; β is the heat transfer correction coefficient; k 传 is the heat transfer coefficient; D is the average fruit diameter of litchi, unit: mm.
[0009] Preferably, the heat transfer coefficient k 传 is obtained from formula (2): Formula (2); Wherein, W is the pulp water content; H is the average thickness of peel, unit: mm.
[0010] Preferably, S3 calculates the temperature difference between the average center temperature of the pulp and the empirical freezing point temperature of the pulp according to formula (3). ΔT ,when ΔT If the temperature is ≥8℃, the freezing sleep is considered to have met the standard; otherwise, the freezing sleep is considered to have failed to meet the standard. ΔT = T f - T 中 ...Equation (3); in, T f This is the empirical temperature for the freezing point of the fruit pulp.
[0011] In S4, the fruit cracking rate prediction model is represented by equation (4): ...Equation (4); in, P c The percentage of cracked fruit is expressed as %; K This is a category constant; M This refers to the ripeness of the fruit peel; a Weighted by sugar content; b Weighted by moisture content; T C The critical temperature for the pericarp's tolerance is expressed in °C. c Weighted by temperature difference; d Weighting of freeze-sleep time; S Sugar content of the fruit pulp, expressed in °Bx; j This is the sugar content correction constant; f Weighted by sugar content; g Weighted by fruit diameter; h This is a correction constant for peel thickness; i Weighted by peel thickness; F(T l ) This is a function to correct the dormancy partition.
[0012] Preferably, the above-mentioned hibernation partitioning correction function F(T l ) Equation (5) represents: ...Equation (5); in, k 1 Risk coefficient for large ice crystal risk zone; C 1 This is a fundamental constant for the large ice crystal risk region. m 1 The risk coefficient gradient rate for the large ice crystal risk zone is expressed in °C. -1 ; n 1The gradual change rate of the fundamental constants in the first transition region, in °C. -1 ; k 2 Risk coefficient for low-risk areas; C 2 This serves as a basic constant for low-risk areas; m 2 The risk coefficient gradient rate for the second transition zone is expressed in °C. -1 ; n 2 The gradual change rate of the fundamental constants in the second transition region, in °C. -1 ; k 3 Risk coefficient for the embrittlement risk zone; C 3 This is a fundamental constant for the embrittlement risk zone.
[0013] Preferably, the above a It is 0.2. b It is 1.1. c It is 0.4. d It is 0.01. e =1, f It is 0.4. g It is 0.3. h It is 0.1. i It is 0.6. C 1 It is 0.32. m 1 -0.009℃ -1 , n 1 -0.12℃ -1 , C 2 It is 0.7. m 2 -0.01℃ -1 , n 2 0.15℃ -1 , C 3 It is 0.41; β It is 0.3; T f The temperature is -3.8℃.
[0014] Preferably, the above 0.0010 ≤ K ≤0.0030, -16.0℃≤ T C ≤-13.0℃, 0.020≤ k 1 ≤0.030, 0.003≤ k 2≤0.010, 0.020≤ k 3 ≤0.050.
[0015] When the lychee variety is Fei Zi Xiao: K It is 0.0021; T C The temperature is -13.8℃. k 1 It is 0.023; k 2 It is 0.007; k 3 It is 0.17; When the lychee variety is glutinous rice cake: K It is 0.0024; T C The temperature is -13.5℃. k 1 It is 0.027; k 2 It is 0.008; k 3 It is 0.19; When the lychee variety is Black Leaf: K It is 0.0027; T C The temperature is -13.2℃. k 1 It is 0.029; k 2 It is 0.009; k 3 It is 0.20; When the lychee variety is Guiwei: K It is 0.0017; T C The temperature is -14.2℃. k 1 It is 0.025; k 2 It is 0.006; k 3 It is 0.16; When the lychee variety was presented as imperial tribute: K It is 0.0019; T C The temperature is -15.5℃. k 1 It is 0.024; k 2 It is 0.007; k3 It is 0.18.
[0016] Preferably, the above-mentioned fruit peel maturity is the difference between the red and green colors of the current litchi fruit peel, 'a'. The difference between the red and green color of a fully ripe lychee (a) The ratio of the fruit peel to the fruit is less than or equal to 1.
[0017] Preferably, the red-green difference test point for the ripeness of the peel is the suture line of the peel.
[0018] Another objective of this invention is to overcome the shortcomings of existing technologies by providing a fruit cracking rate prediction system for frozen-dormant lychees. This system can predict the fruit cracking rate based on lychee variety constants, pulp moisture content, peel maturity, pulp sugar content, freezing-dormant solution temperature, and freezing-dormant time.
[0019] The above-mentioned objectives of the present invention are achieved through the following technical measures: A fruit cracking rate prediction system for frozen-dormant lychee is provided, which executes the above-mentioned fruit cracking rate prediction method for frozen-dormant lychee.
[0020] This invention discloses a method and system for predicting the cracking rate of dormant lychees. The method for predicting the cracking rate of dormant lychees includes the following steps: S1, obtaining the initial temperature of the lychee, the average diameter of the lychee, the flesh moisture content, the average thickness of the peel, and the temperature of the dormancy solution used during dormancy, and calculating the average center temperature of the lychee flesh; S2, calculating whether the dormancy of the lychee meets the standard based on the average center temperature of the flesh obtained in S1 and the empirical freezing point temperature of the flesh; if the dormancy meets the standard, proceeding to S3; S3, obtaining the peel maturity and flesh sugar content of the lychee; S4, constructing a cracking rate prediction model based on the dormancy solution temperature, peel maturity, flesh sugar content, average diameter of the lychee, flesh moisture content, and average peel thickness, and calculating the cracking rate based on the cracking rate prediction model. This invention enables precise calculation of fruit cracking rate under the synergistic effect of multiple parameters. The method provides exclusive parameters for different lychee varieties, and can quantitatively guide the optimization and adjustment of process parameters such as freezing dormancy solution temperature and freezing dormancy time according to the characteristics of different varieties and fruit conditions. It effectively avoids the problems of blind parameter adjustment and large fluctuations in fruit cracking rate caused by the reliance on experience in traditional processes. It can accurately control the fruit cracking rate within a low range, reduce processing losses, and avoid the increase in energy consumption and quality decline caused by blindly extending the freezing dormancy time or lowering the freezing dormancy solution temperature by reasonably matching process parameters. At the same time, it simplifies the operation process and provides a reliable quantitative basis for improving the quality stability, optimizing production efficiency and controlling costs of frozen dormant lychees. Detailed Implementation
[0021] The technical solution of the present invention will be further described in conjunction with the following embodiments.
[0022] Example 1 A method for predicting the fruit cracking rate of dormant lychee includes the following steps: S1. Obtain the initial temperature of the lychee, the average diameter of the lychee, the moisture content of the pulp, the average thickness of the peel, and the temperature of the freezing solution used during freezing dormancy, and calculate the average center temperature of the lychee pulp. S2. Based on the average center temperature of the pulp obtained in S1 and the empirical freezing point temperature of the pulp, calculate whether the freezing dormancy of the lychee meets the standard. If the freezing dormancy meets the standard, proceed to S3. S3. Obtain the ripeness of the lychee peel and the sugar content of the pulp; S4. Construct a fruit cracking rate prediction model based on the freezing liquid temperature, peel maturity, pulp sugar content, average fruit diameter of lychee, pulp moisture content, and average peel thickness, and calculate the fruit cracking rate based on the fruit cracking rate prediction model.
[0023] In S2, the average center temperature of the litchi pulp is calculated using equation (1); ...Equation (1); in, t The duration of the cryosleep is measured in minutes. T 中 This represents the average core temperature of the fruit pulp, expressed in °C. T l The temperature of the cryopreservation solution is expressed in °C. T 初 The initial temperature of the lychee, in °C; β This is the heat transfer correction factor; k 传 The heat transfer coefficient; D This represents the average diameter of the lychee fruit, in mm. heat transfer coefficient k 传 From equation (2), we get: ...Equation (2); Where W represents the water content of the pulp; H The average thickness of the fruit peel is expressed in mm.
[0024] S3 calculates the temperature difference between the average center temperature of the pulp and the empirical freezing point temperature of the pulp according to formula (3). ΔT ,when ΔT If the temperature is ≥8℃, the freezing sleep is considered to have met the standard; otherwise, the freezing sleep is considered to have failed to meet the standard. ΔT = T f - T 中 ...Equation (3); in, T f This is the empirical temperature for the freezing point of the fruit pulp.
[0025] In S4, the fruit cracking rate prediction model is represented by equation (4): ...Equation (4); in, P c The percentage of cracked fruit is expressed as %; K This is a category constant; M This refers to the ripeness of the fruit peel; a Weighted by sugar content; b Weighted by moisture content; T C The critical temperature for the pericarp's tolerance is expressed in °C. c Weighted by temperature difference; d Weighting of freeze-sleep time; S Sugar content of the fruit pulp, expressed in °Bx; j This is the sugar content correction constant; f Weighted by sugar content; g Weighted by fruit diameter; h This is a correction constant for peel thickness; i Weighted by peel thickness; F(T l ) This is a function to correct the dormancy partition.
[0026] Freeze-hibernation partition correction function F(T l ) Equation (5) represents: ...Equation (5); in, k 1 Risk coefficient for large ice crystal risk zone; C 1 This is a fundamental constant for the large ice crystal risk region. m 1 The risk coefficient gradient rate for the large ice crystal risk zone is expressed in °C. -1 ; n 1 The gradual change rate of the fundamental constants in the first transition region, in °C. -1 ; k 2 Risk coefficient for low-risk areas; C 2 This serves as a basic constant for low-risk areas; m 2 The risk coefficient gradient rate for the second transition zone is expressed in °C. -1 ; n 2 The gradual change rate of the fundamental constants in the second transition region, in °C. -1 ; k 3Risk coefficient for the embrittlement risk zone; C 3 This is a fundamental constant for the embrittlement risk zone.
[0027] Among them, the present invention a It is 0.2. b It is 1.1. c It is 0.4. d It is 0.01. e =1, f It is 0.4. g It is 0.3. h It is 0.1. i It is 0.6. C 1 It is 0.32. m 1 -0.009℃ -1 , n 1 -0.12℃ -1 , C 2 It is 0.7. m 2 -0.01℃ -1 , n 2 0.15℃ -1 , C 3 It is 0.41; T f The temperature is -3.8℃. 0.0010≤ K ≤0.0030, -16.0℃≤ T C ≤-13.0℃, 0.020≤ k 1 ≤0.030, 0.003≤ k 2 ≤0.010, 0.020≤ k 3 ≤0.050.
[0028] When the lychee variety is Fei Zi Xiao: K It is 0.0021; T C The temperature is -13.8℃. k 1 It is 0.023; k 2 It is 0.007; k 3 It is 0.17; When the lychee variety is glutinous rice cake: KIt is 0.0024; T C The temperature is -13.5℃. k 1 It is 0.027; k 2 It is 0.008; k 3 It is 0.19; When the lychee variety is Black Leaf: K It is 0.0027; T C The temperature is -13.2℃. k 1 It is 0.029; k 2 It is 0.009; k 3 It is 0.20; When the lychee variety is Guiwei: K It is 0.0017; T C The temperature is -14.2℃. k 1 It is 0.025; k 2 It is 0.006; k 3 It is 0.16; When the lychee variety was presented as imperial tribute: K It is 0.0019; T C The temperature is -15.5℃. k 1 It is 0.024; k 2 It is 0.007; k 3 It is 0.18.
[0029] It should be noted that the formulas for calculating the average core temperature of the pulp, the heat transfer coefficient, the fruit cracking rate prediction model, and the dormancy zone correction function of this invention were all obtained using MATLAB.
[0030] The ripeness of the fruit peel is represented by the difference between the red and green colors of the current lychee peel, denoted as 'a'. The difference between the red and green color of a fully ripe lychee (a) The ratio of red to green color to fruit peel maturity is less than or equal to 1. The test point for the red-green color difference of fruit peel maturity is the suture line of the fruit peel.
[0031] It should be noted that the method for determining the full ripeness of lychees in this invention involves five technicians with over 15 years of experience in lychee cultivation. Each technician selects 20 fully ripe lychees of the same variety, and then measures the red-green color difference (a) at three points along the suture line of each lychee. The average value is taken as the red-green difference value 'a' of the lychee. Finally, the red-green difference value a of all lychees was calculated. Take the average value as the red-green color difference 'a' of this type of lychee when fully ripe. The current difference between the red and green colors of lychee peel is a. The determination method involves randomly selecting 30 lychees from those awaiting freeze-drying, and taking 3 points along the suture line of each lychee to measure the red-green color difference 'a'. The average value is taken as the red-green difference value 'a' of the lychee. Finally, the red-green difference value a of all lychees was calculated. Take the average value as the current red-green difference value 'a' of the lychee peel. Then calculate the red-green difference value a of the current lychee peel. The difference between the red and green color of a fully ripe lychee (a) The ratio of to is used to obtain the peel maturity of fruits that is less than or equal to 1.
[0032] The moisture content of the fruit pulp in this invention is tested using a constant temperature and atmospheric pressure drying method. Specifically, 50 lychees from the same batch are randomly selected, peeled, and pitted, leaving only the pulp. The pulp is then homogenized into a pulp slurry, and the slurry is dried in a 105℃ constant pressure drying oven to constant weight. 5g of the slurry is weighed and dried at 105℃ constant pressure for 4 hours, cooled, and weighed. The moisture content is calculated using the formula, and the measurement is repeated three times. The average value is taken as the final result: Moisture content = (Pulp weight before drying - Pulp weight after drying) / Pulp weight before drying. The sugar content of the fruit pulp in this invention is tested using a digital handheld refractometer.
[0033] The critical temperature for peel tolerance in this invention T C The method to obtain it is as follows: I. Sample Preparation Step 1, Sample selection: Select random samples from fully ripe lychees of the same variety; Step 2, Peeling: Gently peel the complete lychee peel along the suture line to remove any attached pulp residue; Step 3, Sample cutting: Cut the peeled fruit peel into pieces 30mm long, 10mm wide, and retain the original fruit peel thickness.
[0034] II. Test Steps Step 1: Set the low temperature gradient Based on the characteristics of lychee peel, eight low-temperature gradients were preset: -11.0℃, -12.0℃, -13.0℃, -14.0℃, -15.0℃, -16.0℃, -17.0℃, and -18.0℃. Step 2: Low-temperature constant temperature treatment Place the cut standard fruit peel samples into the sample rack of the programmed cooling chamber, ensuring that the samples do not overlap or squeeze. According to the set low temperature gradient, different groups of samples were subjected to constant temperature treatment in sequence: first, the cooling chamber was lowered from room temperature to the target temperature at a rate of 1℃ / min, and after reaching the target temperature, it was kept constant for 2 hours; after the constant temperature was completed, the samples were immediately taken out and placed in the matching low temperature constant temperature clamping device.
[0035] Step 3: Mechanical property testing Install the low-temperature constant temperature clamping device on the universal testing machine, adjust the clamping distance to 0 mm, and set the tensile rate to 5 mm / min; perform tensile tests on the specimens and record the maximum tensile force and elongation at fracture for each specimen. Calculation formula: Tensile strength (MPa) = Maximum tensile force (N) / (Specimen width (mm) × Specimen thickness (mm)); The tensile strength of each of the 10 specimens in each group was calculated, and the average value was taken as the mechanical property data under the low temperature gradient.
[0036] Step 4: Determine the critical temperature tolerance of the fruit peel. Plot a temperature-tensile strength curve to identify the temperature at which the tensile strength suddenly decreases by more than 30%. This temperature is the point of abrupt change in mechanical properties. Then, use this temperature as the critical temperature for the peel's tolerance. T C .
[0037] The empirical temperature of fruit pulp freezing point in this invention T f The method to obtain it is as follows: I. Sample Preparation Step 1, Sample selection: Randomly select samples from fully ripe lychees of the same variety; Step 2, Pulp Removal: Peel off the skin and pit to remove the whole pulp; Step 3, pulp processing: Put the pulp into a tissue homogenizer and blend it into a uniform pulp paste.
[0038] II. Testing Methods Take 10 mg of fruit pulp homogenate and place it in a sealed aluminum dish; set the low-temperature differential scanning calorimetry (DSC) parameters: cooling rate 5℃ / min, from 25℃ to -20℃, record the heat flow curve running program, and record the heat flow-temperature curve; when the temperature drops to a certain value, the heat flow will show a plateau inflection point, and the temperature of this inflection point is the empirical freezing point temperature of the corresponding fruit pulp sample. T f Repeatedly test the pulp homogenate of 30 lychees to obtain 30 individual freezing point values; remove outliers (values deviating from the average by more than 0.2℃), and take the average of the remaining values, which is the empirical freezing point temperature of the pulp for this type of lychee. T f .
[0039] The average diameter of the lychee in this invention is determined by randomly selecting 20 lychees from the same batch and averaging the results. The average peel thickness is determined by measuring the suture line of 20 randomly selected lychees from the same batch and averaging the results.
[0040] This method for predicting the cracking rate of frozen-dormant lychees achieves accurate calculation of the cracking rate under the synergistic effect of multiple parameters. It provides specific parameters for different lychee varieties, and can quantitatively guide the optimization and adjustment of process parameters such as the temperature of the dormancy solution and the dormancy time based on the characteristics of different varieties and the state of the fruit. This effectively avoids the problems of blind parameter adjustment and large fluctuations in the cracking rate caused by the reliance on experience in traditional processes. It can accurately control the cracking rate within a low range, reducing processing losses, and by reasonably matching process parameters, avoid the increased energy consumption and decreased quality caused by blindly extending the dormancy time or lowering the dormancy solution temperature. At the same time, it simplifies the operation process and provides a reliable quantitative basis for improving the quality stability, optimizing production efficiency, and controlling costs of frozen-dormant lychees.
[0041] Example 2 An embodiment 1 describes a method for predicting the cracking rate of frozen-dormant lychees. This embodiment uses the Fei Zi Xiao variety of lychee for testing. The Fei Zi Xiao variety corresponds to... K It is 0.0021; T C The temperature is -13.8℃. k 1 It is 0.023; k 2 It is 0.007; k 3 The value is 0.17. Other parameters in the fruit cracking rate prediction model are as follows: a It is 0.2. b It is 1.1. c It is 0.4. d It is 0.01. e =1, f It is 0.4. g It is 0.3. hIt is 0.1. i It is 0.6. C 1 It is 0.32. m 1 -0.009℃ -1 , n 1 -0.12℃ -1 , C 2 It is 0.7. m 2 -0.01℃ -1 , n 2 0.15℃ -1 , C 3 It is 0.41; β It is 0.3; T f The temperature is -3.8℃.
[0042] This embodiment uses the same batch of Fei Zi Xiao chrysanthemum tea as an example, where the initial temperature... T 初 At 1℃, the water content of the pulp W The value was 0.83, indicating the fruit peel maturity. M The value is 0.9, the sugar content of the pulp is 16°Bx, and the temperature of the freezing liquid is... T l The temperature was -30.5℃. The average diameter of the litchi fruit was... D The average thickness of the peel is 32.5 mm. H 0.92mm; cryotherapy time t It takes 20.5 minutes. The empirical temperature for the freezing point of the fruit pulp. T f The temperature is -3.8℃.
[0043] The heat transfer coefficient calculated using equation (2) is 1.09; then, the heat transfer coefficient calculated using equation (1) is... T 中 The temperature is -30.12℃, and the temperature difference is calculated using equation (3). ΔT The temperature is 26.32℃. Since dormancy is achieved when 26.32℃ is ≥ 8℃, the process can proceed to S4 for fruit cracking rate calculation.
[0044] The freezing dormancy solution temperature, variety constant, pulp moisture content, peel maturity, and pulp sugar content of the Fei Zi Xiao variety are input into the corresponding fruit cracking rate prediction model. Since the freezing dormancy solution temperature is -30.5℃, the freezing dormancy zoning correction function is... F(T l ) The final fruit cracking rate is calculated based on the brittleness risk zone. P cIt is 9.79%.
[0045] A freeze-drying experiment was conducted based on the above parameters. After 20.5 minutes of freeze-drying, 500 Fei Zi Xiao lychees were counted, and 45 of them cracked. The actual cracking rate was 45 / 500 = 9.0%, which is close to the predicted value. This proves that the method for predicting the cracking rate of freeze-drying lychees in this invention is reliable.
[0046] Example 3 An embodiment 1 describes a method for predicting the cracking rate of frozen-dormant lychees. This embodiment uses the Fei Zi Xiao variety of lychee for testing. The Fei Zi Xiao variety corresponds to... K It is 0.0021; T C The temperature is -13.8℃. k 1 It is 0.023; k 2 It is 0.007; k 3 The value is 0.17. Other parameters in the fruit cracking rate prediction model are as follows: a It is 0.2. b It is 1.1. c It is 0.4. d It is 0.01. e =1, f It is 0.4. g It is 0.3. h It is 0.1. i It is 0.6. C 1 It is 0.32. m 1 -0.009℃ -1 , n 1 -0.12℃ -1 , C 2 It is 0.7. m 2 -0.01℃ -1 , n 2 0.15℃ -1 , C 3 It is 0.41; β It is 0.3; T f The temperature is -3.8℃.
[0047] This embodiment uses the same batch of Fei Zi Xiao chrysanthemum tea as an example, where the initial temperature... T 初 At 1℃, the water content of the pulp W The value was 0.82, indicating the ripeness of the fruit peel. MThe value is 0.8, the sugar content of the pulp is 13°Bx, and the temperature of the freezing liquid is... T l The temperature was -13.5℃. The average diameter of the litchi fruit was... D The average thickness of the peel is 27.8 mm. H 1.02mm; cryotherapy time t It takes 40 minutes.
[0048] The heat transfer coefficient calculated using equation (2) is 1.04; then, the heat transfer coefficient calculated using equation (1) is... T 中 The temperature is -13.50℃, and the temperature difference is calculated using equation (3). ΔT The temperature is 9.70℃. Since dormancy is achieved when 9.70℃ is ≥ 8℃, the fruit cracking rate can be calculated in S4.
[0049] The freezing dormancy solution temperature, variety constant, pulp moisture content, peel maturity, and pulp sugar content of the Fei Zi Xiao variety are input into the corresponding fruit cracking rate prediction model. Since the freezing dormancy solution temperature is -13.5℃, the freezing dormancy zoning correction function is... F(T l ) The final fruit cracking rate was calculated using the first transition zone. P c It is 0.38%.
[0050] A freeze-drying experiment was conducted based on the above parameters. After 40 minutes of freeze-drying, 500 Fei Zi Xiao lychees were counted, and 3 fruits were found to be cracked. The actual cracking rate was 3 / 500 = 0.6%, which was close to the predicted value, proving that the method for predicting the cracking rate of freeze-drying lychees in this invention is reliable.
[0051] Example 4 An example of a method for predicting the cracking rate of frozen-dormant lychees (Example 1). This example uses the lychee variety "Nuomici" for testing, where Nuomici corresponds to... K It is 0.0024; T C The temperature is -13.5℃. k 1 It is 0.027; k 2 It is 0.008; k 3 The value is 0.19. Other parameters in the fruit cracking rate prediction model are as follows: a It is 0.2. b It is 1.1. c It is 0.4. d It is 0.01. e =1, f It is 0.4. g It is 0.3. hIt is 0.1. i It is 0.6. C 1 It is 0.32. m 1 -0.009℃ -1 , n 1 -0.12℃ -1 , C 2 It is 0.7. m 2 -0.01℃ -1 , n 2 0.15℃ -1 , C 3 It is 0.41; β It is 0.3; T f The temperature is -3.8℃.
[0052] This embodiment uses the same batch of glutinous rice balls as an example, where the initial temperature... T 初 At 5℃, the water content of the pulp W The value was 0.78, indicating the fruit peel maturity. M The value is 1, the sugar content of the pulp is 17°Bx, and the temperature of the freezing liquid is 1. T l The temperature was -18.5℃. The average diameter of the litchi fruit was... D The average thickness of the peel is 32.5 mm. H 1.18mm; cryotherapy time t It takes 15 minutes.
[0053] The heat transfer coefficient calculated using equation (2) is 0.95; then, the heat transfer coefficient calculated using equation (1) is... T 中 The temperature is -17.08℃, and the temperature difference is calculated using equation (3). ΔT The temperature is 13.28℃. Since dormancy is achieved when 13.28℃ is ≥ 8℃, the process can proceed to S4 for fruit cracking rate calculation.
[0054] The freezing dormancy solution temperature, variety constant, pulp moisture content, peel maturity, and pulp sugar content corresponding to glutinous rice balls are input into the corresponding fruit cracking rate prediction model. Since the freezing dormancy solution temperature is -18.5℃, the freezing dormancy zoning correction function is... F(T l ) The final fruit cracking rate was calculated using low-risk areas. P c It is 0.21%.
[0055] A freeze-drying experiment was conducted based on the above parameters. After 15 minutes of freeze-drying, 500 glutinous rice lychees were counted, and the number of cracked fruits was 2. The actual cracking rate was 2 / 500 = 0.4%, which is close to the predicted value, proving that the method for predicting the cracking rate of freeze-drying lychees in this invention is reliable.
[0056] Example 5 An embodiment of the method for predicting the fruit cracking rate of frozen-dormant lychee (Example 1) uses the Black Leaf variety for testing. K It is 0.0027; T C The temperature is -13.2℃. k 1 It is 0.029; k 2 It is 0.009; k 3 The value is 0.20. Other parameters in the fruit cracking rate prediction model are as follows: a It is 0.2. b It is 1.1. c It is 0.4. d It is 0.01. e =1, f It is 0.4. g It is 0.3. h It is 0.1. i It is 0.6. C 1 It is 0.32. m 1 -0.009℃ -1 , n 1 -0.12℃ -1 , C 2 It is 0.7. m 2 -0.01℃ -1 , n 2 0.15℃ -1 , C 3 It is 0.41. β It is 0.3.
[0057] This embodiment uses the same batch of black leaves as an example, where the initial temperature T 初 At 1℃, the water content of the pulp W The value is 0.75, indicating the ripeness of the fruit peel. M The value is 0.9, the sugar content of the pulp is 17°Bx, and the temperature of the freezing liquid is... T l The temperature was -19.5℃. The average diameter of the litchi fruit was... DThe average thickness of the peel is 31.5 mm. H 0.88mm; cryotherapy time t It takes 30 minutes.
[0058] The heat transfer coefficient calculated using equation (2) is 1.06; then, the heat transfer coefficient calculated using equation (1) is... T 中 The temperature is -19.35℃, and the temperature difference is calculated using equation (3). ΔT The temperature is 15.55℃. Since the dormancy standard is met when the temperature is 15.55℃ or higher than 8℃, the fruit cracking rate can be calculated in S4.
[0059] The freezing dormancy solution temperature, variety constant, pulp moisture content, peel maturity, and pulp sugar content corresponding to the Black Leaf variety are input into the corresponding fruit cracking rate prediction model. Since the freezing dormancy solution temperature is -19.5℃, the freezing dormancy zoning correction function is... F(T l ) The final fruit cracking rate was calculated using low-risk areas. P c It is 0.30%.
[0060] A freeze-drying experiment was conducted based on the above parameters. After 30 minutes of freeze-drying, 500 black-leaf lychees were counted, and the number of cracked fruits was 2. The actual cracking rate was 2 / 500 = 0.4%, which is close to the predicted value, proving that the method for predicting the cracking rate of freeze-drying lychees in this invention is reliable.
[0061] Example 6 An example of a method for predicting the cracking rate of frozen dormant lychees (Example 1). This example uses the Guiwei variety of lychee for testing, where Guiwei corresponds to... K It is 0.0017; T C The temperature is -14.2℃. k 1 It is 0.025; k 2 It is 0.006; k 3 The value is 0.16. Other parameters in the fruit cracking rate prediction model are as follows: a It is 0.2. b It is 1.1. c It is 0.4. d It is 0.01. e =1, f It is 0.4. g It is 0.3. h It is 0.1. i It is 0.6. C 1 It is 0.32. m 1-0.009℃ -1 , n 1 -0.12℃ -1 , C 2 It is 0.7. m 2 -0.01℃ -1 , n 2 0.15℃ -1 , C 3 It is 0.41; β It is 0.3; T f The temperature is -3.8℃.
[0062] This embodiment uses the same batch of Guiwei brand as an example, where the initial temperature... T 初 At 1℃, the water content of the pulp W The value was 0.82, indicating the ripeness of the fruit peel. M The value is 0.9, the sugar content of the pulp is 17°Bx, and the temperature of the freezing liquid is... T l The temperature was -28.5℃. The average diameter of the litchi fruit was... D The average thickness of the peel is 30.6 mm. H 1.09mm; cryotherapy time t It takes 5 minutes.
[0063] The heat transfer coefficient calculated by equation (2) is 1.01; then, the heat transfer coefficient calculated by equation (1) is... T 中 The temperature is -18.90℃, and the temperature difference is calculated using equation (3). ΔT The temperature is 15.10℃. Since the dormancy standard is met when the temperature is 15.10℃ or higher than 8℃, the fruit cracking rate can be calculated in S4.
[0064] The freezing dormancy solution temperature, variety constant, pulp moisture content, peel maturity, and pulp sugar content corresponding to the Guiwei variety are input into the corresponding fruit cracking rate prediction model. Since the freezing dormancy solution temperature is -28.5℃, the freezing dormancy zoning correction function is... F(T l ) The final fruit cracking rate was calculated using the second transition zone. P c It is 1.87%.
[0065] A freeze-drying experiment was conducted based on the above parameters. After 5 minutes of freeze-drying, 500 Guiwei lychees were counted, and 9 of them cracked. The actual cracking rate was 9 / 500 = 1.8%, which is close to the predicted value. This proves that the method for predicting the cracking rate of freeze-drying lychees in this invention is reliable.
[0066] Example 7 An embodiment 1 describes a method for predicting the fruit cracking rate of frozen-dormant lychees. This embodiment uses the lychee variety "Xianjinfeng" for testing, where "Xianjinfeng" corresponds to... K It is 0.0019; T C The temperature is -15.5℃. k 1 It is 0.024; k 2 It is 0.007; k 3 The value is 0.18. Other parameters in the fruit cracking rate prediction model are as follows: a It is 0.2. b It is 1.1. c It is 0.4. d It is 0.01. e =1, f It is 0.4. g It is 0.3. h It is 0.1. i It is 0.6. C 1 It is 0.32. m 1 -0.009℃ -1 , n 1 -0.12℃ -1 , C 2 It is 0.7. m 2 -0.01℃ -1 , n 2 0.15℃ -1 , C 3 It is 0.41; β It is 0.3; T f The temperature is -3.8℃.
[0067] This embodiment takes the same batch of Xianjinfeng as an example, where the initial temperature T 初 At 5℃, the water content of the pulp W The value was 0.87, indicating the fruit peel maturity. M The value is 1, the sugar content of the pulp is 20°Bx, and the temperature of the freezing liquid is 1. T l The temperature was -23.5℃. The average diameter of the litchi fruit was... D The average thickness of the peel is 30.0 mm. H 1.23mm; cryotherapy time tIt takes 25 minutes.
[0068] The heat transfer coefficient calculated using equation (2) is 0.97; then, the heat transfer coefficient calculated using equation (1) is... T 中 The temperature is -23.41℃, and the temperature difference is calculated using equation (3). ΔT The temperature was 19.61℃. Since the dormancy standard is met when the temperature is 19.61℃ or higher than 8℃, the fruit cracking rate can be calculated in S4.
[0069] The freezing dormancy solution temperature, variety constant, pulp moisture content, peel maturity, and pulp sugar content corresponding to Xianjinfeng are input into the corresponding fruit cracking rate prediction model. Since the freezing dormancy solution temperature is -23.5℃, the freezing dormancy zoning correction function is... F(T l ) The final fruit cracking rate was calculated using the second transition zone. P c It is 0.18%.
[0070] A freeze-drying experiment was conducted based on the above parameters. After 25 minutes of freeze-drying, 500 Xianjinfeng lychees were counted, and the number of cracked fruits was 1. The actual cracking rate was 1 / 500 = 0.2%, which is close to the predicted value, proving that the method for predicting the cracking rate of freeze-drying lychees in this invention is reliable.
[0071] Example 8 An embodiment 1 describes a method for predicting the fruit cracking rate of frozen-dormant lychees. This embodiment uses the lychee variety "Xianjinfeng" for testing, where "Xianjinfeng" corresponds to... K It is 0.0019; T C The temperature is -15.5℃. k 1 It is 0.024; k 2 It is 0.007; k 3 The value is 0.18. Other parameters in the fruit cracking rate prediction model are as follows: a It is 0.2. b It is 1.1. c It is 0.4. d It is 0.01. e =1, f It is 0.4. g It is 0.3. h It is 0.1. i It is 0.6. C 1 It is 0.32. m 1 -0.009℃ -1 , n1 -0.12℃ -1 , C 2 It is 0.7. m 2 -0.01℃ -1 , n 2 0.15℃ -1 , C 3 It is 0.41; β It is 0.3; T f The temperature is -3.8℃.
[0072] This embodiment takes the same batch of Xianjinfeng as an example, where the initial temperature T 初 At 0℃, the water content of the pulp is... W The value was 0.88, indicating the fruit peel maturity. M The value is 0.9, the sugar content of the pulp is 19°Bx, and the temperature of the freezing liquid is... T l The temperature was -33.5℃. The average diameter of the litchi fruit was... D The average thickness of the peel is 28.4 mm. H 1.00 mm; cryotherapy time t It takes 30 minutes.
[0073] The heat transfer coefficient calculated using equation (2) is 1.08; then, the heat transfer coefficient calculated using equation (1) is... T 中 The temperature is -33.49℃, and the temperature difference is calculated using equation (3). ΔT The temperature was 29.69℃. Since dormancy is achieved when 29.69℃ is ≥ 8℃, the process can proceed to S4 for fruit cracking rate calculation.
[0074] The freezing dormancy solution temperature, variety constant, pulp moisture content, peel maturity, and pulp sugar content corresponding to Xianjinfeng are input into the corresponding fruit cracking rate prediction model. Since the freezing dormancy solution temperature is -33.5℃, the freezing dormancy zoning correction function is... F(T l ) The final fruit cracking rate is calculated based on the brittleness risk zone. P c It is 10.15%.
[0075] A freeze-drying experiment was conducted based on the above parameters. After 30 minutes of freeze-drying, 500 Xianjinfeng lychees were counted, and 55 of them cracked. The actual cracking rate was 55 / 500 = 11.0%, which is close to the predicted value. This proves that the method for predicting the cracking rate of freeze-drying lychees in this invention is reliable.
[0076] Example 9 A method for predicting the cracking rate of frozen-dormant lychees in Example 1, which is otherwise the same as that in Example 8, except that the temperature of the dormancy solution is different. T l The temperature is -15.5℃.
[0077] The heat transfer coefficient calculated using equation (2) is 1.08; then, the heat transfer coefficient calculated using equation (1) is... T 中 The temperature is -15.50℃, and the temperature difference is calculated using equation (3). ΔT The temperature is 11.70℃. Since the dormancy standard is met when the temperature is ≥8℃ (11.70℃), the fruit cracking rate can be calculated in S4.
[0078] The freezing dormancy solution temperature, variety constant, pulp moisture content, peel maturity, and pulp sugar content corresponding to Xianjinfeng are input into the corresponding fruit cracking rate prediction model. Since the freezing dormancy solution temperature is -15.5℃, the freezing dormancy zoning correction function is... F(T ΔT F(T ΔT F(T ΔT F(T l ) The final fruit cracking rate was calculated using the first transition zone. P c It is 0%.
[0079] A freeze-drying experiment was conducted based on the above parameters. After 30 minutes of freeze-drying, 500 Xianjinfeng lychees were counted, and the number of cracked fruits was 1. The actual cracking rate was 1 / 500 = 0.2%, which is close to the predicted value. This proves that the method for predicting the cracking rate of freeze-drying lychees in this invention is reliable.
[0080] Example 10 A fruit cracking rate prediction system for dormant lychee, the system performing the fruit cracking rate prediction method for dormant lychee as described in Examples 1 to 9.
[0081] This system for predicting the cracking rate of dormant lychees achieves accurate calculation of the cracking rate under the synergistic effect of multiple parameters. The method provides specific parameters for different lychee varieties, and can quantitatively guide the optimization and adjustment of process parameters such as dormancy solution temperature and dormancy time based on the characteristics of different varieties and fruit conditions. This effectively avoids the problems of blind parameter adjustment and large fluctuations in cracking rate caused by the reliance on experience in traditional processes. It can precisely control the cracking rate within a low range, reducing processing losses, and by reasonably matching process parameters, avoid the increased energy consumption and quality decline caused by blindly extending the dormancy time or lowering the dormancy solution temperature. At the same time, it simplifies the operation process and provides a reliable quantitative basis for improving the quality stability, optimizing production efficiency, and controlling costs of dormant lychees.
[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.
Claims
1. A method for predicting the fruit cracking rate of dormant lychee, characterized in that, Includes the following steps: S1. Obtain the initial temperature of the lychee, the average diameter of the lychee, the moisture content of the pulp, the average thickness of the peel, and the temperature of the freezing solution used during freezing dormancy, and calculate the average center temperature of the lychee pulp. S2. Calculate based on the average center temperature of the pulp obtained in S1 and the empirical freezing point temperature of the pulp to determine whether the freezing dormancy of the lychee meets the standard. If the freezing dormancy meets the standard, proceed to S3. S3. Obtain the ripeness of the lychee peel and the sugar content of the pulp; S4. Construct a fruit cracking rate prediction model based on the freezing liquid temperature, the fruit peel maturity, the fruit pulp sugar content, the average fruit diameter of the lychee, the fruit pulp moisture content, and the average fruit peel thickness, and calculate the fruit cracking rate based on the fruit cracking rate prediction model.
2. The method for predicting the fruit cracking rate of dormant lychee according to claim 1, characterized in that: In S2, the average center temperature of the litchi pulp is calculated using equation (1); ...Equation (1); in, t The duration of the cryosleep is measured in minutes. T 中 This represents the average core temperature of the fruit pulp, expressed in °C. T l The temperature of the cryopreservation solution is expressed in °C. T 初 The initial temperature of the lychee, in °C; β This is the heat transfer correction factor; k 传 The heat transfer coefficient; D This represents the average diameter of the lychee fruit, in mm. heat transfer coefficient k 传 From equation (2), we get: ...Equation (2); in, W This refers to the water content of the fruit pulp. H The average thickness of the fruit peel is expressed in mm.
3. The method for predicting the fruit cracking rate of dormant lychee according to claim 1, characterized in that, S3 calculates the temperature difference between the average center temperature of the pulp and the empirical freezing point temperature of the pulp according to formula (3). ΔT ,when ΔT If the temperature is ≥8℃, the freezing sleep is considered to have met the standard; otherwise, the freezing sleep is considered to have failed to meet the standard. ΔT=T f - T 中 ...Equation (3); in, T f This is the empirical temperature for the freezing point of the fruit pulp.
4. The method for predicting the fruit cracking rate of dormant lychee according to claim 3, characterized in that, In S4, the fruit cracking rate prediction model is represented by equation (4): ...Equation (4); in, P c The percentage of cracked fruit is expressed as %; K This is a category constant; M This refers to the ripeness of the fruit peel; a Weighted by sugar content; b Weighted by moisture content; T C The critical temperature for the pericarp's tolerance is expressed in °C. c Weighted by temperature difference; d Weighting of freeze-sleep time; S Sugar content of the fruit pulp, expressed in °Bx; j This is the sugar content correction constant; f Weighted by sugar content; g Weighted by fruit diameter; h This is a correction constant for peel thickness; i Weighted by peel thickness; F(T l ) This is a function to correct the dormancy partition.
5. The method for predicting the fruit cracking rate of dormant lychee according to claim 4, characterized in that: The freeze partition correction function F(T l ) Equation (5) represents: ...Equation (5); in, k 1 Risk coefficient for large ice crystal risk zone; C 1 This is a fundamental constant for the large ice crystal risk region. m 1 The risk coefficient gradient rate for the large ice crystal risk zone is expressed in °C. -1 ; n 1 The gradual change rate of the fundamental constants in the first transition region, in °C. -1 ; k 2 Risk coefficient for low-risk areas; C 2 This serves as a basic constant for low-risk areas; m 2 The risk coefficient gradient rate for the second transition zone is expressed in °C. -1 ; n 2 The gradual change rate of the fundamental constants in the second transition region, in °C. -1 ; k 3 Risk coefficient for the embrittlement risk zone; C 3 This is a fundamental constant for the embrittlement risk zone.
6. The method for predicting the fruit cracking rate of dormant lychee according to claim 5, characterized in that: a It is 0.
2. b It is 1.
1. c It is 0.
4. d It is 0.
01. e =1, f It is 0.
4. g It is 0.
3. h It is 0.
1. i It is 0.
6. C 1 It is 0.
32. m 1 -0.009℃ -1 , n 1 -0.12℃ -1 , C 2 It is 0.
7. m 2 -0.01℃ -1 , n 2 0.15℃ -1 , C 3 It is 0.41; β It is 0.3; T f The temperature is -3.8℃. 0.0010≤ K ≤0.0030，-16.0℃≤ T C ≤-13.0℃，0.020≤ k 1 ≤0.030，0.003≤ k 2 ≤0.010，0.020≤ k 3 ≤0.050。 7. The method for predicting the fruit cracking rate of dormant lychee according to claim 6, characterized in that, When the lychee variety is Fei Zi Xiao: K It is 0.0021; T C The temperature is -13.8℃. k 1 It is 0.023; k 2 It is 0.007; k 3 It is 0.17; When the lychee variety is glutinous rice cake: K It is 0.0024; T C The temperature is -13.5℃. k 1 It is 0.027; k 2 It is 0.008; k 3 It is 0.19; When the lychee variety is Black Leaf: K It is 0.0027; T C The temperature is -13.2℃. k 1 It is 0.029; k 2 It is 0.009; k 3 It is 0.20; When the lychee variety is Guiwei: K It is 0.0017; T C The temperature is -14.2℃. k 1 It is 0.025; k 2 It is 0.006; k 3 It is 0.16; When the lychee variety was presented as imperial tribute: K It is 0.0019; T C The temperature is -15.5℃. k 1 It is 0.024; k 2 It is 0.007; k 3 It is 0.
18.
8. The method for predicting the fruit cracking rate of dormant lychee according to any one of claims 1 to 7, characterized in that: The fruit peel maturity is defined as the difference between the red and green colors of the current lychee fruit peel, denoted as 'a'. The difference between the red and green color of a fully ripe lychee (a) The ratio of the fruit peel to the fruit peel's maturity is less than or equal to 1.
9. The method for predicting the fruit cracking rate of dormant lychee according to claim 8, characterized in that: The red-green difference test point for the ripeness of the fruit peel is the suture line of the fruit peel.
10. A system for predicting the cracking rate of dormant lychee, characterized in that: Perform the method for predicting the cracking rate of frozen dormant lychees as described in any one of claims 1 to 9.