CN114532467A

CN114532467A - HPP (HPP) sterilization and preservation method of fruit juice

Info

Publication number: CN114532467A
Application number: CN202210257539.XA
Authority: CN
Inventors: 徐建强; 苏芬; 于丽; 李丹; 马淑珍; 徐林杰
Original assignee: Laiyang Yongan Food Co ltd
Current assignee: Laiyang Yongan Food Co ltd
Priority date: 2022-03-16
Filing date: 2022-03-16
Publication date: 2022-05-27

Abstract

The application relates to a HPP (HPP) sterilization and preservation method of fruit juice, which comprises the following steps: (1) cleaning raw material fruits, cutting into pieces, peeling, removing kernels, soaking the cut pulp in a promoter, and squeezing the pulp to obtain a fruit juice stock solution; (2) adding a clarifying agent into the juice stock solution, stirring uniformly, standing, and filtering the juice stock solution to obtain primary juice; (3) packaging the primary juice to obtain a packaged juice product; (4) the fruit juice product is sterilized under a certain pressure by taking water as a medium, and then the sterilized fruit juice product is obtained. The application adds the clarifier when fruit juice is squeezed, can make the juice yield of fruit juice obtain showing and promote.

Description

HPP (high Performance liquid chromatography) sterilization and preservation method of fruit juice

Technical Field

The application relates to the field of food sterilization, in particular to a HPP (high pressure propylene glycol) sterilization and preservation method for fruit juice.

Background

HPP sterilization, namely an ultrahigh pressure sterilization technology, is characterized in that in a closed ultrahigh pressure container, water is used as a medium to apply pressure of 400-.

Chinese patent application publication No. CN105211992A discloses a method for preparing mango juice by using an ultra-high pressure technology, comprising the following steps: (1) selection of raw materials: selecting fresh mango without plant diseases and insect pests as a raw material; (2) pretreatment of raw materials: cleaning, peeling and removing kernels of the raw materials, and cutting the raw materials into 3-5 mm thin slices; (3) blanching: performing steam blanching treatment on the mango slices for 1-2 min to passivate endogenous enzymes in mangoes; (4) pulping and blending: according to the mango: adding water in a ratio of 1:3, pulping, and adding white granulated sugar and food-grade citric acid to adjust the soluble solid and the pH value to 8.9 Baume degree and 3.9 respectively; (5) filling: homogenizing and mixing the prepared mango juice by using a colloid mill, filling into a sterile PET bottle, and placing in an environment at 4 ℃ for refrigeration for later use; (6) ultrahigh pressure treatment: placing the prepared mango juice into a treatment kettle of ultrahigh pressure equipment, setting the pressure to be 400MPa, and treating at room temperature for 15 min; (7) the finished product is obtained after the product is inspected to be qualified. The juice after the ultrahigh pressure treatment can be made to have original taste and flavor on the basis of sterilization, and most of vitamins and minerals in the juice can be mostly reserved.

In view of the above-mentioned related technologies, the inventor believes that the juice yield is low during the juice extraction process, so that the yield of the juice is reduced and the quality of the juice is turbid, and therefore needs to develop a method for improving the juice yield and clarity.

Disclosure of Invention

In order to improve the juice yield and clarity of the juice, the application provides a HPP (high pressure propylene glycol) sterilization and preservation method of the juice.

The HPP sterilization and preservation method for the fruit juice adopts the following technical scheme:

a HPP sterilization and fresh-keeping method for fruit juice comprises the following steps:

(1) cleaning raw material fruits, cutting into pieces, peeling, removing kernels, soaking the cut pieces of pulp in an accelerant, and then squeezing the pulp to obtain a juice stock solution;

(2) adding a clarifying agent into the juice stock solution, stirring uniformly, standing, and filtering the juice stock solution to obtain primary juice;

(3) packaging the primary juice to obtain a packaged juice product;

(4) the fruit juice product is sterilized under a certain pressure by taking water as a medium, and then the sterilized fruit juice product is obtained.

The accelerant can degrade pectin in the pulp to degrade the pectin into micromolecular soluble oligomers or monomers, so that cell cortex in the pulp can be separated conveniently, the juice yield in the pulp is improved, the juice yield of the pulp is improved, and the juice yield of the product is improved; the clarifier can make the suspended substance in the juice gather and precipitate, and can obtain more clear juice after filtering, thereby improving the clarity of the juice.

Preferably, the preparation method of the accelerator comprises the following steps: adding the yeast peptide and the complex enzyme into a phosphate solution for dispersing, uniformly stirring, drying to obtain a solid, cleaning with deionized water for desalting, and drying again to obtain the promoter.

The complex enzyme is the cooperation of a plurality of enzymes, and under the synergistic action of the enzymes, the juice of the pulp can be quickly leached, so that the juice yield of the pulp is improved; the yeast peptide is a short peptide, and can promote soluble expression of protein, so that the expression amount of enzyme is increased, the reaction efficiency of the enzyme is increased, and the juice yield of fruit juice is increased.

Preferably, the preparation method of the clarifying agent comprises the following steps: dissolving chitosan in an acetic acid solution, uniformly stirring to obtain a chitosan-acetic acid solution, dissolving p-coumaric acid in ethanol, and uniformly stirring to obtain a p-coumaric acid-ethanol solution; mixing the chitosan-acetic acid solution and the p-coumaric acid-ethanol solution, adding a cross-linking agent, removing residues after centrifugation, removing supernate, and freeze-drying to obtain the clarifying agent.

The p-coumaric acid is used as a substrate, and the chitosan and the p-coumaric acid are synthesized by a cross-linking method to obtain a high-molecular copolymer, so that the clarifying agent is obtained, and the clarifying effect and the stability of the clarifying agent can be greatly improved.

Preferably, the complex enzyme comprises pectinase, tannase and cellulase.

The pectinase can promote pectin to remove methyl ester and generate tartaric acid, and simultaneously reduce the viscosity of pectin, so that the juice yield of pulp is remarkably improved, and meanwhile, the pectinase can also reduce the generation of pomace, so that the juice is further clarified; the cellulase can degrade cellulose in the pulp, so that the dissolved matters in the pulp cells can be fully released, and the juice yield of the pulp is greatly improved; the tannase is added, so that the content of soluble solids can be increased, and the stability and the clarity of the juice can be improved; the addition of various complex enzymes can achieve synergistic effect on the juice yield of the fruit juice and improve the clarity of the fruit juice together.

Preferably, the mass ratio of the pectinase to the tannase to the cellulase is 1: (0.9-1.1): (1.3-1.8).

The pectinase, the tannin plum and the cellulase are controlled within the mass ratio range, so that the juice yield and the clarity of the juice can be effectively improved.

Preferably, the mass ratio of the chitosan to the p-coumaric acid is (17-19): 1.

the mass ratio of the chitosan to the p-coumaric acid is controlled within the range, so that the performance of the clarifying agent can be improved.

Preferably, the crosslinking agent is N-hydroxysuccinimide and 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide.

N-hydroxysuccinimide and 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride are nontoxic and good-compatibility cross-linking agents, and carboxyl groups of p-coumaric acid and amino and carboxyl groups of chitosan are further synthesized by the cross-linking agents to obtain a high-molecular copolymer, namely the clarifying agent.

Preferably, the raw material fruit is one or more of apple, pear, strawberry and grape.

In summary, the present application includes at least one of the following beneficial technical effects:

1. after the pulp is soaked in the accelerant, pectin in the pulp can be degraded, the pectin is dissolved into micromolecular oligomer or monomer, and the separation of the cortex of cells in the pulp is improved, so that the juice yield of the pulp is improved, and the juice yield of the juice is improved; when the fruit juice is filtered, a clarifying agent is added, so that suspended matters in the fruit juice can be gathered by the clarifying agent, and the clarity of the fruit juice can be improved after the filtering;

2. chitosan and p-coumaric acid are crosslinked to obtain a high molecular polymer, suspended matters in the fruit juice are gathered together, and the transparency of the fruit juice can be effectively improved after filtering, so that the fruit juice is clarified;

3. the cross-linking agent in the clarifying agent selects N-hydroxysuccinimide and 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride, both of which are nontoxic, safe and well compatible, and the carboxyl of p-coumaric acid and the amino group of chitosan can be further synthesized by the cross-linking agent, so that the high-molecular polymer is obtained for clarifying the fruit juice.

Detailed Description

The present application will be described in further detail with reference to examples.

The embodiment of the application discloses a HPP (HPP) sterilization and preservation method for fruit juice.

Preparing juice: cleaning selected fresh fruits, cutting into blocks, removing peels and kernels, soaking the cut pulp in an accelerant for 2 hours to ensure that the accelerant is fully contacted with the pulp, and then juicing the pulp to obtain a juice stock solution; adding a clarifying agent into the juice stock solution, uniformly stirring, standing for precipitating for 3h, filtering the juice, and removing suspended matters in the juice to obtain primary juice; filling and sealing the primary juice to obtain a packaged juice product; the packaged fruit juice product is placed under 500Mpa for 60min with water as medium, harmful microorganisms such as Escherichia coli, mould, yeast, etc. in the fruit juice are killed under pressure, the fruit juice after ultra-high pressure sterilization is original juice and original taste, and most vitamins and minerals can be well retained.

Example 1

Preparing an accelerant: mixing 15g of pectinase, 13g of tannase and 19g of cellulase to obtain mixed enzyme powder, adding 20g of the mixed enzyme powder and 7g of cycloprotein into phosphate solution, stirring for 15min at the rotating speed of 1000rpm by using a magnetic stirrer to obtain mixed solution, cleaning with deionized water to remove salt, and drying again to obtain the accelerator.

Preparing a clarifying agent: dissolving 68g of chitosan in 0.5% acetic acid solution, uniformly stirring to obtain chitosan-acetic acid solution, dissolving 4g of p-coumaric acid in ethanol, uniformly stirring to obtain p-coumaric acid-ethanol solution, adding 7.5mmol of N-carboxysuccinimide solution and 7.5mmol of 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride solution to the p-coumaric acid-ethanol solution, uniformly stirring, carrying out ice bath for 1h to obtain mixed solution, adding the chitosan-acetic acid solution to the mixed solution, continuously stirring for 4h, dialyzing for 12h with distilled water, centrifuging to remove residual p-coumaric acid, taking supernatant, and freeze-drying to obtain the clarifier.

Example 2

Preparing an accelerant: mixing 20g of fruit with collagenase, 23g of tannase and 19g of cellulase to obtain mixed enzyme powder, adding 40g of mixed enzyme powder and 11g of cycloprotein into phosphate solution, stirring for 15min at the rotating speed of 1000rpm by using a magnetic stirrer to obtain mixed solution, cleaning with deionized water to remove salt, and drying again to obtain the promoter.

Preparing a clarifying agent: dissolving 76g of chitosan in 0.5% acetic acid solution, uniformly stirring to obtain chitosan-acetic acid solution, dissolving 4g of p-coumaric acid in ethanol, uniformly stirring to obtain p-coumaric acid-ethanol solution, adding 7.5mmol of N-carboxysuccinimide solution and 7.5mmol of 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride solution to the p-coumaric acid-ethanol solution, uniformly stirring, carrying out ice bath for 1h to obtain mixed solution, adding the chitosan-acetic acid solution to the mixed solution, continuously stirring for 4h, dialyzing for 12h with distilled water, centrifuging to remove residual p-coumaric acid, taking supernatant, and freeze-drying to obtain the clarifier.

Example 3

Weighing 17g of pectinase, 17g of tannase, 25.5g of cellulase, 9g of cycloprotein, 72g of chitosan, 4g of p-coumaric acid, a 0.5% acetic acid solution, absolute ethyl alcohol, 7.5mmol of 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride solution and 7.5mmol of N-carboxysuccinimide solution;

preparing an accelerant: mixing 17g of pectinase, 17g of tannase and 25.5g of cellulase to obtain mixed enzyme powder, adding 30g of the mixed enzyme powder and 9g of cycloprotein into phosphate solution, stirring for 15min at the rotating speed of 1000rpm by using a magnetic stirrer to obtain mixed solution, cleaning with deionized water to remove salt, and drying again to obtain the accelerator.

Preparing a clarifying agent: dissolving 72g of chitosan in 0.5% acetic acid solution, uniformly stirring to obtain chitosan-acetic acid solution, dissolving 4g of p-coumaric acid in ethanol, uniformly stirring to obtain p-coumaric acid-ethanol solution, adding 7.5mmol of N-carboxysuccinimide solution and 7.5mmol of 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride solution to the p-coumaric acid-ethanol solution, uniformly stirring, carrying out ice bath for 1h to obtain mixed solution, adding the chitosan-acetic acid solution to the mixed solution, continuously stirring for 4h, dialyzing for 12h with distilled water, centrifuging to remove residual p-coumaric acid, taking supernatant, and freeze-drying to obtain the clarifier.

Example 4

Example 4 is based on example 3, and example 4 differs from example 3 only in that: in example 4, the mass ratio of pectinase, tannase and cellulase was 1:0.7: 1.5.

Example 5

Example 5 is based on example 3, and example 5 differs from example 3 only in that: in example 5, the mass ratio of pectinase, tannase and cellulase is 1:1.3:1.5

Example 6

Example 6 is based on example 3, and example 6 differs from example 3 only in that: in example 6, the mass ratio of pectinase, tannase and cellulase is 1:1: 2.

Example 7

Example 7 is based on example 3, and example 7 differs from example 3 only in that: in example 7, the mass ratio of chitosan to p-coumaric acid was 15: 1.

Example 8

Example 8 is based on example 3, and example 8 differs from example 3 only in that: in example 8, the mass ratio of chitosan to p-coumaric acid was 21: 1.

Comparative example 1

Comparative example 1 is based on example 3, and comparative example 1 differs from example 3 only in that: in comparative example 1 the cyclic protein was replaced by TrP.

Comparative example 2

Comparative example 2 is based on example 3, which comparative example 2 differs from example 3 only in that: in comparative example 2 coumaric acid was changed to caffeic acid.

Comparative example 3

Comparative example 3 is based on example 3, which differs from example 3 only in that: in comparative example 3, 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide was used as the crosslinking agent alone.

Performance test

Performance test of juice yield and transmittance

Sampling the accelerating agent and the clarifying agent of examples 1-8 and comparative examples 1-6, selecting pulp, cleaning, cutting into pieces, mixing uniformly, selecting pulp from the pulp, juicing the pulp by using a sample under the same environment, temperature and time, adding the clarifying agent into the sample after testing the juice yield, filtering the juice after standing the juice for the same end time, and then measuring the light transmittance of the juice; each sample was tested three times and the test results were filled in table 1;

wherein, the formula for calculating the juice yield of the juice is as follows:

C＝(M₁/M₂)×100％

wherein C is the juice yield (%), M₁For squeezing juice and clarifying the quality of the filtered juice, M₂Is the mass of the pulp before juicing.

TABLE 1

Test items	Juice yield (%)	Fruit juice transmittance (%)
			Example 1	91.2	93.4
Example 2	91.4	93.1
			Example 3	93.2	96.7
Example 4	89.6	89.1
			Example 5	87.6	88.6
Example 6	86.4	86.7
			Example 7	90.7	85.8
Example 8	90.4	86.4
			Comparative example 1	84.8	87.4
Comparative example 2	90.5	83.7
			Comparative example 3	90.1	84.3

As can be seen from Table 1, the juice yield in examples 1-3 is above 90%, so that the accelerator prepared by the method has a good effect of increasing the juice yield of the fruit juice; the light transmittance of the fruit juices of examples 1-3 is above 90%, so that the clarifying agent prepared by the method has a good clarifying effect.

As can be seen from table 1, example 4 differs from example 3 only in that: the mass ratio of pectinase, tannase and cellulase in the composite enzyme in example 3 is 1:1:1.5, the mass ratio of pectinase, tannase and cellulase in the composite enzyme in example 4 is 1:0.7:1.5, the ratio of tannase in example 4 is reduced, and the juice yield of example 4 is reduced compared with example 3, probably because the tannin content in pulp is higher and the juice viscosity is high after the ratio of tannase is reduced, and the juice yield is reduced due to the juice yield.

Example 4 compared with example 3, the light transmittance of the juice is reduced, mainly because the tannin in the juice is difficult to degrade after the content of the tannase is reduced, the tannin can generate turbid sediment after being combined with protein in the juice, the turbid juice can make the juice difficult to clear and bright, and the light transmittance of the juice is reduced.

Example 5 differs from example 3 only in that: the mass ratio of pectinase, tannase and cellulase in the complex enzyme in example 3 is 1:1:1.5, the mass ratio of pectinase, tannase and cellulase in the complex enzyme in example 5 is 1:1.3:1.5, and the juice yield in example 5 is reduced compared with example 3, probably because the content of pectinase in the complex enzyme is reduced, the decomposition effect on pectin is reduced, the methyl removal effect of pectin is reduced, the viscosity of pectin is difficult to improve, and the juice yield of pulp is reduced.

Example 5 the light transmittance of the juice was reduced compared to example 3 because the fruit juice had a lower light transmittance because too much pomace remained in the juice after the content of pectinase was reduced, and the fruit juice became cloudy due to the pomace.

Example 6 differs from example 3 only in that: the ratio of cellulase in example 6 was increased, and the juice yield of fruit juice was decreased in example 6 as compared with example 3, because the ratio of pectinase to tannase was decreased when the ratio of cellulase was too large, and the viscosity-improving effect of pectin in fruit juice was small, and thus the juice yield was decreased in example 6.

Example 6 the transmittance of the juice was reduced compared to example 3 because the pectin viscosity was higher and the juice had more turbidity when the pectinase and tannase content was reduced, and the tannin bound to the protein in the juice to form more turbidity, which increased the turbidity of the juice and reduced the transmittance of the juice.

Example 7 differs from example 3 only in that: example 3 mass ratio of chitosan to p-coumaric acid 18:1 example 7 mass ratio of chitosan to p-coumaric acid 15: example 7 compared with example 3, the transmittance of the juice was reduced because chitosan had a good flocculation effect, and after the quality of chitosan was reduced, the flocculation effect of chitosan on the precipitate and the suspension in the juice was reduced, and the suspension in the juice increased the turbidity of the juice, thus reducing the transmittance of the juice.

Example 8 differs from example 3 only in that: in example 8, the mass ratio of chitosan to p-coumaric acid is 21:1, and in example 7, compared with example 3, the light transmittance of the fruit juice is reduced, because the mass ratio of p-coumaric acid is reduced, the p-coumaric acid monomer molecules near the polymer main chain are reduced, the binding rate of p-coumaric acid and active sites on the polymer chain is reduced, the grafting rate between p-coumaric acid and chitosan is reduced, so that the stability of the clarifying agent is reduced, the synergistic adsorption effect on protein and suspended solids in the fruit juice is also reduced, the adsorption performance of the clarifying agent on the suspended solids in the fruit juice is weaker, and the light transmittance of the fruit juice is reduced.

Comparative example 1 differs from example 3 only in that: the comparison example 1 replaces the cycloprotein with the TrP, and the comparison example 1 has a lower juice yield compared with the comparison example 3, probably because the TrP is a long peptide, the weak interaction force between the long peptide and the compound enzyme is lower, so the promotion effect on the enzyme is weaker, the degradation effect of the compound enzyme on pectin, tannin, cellulose and the like in the juice is weaker, and the juice yield of the juice is lower.

Comparative example 1 the light transmittance of comparative example 3 was reduced compared to example 3, probably because the enzyme-promoting effect of the long peptide was reduced, and thus the pectinase had a weaker improvement in the viscosity of pectin in juice and more suspended matter in juice, because the transmittance was reduced.

Comparative example 2 differs from example 3 only in that: the p-coumaric acid in the comparative example 2 is replaced by caffeic acid, compared with the comparative example 3, the light transmittance of the fruit juice is reduced in the comparative example 2, which is probably because the number of carboxyl groups of caffeic acid is less, on one hand, the grafting capacity between chitosan is reduced, so that the grafting rate of chitosan and caffeic acid is reduced, part of chitosan and caffeic acid are in a free state, so that the dispersion degree of suspended matters in the fruit juice is higher, the flocculation effect is weakened, and on the other hand, the suction effect of caffeic acid on the suspended matters in the fruit juice is weaker, so that the light transmittance in the comparative example 2 is reduced.

Comparative example 3 differs from example 3 only in that: in comparative example 3, N-carboxysuccinimide is not added to the cross-linking agent, and in comparative example 3, compared with example 3, the light transmittance is reduced in comparative example 3, which is probably because 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide and carboxyl groups in p-coumaric acid form acyl intermediates, and the acyl intermediates are hydrolyzed under the condition of no amine to release carboxyl groups again, so that the grafting ratio between chitosan and p-coumaric acid is reduced, part of p-coumaric acid and chitosan are in a free state, the stability is reduced, the adsorption effect on suspended matters in the fruit juice is reduced, and the light transmittance of the fruit juice is reduced.

The present embodiment is merely illustrative and not restrictive, and various changes and modifications may be made by persons skilled in the art without departing from the scope of the present invention as defined in the appended claims. The technical scope of the present application is not limited to the content of the specification, and must be determined according to the scope of the claims.

Claims

1. The HPP sterilization and preservation method of the fruit juice is characterized by comprising the following steps: the method comprises the following steps:

(3) packaging the primary juice to obtain a packaged juice product;

2. The HPP sterilization and preservation method for fruit juice according to claim 1, characterized in that: the preparation method of the accelerator comprises the following steps: adding the yeast peptide and the complex enzyme into a phosphate solution for dispersion, uniformly stirring, drying to obtain a solid, cleaning with deionized water for desalting, and drying again to obtain the accelerator.

3. The HPP sterilization and preservation method for fruit juice according to claim 1, characterized in that: the preparation method of the clarifying agent comprises the following steps: dissolving chitosan in an acetic acid solution, uniformly stirring to obtain a chitosan-acetic acid solution, dissolving p-coumaric acid in ethanol, and uniformly stirring to obtain a p-coumaric acid-ethanol solution; mixing the chitosan-acetic acid solution and the p-coumaric acid-ethanol solution, adding a cross-linking agent, removing residues after centrifugation, removing supernate, and freeze-drying to obtain the clarifying agent.

4. The HPP sterilization and preservation method for fruit juice according to claim 2, characterized in that: the compound enzyme comprises pectinase, tannase and cellulase.

5. The HPP sterilization and preservation method for fruit juice according to claim 4, characterized in that: the mass ratio of the pectinase to the tannase to the cellulase is 1: (0.9-1.1): (1.3-1.8).

6. The HPP sterilization and preservation method for fruit juice according to claim 3, characterized in that: the mass ratio of the chitosan to the p-coumaric acid is (17-19): 1.

7. the HPP sterilization and preservation method for fruit juice according to claim 3, characterized in that: the cross-linking agent is N-hydroxysuccinimide and 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide.

8. The HPP sterilization and preservation method for fruit juice according to claim 1, characterized in that: the raw material fruit is one or more of apple, pear, strawberry and grape.