CN1044308C

CN1044308C - Fruit fresh-keeping method using chemical enzyme inactivation method

Info

Publication number: CN1044308C
Application number: CN94107278A
Authority: CN
Inventors: 廖玉
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-06-27
Filing date: 1994-06-27
Publication date: 1999-07-28
Anticipated expiration: 2014-06-27
Also published as: CN1098855A

Abstract

The present invention relates to a fruit refreshing method using a chemical enzyme inactivation method, which adopts edible acid, base, salt or proteolytic enzymes to change enzyme activities in fruits and reduce the enzyme activities to an enzyme activity critical point which is higher than maintaining fruits as active fruits. A plurality of refreshing measures can be singly adopted, and can also be compounded to use. The compound use using a plurality of measures can increase the strength of processing and shorten processing time.

Description

Fruit fresh-keeping method using chemical enzyme inactivation method

The invention belongs to agricultural product warehousing technology, particularly fruit freshness preserving processing method.

Fruit freshness preserving generally adopts the method for refrigeration, controlled atmosphere to change the fruit environmental condition at present, and the spontaneous elderization of fruit slows down.Be aided with anticorrosion, the water conservation of multiple medicine film.Be in a word set about from external environment condition fresh-keeping.Refrigeration controlled atmosphere method is poor for applicability to shelf life.Some fruit are not suitable for also that cold storing and fresh-keeping, for example mango can be hurt, honey peach can lose its relish, and lichee does not then still have desirable shelf preservation method.

The objective of the invention is to propose a kind of fruit fresh-keeping method using chemical enzyme inactivation method technical scheme, solve its fresh-keeping problem from reducing fruit self enzymatic activity.

Content of the present invention is: a kind of fruit fresh-keeping method using chemical enzyme inactivation method, and adopt edible acid, alkali, salt or proteolytic enzyme to change enzymatic activity in the fruit, make it to be reduced to and be higher than the enzymatic activity critical point that fruit remains the fruit that lives.Can adopt citric acid, lactic acid, tartaric acid, malic acid, acetic acid, hydrochloric acid or their any mixed liquor to handle fruit, make the pH value reduction of fruit be not more than 3.Can adopt Na ₂CO ₃, NaHCO ₃, (NH ₄) ₂CO ₃, NH ₄HCO ₃, or their any mixture handles fruit, the PH-value of fruit increased be not more than 3.Can adopt Na ₂SO ₃, Na ₂S ₂O ₅, NaHSO ₃, Na ₂S ₂O ₄, S or KMnO ₄, H ₂O ₂Handle fruit as oxidant or reducing agent, cut off the Hai base of part organized enzyme in the fruit, its respiratory intensity is reduced be no more than 50%.Can adopt pepsin, wooden pawl aqueous solution of protease immersion treatment fruit, its respiratory intensity be descended be no more than 50%.The acid, alkali, the salt that use can be sneaked into gelatin, shellac, shitosan is answered film on fruit in the colloidality liquid of dextrin or Arabic gum, infiltrate and handle fruit.Can in colloid, add 1% human, poultry is used antibiotic.Can adopt Na ₂S ₂O ₃, Na ₂S ₂O ₄Or the aqueous solution soaking of their mixture, or the stifling lichee housing of handling of solid, make the housing bleaching.

Characteristics of the present invention are to start with from the vital movement of fruit self, utilize chemical method that the enzymatic activity in the fruit is reduced, thereby the fruit metabolism of slowing down are aging with the fruit growth, reaches fresh-keeping purpose.Perhaps change the zymolyte form, make the ineffective object of enzyme, reach fresh-keeping purpose.

The spontaneous elderization of fruit is carried out under enzyme, hormone catalysis, if make enzyme deactivation, it is slowed down from aging.But the degree of enzyme deactivation should be exceeded still can keep " fruit lives " state, makes fruit can keep the disease-resistant ability of losing and only hold intrinsic local flavor.

The method of measuring the critical point that enzymatic activity remains in the fruit " fruit lives " can be that demarcation fruit respiratory intensity---time graph is done reference earlier.The fruit that adopts the inventive method to cross with different processing advanced treating is made a series of respiratory intensity---time graph, and then compared.When wherein being zero with reference curve respiratory intensity, the processing degree of depth that curve reflected that time coordinate is identical is the critical processing degree of depth, and the respiratory intensity when this curve time is zero is exactly the alleged enzymatic activity critical point of the present invention.

The present invention adopts following several technical measures that the activity in the fruit is reduced:

First kind of measure is to utilize edibility acid, alkaline matter for processing fruit, changes acid, the alkalescence of enzyme living environment in the fruit, and enzymatic activity is descended.Reaching is a kind of reversible reduction enzymatic activity measure.Acid, alkaline environment can change so that recover home with the variation of fruit maturation or because of factors such as water content variations.Enzymatic activity not to be reduced to live the subcritical method of fruit property be to face the respiratory intensity of surveying fruit to change in control when adopting this method.Generally being no more than 50% with the respiratory intensity variation exceeds.When handling lichee, mango, honey peach, control makes respiratory intensity descend 30%, can prolong one times of freshness date thereafter, can be extended for 10 days in promptly 5 days.

One of embodiment:

Adopt salt acidleach fruit.The pH value of the salt pickle liquor of using should be than the pH value of fruit low 1-4, value difference can shorten the processing time greatly relatively, fruit is in immersion liquid, its pH value changes, and just can take out when generally treating the pH value decline 1-2.5 of fruit, minimumly should not surpass 3.The pH value of immersion liquid and fresh fruit PH differ less than 1 o'clock and just will replenish new hydrochloric acid solution.Experiment shows that pH value variation 2 just has a significant effect to enzymatic activity in the fruit, and it is obvious particularly height to be contained syrup influence really.This class fruit pH value is many about 5.Obviously suppress its enzymatic activity when reducing to 3-4, can prolong storage period.

Two of embodiment:

Adopted 2-10% lemon acidleach fruit 8-16 hour, the fruit pH value can descend 2 or the fruit respiratory intensity descend 30%, prolong storage period one times.

Three of embodiment:

Adopt 2-10% apple acidleach fruit, make the fruit respiratory intensity descend 30%, prolong storage period one times.

Four of embodiment:

Adopt 1-3%Na ₂CO ₃Soak fruit, make the fruit respiratory intensity descend 30%, prolong storage period one times.

Second kind of measure is that the tannin form of utilizing edibility acid, alkali to make to contain in the fruit changes, and makes that enzyme loses the substrate that can act in the fruit, reaches fresh-keeping purpose.

Five of embodiment:

Adopt the hydrochloric acid of PH1-3, the citric acid of 2-10% soaks lychee exocarp, changes the form that exists of tannin in the shell, makes enzyme lose substrate, keeps not blackening of fruit colour.

The third measure be adopt enzyme base in the chemical method of oxidation, the reduction excision fruit (SH), thus the activity of destructive enzyme.This is a kind of irreversible processing method.The oxidation, the reducing agent that adopt comprise Na ₂SO ₃, Na ₂S ₂O ₅, NaHSO ₃, Na ₂S ₂O ₄, S or KMnO ₄, H ₂O ₂But the same sex is used with, also can singly use.Enzyme content is less than some thousandths of in the fruit, so oxidation, reducing agent consumption also only need the heavy some thousandths of of fruit to get final product.

Six of embodiment:

Adopt one or more mixed liquors of aforesaid oxidant, or one or more mixed liquid dipping fruits of reducing agent.Method for supervising is to survey the fruit respiratory intensity to change, and grasps in respiratory intensity decline and is no more than 50%, is advisable to be no more than 30% range of decrease.On critical point generally be respiratory intensity fall big, long fresh-keeping period.

Seven of embodiment:

Adopt the colloid thing, for example gelatin, shellac, shitosan, dextrin or Arabic gum dissolve in oxidant or reducing agent makes the multiple film of fruit, infiltrates and handles.Can suppress the fruit enzymatic activity.

Eight of embodiment:

Adopt 0.02-0.5%Na ₂S ₂O ₃Liquid soaks lichee can make the shell bleaching of browning, reddens after the fluid.

The 4th kind of measure is to use pepsin, the partial enzymatic hydrolysis in papain and other hydrolysising protease, the general fruit.Making its loss of activity, is irreversible treatment measures.Its operation is to use immersion method, fruit is immersed in the hydrolase liquid, with the way monitoring of surveying the fruit respiratory intensity.Grasp is no more than 50% in that fruit respiratory intensity decline about 30% is advisable.

Nine of embodiment

With hydrochloric acid pepsin liquid is transferred to PH1-2, immersion liquid is 0.003% pepsin liquid, soaks lichee 12 hours, can make respiratory intensity descend 30%, the freshness-retained 10-15 of lichee days.

The fresh-keeping measure of fruit also must cooperate prophylactic measures, and the fruit surface that particularly resembles mango one class is easily given birth to anthracnose, and the measure of solution is to adopt some antibiotic of human, poultry usefulness to mix in fresh-keeping liquid or the colloid to get final product.

Ten of embodiment:

In seven colloids of being joined, mix 1% norfloxacin or josamycin as embodiment, or other people, animal antibiotic, glue is made mango, the multiple film of loquat can be prevented and treated blossom-end rot, anthracnose.Adopt other antibiotic also can.This example is equally applicable to other various fruit.

Described several fresh-keeping measure can be adopted separately, also can compoundly use.Promptly can adopt the form that changes the fruit pH value, changes tannin in the fruit simultaneously, cut base, any two kinds, three kinds or whole four kinds of measures in the decomposition fruit in four kinds of measures of enzyme except that Hai.The multiple measure of compound use can increase the dynamics of processing, shortens the processing time.But wherein certain measure may have passive treatment effect to certain fruit, then should avoid using.For example oxidant can make the lychee exocarp blackening, and hydrolase easily makes mango mildew, and should avoid using.Can be when making composite fresh-keeping liquid at the fruit characteristics, the maximize favourable factors and minimize unfavourable ones various acid of ground adapted, alkali, salting liquid and protein enzyme solution.For example when processing contains the fruit of tannin, add a little acid in the complex liquid and can change the tannin form, make enzyme lose substrate, preservation is arranged equally.

Claims

1, a kind of fruit fresh-keeping method using chemical enzyme inactivation method is characterized in that adopting edible acid, alkali, salt or proteolytic enzyme to change enzymatic activity in the fruit, makes it to be reduced to be higher than the enzymatic activity critical point that fruit remains the fruit that lives.

2, fruit preservation method as claimed in claim 1 is characterized in that adopting citric acid, lactic acid, tartaric acid, malic acid, acetic acid, hydrochloric acid or their any mixed liquor to handle fruit, makes the pH value reduction of fruit be not more than 3.

3, fruit preservation method as claimed in claim 1 is characterized in that adopting Na ₂CO ₃, NaHCO ₃, (NH ₄) ₁CO ₃, NH ₄HCO ₃, or their any mixture handles fruit, the pH value of fruit increased be not more than 3.

4, fruit preservation method as claimed in claim 1 is characterized in that adopting pepsin, papain aqueous solution soaking to handle fruit, its respiratory intensity is descended be no more than 50%.

5, as claim 2 or 3 described fruit preservation methods, it is characterized in that the acid, alkali, the salt that use are sneaked into gelatin, shellac, shitosan is answered film on fruit in the colloidality liquid of dextrin or Arabic gum, infiltrate and handle fruit.

6, fruit preservation method as claimed in claim 5 is characterized in that in colloid adding 1% human, poultry and uses antibiotic.

7, fruit preservation method as claimed in claim 1 is characterized in that adopting Na ₂S ₂O ₅, Na ₂S ₂O ₄Or the aqueous solution soaking of their mixture, or the stifling lichee housing of handling of solid, make the housing bleaching.