Method for peeling canna edulis ker

Abstract

The invention provides a method for peeling canna edulis ker, and belongs to the technical field of agricultural product processing. Comprising the following steps: freezing canna edulis ker to be peeled, then carrying out high-pressure steam treatment, finally putting the canna edulis ker into a composite enzymatic hydrolysate for enzymolysis, and kneading and peeling after cooling. The canna edulis ker is frozen, so that the enzymatic reaction of the canna edulis ker is reduced, the degradation of nutritional ingredients is reduced, the compactness of the canna edulis ker peel is dispersed, and the affinity of the canna edulis ker peel and enzymatic hydrolysate is enhanced; through high temperature and high pressure, the canna edulis ker peel is more obviously layered from the internal moisture-filled taro pulp and taro peel; the compound enzymatic hydrolysate is used for removing wax and cuticle on the surface of the canna edulis ker peel and dissolving cell walls and middle glue layers of the canna edulis ker peel, so that the canna edulis ker peel is separated from the canna edulis ker pulp, nutritional ingredients are reserved to the maximum extent, the peeling efficiency of the canna edulis ker is improved, the canna edulis ker is not prone to browning, and the processing integrity of the canna edulis ker is guaranteed. According to the peeling method of canna edulis ker, the browning speed of the canna edulis ker pulp can be reduced, peeling is easy, and the peeling effect is good.

Description

Technical Field

[0001] The invention relates to the technical field of agricultural product processing, in particular to a method for peeling taro. Background Art

[0002] The tubers of taro are rich in starch, crude protein, dietary fiber and various secondary metabolites, and the proportion of R3 resistant starch is high. It is an ideal low-calorie, low-fat high-grade starch. The high content of mucin in taro tubers can accelerate the synthesis and regeneration of human immunoglobulin, and has multiple functions such as weight loss, beauty, detoxification, swelling, and cancer prevention and anti-cancer. The development and utilization of taro is mainly based on the production of starch. On the one hand, the raw material skin used for processing taro starch accounts for about 30% of the fresh weight, and is rich in cellulose and pectin. The processing has high requirements for equipment, which is easy to cause machine blockage, incomplete starch extraction, low starch yield, and large raw material demand, which affects the processing efficiency and production benefits. On the other hand, due to the irregular shape of taro tubers and the untidy surface, the peeled tubers are prone to browning, which affects the quality of starch. Artificial peeling is inefficient, has high losses, and browning is fast. At present, it is generally not processed with the skin.

[0003] At present, the main method of peeling fruits and vegetables in production and processing is hot alkaline solution peeling. The alkaline solution uses strong corrosiveness under high temperature conditions to accelerate degradation and peeling. The advantages are short time and high efficiency. The disadvantages are excessive dissolution of the taro peel, damage to the taro flesh tissue, and affect the quality of the taro flesh. The generated wastewater needs to be neutralized and cleaned with acid, which consumes a lot of water. The residual chemicals carried enter the sewage treatment system together, inactivating the microorganisms in the sewage treatment system, causing the sewage treatment capacity to decrease or even inactivate, which is likely to cause greater environmental pollution discharge pressure on processing companies.

[0004] Therefore, it is an urgent technical problem to realize peeling of taro without using chemical reagents and minimizing environmental pollution, reduce processing links, balance energy consumption and cost, and improve the processing efficiency of production enterprises. The development of an efficient method for peeling taro has great practical significance. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] The invention provides a method for peeling a taro, comprising the following steps:

[0007] (1) freezing the peeled yam;

[0008] (2) subjecting the frozen taro to a high-pressure steam treatment;

[0009] (3) placing the taro treated with high-pressure steam in a composite enzymatic hydrolysis solution for enzymatic hydrolysis, cooling, and rubbing to peel the taro.

[0010] Preferably, the freezing treatment in step (1) is carried out at -20 to -15°C for 2 to 3 hours.

[0011] Preferably, the steam temperature of the high-pressure steam treatment in step (2) is 120-150° C., the pressure is 0.3-0.6 MPa, and the treatment time is 1-3 min.

[0012] Preferably, the composite enzyme in the composite enzymatic hydrolysis solution of step (3) consists of cellulase and pectinase in a mass ratio of 1 to 3:1.

[0013] Preferably, the enzymatic activity of the cellulase is 18,000 to 22,000 U / g, and the enzymatic activity of the pectinase is 28,000 to 32,000 U / g.

[0014] Preferably, the volume concentration of the composite enzyme in the composite enzymatic hydrolysis solution is 1.0-2.0%.

[0015] Preferably, the pH of the complex enzyme solution is 4.0-4.5.

[0016] Preferably, the enzymatic hydrolysis conditions are 45-55° C. for 20-30 min.

[0017] Beneficial effects:

[0018] First, the present invention can reduce the enzymatic reaction of the canna by pre-freezing the canna, reduce the degradation of nutrients, and preliminarily separate the skin and the flesh under physical conditions, while making the density of the canna skin loose, further enhancing its affinity with the enzymatic solution;

[0019] Second, the present invention uses high temperature and high pressure to make the separation of the taro peel from the taro flesh and taro peel filled with water more obvious, and can achieve integrated processing without using any chemical agents and minimizing environmental pollution, reducing processing links, ensuring the peeling effect and improving production efficiency;

[0020] 3. The present invention utilizes food-grade additives cellulase and pectinase to immerse in citric acid-sodium citrate buffer to remove wax and cuticle on the surface of the taro peel, dissolve the cell wall and middle gelatinous layer of the taro peel to separate the taro peel from the taro flesh, which can retain nutrients to the greatest extent, improve the peeling efficiency of the taro, and is not prone to browning, which can ensure the integrity of the taro processing and is suitable for the subsequent processing of the present invention.

[0021] In summary, the method for peeling taro provided by the present invention can reduce the browning speed of taro flesh, will not damage the taro flesh tissue, and reduce the impact on the quality of the taro flesh; the present invention can make the peeling process very easy, and can completely separate the taro peel and the taro flesh in a relatively short time, the residual rate of taro flesh on the taro peel is extremely small, the peeling rate is high, and the peeling effect is good. DETAILED DESCRIPTION

[0022] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0023] Example 1

[0024] A method for peeling taro comprises the following steps:

[0025] (1) Select fresh, pest-free, uniform-sized, mature, root-free, and scale-free banana taro, clean it, remove the dirt and impurities on the surface, dry it, and place it at -15°C for 2 hours;

[0026] (2) subjecting the frozen taro to a high-pressure steam treatment under the conditions of a steam temperature of 120° C., a pressure of 0.3 MPa, and a treatment time of 1 min;

[0027] (3) Prepare enzymatic hydrolysis solution, adjust the pH of citric acid-sodium citrate buffer to 4.0, add 1.0% complex enzyme (pectinase and cellulase, mass ratio of 1:1, cellulase activity of 20,000 U / g, pectinase activity of 20,000 U / g, the same below) at a volume concentration of the enzyme solution, and place the taro treated with high-pressure steam at 45°C for enzymatic hydrolysis for 20 min.

[0028] (4) Cool the enzymatically hydrolyzed taro, wipe off the taro skin with a rigid brush made of steel wire, and after washing, manually remove the skin residue remaining on the taro surface.

[0029] Embodiment 2:

[0030] A method for peeling taro comprises the following steps:

[0031] (1) Select fresh, pest-free, uniform-sized, mature, root-free, and scale-free banana taro, clean it, remove the dirt and impurities on the surface, dry it, and place it at -20°C for 3 hours;

[0032] (2) subjecting the frozen taro to a high-pressure steam treatment under the conditions of a steam temperature of 150° C., a pressure of 0.4 MPa, and a treatment time of 2 min;

[0033] (3) preparing an enzymatic hydrolysis solution, adjusting the pH of the citric acid-sodium citrate buffer to 4.5, adding 1.0% of the complex enzyme (pectinase and cellulase, mass ratio of 2:1) to the enzyme solution, and placing the taro treated with high-pressure steam at 45° C. for enzymatic hydrolysis for 30 min;

[0034] (4) After the enzymatically hydrolyzed taro is cooled, the taro skin is wiped off with a rigid brush made of steel wire. After washing, the skin residue remaining on the surface of the taro is manually removed.

[0035] Embodiment 3:

[0036] A method for peeling taro comprises the following steps:

[0037] (1) Select fresh, pest-free, uniform-sized, mature, root-free, and scale-free banana taro, clean it, remove the dirt and impurities on the surface, dry it, and place it at -20°C for 3 hours;

[0038] (2) subjecting the frozen taro to a high-pressure steam treatment under the conditions of a steam temperature of 150° C., a pressure of 0.6 MPa, and a treatment time of 3 min;

[0039] (3) preparing an enzymatic hydrolysis solution, adjusting the pH of the citric acid-sodium citrate buffer to 4.5, adding 2.0% of the complex enzyme (pectinase and cellulase, mass ratio of 3:1) at the volume concentration of the enzyme solution, and placing the taro treated with high-pressure steam at 55° C. for enzymatic hydrolysis for 30 min;

[0040] (4) After the enzymatically hydrolyzed taro is cooled, the taro skin is wiped off with a rigid brush made of steel wire. After washing, the skin residue remaining on the surface of the taro is manually removed.

[0041] Comparative Example 1:

[0042] The difference from Example 3 is that in this comparative example, the taro is not subjected to enzymatic hydrolysis.

[0043] Comparative Example 2:

[0044] The difference from Example 3 is that in this comparative example, the taro is not subjected to freezing treatment.

[0045] Comparative Example 3:

[0046] The difference from Example 3 is that in this comparative example, the taro is not subjected to freezing treatment and high-pressure steam treatment.

[0047] The same batch of taro was divided into six groups, and the peeling methods of Examples 1 to 3 and Comparative Examples 1 to 3 were used to treat the taro respectively. The browning speed of the taro, the degree of difficulty in peeling, and the residual rate of taro flesh on the skin were statistically analyzed (the process parameters and test results of the examples and comparative examples are shown in Table 1):

[0048] The rate of taro flesh remaining on the skin (%) = the number of taro skins with taro flesh remaining on the removed skins / the total number of taro skins of taro tubers × 100%;

[0049] Table 1: Process parameters and test results of various embodiments and comparative examples

[0050]

[0051]

[0052] As can be seen from the above embodiments, the present invention provides a method for peeling taro, and the browning speed is significantly slower than that of comparative examples 1 to 3, thereby ensuring the quality of taro flesh. At the same time, compared with comparative examples 1 to 3, the present invention can completely separate the taro peel and taro flesh in a relatively fast time, making the peeling process very easy, and the taro flesh residue rate on the taro peel is extremely small, and the peeling effect is improved by more than 70% compared with comparative examples 1 to 3.

[0053] The skin of the banana tuber is different from the skin of fruits such as apples and pears. Its outer layer is a waxy layer of scales, and its inner layer is similar to the skin of white radish, which is about 3 to 5 mm thick. The inventor has tried to first perform high-temperature steam treatment and then freeze it, but the peeling effect of the banana tuber is not ideal, and the peeling rate is less than 10% (peeling rate (%) = the number of banana tubers that are completely peeled / the total number of banana tubers × 100%), and the skin cannot be completely removed. The peeling rate of the present application can reach 100%. At the same time, considering the processing flow of banana tuber production, starch quality preservation, energy saving and other factors, it is more reasonable to first freeze and then perform high-temperature steam treatment. The invention firstly performs low-temperature treatment to reduce the enzymatic reaction of the taro, reduces the degradation of the nutrient components, makes the density of the taro peel dispersed, enhances the affinity of the taro peel with the enzymatic hydrolyzate, then performs high temperature and high pressure treatment to make the taro peel, the taro flesh and the taro peel filled with water more obviously separated, and the peeling rate is higher, finally, cellulase and pectinase are used to perform enzymolysis on the taro, remove the wax and the cuticle on the surface of the taro peel, dissolve the cell wall and the middle gelatinous layer of the taro peel to separate the taro peel from the taro flesh, can retain the nutrient components to the greatest extent, improve the peeling efficiency of the taro, is not easy to brown, can ensure the integrity of the taro processing, and is suitable for subsequent processing.

[0054] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for peeling taro, characterized in that: The following steps are involved: (1) freezing the peeled yam; (2) subjecting the frozen taro to a high-pressure steam treatment; (3) placing the taro treated with high-pressure steam in a composite enzymatic hydrolysis solution for enzymatic hydrolysis, cooling, and rubbing to peel the taro.

2. The method for peeling taro according to claim 1, characterized in that: The freezing treatment conditions in step (1) are -20 to -15°C for 2 to 3 hours.

3. The method for peeling taro according to claim 2, characterized in that: The steam temperature of the high-pressure steam treatment in step (2) is 120-150° C., the pressure is 0.3-0.6 MPa, and the treatment time is 1-3 min.

4. The method for peeling taro according to claim 3, characterized in that: The composite enzyme in the composite enzymatic hydrolysis solution of step (3) is composed of cellulase and pectinase in a mass ratio of 1 to 3:

1.

5. The method for peeling taro according to claim 4, characterized in that: The enzyme activity of the cellulase is 18,000 to 22,000 U / g, and the enzyme activity of the pectinase is 28,000 to 32,000 U / g.

6. The method for peeling taro according to claim 5, characterized in that: The volume concentration of the composite enzyme in the composite enzymatic hydrolysis solution is 1.0 to 2.0%.

7. The method for peeling taro according to claim 6, characterized in that: The pH of the complex enzyme solution is 4.0-4.

5.

8. The method for peeling taro according to claim 7, characterized in that: The conditions for enzymatic hydrolysis are 45-55°C for 20-30 minutes.

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