Method for inhibiting yellowing of fresh peeled water chestnuts and slowing down quality reduction of fresh peeled water chestnuts

Abstract

The invention discloses a method for inhibiting yellowing of fresh peeled water chestnuts and slowing down quality reduction of the fresh peeled water chestnuts. The method comprises the following steps: (1) cleaning the water chestnuts, and peeling the cleaned water chestnuts; and (2) soaking the fresh peeled water chestnuts in distilled water, sterilizing and disinfecting, taking out and draining, soaking in a 3-deoxy-D-ergooctyl sugar ester aqueous solution with the concentration of 0.1% or more for 30 minutes, taking out and draining, and storing at 1-4 DEG C. According to the method, the technical operation is simple, and only 0.1% or more of 3-deoxy-D-ergocaprylate water solution needs to be used for soaking for 30 minutes; the 1, 3-deoxy-D-ergooctyl sugar ester is nontoxic and free of residues, and food safety problems cannot be caused; raw material consumption is low, and cost is low; the method has a good effect and can delay yellowing of the freshly-cut water chestnuts for 30 days or more.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fresh-cut fruit and vegetable preservation, and particularly relates to a method for inhibiting yellowing of fresh peeled water shield by 3-deoxy-D-erythronolide. BACKGROUND

[0002] Water shield contains rich nutrients and is a kind of agricultural product for both food and medicine, which is favored by consumers. The epidermis of water shield is attached with a large number of pathogenic bacteria, and it is not suitable to eat with the skin. Fresh peeled water shield is safe and healthy, and has a sweet taste, and is currently the main form of water shield consumption. The surface of fresh peeled water shield quickly turns yellow, which is called yellowing (early studies believe it is browning). Yellowing reduces the sensory quality and eating quality of fresh peeled water shield, and shortens the storage period, which is an important problem that needs to be solved urgently.

[0003] Xiao et al. used 1.5% sodium diacetate combined with heat treatment at 55℃ to inhibit the browning of fresh peeled water chestnut. High concentration of sodium diacetate soaking fresh peeled water chestnut made it sour, reducing the eating quality of fresh peeled water chestnut (Xiao L Z. Effect of fresh-keeping solution combined with heat treatment on the quality of fresh-cut water chestnut during cold storage [J]. Grain and Food Industry, 2017, 24(1): 44-52.). Wang et al. used 80g / L of salt + 3g / L of sugar + 100g / L of white vinegar to form a composite preservative solution to soak fresh peeled water chestnut, which can inhibit enzymatic browning and prolong its storage period by 6 days. 100g / L of white vinegar made fresh peeled water chestnut very sour, reducing the eating quality of fresh peeled water chestnut (Wang J X, Yang F X, Si W F. Effect of composite preservative solution on fresh-cut water chestnut [J]. Food and Machinery, 2018, 34(12): 129-34.). Wang et al. used 0.2% L-cys + 0.6% CA + 0.6% Vc to form a composite color protection agent to treat fresh peeled water chestnut, which inhibited enzymatic browning. 0.6% acetic acid made fresh peeled water chestnut very sour, reducing the eating quality of fresh peeled water chestnut (Wang Y. Inhibition of browning of fresh-cut water chestnut by composite color protection treatment [J]. Food Safety Guide, 2013, (4): 76-8.). Deng et al. used alkaline magnesium hypochlorite to treat fresh peeled water chestnut. Alkaline magnesium hypochlorite is a chemical preservative, which has residues in fresh peeled water chestnut, causing food safety problems (Deng J, Wang J H, Li W, et al. Study on the effect of alkaline magnesium hypochlorite on color protection and preservation of fresh-cut water chestnut [J]. Packaging Engineering, 2016, 5(3): 20-3.). Qiu et al. used chitosan / nano-TiO2 composite coating to treat fresh peeled water chestnut, but did not give the specific number of days of extended storage period (Xing Y G, Qiu S S, Li X H, et al. Study on the preservation effect of chitosan-nano-TiO2 composite coating on fresh-cut water chestnut [J]. Food and Fermentation Industries, 2008, 34: 149-51.). Peng et al. used 0.5%-2% chitosan coating to treat fresh peeled water chestnut, but did not give the specific number of days of extended storage period (Peng L T, Jiang Y M, Yang S Z, et al. Inhibition of browning of fresh-cut water chestnut by chitosan coating [J]. Plant Physiology Communications, 2002, 38(6): 554-6.). Peng et al. used chitosan and sodium alginate films to treat fresh peeled water chestnut, but did not give the specific number of days of extended storage period (Peng Y, Li Y F. Effects of chitosan and sodium alginate coating on browning, rotting and quality of fresh-cut water chestnut [J]. Food Industry Science and Technology, 2013, 34(17): 334-41.). Xu et al. used nano-SiOx / chitosan composite coating to treat fresh peeled water chestnut, but did not give the specific number of days of extended storage period (Xu T Q, Luo Z S, Jie J. Effects of nano-SiOx-chitosan composite on quality and physiology of fresh-cut water chestnut [J]. Chinese Journal of Food Science, 2011, 11(4): 123-8.).Hou Chuanwei et al. used a composite color protection agent (0.2% phytic acid + 0.1% L-cysteine + 0.25% zinc acetate + 1% sodium diacetate) to treat fresh peeled water chestnuts. The 0.25% zinc acetate and 1% sodium diacetate made the fresh peeled water chestnuts very sour, reducing the eating quality of fresh peeled water chestnuts. Zinc acetate and sodium diacetate are chemical preservatives, which have residues in fresh peeled water chestnuts, causing food safety problems. Hou Chuanwei et al. used a composite sulfur-free color protection agent (optimal formula (mass fraction): 0.25% L-cysteine + 0.8% sodium chloride + 0.6% citric acid + 1.0% sodium pyrophosphate) to protect the color of fresh peeled water chestnuts. The 0.6% citric acid made the fresh peeled water chestnuts very sour, reducing the eating quality of fresh peeled water chestnuts. Sodium pyrophosphate is a chemical preservative, which has residues in fresh peeled water chestnuts, causing food safety problems (Hou Chuanwei, Wei Shuxin, Wang Anjian. Development of fresh-cut water chestnut composite preservative [J]. Food Science and Technology, 2007, 12: 195-7.). Deng Yuanxi et al. (Deng Yuanxi, Chen Jia, Wu Jie, et al. Optimization of fresh-cut water chestnut sulfur-free color protection agent formula by response surface method [J]. Food Industry, 2018, 39: 126-31.). Zeng Kaifang et al. used heat treatment to protect the color of fresh peeled water chestnuts, but did not obtain the specific number of days of extended storage period. Heat treatment caused more water loss in fresh peeled water chestnuts, and the eating quality decreased a lot (Zeng Kaifang, Tian Weina, Ming Jian. Effect of heat treatment on the quality of fresh-cut water chestnuts by response surface method [J]. Food Industry Science and Technology, 2010, 31(2): 70-6.). Jiang Yue et al. used 40% ethanol to inhibit the browning of fresh peeled water chestnuts. The 40% ethanol made the fresh peeled water chestnuts have a strong wine smell, which was unacceptable (Jiang Yue, He Fengping, Zhong Huiling, et al. Effect of ethanol treatment on yellowing and related enzymes of fresh-cut water chestnuts [J]. Food Industry Science and Technology, 2017, 38(10): 326-30.). Fan Chuanhui et al. used 55% ethanol to treat fresh peeled water chestnuts, but did not obtain the specific number of days of extended storage period. The 55% ethanol made the fresh peeled water chestnuts have a strong wine smell, which was unacceptable (Fan Chuanhui, Chen Xuelin, Wang Shaohua, et al. Effect of ethanol soaking on the storage quality changes of fresh peeled water chestnuts [J]. Modern Food Science and Technology, 2018, 34(12): 122-8.). Deng Lili et al. used acetaldehyde fumigation to treat fresh peeled water chestnuts, but did not obtain the specific number of days of extended storage period. Acetaldehyde is a chemical preservative, which has residues in fresh peeled water chestnuts, causing food safety problems (Deng Lili, Ming Jian, Tian Weina, et al. Effect of acetaldehyde fumigation on the quality changes of fresh-cut water chestnuts [J]. Food Science, 2010, 31(2): 233-6.).Wang Haiping et al. soaked fresh peeled water chestnut in a mixed solution composed of NaCl, citric acid and Vc for 15 min, which can protect the color of fresh peeled water chestnut, but it did not come out how long the color protection can be, citric acid can make fresh peeled water chestnut sour and inedible (Wang Haiping, Huang He-sheng, Tian Qing. Fresh-cut water chestnut sulfur-free color protection conditions optimization and storage quality research [J]. Food science and technology, 2019, 2019 (44): 6.). Niu Lifang et al. treated fresh peeled water chestnut with ultraviolet and ethanol, which can reduce its browning, and the effect of combined treatment of ultraviolet and ethanol is better, but it did not come out the specific number of days of prolonged storage period, and ultraviolet needs special equipment, the cost is high, ethanol makes fresh peeled water chestnut have wine taste, and the food quality is reduced (Niu Lifang, Yang Ying, Yi Yang, et al. The effect of ultraviolet irradiation and ethanol treatment on the browning of fresh-cut water chestnut [J]. Food science and technology, 2019, 44 (11): 6.).

[0004] 3-deoxy-D-ergothioneine inhibits fresh peeled water chestnut yellowing is a kind of biological technology, which will not cause food safety problems and reduce food quality. At present, there is no report on the use of 3-deoxy-D-ergothioneine to inhibit fresh peeled water chestnut yellowing. SUMMARY

[0005] The purpose of the present application is to overcome the above-mentioned defects of the prior art, and to provide a method for inhibiting fresh peeled water chestnut yellowing by 3-deoxy-D-ergothioneine, which is efficient, safe, does not reduce food quality, simple to operate and low in cost.

[0006] To achieve the above-mentioned purpose, the present application provides a method for inhibiting fresh peeled water chestnut yellowing by 3-deoxy-D-ergothioneine, characterized in that it comprises the following steps:

[0007] (1) washing and peeling the water chestnut, and removing the roots and buds;

[0008] (2) soaking the fresh peeled water chestnut of step (1) in distilled water, sterilizing and disinfecting, taking out and draining, soaking in 3-deoxy-D-ergothioneine aqueous solution, taking out and draining, and storing.

[0009] Preferably, the fresh peeled water chestnut of step (1) is the white corm after peeling, removing the roots and buds; the distilled water soaking of step (2) is to immerse the fresh peeled water chestnut in distilled water, the sterilizing and disinfecting is treated by ozone for 30 min, the draining time is 10 min, the soaking in 3-deoxy-D-ergothioneine aqueous solution is to soak in 3-deoxy-D-ergothioneine aqueous solution with a mass percentage concentration of 0.1% or more for 30 min, and the storage is at 1-4℃.

[0010] The beneficial effects of the present application are: ① simple operation, only need to soak fresh peeled water chestnut in 0.1% and above 3-deoxy-D-ergothioneine ester aqueous solution for 30 min; ② 3-deoxy-D-ergothioneine ester does not cause food safety problems; ③ low raw material consumption and low cost; ④ good effect, can inhibit the yellowing of fresh peeled water chestnut for 30 days and above. DETAILED DESCRIPTION

[0011] The technical solutions of the present application will be described in detail in combination with examples. It should be understood that the following examples are only used to illustrate the present application and not to limit the scope of the present application. Modifications or replacements of the steps or conditions of the present application without departing from the spirit and essence of the present application all belong to the scope of the present application.

[0012] If not specifically indicated, the technical means used in the examples are conventional means known to those skilled in the art.

[0013] In the present example, the degree of yellowing is measured and calculated by area method: the percentage of the yellowing area of fresh peeled water chestnut to the total area of its air contact surface. The air contact surface of fresh peeled water chestnut is completely free of yellowing, and its degree of yellowing is 0. When the air contact surface of fresh peeled water chestnut is completely yellowing, it is completely yellowing, and its degree of yellowing is 100%. The storage time of the completely yellowing treatment sample minus the storage time of the completely yellowing control sample is the number of days that the treatment method prolongs the storage period of fresh peeled water chestnut.

[0014] (1) Sample treatment

[0015] Select fresh water chestnuts without rotting, peeling, damage, and basically uniform size, wash them with tap water, peel them with a peeling knife, and remove the roots and buds. Soak the fresh peeled water chestnuts in distilled water, which completely submerges the fresh peeled water chestnuts, and treat them with ozone sterilization and disinfection for 30 min. Take out the fresh peeled water chestnuts and drain them for 10 min. Take 100±10 g of fresh peeled water chestnuts as a sample, soak them in 1±0.01 liter of 0.1% and above 3-deoxy-D-ergothioneine ester aqueous solution for 30 min, take them out and drain them for 10 min, and put them in a fresh-keeping box. Store them at 1-4℃, and measure and calculate the degree of yellowing every 3 days. Do not soak the control sample in 3-deoxy-D-ergothioneine ester aqueous solution.

[0016] (2) Experimental results

[0017] The control sample is completely yellowing on the 12th day, the sample treated with 0.1% 3-deoxy-D-ergothioneine ester aqueous solution is completely yellowing on the 42nd day, and the samples treated with 0.1% and above 3-deoxy-D-ergothioneine ester aqueous solution gradually yellow after the 42nd day, respectively.

[0018] It can be seen that in the present embodiment, the effect of 3-deoxy-D-lycochalose ester on inhibiting the yellowing of fresh peeled water chestnut is good, and the 0.1% and above 3-deoxy-D-lycochalose ester aqueous solution can inhibit the yellowing of fresh peeled water chestnut for 30 days and above.

Claims

1. A method for inhibiting yellowing of fresh peeled water chestnuts and slowing down their quality decline, characterized in that The steps are as follows: soak 100±10g of fresh peeled water chestnuts in 1±0.01 liter of 0.1% or above 3-deoxy-D-ergosterol aqueous solution for 30 minutes.