阅读说明：本技术 一种延长鲜切马铃薯保鲜期的方法及应用 (Method for prolonging preservation period of fresh-cut potatoes and application of method ) 是由 张鹏 李江阔 魏宝东 贾晓昱 于 2021-03-04 设计创作，主要内容包括：本发明公布了一种延长鲜切马铃薯保鲜期的方法,该方法为马铃薯经挑选、清洗、去皮、切片后,将鲜切马铃薯放置于防褐变剂水溶液中浸泡后沥干,装入包装盒中并在冷库操作间中充分预冷后装入相温箱中存放。通过上述技术及工艺参数的组合,可以抑制鲜切马铃薯冷藏期间的褐变现象,较好地保持原有营养成分并延缓衰老,使保鲜期延长到6 d以上。(The invention discloses a method for prolonging the fresh-keeping period of fresh-cut potatoes, which comprises the steps of selecting, cleaning, peeling and slicing the potatoes, placing the fresh-cut potatoes in an anti-browning agent aqueous solution for soaking, draining, placing the potatoes into a packaging box, fully precooling the potatoes in a refrigeration house, and placing the potatoes into a phase temperature box for storage. Through the combination of the technology and the process parameters, the browning phenomenon of the fresh-cut potatoes during the refrigeration can be inhibited, the original nutritional ingredients are well kept, the aging is delayed, and the preservation period is prolonged to more than 6 days.)

1. A method for prolonging the preservation period of fresh-cut potatoes is characterized by comprising the following steps:

step 1: selecting potatoes which are uniform in shape and size, free of mechanical damage, diseases and germination and greening as materials;

step 2: washing the soil on the surfaces of the potatoes with water, removing the skins of the potatoes with a peeler, putting the potatoes into a tank filled with water in advance, manually cutting the potatoes into slices with the thickness of about 4-6 mm one by one, and putting the slices into a new tank filled with water in advance;

and step 3: precooling for 2-4 h at the temperature of 0-4 ℃, taking out the potato slices, washing the potato slices twice with water, and sequentially putting the potato slices into a plastic basket to drain excessive moisture on the surface;

and 4, step 4: soaking the potato slices in an anti-browning agent aqueous solution for 3-5 min, then fishing out the potato slices, and putting the potato slices into a plastic basket to drain excessive water on the surface; the formula of the anti-browning agent is as follows: 1.5% anhydrous citric acid +0.3% papain +0.4% bromelain;

and 5: the potato slices are put into a packaging box, put into a refrigeration house for full precooling and then put into a phase temperature box for storage.

2. The method of extending the shelf life of fresh-cut potatoes of claim 1, wherein: the volume of water added to the pot into which the peeled and sliced potato slices are placed is normalized: submerge the potato surface to prevent oxidation.

3. The method of extending the shelf life of fresh-cut potatoes of claim 1, wherein: precooling for 2-3 h at the temperature of 0-2 ℃, and precooling for 3-4 h at the temperature of 2-4 ℃.

4. The method of extending the shelf life of fresh-cut potatoes of claim 1, wherein: the volume of the packaging box is 6-10 cm³And the volume ratio of the fresh-cut potatoes to the packaging box is 2-3: 5.

5. The method of extending the shelf life of fresh-cut potatoes of claim 1, wherein: the temperature of the refrigeration house is 0-4 ℃, the packaging boxes and the phase temperature boxes are simultaneously placed into the refrigeration house, after precooling is carried out for 12-24 hours, the packaging boxes filled with the potato slices are placed in the phase temperature boxes in order, the gaps are covered after the ice boxes are placed, and the fluctuation of the environmental temperature in the box body is +/-0.2 ℃.

6. The use of the method for extending the fresh-keeping time of fresh-cut potatoes of claim 1 to effectively inhibit browning of the fresh-cut potatoes and maintain their nutritional quality, delay senescence, extend the fresh-keeping time.

Technical Field

The invention belongs to the technical field of storage and preservation of agricultural products, and particularly relates to a green preservation method for pretreatment, development of an anti-browning agent and precise temperature control storage of fresh-cut potatoes.

Background

Potato (A)Solanum tuberosumL.) is one of four worldwide food crops, namely potatoes, netherlands, sweet potatoes, Chinese yam eggs and the like, and belongs to the solanaceae family in herbaceous plants. The potato is most fond of shade and cool, can not resist high temperature, the optimum temperature is not higher than 21 ℃, the plant is in the shape of a tuber, the shape of the plant is similar to a sphere, the plant is divided into an upper stem and a lower stem, and the potato peel is divided into white, yellow, powder and the like. China is thatIn countries with the highest potato yield, potatoes are rich and complete in nutrition, contain abundant nutrients such as vitamin C, minerals, proteins and saccharides, and are easily absorbed by human bodies, so that the potatoes are called 'King of nutrition'. The browning phenomenon of fresh-cut potatoes is one of the common problems in fruit and vegetable processing, which not only influences the appearance color and taste of the potatoes, but also reduces the nutritional value and the storage period. Therefore, the development of safe and economical technology capable of inhibiting the browning of potatoes is an urgent problem to be solved at present.

At present, people treat fresh-cut potatoes by various chemical browning agents to delay the browning phenomenon of the fresh-cut potatoes. Liu li et al (2018) when studied on single browning agents at different concentrations found that the browning was minimal after treatment of fresh cut potatoes with 0.6% ascorbic acid. The L-cysteine and the sodium benzoate can inhibit the browning and VC loss of the fresh-cut potatoes by inhibiting ASO enzyme and APX enzyme under the condition of low temperature. In 2005, the browning degree and polyphenol oxidase of fresh-cut potatoes were significantly reduced after plum macros and the like were treated with L-cysteine, cinnamic acid, benzoic acid. In 2011, Dingjie et al obtained fresh-cut potato processed with 0.005% kojic acid, 0.045% sodium isoascorbate, 0.045% cysteine (L-Cys), 0.01% CaCl₂、0.2992%EDTA-Na₂After the mutually combined composite brown stain inhibitor is treated, the brown stain inhibition effect is good, and the PPO activity in the potatoes is better inhibited. In 2014, the Yuanhong research and the like discovers that fresh-cut potatoes are subjected to different treatments to inhibit the browning of the fresh-cut potatoes, and 2.0% of citric acid, 0.6% of D-sodium erythorbate and 0.2% of calcium chloride are optimized to be the optimal color fixative through orthogonal tests in the determined optimal appropriate concentration range. Sodium bisulfite has a highly effective inhibitory effect (2017) on enzymatic browning of fresh-cut potatoes at a level of 0.4 g/kg (as sulfur dioxide), but has been limited in view of safety. With the increasing importance of food safety, safe and green anti-browning agents become a new research direction.

Temperature is one of the problems of the current fresh-cut technology. Since fresh-cut vegetables are susceptible to microbial contamination during storage, most of the fresh-cut vegetables are stored in a low temperature environment (2017). Liu war Li et al (2012) discovered that weight loss, respiration intensity, PPO and POD activity of fresh-cut potatoes are inhibited under storage at a temperature of 2 ℃ through research on the fresh-cut potatoes at different temperatures (2 ℃, 12 ℃, 25 ℃), thereby slowing browning of the fresh-cut potatoes. Sclerafen (2014) found that storing fresh-cut vegetables at different temperatures had a significant effect on their quality by studying three fresh-cut vegetables (carrot, potato, spinach). With the temperature rise, the rotting progress and the total number of bacterial colonies of each fresh-cut vegetable are accelerated, wherein the polyphenol oxidase activity of the fresh-cut potatoes is highest, the soluble sugar content of the fresh-cut carrots is sharply reduced, the chlorophyll content of the fresh-cut spinach is lowest, and the sensory evaluation and measurement indexes of each fresh-cut vegetable are superior to those of other temperatures when the storage temperature is 0 ℃. One of the major factors in inhibiting browning at temperature during storage of fresh-cut vegetables. In order to establish a fresh-cut potato anti-browning process suitable for commercial operation, all links and process parameters are researched from the aspects of potato pretreatment, anti-browning development and accurate temperature control technology, so that a simple, effective and better-browning-effect optimized anti-browning agent is obtained, and the preservation period of fresh-cut potatoes is prolonged.

Disclosure of Invention

The invention aims to fill up the blank of the previous research and provide a method for prolonging the preservation period of fresh-cut potatoes. The invention provides a green preservation method for pretreatment of fresh-cut potatoes, development of an anti-browning agent and precise temperature control storage.

In order to achieve the purpose, the invention discloses the following technical contents:

the invention discloses a process for prolonging the preservation of fresh-cut potatoes, which comprises the following steps:

step 1: selecting potatoes which are uniform in shape and size, free of mechanical damage, diseases and germination and greening as materials;

step 2: the method comprises the steps of washing soil on the surfaces of potatoes with water, removing the skins of the potatoes with a peeler, putting the potatoes into a tank filled with water in advance, manually cutting the potatoes into slices with the thickness of about 4-6 mm one by one, and putting the slices into a new tank filled with water in advance.

And step 3: and (3) placing the pot containing the potato slices in a temperature environment of 0-4 ℃ for 2-4 h, taking out the potato slices, washing the potato slices twice with water, and sequentially placing the potato slices into a plastic basket to drain excessive moisture on the surface.

And 4, step 4: soaking the potato slices in an anti-browning agent aqueous solution consisting of anhydrous citric acid, papain and bromelain for 3-5 min, and then fishing out the potato slices, putting the potato slices into a plastic basket, and draining off excessive water on the surface.

And 5: the potato slices are put into a packaging box, put into a refrigeration house for full precooling and then put into a phase temperature box for storage.

The invention discloses that the water in the pot filled with potatoes is higher than the potatoes, so as to avoid the contact with air, and the slice thickness of the potatoes is preferably 5 mm.

The invention discloses a method for controlling the temperature of a freezer operating room to be 0-4 ℃, the precooling time of potato slices is controlled according to the actual temperature, the temperature is 0-2 ℃ for 2-3 h, and the temperature is 2-4 ℃ for 3-4 h.

The invention discloses an anti-browning agent which is composed of anhydrous citric acid, papain and bromelain, and the optimal formula is 1.5% of anhydrous citric acid, 0.3% of papain and 0.4% of bromelain.

The invention discloses a packing box with the volume of 6-10 cm³The volume ratio of the fresh-cut potatoes to the packaging box is 2-3: 5, and specific parameters can be adjusted according to actual conditions.

The invention discloses a method for putting a packaging box and a phase temperature box into a refrigeration house at the same time, wherein the packaging box containing potato slices is placed into the phase temperature box in order after precooling for 12-24 h, an ice box is placed in a gap and then the box is covered, and the fluctuation of the environmental temperature in the box body is +/-0.2 ℃.

The invention further discloses application of the method for prolonging the preservation period of the fresh-cut potatoes in prolonging the preservation period of the fresh-cut potatoes and inhibiting browning, water loss and nutrient loss of the fresh-cut potatoes during slow storage, can effectively inhibit the browning of the fresh-cut potatoes, maintain the nutrient quality of the fresh-cut potatoes and delay senescence, and prolongs the preservation period by more than 6 days.

The invention mainly solves the problems that the fresh-cut potatoes are easy to brown and lose nutrition, mainly inspects the influence of the fresh-keeping method combining the anti-browning agent with the accurate temperature control on the browning and the quality of the fresh-cut potatoes, and has the main difficulty that the formula of the anti-browning agent and the accurate temperature control operation are determined.

Compared with the prior art, the method for prolonging the preservation period of the fresh-cut potatoes has the positive effects that:

(1) the anti-browning agent formula obtained by the patent is based on a single factor, takes the browning degree as an index, combines sensory quality relative ratio, screens out the optimal anti-browning agent through a response surface test and a plurality of verification tests, and is composed of safe and green reagents.

(2) Compared with the existing packaging mode, the phase temperature box integrating storage, transportation and sale is convenient to transport and sell, has the function of integrating storage, transportation and sale, has the characteristic of portability, and can ensure that the fresh-cut potatoes are in a proper environment during storage.

(3) Compared with the traditional refrigeration, the technology emphasizes the accurate control of the temperature in the storage environment, and provides that the fluctuation in the phase temperature box body is +/-0.2 ℃, so that the physiological activity of the fresh-cut potatoes during the storage period is reduced to the maximum extent, and the nutrient loss and the browning of the fresh-cut potatoes are delayed.

Drawings

FIG. 1 Effect of anhydrous citric acid on browning levels of fresh-cut potatoes;

FIG. 2 Effect of sodium bisulfite on fresh-cut potato browning;

FIG. 3 Effect of papain on the browning of fresh-cut potatoes;

FIG. 4 Effect of Bromelain on fresh-cut potato browning;

FIG. 5 Effect of marine fish oligopeptides on browning level of fresh-cut potatoes;

FIG. 6 Effect of marine fish protein peptides on browning degree of fresh-cut potatoes.

Detailed Description

The invention is described below by means of specific embodiments. Unless otherwise specified, the technical means used in the present invention are well known to those skilled in the art. In addition, the embodiments should be considered illustrative, and not restrictive, of the scope of the invention, which is defined solely by the claims. It will be apparent to those skilled in the art that various changes or modifications can be made in the formulation of the anti-browning agent and the precise temperature control operation of the present invention without departing from the spirit and scope of the invention. The anhydrous citric acid, papain, bromelain, packing boxes and phase incubators used in the invention are all commercially available.

Example 1

Screening of anti-browning agent formulations

Selecting potatoes which are uniform in shape and size, have no mechanical damage, no diseases, no germination and no green change, washing soil on the surfaces of the potatoes with water, removing the skins of the potatoes with a peeler, putting the potatoes into a groove filled with water in advance, manually cutting the potatoes into slices with the thickness of about 5 mm one by one, putting the slices into a new groove filled with water in advance, pre-cooling the slices for 3 hours at the temperature of 0-4 ℃, taking out the potato slices, washing the potato slices with water twice, and sequentially putting the potato slices into a plastic basket to drain off excessive moisture on the surfaces. Soaking the potato slices in different anti-browning agent aqueous solutions for 3 min, taking out the potato slices, putting the potato slices into a plastic basket, draining excessive water on the surface, and packaging in a packaging box for storage. The results are as follows:

(1) one factor design and results

The single factor level design is shown in table 1. With the browning degree as a determination index, 3 levels most suitable for each factor are obtained through single factor analysis, and the results are shown in fig. 1-6, wherein the optimal concentration of anhydrous citric acid is 1.5%, the optimal concentration of sodium bisulfite is 0.02%, the optimal concentration of papain is 0.3%, the optimal concentration of bromelain is 0.4%, the optimal concentration of marine fish oligopeptide is 0.4%, and the optimal concentration of marine fish protein peptide is 0.5%. PCA is carried out on the optimal concentration of each factor to obtain a table 2, as can be seen from the table 2, the anhydrous citric acid, the papain, the bromelain and the sodium bisulfite which are ranked in the first four places respectively have obvious effect of inhibiting the browning of the fresh-cut potatoes, and the sodium bisulfite does not belong to a green and safe preservative, so the sodium bisulfite is not considered in the next response surface analysis.

TABLE 1 Single factor horizontal design Table

TABLE 2 principal Components score Table

(2) Response surface analysis results

Performing quadratic multiple regression fitting on the data in Table 3 by using Design-Expert V8.0.6 software, wherein the analysis result is shown in Table 4, and the determination coefficient of the equation is R²=0.9241, the correction decision coefficient is R²Adj = 0.8266. The P value of the model is 0.0036 and is less than 0.01, and the result has significance; meanwhile, the P value of the mismatching item is 0.1140 and is more than 0.05, and the mismatching item is not significant. Through data analysis, the model is effectively established and has high reliability. Through Design-Expert V8.0.6 software analysis, the optimal combination of the optimized anti-browning agent comprises 1.50% of anhydrous citric acid, 0.27% of papain and 0.43% of bromelain. In combination with actual operations, the factors are adjusted as follows: 1.5% of anhydrous citric acid, 0.3% of papain and 0.4% of bromelain, wherein the predicted value of the browning degree of the optimized anti-browning agent is 0.362%, under the condition, 3 times of parallel experiments are carried out to obtain the browning degree of the optimized anti-browning agent which is 0.363%, and the error is only 0.001%.

Table 3 response surface test design and results

TABLE 4 model and analysis of variance

Note: *. differ significantly by (P< 0.05); marked difference（P＜0.01）

Example 2

Precise temperature control process

Selecting potatoes which are uniform in shape and size, have no mechanical damage, no diseases, no germination and no green change, washing soil on the surfaces of the potatoes with water, removing the skins of the potatoes with a peeler, putting the potatoes into a groove filled with water in advance, manually cutting the potatoes into slices with the thickness of about 5 mm one by one, putting the slices into a new groove filled with water in advance, pre-cooling the slices for 3 hours at the temperature of 0-4 ℃, taking out the potato slices, washing the potato slices with water twice, and sequentially putting the potato slices into a plastic basket to drain off excessive moisture on the surfaces. Soaking the potato slices in the optimal anti-browning agent aqueous solution for 3 min, then fishing out the potato slices, putting the potato slices into a plastic basket, draining excessive water on the surface, putting the potato slices into a packaging box, keeping the temperature of a refrigeration house at 0-4 ℃, putting the packaging box and a phase temperature box into the refrigeration house at the same time, precooling for 24 h, putting the packaging box with the potato slices into the phase temperature box in order, putting an ice box in a gap, covering the ice box, and keeping the environmental temperature in the box body to be within +/-0.2 ℃ so as not to be placed into the phase temperature box for comparison. The browning level, soluble solids, vitamin C, relative conductivity, and malondialdehyde were determined for the different treated fresh potatoes during storage.

The results are shown in table 5, the phase temperature box group can inhibit the browning degree, the soluble solid content, the MDA content and the relative conductivity from gradually increasing, and simultaneously the vitamin C content is kept at a high level, which shows that the browning phenomenon of the fresh-cut potatoes during the cold storage period can be inhibited by adopting the anti-browning agent and the precise temperature control process, the original nutritional ingredients can be well kept, the aging can be delayed, and the preservation period can be prolonged to more than 6 days.

TABLE 5 Effect of different treatments on fresh-cut Potato Brown-index, Nutrition ingredients and aging index