Fresh-keeping method of fresh-cut potatoes

Abstract

The invention discloses a preservation method of fresh-cut potatoes, which comprises the following steps: soaking the fresh-cut potatoes in slightly acidic electrolyzed water for 8-12 minutes, and soaking the fresh-cut potatoes in alkaline electrolyzed water for 55-65 seconds; the method comprises the following steps: soaking fresh-cut potatoes in a natamycin solution for 1-5 minutes, performing ultraviolet irradiation on the fresh-cut potatoes for 25-30 minutes, and finally performing vacuum packaging to realize preservation of the fresh-cut potatoes. Experimental comparison verifies that the fresh-keeping method disclosed by the invention is remarkably superior to other fresh-keeping methods in effect, and particularly, the fresh-keeping effect is remarkably improved by a treatment sequence of soaking the subacid electrolyzed water before the alkaline electrolyzed water. The method can effectively delay the quality deterioration processes of weight loss, hardness reduction, browning and the like of the fresh-cut potatoes, remarkably prolongs the fresh-keeping period of the fresh-cut potatoes, has the advantages of being high in safety, non-toxic and harmless, and is suitable for storage and fresh keeping of the fresh-cut potatoes.

Description

Technical Field

[0001] The invention relates to the technical field of fruit and vegetable storage and preservation, and in particular to a method for preserving fresh-cut potatoes. Background Art

[0002] Fresh-cut potatoes are becoming a new favorite on consumers' tables due to their convenient eating and processing characteristics. This pre-processed food greatly shortens the cooking time and meets the modern people's pursuit of a fast pace of life. However, fresh-cut potatoes are prone to a series of quality deterioration problems during processing and subsequent storage, mainly including browning, water loss, and decreased hardness, which directly weaken the product's commercial value and eating experience.

[0003] In response to the above problems, the industry has tried to adopt a variety of traditional preservation technologies, such as low-temperature storage and modified atmosphere packaging. Low-temperature storage prolongs the shelf life by slowing down the growth of microorganisms and the rate of enzymatic reactions, but long-term low temperatures may cause chilling damage to potatoes and affect the flavor; modified atmosphere packaging inhibits aerobic respiration and microbial activity by adjusting the gas composition in the package (such as reducing the oxygen concentration and increasing the carbon dioxide or nitrogen concentration), but the high cost of high-precision gas control and packaging materials limits its widespread application.

[0004] Given the limitations of traditional preservation methods, such as limited shelf life and unsatisfactory cost-effectiveness, it is particularly urgent to develop a new preservation technology that can effectively improve the preservation effect of fresh-cut potatoes while ensuring easy operation, cost-effectiveness, and safety to the human body. Such a technology can not only meet the market's growing demand for high-quality fresh-cut potatoes, but also promote the sustainable development of the potato industry chain and increase the added value of agricultural products. Summary of the invention

[0005] The invention provides a method for preserving fresh-cut potatoes. The method can effectively delay quality deterioration problems such as weight loss, hardness reduction, and browning of potatoes, prolong the shelf life of fresh-cut potatoes, and has high safety and is non-toxic and harmless.

[0006] The fresh-keeping method of fresh-cut potatoes of the present invention is as follows: 1. Wash, peel, cut or slice the potatoes, and soak the fresh-cut potatoes in slightly acidic electrolyzed water for 8-12 minutes; The slightly acidic electrolyzed water has an effective chlorine concentration of 90-100 ppm and a pH of 5-6, and is prepared using an SX-G30 acidic electrolyzed water generator; 2. Soak fresh-cut potatoes in alkaline electrolyzed water for 55-65 seconds, wherein the pH of the alkaline electrolyzed water is 8-9 and is prepared by a SX-G30 acidic electrolyzed water generator; 3. Soak fresh-cut potatoes in a natamycin solution for 1-5 minutes, wherein the concentration of the natamycin solution is 0.04-0.05 g / L; 4. Expose fresh-cut potatoes to ultraviolet light for 25-30 minutes, and finally vacuum pack and store at 4±1℃ to preserve the fresh-cut potatoes; the intensity of ultraviolet light exposure is 10-15mW / cm².

[0007] The present invention has the following advantages: 1. Slightly acidic electrolyzed water is a new type of disinfectant, which is rich in bactericidal factors such as available chlorine and active chlorine, and can effectively kill microorganisms on the surface of fresh-cut potatoes. It is highly safe, has no pollution residue, is easy to prepare and has a low price. However, the applicant has found that the slightly acidic electrolyzed water of the present invention can not only kill bacteria, but also inhibit the enzymatic browning of fresh-cut potatoes. Therefore, the slightly acidic electrolyzed water of the present invention can significantly improve the fresh-keeping power of fresh-cut potatoes; alkaline electrolyzed water can slow down the loss of water and maintain the original weight and texture of potatoes; at the same time, it may inhibit browning and delay the decline of quality by affecting the activity of phenol oxidase or changing the cell pH environment; in addition, alkaline electrolyzed water can also maintain the hardness of potatoes and maintain a crisp and tender taste, and is highly safe and does not introduce harmful chemicals; natamycin can effectively inhibit the growth of molds and yeasts, extend the shelf life, maintain the texture of potato slices, and reduce softening and decay; at the same time, it slows down the loss of nutrients and maintains the color, taste and nutritional value of potatoes. In addition, sodium dehydroacetate is stable in use and is more natural and safe, ensuring stable potato quality during storage and improving food safety. UV light and vacuum packaging have their own characteristics in preserving fresh-cut potatoes: UV light effectively inhibits the growth of microorganisms by destroying their DNA structure and slowing down the browning reaction. As a physical method, it has no chemical residues and improves food safety. Vacuum packaging inhibits respiration and transpiration by reducing oxygen content, blocks water vapor, reduces water loss, and inhibits microbial growth to maintain stable quality. 2. The method of the present invention can effectively delay the quality deterioration processes of fresh-cut potatoes such as weight loss, hardness reduction and browning, thereby being beneficial to maintaining the sensory quality and nutritional value of fresh-cut potatoes, and increasing the shelf life of fresh-cut potatoes. It is highly safe and non-toxic. DETAILED DESCRIPTION

[0008] The present invention is further explained by examples below, but these examples do not limit the scope of protection of the present invention. The methods in the examples are conventional methods unless otherwise specified, and the reagents used are conventional commercial reagents or reagents prepared according to conventional methods unless otherwise specified; In the following examples, weight loss rate (%): The weight of each group of fresh-cut potatoes was weighed using an electronic scale on day 0 and recorded as m 0, the weight measured at the subsequent storage time is recorded as m; when calculating the mass difference, the mass measured at the storage time point is subtracted from the mass on day 0 to obtain the mass difference, and the weight loss rate is expressed as W, and the calculation formula is as follows: ; Hardness (N): The texture analyzer was used to measure the hardness of the fresh-cut potatoes. Three pieces of fresh-cut potatoes were selected from each group. The probe was placed perpendicular to the fresh-cut potatoes to measure their hardness.

[0009] Browning index: Use a colorimeter to measure the chromaticity of fresh-cut potatoes, including the color values ​​L* (brightness), a* (redness) and b* (yellowness); lay the fresh-cut potato slices flat and try to ensure that the center of the fresh slices is aligned with the light hole for measurement. The calculation formula is as follows:

[0010] ; Embodiment 1: the preservation method of fresh-cut potatoes of the present invention 1. Use SX-G30 acidic electrolyzed water generator to make tap water into slightly acidic electrolyzed water with an effective chlorine concentration of 100ppm and a pH of 5-6; use SX-G30 acidic electrolyzed water generator to make tap water into alkaline electrolyzed water with a pH of 8-9; prepare a natamycin solution with a concentration of 0.05g / L; 2. Wash and peel the selected potatoes, and use a slicer to cut them into 0.5 cm thick slices; 3. Soak the fresh-cut potato slices completely in slightly acidic electrolyzed water at room temperature for 10 minutes, then take them out and drain; 4. Soak the potatoes from step 3 completely in alkaline electrolyzed water at room temperature for 60 seconds, then take them out and drain; 5. Soak the fresh-cut potatoes in step 4 in natamycin solution at room temperature for 5 minutes, take them out and drain them; 6. Irradiate the potatoes from step 5 with ultraviolet light at an intensity of 15 mW / cm² for 10 minutes; 7. Vacuum-pack the processed fresh-cut potatoes with a vacuum degree of 0.1 MPa and store them in a cold storage at 4°C for preservation.

[0011] Comparative Example 1: 1. Wash and peel the selected potatoes, and use a slicer to cut the potatoes into 0.5 cm thick slices; 2. Soak the fresh-cut potato slices completely in tap water at room temperature for 10 minutes, take them out and drain them; after vacuum packaging, store them in a 4°C cold storage to preserve them.

[0012] Comparative Example 2: The slicing is the same as that of Comparative Example 2, except that the fresh-cut potato slices are completely immersed in slightly acidic electrolyzed water (the same as in Example 1) at room temperature for 10 minutes, taken out and drained; vacuum packed, and stored in a 4° C. cold storage for preservation.

[0013] Comparative Example 3: The slicing is the same as that of comparative example 2, except that the fresh-cut potato slices are completely immersed in alkaline electrolyzed water (the same as in example 1) at room temperature for 60 seconds, taken out and drained; vacuum packed, and stored in a 4° C. cold storage for preservation.

[0014] Comparative Example 4: The slicing is the same as that of Comparative Example 2, except that the fresh-cut potato slices are completely immersed in the natamycin solution at room temperature for 5 minutes, taken out and drained, vacuum-packed, and stored in a 4°C cold storage for preservation.

[0015] Comparative Example 5: The slicing is the same as that of comparative example 2, except that the fresh-cut potato slices are irradiated with 15 mW / cm² ultraviolet rays for 10 minutes, vacuum-packed, and stored in a 4°C cold storage for preservation.

[0016] Comparative Example 6: The reagent preparation is the same as in Example 1, except that the fresh-cut potato slices are first soaked in alkaline electrolyzed water and then soaked in slightly acidic electrolyzed water, and the remaining steps are the same; The vacuum-packed fresh-cut potatoes of Example 1 and Comparative Examples 1-6 were placed in a 4° C. cold storage for storage and preservation for a total of 28 days, during which the quality indicators of the fresh-cut potatoes were measured.

[0017] The results of the effects of different treatments on the weight loss rate, hardness, and browning index of fresh-cut potatoes during storage are shown in Table 1;

[0018] ;

[0019] Note: Different letters a, b, c, d in the table indicate significant differences between different groups at the same storage days, p < 0.05.

[0020] It can be seen from the results in the above table that the weight loss rate and browning index of Example 1 of the preservation method of the present invention are lower than those of Comparative Examples 1-6, and the hardness is higher than that of Comparative Examples 1-6, indicating that the combined treatment method of slightly acidic electrolyzed water + alkaline electrolyzed water + natamycin + ultraviolet irradiation can maximize the preservation effect of potatoes.

[0021] The comparison results of Comparative Example 6 and Example 1 show that the preservation effect of soaking in slightly acidic electrolyzed water first is better than that of soaking in alkaline electrolyzed water first; The above results show that the combined treatment method of slightly acidic electrolyzed water + alkaline electrolyzed water + natamycin + ultraviolet irradiation can more effectively inhibit the occurrence of enzymatic browning of potatoes, and can effectively inhibit the loss of moisture and quality of potatoes during storage.

Claims

1. A method for preserving fresh-cut potatoes, characterized in that: First, fresh-cut potatoes are soaked in slightly acidic electrolyzed water for 8-12 minutes, and then soaked in alkaline electrolyzed water for 55-65 seconds; then, fresh-cut potatoes are soaked in natamycin solution for 1-5 minutes, and then the fresh-cut potatoes are irradiated with ultraviolet light for 25-30 minutes, and finally vacuum-packed to achieve the preservation of fresh-cut potatoes.

2. The method for preserving fresh-cut potatoes according to claim 1, wherein: The effective chlorine concentration of slightly acidic electrolyzed water is 90-100ppm and the pH is 5-6.

3. The method for preserving fresh-cut potatoes according to claim 1, wherein: The pH of alkaline electrolyzed water is 8-9.

4. The method for preserving fresh-cut potatoes according to claim 1, wherein: The concentration of natamycin solution is 0.04-0.05g / L.

5. The method for preserving fresh-cut potatoes according to claim 1, wherein: The intensity of UV radiation is 10-15mW / cm².

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