Method for inhibiting greening and germination of harvested potatoes and application

Abstract

The invention belongs to the field of application of postharvest preservation of potatoes, and particularly relates to a method for inhibiting greening and germination of postharvest potatoes and application of the postharvest potatoes, and the method comprises the following steps: screening, warming, cleaning, disinfecting, soaking and airing the potatoes, and then carrying out shelf life test; wherein the soaking is performed by adopting a calcium chloride solution; the shelf life test is illumination or non-illumination treatment. Research finds that after the potatoes are harvested, the potatoes in the non-dormancy period are soaked for 20 minutes by adopting a 0.8 wt% calcium chloride solution, and the potatoes in the dormancy period are soaked for 5 minutes by adopting a 0.6 wt% calcium chloride solution, so that the greening inhibition and the bud inhibition of the potatoes after the harvesting can be simply and effectively realized, and important reference is provided for further exploration of a greening inhibitor and a bud inhibitor of the harvested fruits and vegetables.

Description

Technical Field

[0001] The invention belongs to the application field of post-harvest potato preservation, and particularly relates to a method and application of inhibiting greening and germination of post-harvest potatoes. Background Art

[0002] Potato is one of the most important food crops in the world, with rich nutritional value. However, during the storage and transportation of potatoes, "greening" and "sprouting" are prone to occur, which affects their edible value and economic value. To solve these problems, the research and development of greening inhibitors and sprout inhibitors has become an important technical means in the potato industry.

[0003] Potato greening refers to the accumulation of chlorophyll on the tuber epidermis due to light exposure, which causes the surface of the potato to appear green. Greening is accompanied by the accumulation of toxic alkaloids such as solanine and chaconine. These toxins are harmful to human health at high concentrations and can cause gastrointestinal discomfort, headaches and other symptoms. Most of the greening suppression methods on the market use light-shielding packaging materials. By using opaque or low-light-transmittance materials to package potatoes, the stimulation of light on the tubers is reduced and the accumulation of chlorophyll is prevented; appropriate storage conditions are selected, and a suitable low temperature and low humidity environment is maintained to reduce light exposure and avoid greening.

[0004] Potato sprouting refers to the sprouting of potatoes during storage, which is easily affected by temperature and humidity. Potato sprouting not only leads to the loss of nutrients, but also increases the content of alkaloids, threatening food safety. Sprouting technology mainly uses physical and chemical means to delay or inhibit the growth of potato sprouts. The main methods of sprout inhibition at present: Chemical sprout inhibitors: such as chlorpromazine, which is a commonly used potato sprout inhibitor that delays the germination process by inhibiting plant cell division. Physical sprout inhibition technology: By controlling the storage temperature (usually between 4°C and 8°C) and humidity, the growth activity of potatoes is reduced to achieve the purpose of sprout inhibition. Light control can also be used as a means to prevent light from promoting growth.

[0005] In recent years, due to health and environmental concerns, people have become more cautious about the use of chemical greening inhibitors and sprout inhibitors, which has promoted the research and development of new greening and sprouting inhibition technologies. In the research on inhibiting potato greening and sprouting, green, environmentally friendly and sustainable development technologies are the future trend. Summary of the invention

[0006] The purpose of the present invention is to provide a method and application for inhibiting greening and sprouting of potatoes after harvest. By developing low-toxic and non-toxic natural sprout and greening inhibitors and combining them with physical control measures, the storage quality of potatoes can be better guaranteed and the negative impact on the environment can be reduced.

[0007] In order to achieve the above object, the technical solution of the present invention is: In a first aspect, the present invention provides a method for inhibiting greening and sprouting of potatoes after harvest, comprising the steps of disinfecting the potatoes and then soaking them in a calcium chloride solution.

[0008] During the research process, the inventors found that the use of calcium chloride as a reagent for inhibiting greening and sprouting of potatoes after harvest has the following advantages: (1) Safe development of low-toxic and non-toxic natural properties: Calcium chloride is a substance widely used in the food industry, has low toxicity, is highly safe for the human body, and meets food safety standards; (2) Maintaining the quality of fruits and vegetables after harvest: Calcium chloride can enhance the stability of cell walls and reduce water loss, thereby improving the texture and flavor during storage; (3) Inhibiting physiological processes: By affecting the physiological activities of cells, calcium chloride can effectively delay the growth of sprouts and the accumulation of chlorophyll, thereby reducing the phenomenon of greening. (4) Easy to apply: Calcium chloride solution can be conveniently applied by soaking or spraying, which is suitable for large-scale production. By developing low-toxic and non-toxic natural sprout and greening inhibitors, combined with physical control methods, the storage quality of potatoes can be better guaranteed and the negative impact on the environment can be reduced.

[0009] In some other embodiments, the potatoes are potatoes that are refrigerated at low temperatures during a dormant period or potatoes that are not refrigerated during a non-dormant period.

[0010] In some other embodiments, the potatoes stored at low temperature during dormancy are potatoes stored at 0-4° C. for at least 3 months; Alternatively, the potatoes that are not refrigerated during the non-dormant period are freshly picked potatoes.

[0011] In some other embodiments, the concentration of the calcium chloride solution is 0.2-1.0 wt %; and the immersion time is 5-30 min.

[0012] In some other embodiments, the concentration of the calcium chloride solution used for soaking the potatoes in low-temperature refrigeration during the dormant period is 0.6 wt %, and the soaking time is 5 min; Alternatively, the concentration of the calcium chloride solution used for soaking the potatoes that are not refrigerated during the non-dormant period is 0.8 wt %, and the soaking time is 20 min.

[0013] In some other embodiments, the disinfection is performed by spraying a NaClO solution on the surface of the potatoes.

[0014] In some other embodiments, the concentration of the NaClO solution is 100-300 μL / L, and the disinfection time is 1-5 min; Preferably, the concentration of the NaClO solution is 200 μL / L, and the disinfection time is 3 minutes.

[0015] In some other embodiments, the method further comprises screening and washing the potatoes before disinfection; the screening comprises selecting potatoes of uniform size, without mechanical damage, without sprouting, without green change, and without deformity.

[0016] In some other embodiments, the method further comprises warming up the potatoes stored at low temperature during the dormancy period after screening, wherein the warming up is performed by placing the potatoes stored at low temperature during the dormancy period at room temperature in the dark to warm up.

[0017] In a second aspect, the present invention provides the use of the method for inhibiting greening and sprouting of postharvest potatoes described in the first aspect in improving the freshness of postharvest potatoes.

[0018] Beneficial effects of the present invention: The present invention adopts calcium chloride as a sprout inhibitor and green change inhibitor, combined with physical control means, can better ensure the storage quality of potatoes, effectively reduce the a* value in the color difference value, the chlorophyll content of potatoes in the dormant period and non-dormant period, and slow down the growth of sprouts of potatoes in the non-dormant period; at the same time, reduce the negative impact on the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0020] Figure 1 is the a* value in the color difference value in the embodiment of the present invention; wherein, the light control (FCKL, non-dormant period; CKL, dormant period) and the dark control (FCKD, non-dormant period; CKD, dormant period) calcium chloride treatment (FCaCl 2 , non-dormant period; CaCl 2 , dormant period); Figure 2 is the chlorophyll content in the embodiment of the present invention; Figure 3 For the growth of buds in the embodiment of the present invention; Figure 4 In the embodiment of the present invention, CaCl 2 The concentration was screened; the non-dormant potatoes were immersed in water, and the greening phenotype was observed after 3 days of illumination, with the untreated non-illuminated (FCKD) and illuminated potatoes (FCKL) as controls; the dormant potatoes were treated, and the greening phenotype was observed after 4 days of illumination, with the untreated non-illuminated (CKD) and illuminated potatoes (CKL) as controls; Figure 5 In the embodiment of the present invention, CaCl 2 Screening of immersion time; Among them, CaCl 2The non-dormant potatoes were immersed in the solution, and the green change phenotypes were observed after 6 days of illumination. The untreated non-illuminated (FCKD) and illuminated potatoes (FCKL) were used as controls. 2 Dormant potatoes were immersed in the solution, and their green change phenotypes were observed after 4 days of illumination. Untreated non-illuminated (CKD) and illuminated potatoes (CKL) were used as controls. DETAILED DESCRIPTION

[0021] In order to better illustrate the present invention, the present invention is further described in detail below in conjunction with the examples. If the specific conditions are not specified in the examples, they are carried out according to the normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0022] Example 1 (1) Potato material selection: Potatoes of the Holland 15 variety that have been stored in a 4°C low-temperature cold storage for 3 months are purchased. After the purchase, select potato tubers with uniform tuber size, single weight of 150-250 g, no mechanical damage, no sprouting, no green change, and no deformity. Put them into cartons and place them in a fruit and vegetable preservation cold storage at 0-4°C for later use. Potatoes that have just been harvested and not stored in a cold storage are also kept for later use.

[0023] (2) Rewarming: First, take the potatoes out of the cold storage and place them in a dark room at room temperature (about 25°C) for rewarming. (Potatoes stored in the cold storage need to be rewarmed, but potatoes that have just been harvested do not.) (3) Cleaning and disinfection: After the potatoes have completely returned to temperature, wash off dirt and other impurities on the surface with water, then immerse them in 200 μL / L NaClO solution for disinfection for 3 min. Take them out and use gauze to absorb the solution on the surface of the potatoes.

[0024] (4) Soaking in calcium chloride solution: CaCl 2 Screening of optimal immersion concentration: In testing the optimal CaCl 2 In the soaking treatment condition, the potatoes that have been warmed and disinfected (potatoes in the non-dormant period do not need to be warmed) are placed in the CaCl 2 The samples were immersed in the solution for 10 min. After the immersion was completed, they were taken out and placed on a dry and clean laboratory table to dry. The shelf life test was carried out under the conditions of 20 °C, 80%-85% relative humidity, and 25 W fluorescent irradiation for 24 h / d to screen out the non-dormant period (FCaCl 2 ) and dormant period (CaCl 2) optimal soaking concentration. At the same time, two controls were set in each period, namely light control (FCKL, non-dormancy period; CKL, dormancy period) and dark control (FCKD, non-dormancy period; CKD, dormancy period). Each experiment treated 60 tubers, and observations were made every 3 days during the non-dormancy period, with 3 or more replicates each time; observations were made every 1 day during the dormancy period, with 3 or more replicates each time.

[0025] CaCl 2 Screening of the optimal soaking time: After screening out CaCl 2 Based on the optimal soaking concentration, the pre-treated potatoes are placed in the prepared CaCl 2 The samples were immersed in the solution with the optimal concentration for 5 min, 10 min, 15 min, and 20 min, respectively. After the immersion, the samples were taken out and placed on a dry and clean laboratory table to dry. The shelf life test was carried out under the conditions of 20 °C, 80%-85% relative humidity, and 25 W fluorescent irradiation for 24 h / d to screen out CaCl 2 Optimal soaking time. At the same time, set two Each experiment treated 60 tubers, and observations were performed every 3 days during the non-dormancy period, with 3 or more replicates for each measurement; observations were performed every 1 day during the dormancy period, with 3 or more replicates for each measurement.

[0026] (5) Let it dry: After soaking, take it out and place it on a dry, clean laboratory table to dry.

[0027] (6) Shelf life test: take photos and observe, take samples to measure a* value, chlorophyll and bud length index and analyze During the non-dormant period, observations, measurements and sampling were carried out every 3 days, with 3 or more replicates each time; during the dormant period, observations, measurements and sampling were carried out every 1 day, with 3 or more replicates each time.

[0028] Figure 1 is the a* value in the color difference value in the embodiment of the present invention; wherein, the light control (FCKL, non-dormant period; CKL, dormant period) and the dark control (FCKD, non-dormant period; CKD, dormant period) calcium chloride treatment (FCaCl 2 , non-dormant period; FCaCl 2 , dormant period); from Figure 1 It can be seen that due to the inhibitory effect of calcium chloride, the a* value of the calcium chloride treatment group is significantly lower than that of the light control group. It has a significant inhibitory effect on non-dormant potatoes within 12 days and on dormant potatoes within 4 days.

[0029] Table 1, Table 2 and Figure 2 The chlorophyll content in the tested potatoes is as follows: Table 1 Chlorophyll content in non-dormant potatoes

[0030] Table 2 Chlorophyll content in dormant potatoes

[0031] Figure 2 is the chlorophyll content in the embodiment of the present invention; Figure 2 It can be seen that the chlorophyll content in potatoes increases with the extension of the exposure time in light, and the chlorophyll content after calcium chloride treatment is significantly lower than that in the light control group.

[0032] Figure 3 For the growth of buds in the embodiment of the present invention; from Figure 3 It can be seen that the length of potato sprouts in the non-dormancy period increases with the extension of time, and the average sprout length after calcium chloride treatment is significantly shorter than that of the light control group.

[0033] Figure 4 In the embodiment of the present invention, CaCl 2 The concentration was screened; non-dormant potatoes were soaked, and their greening phenotypes were observed after 3 days of illumination, with untreated non-illuminated (FCKD) and illuminated potatoes (FCKL) as controls; dormant potatoes were treated, and their greening phenotypes were observed after 4 days of illumination, with untreated non-illuminated (CKD) and illuminated potatoes (CKL) as controls; Figure 4 It can be seen that the greening effect of non-dormant potatoes was most obvious when treated with 0.8wt% calcium chloride solution, while the greening effect of dormant potatoes was most obvious when treated with 0.6wt% calcium chloride solution.

[0034] Figure 5 In the embodiment of the present invention, CaCl 2 Screening of immersion time; Among them, CaCl 2 The non-dormant potatoes were immersed in the solution, and the green change phenotypes were observed after 6 days of illumination. The untreated non-illuminated (FCKD) and illuminated potatoes (FCKL) were used as controls. 2 The dormant potatoes were immersed in the solution, and the green change phenotype was observed after 4 days of illumination. Untreated non-illuminated (CKD) and illuminated potatoes (CKL) were used as controls. Figure 5It can be seen that the greening inhibition effect is most obvious when non-dormant potatoes are treated with 0.8wt% calcium chloride solution for 20 minutes, while the greening inhibition effect is most obvious when dormant potatoes are treated with 0.6wt% calcium chloride solution for 5 minutes.

[0035] The present invention utilizes 0.8 wt % calcium chloride solution to soak potatoes in a non-dormant period after harvest for 20 minutes; and 0.6 wt % calcium chloride solution to soak potatoes in a dormant period after harvest for 5 minutes, which can simply and effectively achieve the inhibition of greening and sprouting of potatoes after harvest, and provides an important reference for further exploration of greening inhibitors and sprout inhibitors for postharvest fruits and vegetables.

[0036] Comparative Example 1 The difference from Example 1 is that calcium nitrate is used instead of calcium chloride to soak the sterilized potatoes, and the other steps are exactly the same as those in Example 1.

[0037] Studies have found that calcium nitrate is not as effective as calcium chloride in inhibiting greening. The nitrogen in the nitrate ions will promote greening, and the nitrate ions provided by calcium nitrate may stimulate certain metabolic processes, leading to accelerated greening, especially under light conditions.

[0038] Comparative Example 2 The difference from Example 1 is that the disinfection process is omitted, and the potatoes after being warmed up are directly soaked in calcium chloride. The other steps are exactly the same as those in Example 1.

[0039] Research has found that NaClO disinfection is to kill the germs on the surface of potatoes and prevent them from rotting. It can effectively remove microorganisms and bacteria on the surface of potatoes and reduce the contamination of potatoes by pathogens. This helps to extend the storage time and improve the subsequent treatment effect.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for inhibiting greening and sprouting of postharvest potatoes, characterized in that: After disinfecting the potatoes, soak them in calcium chloride solution.

2. The method for inhibiting greening and sprouting of postharvest potatoes according to claim 1, characterized in that: The potatoes are potatoes that are refrigerated at low temperature during a dormant period or potatoes that are not refrigerated during a non-dormant period.

3. The method for inhibiting greening and sprouting of postharvest potatoes according to claim 2, characterized in that: The potatoes stored at low temperature during dormancy are potatoes stored at 0-4°C for at least 3 months; Alternatively, the potatoes that are not refrigerated during the non-dormant period are freshly picked potatoes.

4. The method for inhibiting greening and sprouting of postharvest potatoes according to claim 1, characterized in that: The concentration of the calcium chloride solution is 0.2-1.0wt%; the soaking time is 5-30min.

5. The method for inhibiting greening and sprouting of postharvest potatoes according to claim 4, characterized in that: The concentration of the calcium chloride solution used for soaking the potatoes in low-temperature refrigeration during the dormant period is 0.6wt%, and the soaking time is 5min; Alternatively, the concentration of the calcium chloride solution used for soaking the potatoes that are not refrigerated during the non-dormant period is 0.8 wt %, and the soaking time is 20 min.

6. The method for inhibiting greening and sprouting of postharvest potatoes according to claim 1, characterized in that: The disinfection is carried out by spraying NaClO solution on the surface of potatoes.

7. The method for inhibiting greening and sprouting of postharvest potatoes according to claim 5, characterized in that: The concentration of the NaClO solution is 100-300 μL / L, and the disinfection time is 1-5 min; Preferably, the concentration of the NaClO solution is 200 μL / L, and the disinfection time is 3 minutes.

8. The method for inhibiting greening and sprouting of postharvest potatoes according to claim 1, characterized in that: The method also includes screening and washing the potatoes before disinfection; the screening is to select potatoes with uniform size, no mechanical damage, no sprouting, no green change, and no deformity.

9. The method for inhibiting greening and sprouting of postharvest potatoes according to claim 8, characterized in that: The method also includes warming up the potatoes stored at low temperature during the dormancy period after screening, wherein the warming up is to place the potatoes stored at low temperature during the dormancy period at room temperature in the dark to warm up.

10. Use of the method for inhibiting greening and sprouting of postharvest potatoes according to any one of claims 1 to 9 in improving the freshness of postharvest potatoes.

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