Method for increasing content of phenols in postharvest induced water chestnut shells

Abstract

The invention relates to the technical field of food processing. More specifically, the invention relates to a method for increasing the content of phenols in a postharvest induced water chestnut shell. According to the method for improving the content of the phenolic substances in the postharvest induced water chestnut shells, the phenolic substances in the water chestnut shells can be effectively induced to be improved, the content of total phenols in the water chestnut shells treated through UV-B can be increased by 37.7% at most, and the content of total flavonoids can be increased by 42% at most. The method is simple and easy to operate, relatively low in investment and operation cost and suitable for large-scale operation.

Description

Technical Field

[0001] This invention relates to the field of food processing technology. More specifically, this invention relates to a method for inducing an increase in the content of phenolic substances in water chestnut shells postharvest. Background Technology

[0002] Water chestnut (Trapa quadrispinosa Roxb.) is a common annual floating aquatic plant found in freshwater wetlands, lakes, ponds, and slow-flowing rivers, widely distributed in Asia and Europe. Studies have found that water chestnut shells are rich in phenolic compounds, possessing analgesic, anti-ulcer, immunomodulatory, and hypoglycemic activities. Furthermore, China has a history of using water chestnut shells as hypoglycemic drugs. In 2022, a team led by Professors Cai Shengbao and Zhou Linyan at Kunming University of Science and Technology discovered that the phenolic compounds in water chestnut shells have good antioxidant activity and can effectively inhibit the activity of α-glucosidase.

[0003] Current research on phenolic substances in water chestnut shells mainly focuses on extraction and application. For example, Chinese invention patent application number 201410810654.0 discloses a method for preparing polyphenol extract from water chestnut shells. This invention primarily improves the extraction rate of phenolic substances from water chestnut shells by optimizing the extraction method. Summary of the Invention

[0004] The purpose of this invention is to provide a method for inducing postharvest increase in the content of phenolic substances in water chestnut shells, thereby effectively increasing the content of phenolic substances in water chestnut shells.

[0005] To achieve these objectives and other advantages according to the present invention, a method for inducing postharvest increase in phenolic content in water chestnut shells is provided, comprising the following steps: The harvested water chestnuts were placed under conditions of 16-24℃ and 40-50% humidity and treated with medium-wave ultraviolet light.

[0006] Furthermore, in the method for inducing the increase of phenolic substances in water chestnut shells after harvest, the treatment time using medium-wave ultraviolet light is 24 hours.

[0007] Furthermore, in the method for inducing the increase of phenolic substances in water chestnut shells after harvest, the wavelength of the medium-wave ultraviolet light used is 311 nm.

[0008] Furthermore, in the method for inducing the increase of phenolic substances in water chestnut shells after harvest, fruits without mechanical damage, cracking, disease, pests, or rot are selected for medium-wave ultraviolet irradiation treatment.

[0009] The beneficial effects of this invention are: The method for inducing postharvest phenolic content enhancement in water chestnut shells according to the present invention can effectively induce an increase in phenolic content in water chestnut shells. After UV-B treatment, the total phenolic content of water chestnut shells can increase by up to 37.7%, and the total flavonoid content can increase by up to 42%. This method is simple and easy to operate, with relatively low input and operating costs, making it suitable for large-scale operations.

[0010] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0011] Figure 1 This is a schematic diagram illustrating the change in total phenolic content of water chestnut shells after 24 hours of treatment in an embodiment of the present invention; Figure 2 This is a schematic diagram illustrating the change in total flavonoid content in water chestnut shells after 24 hours of treatment in an embodiment of the present invention. Detailed Implementation

[0012] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0013] It should be noted that, unless otherwise specified, the experimental methods described in the following implementation plan are all conventional methods, and the reagents and materials described are all commercially available unless otherwise specified.

[0014] Embodiments of the present invention provide a method for inducing an increase in the content of phenolic substances in water chestnut shells after harvest, comprising the following steps: After harvesting mature water chestnuts, select fruits that are uniform in size, free from mechanical damage, cracking, disease, pests, and rot. Place these fruits under conditions of 16-24℃ and 40-50% humidity and treat them with medium-wave ultraviolet light. The ultraviolet light source used is a 20W medium-wave ultraviolet light source (UV-B, 311nm) (Philips, TL20W / 01, Netherlands).

[0015] Experimental Analysis Two experimental groups were used. Experimental group 1 treated the mature water chestnut fruits according to the method described in the above embodiment. Experimental group 1 used the same mature water chestnut fruits and placed them in a dark sealed box under the same temperature and humidity conditions, without light.

[0016] The experiment was set up with 3 replicates, with 10 fruits in each group. After 24 hours of treatment, one batch of samples was immediately frozen and designated as day 0; the remaining samples were stored and sampled on days 2 and 4. When sampling, the pulp of the water chestnut was removed, and the water chestnut shells were immediately flash-frozen in liquid nitrogen and stored at -80℃ for the determination of total phenols and total flavonoids.

[0017] Results analysis: UV-B irradiation effectively promotes the increase of phenolic content in water chestnut shells. In group 1 (UV-B group), irradiated for 24 hours, the total phenol and total flavonoid contents were significantly higher than those in group 2 (CK group) from day 0 to day 4. Within group 1, on day 0 of storage, the group treated with 24 hours of UV-B irradiation showed the highest total phenol and total flavonoid contents, significantly increased by 37.7% and 42%, respectively, compared to group 2. This indicates that within a certain range, UV-B irradiation can more effectively increase the phenolic content in water chestnut shells.

[0018] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and embodiments shown and described herein.

Claims

1. A method for post-harvest induction of an increase in the content of hydroxybenzoic acids in water caltrop fruits, characterized in that, The method comprises the following steps: The picked water caltrop is placed in a condition of 16-24℃ and 40-50% humidity, and is treated by using middle wave ultraviolet rays.

2. The method of claim 1, wherein the method is characterized by, The treatment time of the middle wave ultraviolet rays is 24 hours.

3. The method of claim 1, wherein the method is characterized by, The wavelength of the used middle wave ultraviolet rays is 311nm.

4. The method of claim 1, wherein the method is characterized by, The fruits without mechanical damage, no cracked fruits, no diseases and pests and no rot are selected for the treatment of the middle wave ultraviolet rays.

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