CN-121975904-A - Screening method and application of lactobacillus plantarum Q9 with post-harvest freshness retaining function of agaricus bisporus

Abstract

The invention relates to the technical field of food preservation, and particularly discloses a screening method and application of lactobacillus plantarum Q9 with a post-harvest preservation function of agaricus bisporus. The screening step comprises separating suspected lactobacillus from conventional fermented milk of Qinghai-Tibet plateau and Gannan, identifying by gram positive and hydrogen peroxide enzyme-free activity, screening strain with good growth and high polyphenol conversion rate by using bisphenol of gallic acid, protocatechuic acid and the like as substrate, and screening lactobacillus plantarum Q9 by sensory evaluation. When the method is applied, the suspension containing 1.5X10 8 CFU/mL Q9 bacteria is sprayed on the surface of the agaricus bisporus, so that the browning can be inhibited, the weight loss rate and the respiration rate can be reduced, the growth of pseudomonas can be inhibited, the related enzyme activities can be regulated and controlled, the shelf life can be prolonged, and a safe and efficient biological fresh-keeping scheme can be provided for fresh-keeping of the agaricus bisporus after picking.

Inventors

• YANG XIAOLI
• SHI CHENGRUI
• WEN PENGCHENG
• WANG HUIJUAN
• LI ZHENGTAO
• WANG YAQIN

Assignees

• 甘肃省商业科技研究所有限公司
• 甘肃农业大学

Dates

Publication Date

20260505

Application Date

20251209

Claims (8)

1. 1. A screening method of lactobacillus plantarum Q9 with post-harvest freshness retaining function of agaricus bisporus is characterized by comprising the following steps: S1, separating and purifying suspected lactobacillus from traditional fermented milk of Tibetan autonomous state of Qinghai-Tibet plateau Gannan to obtain a pure strain; s2, carrying out gram staining and catalase activity identification on the pure strain, and retaining the strain which is gram positive and has no catalase activity; S3, screening strains which grow well in a phenolic environment by taking characteristic polyphenol in agaricus bisporus as a substrate, wherein the characteristic polyphenol comprises one or more of gallic acid, protocatechuic acid and catechin; S4, determining the conversion rate of the S3 screening strain to gallic acid and protocatechuic acid by adopting high performance liquid chromatography, and selecting the strain with high conversion rate; s5, applying the strain selected in the S4 to the agaricus bisporus, screening out the strain capable of effectively maintaining the quality of the agaricus bisporus after picking through sensory evaluation, and finally obtaining the lactobacillus plantarum Q9.
2. 2. The method of claim 1, wherein in S2, the screening is performed in MRS liquid medium containing the characteristic polyphenol, and the growth condition of the strain is evaluated by measuring the absorbance value at 600 nm.
3. 3. The method of claim 1, wherein in S5, the sensory evaluation comprises scoring the degree of browning, cap morphology, odor, fruiting body softness and consumer acceptance of the agaricus bisporus.
4. 4. Lactobacillus plantarum Q9, characterized in that it is obtained by the screening method according to any of claims 1-3.
5. 5. The use of lactobacillus plantarum Q9 according to claim 4 for post harvest preservation of agaricus bisporus.
6. 6. The use according to claim 5, characterized in that it is the spraying of a bacterial suspension of lactobacillus plantarum Q9 on the surface of agaricus bisporus.
7. 7. The use according to claim 6, wherein about 1ml of the bacterial liquid is sprayed per ml of the bacterial liquid, and about 1.5X10 8 CFU of lactobacillus plantarum Q9 is contained per ml of the bacterial liquid.
8. 8. The use according to claim 5, wherein the preservation comprises one or more of inhibiting agaricus bisporus browning, reducing weight loss rate, maintaining fruiting body hardness, reducing respiration rate, inhibiting pseudomonas growth, reducing polyphenol oxidase activity, increasing superoxide dismutase and catalase activity, reducing active oxygen accumulation, reducing malondialdehyde content and cell membrane conductivity.

Description

Screening method and application of lactobacillus plantarum Q9 with post-harvest freshness retaining function of agaricus bisporus Technical Field The invention relates to the technical field of food preservation, in particular to a screening method and application of lactobacillus plantarum Q9 with a post-harvest preservation function of agaricus bisporus. Background The existing domestic market circulation edible fungi mostly adopts a cold chain logistics mode, which is the most common fresh-keeping means at the present stage, but the effect of controlling the browning of the mushrooms by cooling is limited, other more efficient methods still need to be researched, and the main stream fresh-keeping methods researched at present comprise air-conditioning packaging, chemical bacteriostat, irradiation treatment, pulse electric field treatment, ozone treatment and the like. However, the above methods have respective limitations, such as that the modified atmosphere packaging requires a high technical level in using the debugging equipment. Chemical bacteriostats are easy to have chemical residues, and have potential unsafe factors for the safety of consumers. The irradiation treatment can cause the modification of partial sub-substances in the fruiting body of the agaricus bisporus, so that the food safety is affected. The pulsed electric field treatment requires a great deal of energy consumption, and the cost control has a difficult problem. The most effective preservation method at present is based on a cold chain or air-drying heat treatment combined with packaging and chemical reagents. The use of microorganisms recognized as safe (GRAS), such as yeasts, lactic acid bacteria and natural metabolites, to inhibit spoilage microorganisms, control color, and extend the shelf life of vegetables and fruits is an efficient and safe means. Recent studies have shown that biological preservatives have been used on a variety of foods, such as meats, plant-derived foods. Lactic acid bacteria have great potential as biological antistaling agent for non-fermented food. Lactic acid bacteria were initially used to make fermented foods to extend the shelf life of the food, and safety was well proven during use. Lactic acid bacteria are also used as biological antistaling agents in the prior nonfermented foods, the single lactic acid bacteria (lactobacillus casei LC1, lactobacillus plantarum LP1 and lactobacillus L3) have obvious inhibition effect on dominant spoilage bacteria of 2 strains of refrigerated sea bass, the fresh-keeping period of 6 days can be delayed, the picked fruits can be kept fresh after being screened by the high-altitude lactic acid bacteria, and the Lactobacillus delbrueckii can delay the decay of strawberry fruits and the like. The research shows that lactic acid bacteria can raise GSH-Px activity in silage, influence hydrogen peroxide induced lipid peroxidation and protect cell membrane rupture, and the bacterial suspension of lactic acid bacteria can also control the color change of litchi post-harvest epidermis effectively. Although lactic acid bacteria have been studied for controlling fruit and vegetable spoilage microorganisms and color, no report has been made on screening anti-browning lactic acid bacteria based on agaricus bisporus characteristics and applying them to post-harvest preservation. Therefore, the lactobacillus strain which is high in safety and is suitable for the physiological characteristics of the agaricus bisporus after being picked and has comprehensive fresh-keeping mechanism is screened, and the method has important practical significance for breaking through the bottleneck of the prior art and promoting the high-quality development of the agaricus bisporus industry. Disclosure of Invention The invention aims to provide a screening method and application of lactobacillus plantarum Q9 with a post-harvest fresh-keeping function of agaricus bisporus. The screening method creatively starts from the novel angle of microbial transformation of polyphenol, can efficiently and directionally obtain the strain with anti-browning function, and the obtained Q9 strain not only can effectively maintain the postharvest quality of agaricus bisporus and prolong the shelf life, but also provides a brand new solution of a safe and efficient microbial preservative for solving the postharvest browning problem of edible fungi. In order to achieve the above purpose, the invention provides a screening method of lactobacillus plantarum Q9 with a post-harvest fresh-keeping function of agaricus bisporus, which comprises the following steps: S1, separating and purifying suspected lactobacillus from traditional fermented milk of Tibetan autonomous state of Qinghai-Tibet plateau Gannan to obtain a pure strain; s2, carrying out gram staining and catalase activity identification on the pure strain, and retaining the strain which is gram positive and has no catalase activity; S3, screening strains which g