The Research Of Cinnamic Acid Compound Antistaling Agent On Fresh-keeping Hypsizygus Marmoreus Postharvest

Hypsizygus marmoreus is a precious edible fungus that is popular among consumers because of its high nutritional value.The Hypsizygus marmoreus is highly susceptible to microbial infestation during post-harvest storage,which causes the Hypsizygus marmoreus to rot.Among them,Trichoderma is one of the main pathogenic fungi of Hypsizygus marmoreus.However,the Hypsizygus marmoreus Trichoderma has not caused widespread concern,which makes the consumption of Hypsizygus marmoreus a certain safety hazard.At present,there are few researches on antisepsis and preservation of Hypsizygus marmoreus.In order to provide safe and effective antisepsis and preservation methods,and to provide theoretical basis and technical support for the development of natural broad-spectrum effective preservatives,the laboratory has screened the preservation formula of Agaricus bisporus(Protocatechuic acid 118.0 mg·L^-1,pullulan 0.3%,CaCl₂ 0.83%,NaCl 0.55%,temperature 4℃,spray amount 13:1),because of its poor preservation effect on Hypsizygus marmoreus,in order to expand the application of this formula in other edible fungi for further promotion,this paper adds a plant active substance with better inhibitory effect on postharvest pathogens of Hypsizygus marmoreus on the basis of the preservation formula to reduce the decay of seafood mushrooms,prolonging the shelf life of the Hypsizygus marmoreus.This experiment took the pathogenic bacteria isolated from the Hypsizygus marmoreus for test material and studied antifungal activity 9 Plant source active substances of cinnamic acid,gallic acid,oleanolic acid,schisandrin A,perillaldehyde,protocatechuic acid,etc.by method of mycelium growth rate.Screening and optimizing studies on fresh-keeping activities of plant-derived active substances based on weight of loss,rot rate and color difference.Based on the single factor experiment results,optimize complex preservatives consisting of plant-derived active substances,film-forming agent by orthogonal test methodology.It was investigated that fresh-keeping effects and induction of resistance of the Hypsizygus marmoreus to Trichoderma harzianum by compound preservative.The main results are as follows:（1）This paper was intend to isolate,purify,and identify Trichoderma harzianum（GenBank:MH284140.1）from Hypsizygus marmoreus with typical disease,This experiment took Trichoderma harzianum for test material and studied antifungal activity of plant-derived active substances by the mycelium growth rate method.The results showed that the inhibition rate of cinnamic acid were 82.10%.The EC₅₀0 of cinnamic acid were tested on the Trichoderma harzianum by the dilution spread plate method.The results showed that the EC₅₀0 of cinnamic acid on the Trichoderma harzianum was 2.6414 mg·mL^-1,similar to carbendazim(2.3865 mg·mL^-1);EC₅₀0 of cinnamic acid on the Trichoderma harzianum spore germination inhibition was 0.1283 mg·mL^-1,lower than carbendazim(0.1519 mg·mL^-1),Indicating that cinnamic acid inhibits Trichoderma harzianum.（2）Adding cinnamic acid on the basis of the formulation of the Agaricus bisporus preservative.Taking the weight loss rate,rot rate and color difference of the mushroom as the evaluation index,the cinnamic acid concentration was screened by single factor to determine the optimum concentration of cinnamic acid was 113.0 mg·L^-1.Taking the weight loss rate,rot rate and color difference of the mushroom as the weighted comprehensive index,the five-factor four-level orthogonal test optimized the composite preservative for the concentration of protocatechuic acid,NaCl,CaCl₂,pullulan and cinnamic acid to obtain the best combination:protocatechuic acid 121.0 mg·L^-1,cinnamic acid 113.0 mg·L^-1,NaCl 0.65%,CaCl₂ 0.83%,pullulan 0.35%.（3）The effect of compound preservative on the storage of Hypsizygus marmoreus,at4℃,each group was treated with 13:1 to treat Hypsizygus marmoreus,and the compound preservative group was compared with CK1（not done）,CK2（clean water）and positive group(1 g·L^-1 chlorine dioxide)at 12 d:the weight loss rate decreased by 29.29%,22.35%,and 8.66%,（P<0.05）;the rot rate decreased by 43.90%,40.73%,and 27.67%,（P<0.05）;the change of color difference decreased by 35.30%,33.71%,and 16.68%（P<0.05）.Physiological and biochemical parameters:browning degree decreased by 17.28%,14.36%,4.5%（P<0.05）;respiratory intensity decreased by 22.68%,21.40%,7.27%（P<0.05）;total phenol decreased by 36.51%,17.81%,7.50%（P<0.05）;malondialdehyde content decreased by 24.55%,20.25%,11.27%（P<0.05）.Resistance-related enzymes index:POD activity increased by 46.81%,48.88%,20.60%（P<0.05）,and PPO activity increased by 29.11%,29.11%,10.87%（P<0.05）;The activity of CAT increased by 61.51%,46.46%,and 14.92%（P<0.05）.The main nutrients and flavor substances:soluble protein decreased by 49.42%,52.94%,18.18%（P<0.05）;nucleic acid decreased by 45.24%,35.56%,23.23%（P<0.05）;free amino acids decreased by 4.25%,4.49%（P<0.05）and 0.60%（P>0.05）.（4）The effects of induction of resistance in Hypsizygus marmoreus against Trichoderma harzianum infection by antistaling agent consisting of cinnamic acid preservative were investigated.The incidence rate of the mushroom was reduced by 16.50%compared with CK2（inoculation of conidial suspension of Trichoderma harzianum）.The cinnamic acid composite preservative group was compared with CK1（sterile water）and CK2.PAL activity increased by 50.96%and 18.97%（P<0.05）;POD activity increased by20.07%and 15.11%（P<0.05）;PPO activity increased by 24.43%and 12.58%（P<0.05）;APX increased by 6.47%and 3.64%,respectively（P<0.05）;the relative conductivity decreased by 20.27%and 10.61%（P<0.05）;the free proline content decreased by 29.37%and 22.12%（P<0.05）;MDA content decreased by 23.83%and 39.93%,respectively（P<0.05）;CHI activity increased by 43.02%and 10.31%（P<0.05）;GLU activity increased by 71.87%and 13.01%（P<0.05）.These results suggested that treatment with cinnamic acid composite preservative may induce the resistance of Hypsizygus marmoreus on controlling Trichoderma harzianum decay.