Abstract:The successful use of antagonistic yeasts to control postharvest diseases of fruits and vegetables relies on commercializing yeast preparations. Antagonistic yeast, namely Debaryomyces hansenii (D. hansenii) was used as the research object to analyze the effect of its freeze-dried formulation on the postharvest soft rot of strawberry. Firstly, the impact of different protective agents at different concentrations on the survival rate of D. hansenii in freeze-drying process was examined by a single-factor test. Then, the response surface methodology was used to optimize the protectant regimen. Finally, the survival rate of freeze-dried D. hansenii preparation during storage and its control effect on postharvest soft rot of strawberry was verified under the optimal protectant regimen. The study exposed that the optimal protectant regimen for freeze-drying of D. hansenii preparation was 2.22% alginate, 17.83% skimmed milk powder, 0.06% L-ascorbic acid and 4.06% sodium L-glutamine. D. hansenii in he freeze-dried formulation obtained by the optimal protectant regimen maintained a high survival rate of 70%~80% during prolonged storage of 90 d, and this formulation effectively controlled the postharvest soft rot of strawberry caused by Rhizopus stolonifer (R. stolonifer).
