Study of the effect of sericin coatings extracted from Bombyx mori silkworm cocoons on fruit degradation

Abstract

Post-harvest fruit production losses are caused by spoilage, infestation and microbial attack. The use of coatings allows to increase the time of conservation of the fruits, these work as a barrier. In this project, sericin coatings extracted from the Bombyx mori silkworm were produced. The process of extraction of sericin was carried out using an aqueous solution of sodium carbonate and later a process of dialysis was carried out in order to eliminate the salts present in the solution, the coatings were made using different techniques of impregnation. The effect of the sericin coatings on the degradation of strawberries and bananas was evaluated; a control sample was taken for both bananas and strawberries, these controls had the same pre-treatment but no coating was applied to them, the fruits were impregnated with layers of the sericin solution until their surface was completely covered, this process was done in one to four layers. They were stored for 5 days, and the temperature and humidity of the experimental site were monitored daily. The technique by immersion generated excess humidity on the surface of the fruit, generating that the fruit ripens faster, and different microorganisms appeared, comparing the two types of techniques it was evident that those made by brushstroke present better results, however when increasing the number of layers there was presence of pathogens, it was verified that the sericin is an alternative for the development of coatings.