Development of fruit diseases of microbial origin during storage at treatment with antioxidant compositions

Abstract

Present study addresses scientific substantiation of appropriateness of conducting after-harvesting treatment with antioxidant compositions for preventing the development of pathogenic microflora on the surface of fruits during long-term storage. We examined the fruits of apple of the varieties Idared, Golden Delicious, Simirenko Renet, the fruits of pear of the varieties Victoria, Izyuminka Crimea and Cure, the fruits of plum of the varieties Voloshka, Stanley, and Ugorka Italian. The fruits were treated by immersion in the following antioxidant compositions: ACM is a mixture of dimethylsulfoxide, ionol and polyethylene glycols; AARL is a mixture of ascorbic acid, rutine and lecithin; DL is a mixture of dimethylsulfoxide, ionol and lecithin. Control fruits were treated with water. Exposure is 10 seconds. Storage was maintained at a temperature of 0±1 oC, at relative air humidity 90–95 %. It was established that during preparation of fruits for storing, the largest mean population of epiphytic microflora was registered on the surface of plums and pears with medium term of ripening. The species composition of epiphytic microflora was dominated by spores of mesophilic aerobic and facultative anaerobic microorganisms. Their mean population on the surface of apples was 9.6•103 cfu/g, on the surface of plums – 18•103 cfu/g. Treating all kinds of fruit with AOC significantly decreased speed of growth of both MAFAnM and micromycetes. It is shown that the application of composition reduced the level of daily losses from microbiological diseases over the entire period of storage by 2...3.5 times. The largest positive effect was obtained when applying the composition based on dystynol and lecithin. By performing a multi-factor analysis, it was revealed that the level of daily losses from microbiological diseases during storage was affected by the dominant influence of factors of generic features of fruit raw materials (factor A) and treatment with antioxidant compositions (factor D). The shares of influence are, respectively, 24 and 21 %