Substantiaton of Selecting the Method of Pre-cooling of Fruits

The research is devoted to the scientific substantiation of the feasibility of combination of pre­cooling the fruits and their treatment by antioxidant compositions before prolonged storage, as well as determining the optimal modes and methods of carrying out the given technological operation. The objects of research were the fruits of apple varieties Aydared, Golden Delicious, Simirenko Renet, Florin, the fruits of pear varieties Izyuminka Crimea and Conference, the fruits of plum varieties Voloshka and Stenley. Pre­cooling was conducted in three ways: by cold air in conventional storing chambers, by cold air in the chambers of intensive cooling and hydro­cooling in the solutions of antioxidant compositions. As a result of the studies, it was found that the most intensive method of pre­cooling is cooling by air at temperature minus 2…minus 4 oC and airflow velocity 3 m/s. Under such circumstances, general period of cooling to a temperature 0 oC of the apple fruits and pear fruits is about 2 hours and the plum fruits – slightly longer than 1 hour. The velocity constant of reduction in the intensity of breathing and heat release of fruits during intensive cooling exceeded the velocity constant of the analyzed indices during slow cooling by 4.3…6.6 times and during hydro­cooling by 1.2...1.6 depending on the type of fruit. Along with this, high speed of air motion increased the natural weight loss of fruits during cooling. The quantitative value of this indicator during intensive method was maximum and varied in the range of 0.56 % for the pear fruits to 0.44 % for the plum fruits. Combined method, which implies initial pre­cooling in the working solutions of antioxidant compositions and further cooling by the intensive method, was characterized by high velocity constant of reduction in the intensity of breathing and heat release of the fruits and low level of the natural loss weight. In this case, the quantitative value of the weight loss varied in the range from 0.005 % for plum fruits to 0.014 % for the apple and pear fruits

Development of Fruit Diseases of Microbial Origin During Storage at Treatment with Antioxidant Compositions

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