The aim of the dissertation was to evaluate the effect of chitosan on the postharvest quality of strawberries. Correlation analysis revealed that the amount of precipitation significantly affects the mass of strawberries (r = 0,92). As the amount of precipitation increased, the mass increased due to the accumulation of a large amount of free moisture in the intercellular space of the fetus. It was studied that in the years when the air temperature in May was above 17 ̊С berries accumulated 0,91–1,1% of organic acids, but at a temperature of 12,5 ̊С the content of organic acids was 0,76%. Tissue density depended on RAH (r = -0,96). The lowest rate was at high relative humidity, while the berries were vulnerable to mechanical damage and quickly lost their attractive appearance. On average, over the years of research, strawberries have accumulated 9,6% of DSS; 6,0% of sugars; 0,92% of organic acids and 65,1 mg / 100 g of ascorbic acid. Analysis of the dynamics of weight loss of strawberries during fourteen days of storage showed that treatment with a solution of chitosan helps to reduce these losses
by 0,5 – 4,7% compared with control in samples stored with free access of air and by 0,7 – 4,4 % in MGA. The mass fraction of DSS decreased throughout the shelf life. It was investigated that pre-treatment of berries helped to reduce the loss of mass fraction of dry soluble substances by 0,2 – 1,9 % and 0,4 – 1,7 % depending on the method of storage. A strong direct correlation between m.f. DSS and concentration of chitosan solution (r=0,95; r=0,98). It is proved that the use of edible chitosan coating with a concentration of 0,2% makes it possible to slow down unwanted physiological changes that lead to the loss of dry soluble substances. The average respiration rate of fresh strawberries was 34,6 mg of CO2 kg/h. This was facilitated by a decrease in temperature to 0 ± 2 ̊С. During subsequent storage, the respiration rate gradually decreased in all samples, but was lowest in variants with a concentration of chitosan treatment of 0,5 % of 1,9 and 2,3 CO2 kg/h depending on the method of storage. The presence of chitosan film slowed down the process of respiration, respectively, reducing the loss of organic acids by 0,03–0,19 % during storage with free access of air and 0,01–0,15 % in a modified gas atmosphere and sugars by 0,2–1,1 % and 0,3–1,6 %. The highest content of ascorbic acid at the end of storage was recorded in the sample with a treatment concentration of 0,5%, which was 35,4 mg/100 g in the version with free access of air and 37,8 mg / 100 g in MGA, which is 11,6 and 11, 4 mg/100 g more than control. It is proved that post-harvest treatment of strawberries with chitosan solutions has a positive effect on the preservation of physical parameters by reducing weight loss by 5,6–5,8 %; tissue density of 0,02 kg/cm2; pH level at 0,6–0,7. Over the years, research has shown that strawberries are mainly affected by four fungal diseases: Botrytis cinerea, Rhizopus stolonifera, Mucor and Aspergillus niger. The technology of applying chitosan on the surface of strawberries by complete immersion of berries in solution has been developed. The technology of applying chitosan on the surface of strawberries by spraying has been developed.
