БІОХІМІЧНІ СКЛАДОВІ ОБРОБЛЕНИХ 1-МЦП ЯБЛУК ПІСЛЯ ЕКСПОЗИЦІЇ ЗА 20 ± 2 ⁰С НА КІНЕЦЬ ЗБЕРІГАННЯ

Abstract

The soluble solids content, level of organic acids, sugars, vitamins and their ratios are the main biochemical indicators of nutritional value that determine the taste of fruits. At the beginning of storage, soluble solids content increases in winter apple varieties, then decreases, and the level of organic acids is mostly reduced due to the active use in respiration. Ascorbic acid is a natural antioxidant, which relatively low content in apples usually reduces during refrigerated storage. The preservation of product’s quality and slowing of ripening achieve by post-harvest treatment of apples with ethylene inhibitor 1-methylcyclopropene (1-MCP), which reduces the loss of soluble solids content, titrated acidity and ascorbic acid. The purpose of the research was to identify the effect of post-harvest treatment of apples with 1-methylcyclopropene on the change in the content of soluble solids, titrated and ascorbic acids in the early winter apple fruits during the extended life cycle at room conditions at the end of long-term storage. Research objects were early-winter apple cultivars ‘Calville’ and ‘Spartan’, treated after harvest with 1-MCP (‘SmartFreshTM’ 0,068 g•m-3) for 24 h at 5 ± 1 ⁰C, during storage at 3 ± 1 ⁰C and relative humidity 85–90 % for two, three, four, five and six months (non-treated fruits – control). Physical-chemical parameters of apple fruits were evaluated monthly at the end of seven days exposure at 20 ± 2⁰C after refrigerated storage. The soluble solids content was determined by refractometer, the content of titrated acids — in recalculation on malic acid - by titration of the aqueous extract, the content of ascorbic acid – by titrimetric method. Data are means of three replicates. It was founded the decrease in soluble solids content of control fruits both varieties as a result of exposure at 20 ± 2⁰C during storage and increase in this indicator for 1-MCP treatment products during the first two and three months of storage with its subsequent decrease. 1-MCP treated fruits contained in twice higher titrated acids content and on 0.51–0.57 mg/100 g significantly higher ascorbic acid content at the end of the seven-day exposure at 20 ± 2⁰C after six months in refrigerator. Consequently, post-harvest 1-MCP treatment is significantly effective for the preservation of the main chemical components’s content of apple fruits at elevated temperature.