PRELIMINARY RESULTS ON THE EFFECT OF 1-METHYLCYCLOPROPENE ON QUALITY OF PLUMS GROWN IN LATVIA

Plums are one of the most popular, perspective and frequently consumed fruits in Latvia. Plums are typical climacteric fruits, respiration occurs during ripening. Respiration rate is mainly associated with synthesis of autocatalytic ethylene and depends of the cultivar of fruits. Metabolic processes occurring during plum storage cause changes in fruit quality. The aim of this work was to determine the effect of treatment by 1-methylcyclopropene (1-MCP) on physical and chemical characteristics and sensory qualities of five plum (Prunus domestica L.) cultivar fruits (‘Adele’, ‘Sonora’, ‘Victoria’, ‘Stanley’, ‘Minjona’) during four weeks of storage in a cool store-room at temperature 3±1 °C. The following analyses were performed to evaluate quality changes during storage: mass loss, concentration of total acids and soluble solids, firmness, and sensory qualities (colour, flavour, acidity, sweetness, firmness, and stone adherence). The study showed that treatment with 1-MCP had positive effect on fruit firmness during four weeks of plum storage, and there were significant differences in the content of total acids and soluble solids between 1-MCPtreated and control plum fruits. The results indicated that there were no significant differences in flavour (aroma) and colour between treated and untreated plum fruits, while 1-MCP-treated fruits were firmer and more sour.