THE QUALITY OF PLUM FRUITS AFTER STORAGE DEPENDEND OF QUALITY PARAMETERS DURING HARVEST

European plums 'Bluefre', 'Valor', 'Valjevka' and 'Elena' cvs. were harvested and graded according to colour and firmness, and on this basis divided into three maturity fractions. The fruits were analysed for mass loss, flesh firmness, total soluble solids (TSS), skin ground colour as well as incidence of fungal diseases and physiological disorders after 4 weeks of cold storage at 1 degrees C and 2 days of ripening at 20 degrees C. Significant differences were found in fruit weight loss, skin colour, firmness and TSS among maturity fraction during and after storage. A decrease in firmness, fruit mass, and skin colour as well as an increase in TSS were observed, however all changes depended on the maturity stage during harvest. Less mature fruits withstood better cold storage than more mature. All fruits showed flesh browning symptoms after 4 weeks of storage and the least browning symptoms were found for 'Valor', regardless of the fruit maturity during harvest. The most browning symptoms were observed for 'Valjevka', which indicates the low suitability of this cultivar for 4-week storage. The best storability was observed for 'Valor' due to the best after-storage quality. Both firmness and skin colour can be applied to the assessment of the optimum harvest date of fruits intended for storage.