Effect of harvest date on changes in quality attributes, antioxidant capacity and physiological disorders of Red delicious and Golden delicious apple cultivars during storage

Apples (Malus domestica Borkh) belong to the Rosaceae family and are the most valuable fruits in the world. West Azerbaijan province is one of the major regions for production of apples in Iran. One of the major factors for determination of final quality and shelf life of fruit is the degree of maturation and ripening of fruit at harvest time. In this study, the effects of different harvest times on starch index, firmness, TSS, TA, TSS/TA, total phenolics, total flavonoids, antioxidant capacity, polyphenol oxidase activity and bitter pit were measured in two apple varieties (Red and Golden delicious) in west Azerbaijan (Urmia). The results showed that the effects of harvest maturity on most of the measured traits were statistically significant at 1% level. The starch index, TA and fruit firmness were reduced and TSS, antioxidant capacity, total phenolics and total flavonoids and polyphenol oxidase activity were increased with delay in harvest time. Furthermore, fruit TSS, flavor index, polyphenol oxidase activity were increased and antioxidant capacity, total flavonoids and fruit firmness were significantly decreased during storage. In general, the results of this study showed that for fresh consumption and short-term storage, Red deliciousand Goldendelicious appless could be harvested later (7th stage), while for long-term storage, it is better to harvest earlier (3th stage).