Relationships among simple phenol, flavonoid and anthocyanin in apple fruit peel at harvest and scald susceptibility

Abstract Three years of experiments with ‘Delicious’ and ‘Ralls’ apples showed that simple phenols were positively correlated, anthocyanin was negatively correlated and flavonoids were not correlated with scald development during storage. Fruit peel exposed to light during growth contained less simple phenols, more anthocyanin and developed less scald than peel from the shaded sides. Delay of harvest reduced simple phenol content, increased anthocyanin accumulation and decreased scald incidence. Bagging fruit from 15 July to harvest inhibited anthocyanin accumulation, but did not affect concentration of simple phenols or flavonoids. When harvested on 1 August, bagged fruit had less simple phenols but developed the same amount of scald (near 100%) as control fruit. In later harvests, however, bagged fruit had the same amount of (harvested on 1 September) or more (harvested on 1 October) simple phenols and developed more scald than the controls. Simple phenol, flavonoid and anthocyanin contents did not change significantly in fruit from the latter two harvests during 4 to 5 months of storage at 0 °C, but in the earliest harvested fruit, simple phenols decreased after 3 months of storage. During 7 days at 20 °C following storage, simple phenol and flavonoid contents decreased rapidly. Anthocyanin decreased only at the end of warming in earliest harvested fruit, after severe scald had developed. Our results suggest that concentration of simple phenols in fruit peel at harvest affects tissue browning during scald development, and that anthocyanin may have played a protective antioxidant role against scald development.