Effect of solar radiation on pigmentation, phenolic content and antioxidant activity in 'Forelle' pears during fruit growth and ripening

Blush development is an important commercial quality attribute in European pear, but some cultivars exhibit reduced red colouration at harvest due to environmental stress. The objective of this study was to evaluate the effects of bagging 'Forelle' pear fruit at 85, 57 and 27 d before commercial harvest on ripening, pigment concentration, phenolic content and antioxidant activity, with unbagged fruit (0 d) considered a control treatment. It was found that bagging reduced the fruit colouration and concentration of pigments, particularly anthocyanins and carotenoids, as well as the phenolic and antioxidant contents, but did not affect fruit ripening. During fruit growth, the anthocyanin concentration of fruit in the control treatment peaked at 57 d before harvest and then decreased at 27 d before harvest, but at the time of harvest, both this variable and blush development were higher in unbagged fruit than in bagged fruit, particularly where longer periods of bagging had been used. These results indicate that reducing radiation stress through continuous bagging of the fruit does not improve the colour intensity of 'Forelle' pears at harvest, and the 27 d prior to harvest appear to be most important for blush development.