Heat Processing of Blueberries and Its Effect on Their Physicochemical and Bioactive Properties

Abstract The current study aimed to evaluate the dehydration process of blueberry fruits at temperatures of 70, 80 and 90C and its effect on their physicochemical and bioactive properties. The values for moisture content and water activity (aw) were still high for dehydrated fruits, although at temperatures of 80 and 90C, the dried fruits showed a aw below the limit for contamination by pathogenic microorganisms. The antioxidant activity increased during the first half of dehydration at 80C, but after 3 h suffered a significant reduction (P < 0.05), which continued up to the end of the process. The anthocyanins showed mean half‐lives of 7.7 and 6.8 h for dehydration at 70 and 80C, respectively. These results indicated that the stability of the anthocyanins and the antioxidant capacity of the fruits could be related to both the intensity and the duration of the dehydration. Practical Applications The present work consists of a study of the dehydration of blueberry fruits at different temperatures in order to extend their shelf life and provide their consumption at any time of the year in the form of dried blueberries. Thus, mathematical modeling of the process was carried out to evaluate the behavior of water activity and moisture, and to determine the degradation of its antioxidant compounds. The optimization of the drying time and temperature of these products is essential to avoid losses in the bioactive properties of blueberries.