Effect of UV– C Light Treatment on Physicochemical and Bioactive Compounds in Apple and Pineapple Juices

Abstract

The effect of ultraviolet (UV-C) on physicochemical (viz. pH, total soluble solids (TSS), Absorbance, total color difference), bioactive component (viz. ascorbic acid, total phenolic content, antioxidant activity) of apple and pineapple were studied during this research work. The process conditions for ultraviolet treatment were treatment time (5, 10, 15 min) and distance of sample from lamp source (8.6, 13.7, 18.6 and 22.8 cm) at 1 mm sample thickness. The results obtained from this study showed that the ultraviolet treatment (UV) doesn’t have any significant effect on pH, TSS of apple and pineapple juices. However, the UV treatment conditions had significant effect on vitamin-C content. The color parameters (viz. L*, a* and b*) were slightly affected by ultraviolet treatment. The bioactive components of apple and pineapple juices were affected by the treatment conditions. The Antioxidant activity of both the juices showed a decreasing trend with respect to an increase in dosage level. The obtained results suggested that, ultraviolet treatment conditions slightly affect the quality parameters of apple and pineapple juices. However, the changes were found to be minimum as that of thermal treatments in literature.