Enhanced Antioxidant Capacity of Fresh Blueberries by Pulsed Light Treatment

Abstract

As a novel technology for food safety risk mitigation, pulsed light (PL) has been shown effective in surface decontamination of fresh blueberries in literature. However, little is known about the effects of PL on the antioxidant capacity and quality characteristics of fresh blueberries. Fresh blueberries from a local farm were treated with PL for 30, 60, 90 and 120 s. Results show that PL exposure enhanced the antioxidant activity (ORAC) and total phenolic content of fresh blueberries 50 and 48% respectively, relative to the control. Pulsed light also significantly increased the total anthocyanin contents, which may be due to the upregulation of Phenylalanine Ammonium Lyase (PAL) enzymes. There was no significant difference (<em>P </em>≤ 0.05) in the soluble solids, pH, titratable acidity, firmness, color and mass of the fresh blueberries within 120 s PL exposure. In conclusion, PL illumination enhanced the antioxidant capacity of fresh blueberries while maintaining other quality characteristics.