Microwave heating effect on total phenolics and antioxidant activity of green and mature coconut water

Abstract

Coconut water (Cocos nucifera L.) from fruits of two ripening stages (green and mature) was used to perform microwave heat treatments. Three different heating conditions with maximum temperatures of 70, 80 and 90 °C were tested in three holding times (0, 2 and 4 min). The Total Phenolic Content (TPC) using the Folin-Ciocalteu method and ABTS radical scavenging capacity were evaluated for each combination of coconut fruit age, heating temperature and holding time. It was observed that green coconut water exhibited significant differences (p < 0.05) compared to mature coconuts in terms of TPC (46.03 and 69.16 mg GAE/L, respectively) and ABTS radical scavenging capacity (422.31 and 549.1 μmol TE/L, respectively). An increase in TPC (up to 23%) and antioxidant activity (up to 19%) was also observed with increasing temperature in the range of 70–90 °C. Green coconut water showed the largest increase in both TPC and antioxidant activity.

Improvement of coconut water shelf‐life through low‐temperature concentration process: Understanding impact of non‐thermal process on shelf‐life

“…The TPC of coconut water is an essential property used to determine the quality of processed coconut water. Previous literature has reported that processing of coconut water in thermal techniques impacts TPC and antioxidant activity in coconut water (Arzeta‐Ríos et al, 2020; Mahdavi et al, 2011). This work records the TPC and antioxidant activity (AAO) of lyophilized coconut water.…”