Inactivation of Oxidative Enzymes Using UV-C LEDs and Sensory Quality Assessment Using E-Nose and E-Tongue in Tender Coconut Water

This study explores the impact of 280 nm ultraviolet-C light emission diodes (UV-C LEDs) on (polyphenol oxidase (PPO) and peroxidase (POD) enzymes in tender coconut water (TCW), addressing browning and flavour changes. Tender coconut water was treated with four doses (1, 2, 3, and 4 J/cm2). At the highest dose (4 J/cm2), both enzyme activities decreased, with PPO reduction (83%) exceeding POD (77%). No significant changes occurred in pH (4.88 +/- 0.01), titratable acidity (0.067 +/- 0.0), Brix (5.97 +/- 0.12), minerals, and sugars at 4 J/cm2. Although L* and a* values remained consistent, a shift towards b* (0.15 +/- 0.01 to 0.37 +/- 0.02) occurred. Total phenolics and ascorbic acid decreased by 49.32% and 21.24%, respectively. E-Nose analysis showed no significant aroma changes, except a propanol peak in treated samples. E-Tongue revealed taste profile alterations, but multivariate data processing found no significant differences among treated TCW samples. This study suggests that environmentally sustainable 280 nm UV-C LEDs have the potential to control enzyme activity in TCW without adversely affecting key physico-chemical attributes.