Protective effect of natural and processed coconut water by non-thermal technologies against oxidative stress in brine shrimp (Artemia salina)

Abstract

Coconut water is widely consumed and appreciated due its sensory, nutritional, and functional characteristics. Despite being widely consumed, this beverage has a short shelf life that can be improved through processing technologies including nonthermal technologies. Although this processing is promising, it also can generate toxic bioactive compounds of natural and synthetic origin. Their safety has been long discussed, and concern for human food security is now clearly manifested by warnings added on products labels. The aim of this work was to evaluate the toxic and the protective effect of natural and processed coconut water by non-thermal technologies against oxidative stress in brine shrimp (Artemia salina). For acute toxicity test, A. salina nauplii instar II were exposed to different concentrations and ozone-processed (OTCW), plasma-processed (PTCW), and ultrasound-processed (UTCW) coconut water. The non-processed sample was the negative control. By the end of experiment (48 h), dead nauplii were counted and investigated under optical and electron microscopy. The protective effect was evaluated against H2O2 and morphological changes were also investigated. Coconut water treated with plasma and ultrasound was not toxic to Artemia salina nauplii at 10, 100, or 1000 μg mL−1; however, ozone-treated artificial seawater caused a mild toxicity to nauplii exposed to 1000 μg mL−1. All coconut water samples, included untreated samples, presented protective effect against oxidative stress caused by H2O2 reaching levels of 87.5% protection compared to control (24 h of experiment).