Effect of solvent type on melanosis inhibition in white-leg shirmp during iced-storagage by different extracts from mangosteen (garcinia mangostana) pericarp

Abstract

This study was aimed to find out the impact of the extraction solvent on anti-melanosis in Mangosteen pericarp extract. The effects of 5 different extraction solvents on the anti-melanosis capacity of the extracts from Mangosteen pericarp were studied. Extraction was done using different pure solvents (acetone, ethanol, methanol, ethyacetate) and distilled water. The crude extracts were analyzed for extraction yield, total phenolic content, antioxidant capacity, ability to inhibit Polyphenol oxidase enzymes activity, and ability to prevent black spot forming on white-leg shrimp. Through the experiments, the effects of solvents on extraction yield, total phenolic content, antioxidant capacity gradually increases in order: Methanol > Ethanol > Acetone > Ethyl acetate > Distilled water. The Mangosteen pericarp extract in Methanol produced the most antioxidative extract with the highest extraction yield (36.47 ± 0.59%), content of total phenolic compounds (72.74 ± 0.68 mg GAE/g mangosteen hull powder) and highest antioxidant capacity (88% ± 0.80%DPPH scavenging). The highest polyphenol oxidase inhibitory solution is Mangosteen peel extract in Methanol-2% (72.93 ± 4.90%). In contrast, Mangosteen peel extract in distilled water show lowest results in selected solvents. The efficacy of Mangosteen peel extract inhibiting polyphenol oxidase and black spot formation was in dose dependent manner. After 10 days stored, the color of shrimps treated by 15g/1L Mangosteen peel extract was better than 7.5g/1L. The results of this study showed that mangosteen pericarp extract could be used as natural inhibitor of white-leg shrimp polyphenol oxidase. This study indicated that that the polarity of the solvent has a high effect on total phenolic content, antioxidant capacity and ability to inhibit the polyphenol oxidase activity. Futhermore, Methanol can be considered the best solvent to extract anti-melanosis substances in mangosteen. Key words: Mangosteen pericarp, melanosis, Polyphenol oxidase inhibition, solvents, white-leg shrimp.