Stabilizing cooking oil by mangosteen (Garcinia mangostana L.) peel crude extract

Abstract

Increase use of cooking oil with decrease source available has made the price going rise. This had made people use cooking oil repeatedly. Repeated use of cooking oil will break the oil structure and create harmful effect. Disruption on oil structure cannot be hindered but it can be slower by adding stabilizing agent. The purpose of this study was to assess the role of mangosteen in stabilizing cooking oil. Preliminary descriptive study was done against flavonoid content and DPPH radicals scavenging activity of some antioxidant plant. Samples used were mangosteen peel, celery leaves, tea leaves and citrus fruit. Experimental method of mangosteen activity used was CRD (completely randomized design) with 3x4 factors. Factors applied was solvent type (chloroform, aquadest, ethanol) and extract concentration (0 μg/ml, 90 μg/ml, 100 μg/ml, and 110 μg/ml). Each procedure was repeated 5 times. Parameter measured was free fatty acid number (FFA) and oil turbidity. Data was analyzed with two ways Anava followed by DMRT. Preliminary results showed that the highest levels of flavonoid were found in mangosteen peel (72 g/kg) followed by celery (37.9 g/kg), citrus fruit (25,5 g/kg) and tea leaves powder (13,9 g/kg). DPPH radicals scavenging activity ranging from 71,1 % of mangosteen peel, 48,2% of the celery, 13,2% of citrus fruit and 11,2% of tea leaves powder. Preliminary result confirmed the best use of antioxidant from mangosteen compare to others. Experimental result showed that 110 μg/ml aquadest was the best combination to give lowest FFA value (1.24%). 90 μg/ml whilst, oil turbidity didn’t show differences under treatment given. Ethanol was found give highest FFA value (5.11%). It can be concluded that mangosteen peel is able to stabilize cooking oil and solvent with extract combination give impact on free fatty acid number of cooking oil.