Lipid Quality Assessment of Virgin Coconut Oil Produced with Different Blanching Methods

Abstract

Virgin Coconut Oil (VCO) is prone to oxidation due to the natural enzymes present in the coconut. Blanching has been studied to inactivate lipase and peroxidase enzymes that create deterioration in the product. Adding citric acid in hot water during blanching resulted in a higher quality product due to complexing agent properties to chelate metal substances and lowering the pH to reduce the enzymatic activities of the products. This research aims to analyze the effect of different blanching methods on VCO's lipid quality, antioxidant properties, and total phenolic content. Fresh coconut was subjected to water blanching at 95ºC for 5 minutes and 80ºC for 10 minutes with and without 0.05% citric acid addition. After that, VCO was produced using the chilling thawing method, which combines centrifugation and low-temperature incubation. VCO was analyzed in the free fatty acid (FFA), iodine value (IV), peroxide value (PV), TBARS value, the antioxidant activities by ABTS and DPPH, and total phenolic content (TPC). The results showed that water blanching with 0.05% citric acid at 80ºC for 10 minutes obtained better lipid quality compared to control with high IV (6.612±0.085 g iodine/g sample), low FFA (0.0241±0.0023 mg KOH/g sample), and low TBARS value (2.76±0.23 mg MDA/g sample). However, there is a contrary result between antioxidant activities and TPC that might reveal exciting findings. Despite a decrease in the antioxidant activities (DPPH: 39.93±3.11%RSA, ABTS: 9.80±0.91%RSA), the TPC value was increased (9.16±1.56 mg GAE/g sample). Therefore, hot water blanching with 0.05% citric acid addition can be conducted as a pre-treatment in the production of VCO to maintain the lipid quality, even though there is a contradiction in the TPC and antioxidant results.