EMULSIFYING PROPERTIES AND ANTIOXIDANT ACTIVITY OF PHOSPHOLIPIDS FRACTIONS FROM PALM PRESSED FIBRE

Abstract

Palm pressed fibre (PPF) is a by-product of crude palm oil (CPO) extraction and has great potential as a source of phospholipids (PL). PPF was extracted from chloroform:methanol to extract total lipid, and polar lipid was separated using methanol. PL from PPF was fractionated by ethanol, and subsequently, the ethanol-soluble fraction was fractionated by acetone. Four fractions were obtained: ethanol-soluble, ethanol-insoluble, ethanol-acetone soluble, ethanol soluble-acetone insoluble. All fractions had different PL molecular species compositions. Different compositions of PL in the fractions resulted in different hydrophilic-lipophilic balance (HLB) values, emulsifying properties, and antioxidant activity. HLB value of crude PL from PPF was 6.07 that was suitable for water in oil (w/o) emulsion indicated by low emulsifying activity index (EAI) and emulsion stability index (ESI) in oil-water (o/w) emulsion systems. Ethanol-soluble and ethanol-acetone soluble fractions exhibited better emulsifying properties and higher HLB values of around 10. Crude PL and its fractions showed a potential antioxidant activity to prevent bulk soybean oil in a single antioxidant system. Synergism with α-tocopherol appeared in a binary antioxidant system indicated by low peroxide value compared to the single one. PL composition affected the ability of PL fractions as antioxidants.