Fractionability of saturated and unsaturated fatty acid concentrates of rambutan oil with a freeze‐thaw cold crystallization procedure

Abstract

Rambutan oil is a promising source of fatty acids rich in saturated long-chain fatty acids and in monounsaturated long-chain fatty acids. The C20 fatty acid content is of 37.1%. The enzymatic hydrolysis of the triacylglycerols from the rambutan oil provides a new pathway for the use of these fatty acids. The physical separation of the monounsaturated fatty acid (MUFA) and saturated fatty acid (SFA) families, at 40°C by a freeze/thaw process involving centrifugation, gives two enriched fractions. The fluid fraction at 40°C is enriched in MUFA (C18:1, 55.0%, and C20:1, 9.0%) representing 68.9% of total content. The solid fraction at 40°C is enriched in saturated fatty C20:0, C22:0, and C18:0, giving a SFA content of 46.2%. The thermal properties of these fractions, the MUFA fraction of low melting temperature, and the SFA fraction of high melting temperature, open new possibilities for using rambutan fatty acids in oleochemistry. Practical applications Rambutan oil is of great interest to food industry and the chemical industry. The free fatty acid fractions rich in MUFA and in SFA represent a new pathway in oleochemistry to produce low melting and high melting temperature lipids. C20-C22 acids can provide reinforcing power in the manufacture of margarine. Fluid fractions enriched in monounsaturated fatty acids (C18:1 and C20:1) give opportunities to produce oils presenting a low melting temperatures to be involved in shortening oily systems with the presence of C20:1, which is enriched up to 9.0%. They are also suitable for the manufacture of cooking oils and chocolates, without having to resort to hydrogenation.