Production of trans-free margarine stock by enzymatic interesterification of rice bran oil, palm stearin and coconut oil

Abstract

Background: Trans-free interesterified fat was produced for possible usage as a spreadable margarine stock. Rice bran oil, palm stearin and coconut oil were used as substrates for lipase-catalyzed reaction.

Results: After interesterification, 137-150 g kg(-1) medium-chain fatty acid was incorporated into the triacylglycerol (TAG) of the interesterified fats. Solid fat contents at 25 degrees C were 15.5-34.2%, and slip melting point ranged from 27.5 to 34.3 degrees C. POP and PPP (beta-tending TAG) in palm stearin decreased after interesterification. X-ray diffraction analysis demonstrated that the interesterified fats contained mostly beta' polymorphic forms, which is a desirable property for margarines.

Conclusions: The interesterified fats showed desirable physical properties and suitable crystal form (beta' polymorph) for possible use as a spreadable margarine stock. Therefore, our result suggested that the interesterified fat without trans fatty acid could be used as an alternative to partially hydrogenated fat.