Enzymatic Interesterification of Palm Stearin, Flaxseed Oil and Cottonseed Stearin to Produce Stable Plastic Fat with Balanced Omega-6 and Omega-3 Fatty Acids.

Abstract

This study aimed to produce stable plastic fat with desired physicochemical characteristics and ω-6/ω-3 fatty acid ratio (1:1-4:1) from palm stearin (PS), flaxseed oil (FSO) and cottonseed stearin (CS) via enzymatic interesterification (EIE). For the first time, the EIE variables of the blends containing PS, FSO and CS were investigated and optimized through single-factor experiments and response surface design to achieve a high interesterification degree. The optimized enzymatic interesterification conditions were: 60°C, 6 wt% Lipase UM1, and 6 h. Lipase UM1 had a similar effect on ID values with commercial lipases. The EIE improved the compatibility of the lipid blends, with the interesterified product EIE-721 (7:2:1, PS:FSO:CS) being the best candidate base stock for shortening considering its solid fat content, desired ω-6/ω-3 fatty acid ratio, wide melting range, abundant β' form crystal, and compact microstructure. This study provides a strategy to produce balanced ω-6/ω-3 fatty acid plastic fat through enzymatic interesterification and validates the application of Lipase UM1 in the preparation of plastic fat.