Studies of Reaction Variables for Lipase-Catalyzed Production of Alpha-Linolenic Acid Enriched Structured Lipid and Oxidative Stability with Antioxidants

: Alpha‐linolenic acid (ALA) enriched structured lipid (SL) was produced by lipase‐catalyzed interesterification from perilla oil (PO) and corn oil (CO). The effects of different reaction conditions (substrate molar ratio [PO/CO 1:1 to 1:3], reaction time [0 to 24 h], and reaction temperature [55 to 65 °C]) were studied. Lipozyme RM IM from Rhizomucor miehei was used as biocatalyst. We obtained 32.39% of ALA in SL obtained under the optimized conditions (molar ratio—1:1 [PO:CO], temperature—60 °C, reaction time—15 h). In SL, the major triacylglycerol (TAG) species (linolenoyl‐linolenoyl‐linolenoyl glycerol [LnLnLn], linolenoyl‐linolenoyl‐linoleoyl glycerol [LnLnL]) mainly from PO and linoleoyl‐linoleoyl‐oleoyl glycerol (LLO), linoleoyl‐oleoyl‐oleoyl glycerol (LOO), palmitoyl‐linoleoyl‐oleoyl glycerol (PLO) from CO decreased while linolenoyl‐linolenoyl‐oleoyl glycerol (LnLnO) (18.41%), trilinolein (LLL) (9.06%), LLO (16.66%), palmitoyl‐linoleoyl‐linoleoyl glycerol (PLL) (9.69%) were increased compared to that of physical blend. Total tocopherol content (28.01 mg/100 g), saponification value (SV) (192.2), and iodine value (IV) (161.9) were obtained. Furthermore, oxidative stability of the SL was also investigated by addition of 3 different antioxidants (each 200 ppm of rosemary extract [SL‐ROS], BHT [SL‐BHT], catechin [SL‐CAT]) was added into SL and stored in 60 °C oven for 30 d. 2‐Thiobabituric acid‐reactive substances (TBARS) value was 0.16 mg/kg in SL‐CAT and 0.18 mg/kg in SL‐ROS as compared with 0.22 mg/kg in control (SL) after oxidation. The lowest peroxide value (POV, 200.9 meq/kg) and longest induction time (29.88 h) was also observed in SL‐CAT.