Lipase‐Catalyzed Concentration of Stearidonic Acid in Modified Soybean Oil by Partial Hydrolysis

Abstract

Stearidonic acid (SDA, 18:4 ω‐3) content of modified soybean oil (MSO) containing ~25 % SDA, was increased by lipase‐catalyzed hydrolysis. Four non‐immobilized powdered lipases, Lipase AY 30 (Candida rugosa), Lipase G 50 (Penicillium camembertii), Lipomod™ 34P‐L034P (Candida cylindracea [rugosa]), Lipomod™ 36P‐L036P (Rhizopus oryzae), and an immobilized lipase, Lipozyme RM IM (Rhizomucor miehei) were assessed, at various incubation times, for their ability to hydrolyze MSO and specificity toward SDA. The SDA enriched products contained triacylglycerols (TAG), diacylglycerols (DAG) and monoacylglycerols (MAG). Lipase 34P‐L034P exhibited specificity towards SDA, while Lipase AY was able to discriminate against it. The highest total SDA content (40.9 mol%) was obtained with Amano AY lipase at 4 h incubation (66.2 % hydrolysis). Unhydrolyzed TAG, 1,3‐DAG, 2,3(1)‐DAG, and MAG contained 37.7 (56.4 at the sn‐2 position), 41.6, 51.5 (54.9 at the sn‐2 position), and 49.9 % SDA, respectively. Amano AY lipase was also used to hydrolyze previously SDA‐enriched TAG (48.7 % SDA) obtained from low temperature crystallization of MSO. The highest total SDA content (62.7 mol%) was obtained at 12 h incubation (85.9 % hydrolysis). The SDA contents of unhydrolyzed TAG, 1,3‐DAG, 2,3(1)‐DAG, and MAG were 58.7 (65.7 at the sn‐2 position), 71.2, 70.2 (52.9 at the sn‐2 position), and 59.4 %, respectively.

Chemoenzymatic Method for Producing Stearidonic Acid Concentrates from Stearidonic Acid Soybean Oil

“…These observations suggest that ALA, palmitic, oleic, and linoleic acids were preferentially hydrolyzed from SDASO by lipase AY 30 over SDA and GLA. This pattern was also observed by Kleiner et al [17] and thus guided our choice of nonimmobilized lipase AY 30 for the lipase-mediated SDA enrichment step. We made no further attempt to immobilize the C. rugosa lipase since this may alter the catalytic behavior of the lipase.…”

“…The process involved chemical hydrolysis, low temperature crystallization, and enzymatic hydrolysis and acidolysis. In previous studies [15][16][17], these unit operations were studied independently while the enzymatic steps were performed on a small scale. In the present study, however, these operations were successfully combined for gram scale production of SDA concentrates from SDASO.…”

“…The method for enzymatic hydrolysis of SDASO was modified from that described by Kleiner et al [17]. SDASO (100 g) and phosphate buffer (150 mL of a 0.1 M solution; pH 7.0) were placed in a stirred tank glass reactor (1 L) and heated to 40°C with stirring at 200 rpm (3.589g).…”

“…Shahidi and Wanasundara [13] reviewed technologies available for production of omega-3 fatty acid concentrates from fish oils, namely: adsorption chromatography, molecular distillation, enzymatic hydrolysis/acidolysis, low-temperature crystallization, supercritical fluid extraction and urea complexation. Some of these technologies have been successfully used for the production of SDA concentrates from SDA soybean oil; namely, adsorption chromatography [14], low temperature crystallization [15], and enzymatic hydrolysis/acidolysis [16,17]. Of these technologies, the enzymatic approach is believed to be the most attractive from a marketing point of view because it leads to the production of PUFA concentrates in the form of triacylglycerols (TAG) which are often endorsed as more 'natural' than the fatty acid derivatives from the other processes [13].…”

Enrichment of ω‐3 fatty acids in flax seed oil by alkaline lipase of Aspergillus fumigatus MTCC 9657

“…Similarly, Kleiner et al . () showed that an initial hydrolysis of stearidonic acid (SDA) free TAG molecules occurred in the first 4 h followed by the hydrolysis of SDA‐enriched ones, resulting in decrease in SDA in the acylglycerol products after 4 h. This would explain the hydrolysis of ω‐3 fatty acids after 8 h which was observed in our study.…”