Oxidative Stability of Stripped Soybean Oil during Accelerated Oxidation: Impact of Monoglyceride and Triglyceride—Structured Lipids Using DHA as sn-2 Acyl-Site Donors

Abstract

The current work aimed to clarify the effects of four structured lipids, including monoglycerides with docosahexaenoic acid (2D-MAG), diacylglycerols with caprylic acid (1,3C-DAG), triglyceride with caprylic acid at sn-1,3 and DHA at sn-2 position (1,3C-2D-TAG) and caprylic triglyceride on the oxidative stability of stripped soybean oil (SSO). The results revealed that compared to the blank group of SSO, the oxidation induction period of the sample with 2 wt% 2D-MAG and that with 1,3C-DAG were delayed by 2–3 days under accelerated oxidation conditions (50 °C), indicating that 2D-MAG and 1,3C-DAG prolonged the oxidation induction period of SSO. However, the inhibitory effect of α-tocopherol on SSO oxidation was reduced by 2D-MAG after addition of 2D-MAG to SSO containing α-tocopherol. 2D-MAG exhibited different antioxidative/pro-oxidative effects in the added/non-added antioxidants system. Compared to caprylic triglyceride, DHA at the sn-2 acyl site induced oxidation of structured lipids, thus further promoting the oxidation of SSO. The antioxidant was able to inhibit not only the oxidation of DHA in the SSO, but also the transesterification of sn-2 DHA to sn-1/sn-3 DHA in the structured lipid.

Chemical transesterification of flaxseed oil and medium‐chain triacylglycerols: MLCT yield, DAG content, physicochemical properties, minor compounds and oxidation stability

“…As Table 3 displays, a lower concentration of PUFA in sn-2 position improved the oxidative stability, which was also reported by Rocha-Uribe & Hernandez (2008). Similarly, Wang et al (2019) found that triglyceride with DHA, one of PUFAs, at sn-2 position induced the oxidation of structured lipids and promotes oxidation. It was evident in numerous studies that reducing tocopherols after CTE showed a significantly negative effect on oxidative stability.…”

“…Similarly, Wang et al . (2019) found that triglyceride with DHA, one of PUFAs, at sn‐2 position induced the oxidation of structured lipids and promotes oxidation. It was evident in numerous studies that reducing tocopherols after CTE showed a significantly negative effect on oxidative stability.…”

“…Moreover, when DAG is converted from TAG, higher DAG content reduces TAG (triacylglycerols), decreasing MCT, long‐chain triacylglycerols (LCT) and MLCT. Some studies even indicated that DAG promotes oil oxidation (Wang et al ., 2019), and DAG content is expected to be as low as possible by reaction optimization or purification (Xu et al ., 1998; Lu et al ., 2017). Hence, correlations of MLCT yield, DAG content, oxidative stability, FA composition, minor compounds, and their relationships after CTE are crucial to MLCT production and deserve effective and systematical evaluation.…”

The heating and storage of structured acylglycerols with succinyl-linked stigmasterol residue does not affect their chemical and biological negative changes

“…Structured acylglycerols are a class of glycerides with speci c molecular structure or function that chemically or enzymatically change composition or position distribution of the glycerol skeleton 19 .…”

Incorporation of Caprylic Acid into a Docosahexaenoic Acid Single Cell Oil for the Production of Specialty Lipids

“…Castejón and Señoráns ( 22 ) used camelina oil to enzymatically produce 2-monoacylglycerols with high α-linolenic acid content using Lipozyme TL IM, which then reacted with EPA and DHA ethyl esters aiming to produce very long-chain structured lipids as functional ingredients. Wang et al ( 23 ) first obtained 2-monoacylglycerols from algal oil and then synthesized TAGs containing caprylic acid (CA) mainly at the sn -1,3 position and DHA at the sn -2 position by reacting the monoacylglycerols with free CA in a solvent medium catalyzed by Lipozyme RM IM. In general, these multistage methods to obtain structured lipids result in higher yields of the desired TAGs, but their disadvantage is the requirement of further separation/purification steps such as evaporation and distillation, which might result in excessively high costs, considering industrial scale production processes.…”