Production of Structured Lipids Containing Medium-Chain Fatty Acids by Soybean Oil Acidolysis Using SBA-15-pr-NH2–HPW Catalyst in a Heterogeneous Manner

A review on preparation and application of low-calorie structured lipids in food system

Low-calorie structured lipids are an advanced form of functional lipids made by changing the position of fatty acids attached to the glycerol backbone. The main reason for their production is to get nutraceutical lipids. Different methods are used to synthesize low-calorie structured lipids, like chemical or enzymatic methods. Initially, these lipids are prepared by using chemical methods. Synthesis of low-calorie structured lipids using enzymes is now in demand due to several advantages like good catalytic efficiency, environmentally friendly, and moderate reaction conditions. Enzymatic interesterification is mostly used in industries to make modified lipids like low-calorie structured lipids, human milk substitutes, cocoa butter equivalents, margarine, and shortenings. This review summarizes the synthesis, uses and clinical applications of modified lipids in food systems.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-024-01689-8.

Effects of a novel medium-long-medium-type structured lipid synthesized using a two-step enzymatic method on lipid metabolism and obesity protection in experimental mice

We synthesized a novel, structured lipid containing caprylic acid at its sn-1,3 position and docosahexaenoic acid at its sn-2 position (1,3C-2D-TAG) by using a two-step enzymatic method and then investigated the relationship between the types of fatty acids in the structured lipid and their physiological functions. Furthermore, we compared the effects of similarly structured lipids on postprandial lipid metabolism and obesity protection. The results revealed that the novel structured lipid synthesized using the enzymatic method not only exhibited better physical properties than traditional oils but also had high oxidation stability and crystallization degree. In terms of physiological function, the low-dose 1,3C-2D-TAG group exhibited higher cholesterol and triglyceride levels, lower kidney weight or body weight, and higher serum aspartate aminotransferase and blood urea nitrogen levels than control group, whereas the high-dose 1,3C-2D-TAG group exhibited higher triglyceride levels. Moreover, the medium-dose 1,3C-2D-TAG group had remarkably higher high-density lipoprotein cholesterol levels and lower low-density lipoprotein cholesterol levels than the high-lipid, control, and 1,2,3C-TAG groups; however, the cholesterol and triglyceride levels and kidney and liver functions did not differ significantly among these groups. The study results suggest that 1,3C-2D-TAG can not only facilitate the effective utilization of the energy supplied by medium-chain fatty acids but also help overcome difficulties in the absorption of long-chain polyunsaturated fatty acids.

Enzymatic synthesis of capric acid-rich structured lipids and their effects on mice with high-fat diet-induced obesity

The objective of this study was to produce structured lipids (SLs) by enzymatic acidolysis using Rhizopus oryzae lipase covalently immobilized in a low-cost material. Grape seed oil was used to synthesize SLs containing the medium-chain fatty acid (C10:0) capric acid. SL synthesis led to 38.8% medium-chain fatty acid incorporation with 5 reuses of the enzymatic derivative. The reaction conditions for the synthesis of MLM-TAGs (triacylglycerols with one long- and two medium-chain acyl residues) were at a molar ratio of fatty acid:oil of 3:1, performed at 40 °C and lipase immobilized load of 5% (w/w). The in vivo effects of SLs were studied in Swiss mice fed premade diets: control (C) diet, high-fat diet (HFD) with 100% lipid content as lard, HFD with 50% lipid content as grape seed oil (HG) or HFD with 50% lipid content as capric acid-containing SLs produced from grape seed oil (HG-MCT). Mice from HG and HG-MCT groups had decreases in body weight gain and reductions in the weights of white adipose tissues. In addition, HG and HG-MCT mice had low plasma levels of glucose and total cholesterol, and improvements in the glucose tolerance. HG and HG-MCT diets have remarkable antioxidant properties, since low plasma levels of TBARS (thiobarbituric acid reactive substances, biomarkers of lipid peroxidation) were found in mice fed these diets. Interestingly, TBARS levels in HG-MCT mice were further decreased than values of HG mice. Mice fed HG and HG-MCT diets also showed preservation in the activity of the antioxidant enzyme paraoxonase 1. Both HG and HG-MCT diets promoted reduction of IL-6 and IL-10 production by splenocytes. The capric acid-containing SLs produced from grape seed oil emerges as a functional oil capable to mitigate obesity complications resulting from oxidative stress and inflammation.

Enzymatic synthesis of structured lipids from grape seed (Vitis vinifera L.) oil in associated packed bed reactors

Triacylglycerols (TAGs) can be modified to increase the absorption of fatty acids, prevent obesity, and treat fat malabsorption disorders and metabolic diseases. Medium-long-medium (MLM)-type TAGs, which contain medium-chain fatty acids in the sn-1 and sn-3 positions of the glycerol backbone and a long-chain fatty acid in the sn-2 position, show particularly interesting nutritional characteristics. This study aimed to synthesize MLM-type TAGs by enzymatic acidolysis of grape seed oil with medium-chain capric acid (C10:0) in associated packed bed reactors. The reaction was carried out during 120 H, at 45 °C, using lipase from Rhizomucor miehei (Lipozyme^® RM IM). The residence time distribution of reagents in the reactor was quantified to evaluate the reactor behavior and to diagnose the existence of preferential paths. The reaction progress was monitored by analyzing TAG composition and, at the steady state (after 48 H of reaction), the incorporation degree achieved a value of 39.91 ± 2.77%. To enhance the capric acid incorporation, an acidolysis reaction in associated packed bed reactors was performed. The results showed a good operational stability of the biocatalyst, revealing values of half-life 209.64 H, 235.63 H of packed bed and associated packed bed reactor, respectively, and a deactivation coefficient 0.0061 H^-1.

Codoped Phosphotungstate as an Efficient Heterogeneous Catalyst for the Synthesis of n-Butyl Oleate

A quaternary ammonium and titanium codoped phosphotungstate (QA_0.5Ti_0.5H_0.5PW) catalyst was prepared by the ion exchange method and used as a solid acid catalyst for the synthesis of n-butyl oleate. The catalyst was characterized by Fourier transform infrared, elemental analyzer, energy-dispersive X-ray spectrometry, Brunauer-Emmett-Teller, scanning electron microscopy, and Hammett indicator methods. QA_0.5Ti_0.5H_0.5PW showed a higher catalytic activity than other phosphotungstate solid acid catalysts reported by literature, and the esterification rate reached 99% under optimized conditions. Moreover, QA_0.5Ti_0.5H_0.5PW exhibited well reusability. An esterification rate of 90.1% was still obtained in the eighth run.

Efficient Production of Medium-Chain Structured Phospholipids over Mesoporous Organosulfonic Acid-Functionalized SBA-15 Catalysts

It is highly desirable that efficient recoverable heterogeneous catalysts should be developed to replace the costly biocatalysts used in producing structured phospholipids (SPLs) with medium-chain fatty acids (MCFAs). Thus, mesoporous propyl and phenyl sulfonic acid-functionalized SBA-15 materials synthesized via surface modification methods were investigated for the soybean lecithin interesterification with methyl caprate or caprylate. The physicochemical properties of the synthesized solid acids were deeply studied by small-angle X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared and pyridine adsorption, etc. to build the possible structure–performance relationships. The results revealed that amounts of organosulfonic acid groups were successfully grafted onto the SBA-15 support, and most of the surface acid sites contained in the as-prepared organic–inorganic hybrid samples were assigned as strong Brӧnsted acid sites. Notably, the functionalized SBA-15 materials exhibited promising catalytic behaviors in producing MCFA-enriched SPLs under mild conditions (40 °C, 6 h) when compared with commercial Amberlyst-15 and typical phospholipases or lipases, mostly due to their high surface area, ordered structure and adequate Brӧnsted acid sites. Besides, the as-prepared materials could be easily recycled five times without obvious deactivation. This work might shed light on alternative catalysts for SPL production instead of the costly enzymes.

Effect of Surface Modifications of SBA-15 with Aminosilanes and 12-Tungstophosphoric Acid on Catalytic Properties in Environmentally Friendly Esterification of Glycerol with Oleic Acid to Produce Monoolein

A series of protonated amino-functionalized SBA-15 materials was synthesized and tested as heterogeneous catalysts for the esterification of glycerol with oleic acid to produce monoolein. Mesoporous SBA-15 (S) was functionalized with three different aminosilanes: 3-aminopropyltriethoxysilane (N1); [3-(2-amino-ethylamino)propyltrimethoxysilane] (N2); and (3-trimethoxysilylpropyl) diethylenetriamine (N3), before being impregnated with 40 wt % 12-tungstophosphoric acid (HPW). The resulting nanocatalysts (S-Nx-HPW) were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), N2 adsorption-desorption, SEM equipped with energy dispersive X-ray spectroscopy (SEM-EDX), transmission electron microscopy (TEM), and elemental analysis techniques. The presence of components of the nanocatalysts and the preservation of the hexagonal structure of SBA-15 were confirmed. Using different functionalizing agents considerably affected the textural properties and acidity of the synthesized nanocatalysts, which helped to improve the catalytic performance. In particular, S-N2-HPW was more active and selective than other catalysts in this study, as well as than a number of other commercial acid catalysts, with 95.0% oleic acid conversion and 60.9% monoolein selectivity being obtained after five h of reaction at 160 °C using 2.5 wt % of catalyst loading and glycerol/oleic acid molar ratio of 4:1. Aminosilane functionalization also helped to increase the reusability of the catalysts to at least six cycles without considerable loss of activity through strong electrostatic interactions between HPW anions and the protonated amino-functionalized SBA-15 materials.

WO3–EDA hybrid nanoplates and nanowires: synthesis, characterization, formation mechanism and thermal decomposition

Previously the WO₃–EDA hybrid material was obtained only from solvothermal reactions.

Propylsulfonic and arenesulfonic functionalized SBA-15 silica as an efficient and reusable catalyst for the acidolysis of soybean oil with medium-chain fatty acids

The objective of this work was to develop a feasible ecofriendly process to produce medium-chain fatty acid (MCFA)-enriched structured lipids (SLs) in heterogeneous manners. For this purpose, the propyl-SO3H or arene-SO3H-modified SBA-15 materials were prepared through a surface functionalization of SBA-15 silica with propyl-SO3H and arene-SO3H groups. The organosulfonic acid-functionalized SBA-15 materials were characterized by Brönsted acidity determination, elemental analysis, XRD, C(13) MAS NMR, FT-IR, SEM, TG, TEM, and N2 adsorption-desorption techniques. Results showed that the propyl-SO3H and arene-SO3H groups were successfully tethered on the SBA-15 support, and the ordered mesoporous structure of SBA-15 silica was well retained after the organofunctionalization. This organic-inorganic hybrid material displayed high surface acidities and high activities in the acidolysis of soybean oil with caprylic or capric acid to produce SLs containing MCFAs. The influences of processing parameters on the reaction were investigated. The two studied catalysts showed an excellent recyclability for the reaction.