Effects of equivalent medium-chain diacylglycerol or long-chain triacylglycerol oil intake via muffins on postprandial triglycerides and plasma fatty acids levels

Molecular docking simulation reveals the lipase-substrate binding mechanism in the enzymatic synthesis of diacylglycerol-enriched vegetable oils

Diacylglycerol (DAG) is a functional lipid that is naturally present in vegetable oils in limited concentrations (1 %-5 %). This study proposed an enzymatic method to afford high-content-DAG vegetable oils via a reaction catalyzed by an immobilized lipase, PS@OMS-C8, using high-speed homogenization and molecular distillation. Results indicated that 48.6 % DAG was initially obtained through the enzymatic glycerolysis of rapeseed oil with glycerol, of which 90.2 % was sn-1,3-DAG. PS@OMS-C8 maintained 35.5 % DAG content after 10 reuse cycles, confirming its catalytic stability; this was attributed to lipase immobilization on the ordered mesoporous silica that significantly improve the secondary protein structures, including α-helix and β-sheet, thereby strengthening the rigidity of PS@OMS-C8. In addition to producing DAG-enriched rapeseed oil, other edible oils with 39.4 %-50.2 % DAG content were obtained, as revealed via molecular docking simulation. This study offers new strategies for the sustainable synthesis of vegetable oils with a high content of functional lipids high-content functional lipids.

Effect of dry fractionation of peanut oil-based diacylglycerols on crystallization properties, oxidative stability and safety

This research employed environmentally friendly dry fractionation to systematically modify the physicochemical properties of 80 % diacylglycerol derived from peanut oil (PDAG-80), expanding its potential food applications. The properties of olein and stearin were optimized by adjusting key parameters: crystallization temperatures (11, 13, 15 and 17 °C), cooling rates (2, 5, 8 and 11 °C/h), agitation speeds (10, 20, 30 and 40 rpm)and residence times (3, 6, 9 and 12 h). Lowering the crystallization temperature and extending the residence time increased the iodine value and solid fat content of olein. Additionally, diverse fractionation parameters yieled stearin with varying crystal ratios. The resulting olein fractionated from PDAG-80, a liquid at room temperature and rich in unsaturated fatty acids, exhibited superior cloudy property and oxidative stability. These findings not only deepen the understanding of PDAG-80 physical modification, but also provide a scientific foundation for developing high value-added PDAG products within the food industry.

Enzymatic Esterification of Functional Lipids for Specialty Fats: 1,3-Dipalmitoylglycerol and 1,3-Distearoylglycerol

High-melting point 1,3-diacylglycerols not only provide health benefits, but are also suitable for manufacture of foods containing various specialty fats. It is difficult to prepare such high-melting point diacylglycerols, as the activities of specific enzymes will severely reduce at their melting points. In the present study, a combined technique was developed to prepare 1,3-dipalmitoylglycerol (1,3-DPG) and 1,3-distearoylglycerol (1,3-DSG) using selective esterification, molecular distillation, and solvent fractionation. Lipozyme TL IM was suitable for use as the optimal enzyme to maintain relatively high activity levels at esterification temperatures of 73-75 °C. 1,3-DAG/(DAG + TAG) was selected as the most important index to monitor the esterification and to evaluate the synthesized fats. The obtained 1,3-DPG and 1,3-DSG showed high purities, at more than 83%, and possessed hard attributes at room temperature. Both 1,3-DPG and 1,3-DSG exhibited fat crystals with β' and β crystals. Needle-like and rod-like crystals were observed at 5-25 °C for 1,3-DPG, and closely packed feather-like crystals were found at 5-20 °C for 1,3-DSG, indicating their multiple abilities in modifying the crystallization stabilization of the fat matrix during food processing.

Comparison of the effect of medium-chain fatty acids and long-chain fatty acids on postprandial appetite and lipemia: a randomised crossover trial

Background

Postprandial lipemia (PPL) has been recognised as a cardiovascular disease risk factor. Appetite and PPL can be influenced by the length of saturated fatty acids (FAs). Thus, this study aims to investigate if different FA chain lengths have different impacts on appetite and PPL in healthy volunteers.

Methods

This is a randomised crossover single-blinded intervention study of 20 healthy adults. Coconut oil and palm oil were consumed in the form of biscuits. Blood serum samples were withdrawn after an overnight fast and 1, 2, 4 and 6 hours after eating the test meals and examined for blood lipid profile (total cholesterol (TC), high-density lipoprotein (HDL) and triglycerides (TG)), while Friedewald's equation was used to calculate low-density lipoprotein (LDL). Visual analogue scales were used by participants to rate their appetites, and an ad libitum meal was weighed to determine the energy intake.

Results

The net area under the curve of TG and TC following the coconut oil were significantly lower than following the palm oil (P value ≤0.05). In the mean of the change in TC, LDL and HDL from the baseline, a significant difference was found after 6 hours of eating the biscuits (P value ≤0.05). The perceptions of hunger and fullness did not significantly differ between the two types of FAs. Also, the energy and macronutrient intakes were not significantly different after the two types of oil, neither at the ad libitum meal nor on the day following the treatments.

Conclusion

The selection of FA chain length may influence PPL, and thus cardiovascular disease risk in a way that is functionally significant. However, this study detected no influence of FA chain length on appetite up to 40 hours post-treatment.

Trial registration number

NCT05539742.

Influence of flaxseed-derived diglyceride-based high internal phase Pickering emulsions on the rheological and physicochemical properties of myofibrillar protein gels

The study aimed to investigate the influence of flaxseed-derived diglyceride-based high internal phase Pickering emulsions (HIPPE) at different levels (0%, 10%, 20%, 30%, 40%, and 50%) on the rheological and physicochemical properties of myofibrillar protein (MPs) gels. The study indicated that with increasing HIPPE levels, there was a significant increase in whiteness while a decrease in water-holding capacity. The gels with 10% HIPPE levels had higher ionic bonds, while those with 40% and 50% HIPPE levels showed higher hydrogen bonds. By increasing HIPPE levels in the formation of MP gels, the T2 relaxation time was found to decrease. Additionally, in all MP gels, G' values were significantly higher than G" values over time. Adding lower contents of HIPPE levels resulted in a more compact microstructure. These findings indicate that flaxseed-derived diglyceride-based HIPPEs could be utilized as fat substitutes in meat products to enhance their nutritional quality.

Preparation of functional oils rich in phytosterol esters and diacylglycerols by enzymatic transesterification

Phytosterol esters (PEs) and diacylglycerols (DAGs) have various health benefits in humans. In this study, PEs and DAGs were synthesized by lipase-catalyzed transesterification between a natural oil and phytosterols. First, commercial lipases were screened for transesterification and were further verified using multiple-ligand molecular docking. AYS "Amano" (a lipase from Candida rugosa) was found to be the optimum lipase. Subsequently, the enzymatic transesterification conditions were optimized. The optimized conditions were determined to be a 1:2 M ratio of phytosterols to oil, 100 mmol/L phytosterols, and 9 % AYS "Amano", and 50 °C for 24 h in 20 mL n-hexane. Under these conditions, over 70 % of phytosterols were converted to PEs. In this study, an efficient enzymatic process was developed to produce value-added functional oils rich in PEs and DAGs, with PEs content ≥ 31.6 %, DAGs content ≥ 11.2 %, acid value ≤ 0.91 mg KOH/g, and peroxide value ≤ 2.38 mmol/kg.

Effect of flaxseed-derived diglyceride-based high internal phase Pickering emulsion on the quality characteristics of reformulated beef burgers

The study aimed to fabricate healthier beef burgers using high internal phase Pickering emulsion (HIPPE) as animal fat substitute. In this context, HIPPE stabilized by modified soy protein isolates was produced with flaxseed-derived diglycerides (DAGs). Beef burgers were prepared by substituting beef backfat with HIPPE at varying levels (0%, 25%, 50%, 75%, and 100%). Reformulated burgers showed a significant decrease in WHC (from 89.75 to 77.38%), pH (from 5.73 to 5.58), L* values (from 53.5 to 44.5), and b* values (22.9 to 21.8), while a significant increase in a* values (from 24.4 to 6.7), cooking loss (from 20.25 to 30.62), and cooking shrinkage (from 11.27 to 13.05). Texture attributes, including hardness, chewiness, and gumminess, decreased up to 50% fat substitution and increased with increasing levels of fat substitution. Moreover, the rheological properties (G' and G'') and T2 relaxation time were increased with increasing fat replacement. The reformulation with HIPPE resulted in a decrease in SFA (from 3896 to 1712 mg/100 g), ω-6/ω-3 ratio (from 5.29 to 0.47), atherogenic index (from 0.57 to 0.13), and thrombogenic index (from 1.46 to 0.15) and increase in PUFA/SFA ratio (from 0.20 to 2.79). Notably, burgers with 50% fat substitution were more preferred regarding tenderness, while those with 100% fat substitution obtained higher scores for color and flavor than all other treatments. In conclusion, 50% fat replacement using flaxseed-derived diglyceride-based HIPPE improved beef burgers' textural profile and fatty acid composition without compromising the sensory characteristics.

Ultra-high performance liquid chromatography-quadrupole/time-of-flight mass spectrometry-based lipidomics reveals key lipid molecules as potential therapeutic targets of Polygonum cuspidatum against hyperlipidemia in a hamster model

Polygonum cuspidatum is a homology of traditional medicine and functional food widely distributed around the world. Our previous study on the hyperlipidemic animal model demonstrated that Polygonum cuspidatum was effective in ameliorating hyperlipidemia, which is characterized by lipid disorders. Herein, the regulatory effect of Polygonum cuspidatum on lipid metabolism needs to be known if its hypolipidemic mechanism is desired to clarify. In this study, an ultra-high performance liquid chromatography-quadrupole/time-of-flight mass spectrometry-based lipidomic strategy was first applied to investigate the lipidomic patterns of high-fat diet-induced hyperlipidemic hamsters when treated with Polygonum cuspidatum. The results showed that Polygonum cuspidatum improved the lipidomic profile of hyperlipidemia. A total of 65 differential lipids related to the hypolipidemic effect of Polygonum cuspidatum were screened out and identified, and these differential lipids covered various categories, such as phosphatidylcholines, phosphatidylethanolamines, triacylglycerols, sphingomyelins and so on. Orally administrated Polygonum cuspidatum restored these differential lipids back to normal or nearly normal levels. This study adopted lipidomics to reveal the key lipid molecules as potential therapeutic targets of Polygonum cuspidatum against hyperlipidemia, which would provide a scientific basis for its clinical application.

Short- and long-term cognitive and metabolic effects of medium-chain triglyceride supplementation in rats

Medium-chain triglycerides (MCT) possess neuroprotective properties. However, the long-term metabolic consequences of supplementing a regular diet with cognition-enhancing doses of MCT are largely unknown. We studied the effects of chronic (28 days) supplementation of regular diet with different doses of MCT oil (1, 3, or 6 g/kg/day) or water (control) on working memory (Y-maze), behavior in the Open Field, spatial learning (Morris water maze), and weight of internal organs in male Wistar 2.5-m.o. Rats. In a separate experiment, we evaluated acute (single gavage) and chronic (28 days) effects of MCT or lard supplementation (3 g/kg) on blood biochemical parameters. MCT-1 and MCT-3 doses improved working memory in YM. In MWM, MCT-6 treatment improved spatial memory. Chronic MCT-1 or MCT-3 treatment did not affect internal organ weight, while MCT-6 dose increased liver weight and the brown/white adipose tissue ratio. Acutely, MCT administration elevated blood β-hydroxybutyrate and malondialdehyde levels. Chronic MCT administration (3 g/kg) did not affect the blood levels of glucose, lactate, pyruvate, acetoacetate, β-hydroxybutyrate, total and HDL cholesterol, triglycerides, malondialdehyde, and aspartate transaminase and alanine transaminase activities. Therefore, daily supplementation of standard feed with MCT resulted in mild intermittent ketosis. It improved working memory at lower concentrations without significant adverse side effects. At higher concentrations, it improved long-term spatial memory but also resulted in organ weight changes and is likely unsafe. These results highlight the importance of monitoring the metabolic effects of MCT supplementation alongside cognitive assessment in future studies of MCT's neuroprotective properties.

Fermentative Production of Diacylglycerol by Endophytic Fungi Screened from Taxus chinensis var. mairei

Diacylglycerol (DAG) production by microbial fermentation has broad development prospects. In the present study, five endophytic fungi which could accumulate DAG were screened from Taxus chinensis var. mairei by using potato dextrose agar plate and flask cultivation in potato dextrose broth culture medium. The strains were biologically identified based on morphological features and semi-quantitative PCR. The identification results indicated that the five strains belonged to different genera: Fusarium annulatum (F. annulatum, coded as MLP41), Trichoderma dorotheae (T. dorotheae, coded as MLG23), Colletotrichum aeschynomenes (C. aeschynomenes, coded as MLY23), Pestalotiopsis scoparia (P. scoparia, coded as MLY31W), and Penicillium cataractarum (P. cataractarum, coded as MLGP11). The crude lipids from the strains and their corresponding triacylglycerol, 1,2-DAG, and 1,3-DAG fractions separated via thin-layer chromatography were mainly composed of palmitic acid, stearic acid, oleic acid, and linoleic acid, which in total accounted for higher than 94% of the content. The effects of fermentation conditions on the DAG productivity were discussed, and the yields of DAG were determined based on the ¹H NMR spectra of crude lipids. The highest total DAG yields of F. annulatum, T. dorotheae, C. aeschynomenes, P. scoparia, and P. cataractarum were 112.28, 126.42, 189.87, 105.61, and 135.56 mg/L, respectively. C. aeschynomenes had the strongest potential to produce DAG. The results showed that this may be a new promising route for the production of DAG via fermentation by specific endophytic fungi, such as C. aeschynomenes.

Characteristics and feasibility of olive oil-based diacylglycerol plastic fat for use in compound chocolate

With an aim to prepare the healthier functional chocolate, olive oil-based diacylglycerol plastic fat (ODAGP) was prepared by mixing olive oil-based diacylglycerol stearin (O-DAGS) and olive oil-based diacylglycerol olein (O-DAGO) as confectionery fat in compound chocolate. We reported the physicochemical properties of ODAGP and ODAGP-CB blends, and then evaluated their application potential in compound chocolate based on sensory, blooming property and polymorphic transition. ODAGP (40% O-DAGS) showed a wide plastic range (7.1-45.2%) and high component compatibility. The crystal properties results indicated that ODAGP mainly existed in stable β-forms (β₁ and β₂). On the other hand, the ODAGP-CB binary system containing 10-40% ODAGP displayed similar melt-in-mouth property and crystal polymorphism (Form V) to natural CB. Compound chocolate prepared with ODAGP-CB blends obtained satisfactory overall acceptability (score > 7.8) and showed stronger fat bloom resistance.

Enzymatic Synthesis of Diacylglycerol-Enriched Oil by Two-Step Vacuum-Mediated Conversion of Fatty Acid Ethyl Ester and Fatty Acid From Soy Sauce By-Product Oil as Lipid-Lowering Functional Oil

Soy sauce by-product oil (SSBO), a by-product of the soy sauce production process, is the lack of utilization due to an abundance of free fatty acid (FFA) and fatty acid ethyl ester (EE). The utilization of low-cost SSBO to produce value-added diacylglycerol (DAG)-enriched oil and its applications are promising for the sustainability of the oil industry. The objective of this study was to utilize SSBO containing a high content of EE and FFA as raw material to synthesize DAG-enriched oil and to evaluate its nutritional properties in fish. Based on different behaviors between the glycerolysis of EE and the esterification of FFA in one-pot enzymatic catalysis, a two-step vacuum-mediated conversion was developed for the maximum conversions of EE and FFA to DAG. After optimization, the maximum DAG yield (66.76%) and EE and FFA conversions (96 and 93%, respectively) were obtained under the following optimized conditions: lipase loading 3%, temperature 38°C, substrate molar ratio (glycerol/FFA and EE) 21:40, a vacuum combination of 566 mmHg within the initial 10 h and 47 mmHg from the 10th to 14th hour. Further nutritional study in fish suggested that the consumption of DAG-enriched oil was safe and served as a functional oil to lower lipid levels in serum and liver, decrease lipid accumulation and increase protein content in body and muscle tissues, and change fatty acid composition in muscle tissues. Overall, these findings were vital for the effective utilization of SSBO resources and the development of future applications for DAG-enriched oil as lipid-lowering functional oil in food.

Opinion on the re-evaluation of mono- and diglycerides of fatty acids (E 471) as food additive in foods for infants below 16 weeks of age and follow-up of their re-evaluation as food additives for uses in foods for all population groups

Mono- and diglycerides of fatty acids (E 471) was re-evaluated in 2017 by the former EFSA Panel on Food Additives and Nutrient sources added to Food (ANS). As a follow-up to this assessment, the Panel on Food Additives and Flavouring was requested to assess mono- and diglycerides of fatty acids (E 471) for its use as food additive in food for infants below 16 weeks of age belonging to food categories 13.1.1 (Infant formulae) and 13.1.5.1 (Dietary foods for infants for special medical purposes and special formulae for infants). In addition, the FAF Panel was requested to address the issues already identified during the re-evaluation of the food additive in 2017 when used in food for the general population. The Panel considered that there is no indication of adverse effects from the available animal studies at the highest dose tested and from the post marketing data. A comparison was made between the daily exposure to the sum of mono- and di-acylglycerols from breast milk and that resulting from the use of E 471 in the infant formula. The Panel noted that the resulting exposures are in the same order of magnitude. Overall, the Panel concluded that there is no reason for a safety concern when E 471 used as food additive in FC 13.1.1 and 13.1.5.1 and according to the Annex III to Regulation (EC) No 1333/2008. The risk assessment for toxic elements and impurities clearly indicated the need to lower the current maximum limits for arsenic, lead, cadmium and mercury and to include limits for glycidyl esters, 3-monochloropropane diol and erucic acid in the EU specifications of E 471.

Kinetics and Mechanism of Solvent Influence on the Lipase-Catalyzed 1,3-Diolein Synthesis

1,3-Diacylglycerol preparation has roused increasing attention in recent years as the 1,3-diacylglycerol-rich oils can suppress the deposition of visceral fat and prevent the body weight increasing. Lipozyme TL IM-mediated esterification of oleic acid with monoolein was effective for 1,3-diacylglycerol production. During the esterification process, the solvent shows obvious influence on the diolein synthesis as well as the 1,3-diolein production. This work investigated the related kinetics and mechanism of the solvent effect on the esterification and Lipozyme TL IM performance. The results indicated that both the esterification rate constant and the acyl migration rate constant positively correlated with the logP of the solvent, while the site specificity of lipase has negative correlation with solvent logP. The acylation toward the 2-position of 1-monoolein was more sensitive to the solvent logP compared to the 1-position of glycerides. Molecular dynamics simulation revealed that solvents with different logP influenced the structure of Lipozyme TL IM including RMSD, hydrogen bond, and radial distribution function to a large extent, which subsequently led to the catalytic activity and selectivity variation of the lipase.

Effects of diacylglycerol and triacylglycerol from peanut oil and coconut oil on lipid metabolism in mice

Different chain lengths diacylglycerols (DAG) (long- and medium-chain) were synthesized from peanut and coconut oils. The effects of DAG with different chain lengths on body fat, blood lipids, and lipid metabolism-related enzymes in the liver and adipose tissue of C57BL/6J mice were investigated. Compared to peanut and coconut oils containing triacylglycerol (TAG), DAG-rich oils can significantly reduce the body weight, kidney weight, serum triglyceride (TG) content, hepatic fatty acid synthase (FAS), and Acetyl-CoA carboxylase (ACC) enzyme levels (p < 0.05) in C57BL/6J mice. Therefore, the effect of coconut oil DAG on improving body fat metabolism was probably due to the impact of DAG. Meanwhile, the body weight and serum TG content in coconut oil DAG group were lower than those in peanut oil DAG group. In addition, the spleen weight, hepatic ACC, and lipoprotein lipase (LPL) enzymes in coconut oil DAG group (0.07 ± 0.01 g, 2.08 ± 0.42 ng/mg pro, and 18.44 ± 5.23 ng/mg pro, respectively) were significantly lower than those in peanut oil DAG group. Although coconut oil DAG and peanut oil DAG have different fatty acid compositions, their effects on lipid metabolism showed no significant changes. Coconut oil DAG (peanut oil DAG) showed the improved lipid metabolism than that of coconut oil (peanut oil), which was probably due to the effect of DAG. PRACTICAL APPLICATION: Peanut and coconut oils are common edible oils. The oil containing DAG synthesized decreased the body weight and lipid accumulation in mice. Coconut oil is rich in medium-chain fatty acids, while peanut oil mainly consists of long-chain fatty acids. Due to the different contents of fatty acids, the synthesized structural lipids have different effects on lipid metabolism. Medium-chain triglycerides were considered as agents to alleviate obesity.