Enzymatic Production of Monoacylglycerols (MAG) and Diacylglycerols (DAG) from Fish Oil in a Solvent-Free System

Determination of chloropropanol esters and glycidyl esters in nutritional foods by gas chromatography-tandem mass spectrometry based on acid hydrolysis and solid-phase extraction

This study presents a method based on acid transesterification and the purification by solid-phase extraction (SPE) coupled with gas chromatography-tandem mass spectrometry for quantifying 3- and 2-monochloropropanediol esters (3-MCPDE, 2-MCPDE) and glycidyl esters (GE) in nutritional foods. The fat was extracted by liquid-liquid extraction with petroleum ether and diethyl ether after the sample was hydrolysed with ammonia. Then the extract was purified by a SPE cartridge filled with the aminopropyl sorbents. It was demonstrated that the optimal elution volume for 3-MCPDE, 2-MCPDE and GE greatly depended on the sample matrix and varied from 6 to 12 mL for four different kinds of food matrices. All three analytes in the sample solution could be fully collected in the first 10-12 mL of eluate. By this way, monoacylglycerols commonly present in the samples were fully removed. Therefore, the overestimation of GE quantification was effectively eliminated. The modified analytical procedure was fully validated in a single laboratory and has been recommended as a Chinese Food Safety National Standard. In addition, two derivatisation agents, heptafluorobutyrylimidazole and phenylboronic acid, were proved to be equivalent in method accuracy and precision for the quantification of three analytes.

Future of Structured Lipids: Enzymatic Synthesis and Their New Applications in Food Systems

Structured lipids (SLs) refer to a new type of functional lipid obtained by modifying natural triacylglycerol (TAG) through the restructuring of fatty acids, thereby altering the composition, structure, and distribution of fatty acids attached to the glycerol backbones. Due to the unique functional characteristics of SLs (easy to absorb, low in calories, reduced serum TAG, etc.), there is increasing interest in the research and application of SLs. SLs were initially prepared using chemical methods. With the wide application of enzymes in industries and the advantages of enzymatic synthesis (mild reaction conditions, high catalytic efficiency, environmental friendliness, etc.), synthesis of SLs using lipase has aroused great interest. This review summarizes the reaction system of SL production and introduces the enzymatic synthesis and application of some of the latest SLs discussed/developed in recent years, including medium- to long-chain triacylglycerol (MLCT), diacylglycerol (DAG), EPA- and DHA-enriched TAG, human milk fat substitutes, and esterified propoxylated glycerol (EPG). Lastly, several new ways of applying SLs (powdered oil, DAG plastic fat, inert gas spray oil, and emulsion) in the future food industry are also highlighted.

Treatment with isolated gold nanoparticles reverses brain damage caused by obesity

In this study, we performed two experiments. In the first experiment, the objective was to link gold nanoparticles (GNPs) with sodium diclofenac and/or soy lecithin and to determine their concentration in tissues and their toxicity using hepatic and renal analyzes in mice to evaluate their safety as therapeutic agents in the subsequent treatment of obesity. In the second experiment, we evaluated the effect of GNPs on inflammatory and biochemical parameters in obese mice. In the first experiment, we synthesized and characterized 18 nm GNPs that were administered intraperitoneally in isolation or in association with sodium diclofenac and/or soy lecithin in mice once daily for 1 or 14 days. Twenty-four hours after the single or final administration, the animals were euthanized, following which the tissues were removed for evaluating the concentration of GNPs, and serum samples were collected for hepatic and renal analysis. Hepatic damage was evaluated based on the levels of alanine aminotransferase (ALT), whereas renal damage was evaluated based on creatinine levels. A higher concentration of GNPs was detected in the tissues upon administration for 14 days, and there were no signs of hepatic or renal damage. In the second experiment, the mice were used as animal models of obesity and were fed a high-fat diet (obese group) and control diet (control group). After eight weeks of high-fat diet administration, the mice were treated with saline or with GNPs (average size of 18 nm) at a concentration of 70 mg/L (70 mg/kg) once a day, for 14 days, for 10 weeks. Body weight and food intake were measured frequently. After the experiment ended, the animals were euthanized, serum samples were collected for glucose and lipid profile analysis, the mesenteric fat content was weighed, and the brains were removed for inflammatory and biochemical analysis. In obese mice, although GNP administration did not reduce body and mesenteric fat weight, it reduced food intake. The glucose levels were reversed upon administration of GNPs, whereas the lipid profile was not altered in any of the groups. GNPs exerted a beneficial effect on inflammation and oxidative stress parameters, without reverting mitochondrial dysfunction. Our results indicate that the intraperitoneal administration of GNPs for 14 days results in a significant GNP concentration in adipose tissues, which could be an interesting finding for the treatment of inflammation associated with obesity. Based on the efficacy of GNPs in reducing dietary intake, inflammation, and oxidative stress, they can be considered potential alternative agents for the treatment of obesity.

Purification process for MUFA- and PUFA-based monoacylglycerols from edible oils

Important health benefits have been attributed to monoacylglycerols (MAGs) due to their various physiological functions, owing to which they become candidates for use as functional foods in order to prevent the onset of certain diseases such as colon cancer. In this work, six edible oils, namely: olive, linseed, sunflower, evening primrose, DHASCO^® and ARASCO^® have been processed to obtain different MUFA- and PUFA- based MAGs. First, the oils were hydrolyzed by means of an enzymatic process using porcine pancreatic lipase and then the reaction products were fractionated by using a liquid chromatography column containing silica gel as stationary phase in order to purify the MAGs-enriched fraction. A second chromatography process was performed using silver nitrate coated silica gel as stationary phase, in order to obtain the different MUFA- and PUFA-based MAGs from the corresponding oils. Overall, MAGs based on oleic, linoleic, α-linolenic, γ-linolenic, arachidonic and docosahexaenoic acids have been isolated in high yields and purities (92.6, 97.4, 95.3, 90.9, 100 and 95.3% purity, respectively). Positional distribution was determined by means of ¹H NMR, which revealed a mix of 1(3) and 2-MAGs in variable proportions in the different MAGs.

Comparative in vitro intestinal digestion of 1,3-diglyceride and 1-monoglyceride rich oils and their mixtures

Intestinal in vitro digestion of 1,3-diolein (DO), 1-monoolein (MO), DO:MO (1:1) rich oils, and triolein (TO), was performed to study the rate and extent of hydrolysis as well as their bioaccessibility in detail, with special emphasis on 1,3-DO and 1-MO forms, as potential bioactive lipids with additional technological functions such as self-emulsifying lipids. The importance of in vitro conditions on non-desirable acylmigration was also shown. The rate of in vitro intestinal lipolysis was in increasing order TO<DO<DO:MO<MO. At the end of digestion, DO:MO was hydrolyzed to absorbable products at the same level than the MO sample. The degree of lipolysis positively correlated with the level of 1-MG and negatively with the level of 2-MG. Either DO, MO or DO:MO produced higher level of 1-MG than TO. DO:MO produced the highest level of 1-MG and a high ratio of 1-MG to 2-MG. Most hydrolysis products (>95%) of DO, MO and DO:MO were found within the micellar phase fraction during digestion, suggesting a high bioaccessibility. A positive correlation between the degree of lipolysis and the number of mixed micelles formed at the end of digestion was found. As summary, the obtained results would enhance the selection of glycerides to formulate ingredients with different purposes. Thus, in case a final high level of 1-MO would be desired to take advantage of the bioactivity of 1-MO, oils under the form of DO or DO:MO might be superior to MO. In case a high 1-MO level together with a low 2-MO level would be desired at the same time, mixtures of DO:MO or MO would be preferred. In case a higher self-emulsifying ability would be desired, the preferred forms would be MO and DO:MO. Finally, in case all the potential functionalities would be desired at the same time, namely the highest bioactivity, together with a high self-emulsifying ability, the mixture DO:MO might be suggested as an interesting product, with the additional economical advantage.