Foodborne pathogens are the main factors behind foodborne diseases and food poisoning and thus pose a great threat to food safety.

Zein/pectin core-shell nanoparticles with average diameter of about 235 nm and polydipersity index (PDI) of 0.24 were developed to encapsulate, protect and deliver resveratrol. Biopolymer nanoparticles could be formed containing up to 10.2% (w/w) resveratrol, with a particle yield of 91.7% and a resveratrol loading efficiency of 77.9%. The nanoparticles formed were spherical and had good redispersibility in aqueous solutions. The encapsulated resveratrol had a higher in vitro antioxidant activity than free resveratrol as determined by DPPH•, ABTS• + scavenging ability, and iron (III) reducing power. The encapsulated resveratrol also exhibited higher antiproliferative activity when tested using human hepatocarcinoma Bel-7402 cells than free resveratrol, with IC 50 values of 17.6 µg/mL (77.2 µM) and 25.6 µg/mL (112.0 µM) respectively. The colloidal form of resveratrol developed in this study may be particularly useful for application in functional foods and beverages, as well as in dietary supplements and pharmaceutical products.

No abstract

The present study was aimed at selecting an efficient binary solvent mixture for monoacylglycerol (MAG) synthesis by enzymatic glycerolysis of soybean oil. Solvent combinations of tert-butanol/isopropanol (v/v) at different ratios were studied. Of the investigated cases, tert-butanol:isopropanol at ratio 80:20 was the most suitable organic medium. The optimum conditions for MAG synthesis under the selected mixture were: water 10 wt% based on glycerol, Lipozyme TL IM 15 wt% based on oil and glycerol, weight ratio of solvent to oil 4:1, and molar ratio of glycerol to oil 3.5:1. Under these conditions with a 4-h reaction, the yield of MAG was 72.0% where the triacylglycerol (TAG) content was reduced to only 1.0% (based on acylglycerols). Fatty acid ester (FAE) formation from the solvents was very low in the final product (1.3% based on reaction mixture). The selected binary solvent mixture has good physical properties with low melting point (-26.5°C), which can avoid the risk of crystallization in practical operations.

BackgroundPure 1, 3-diacylglycerols (1, 3-DAG) have been considered to be significant surfactants in food, cosmetics and pharmaceutical industries, as well as the effect on obesity prevention.MethodsIn this study, a vacuum-driven air bubbling operation mode was developed and evaluated for the enzymatic synthesis of 1, 3-DAG of saturated fatty acids, by direct esterification of glycerol with fatty acids in a solvent-free system. The employed vacuum-driven air bubbling operation mode was comparable to vacuum-driven N2 bubbling protocol, in terms of lauric acid conversion and 1, 3-dilaurin content.ResultsSome operation parameters were optimized, and 95.3% of lauric acid conversion and 80.3% of 1, 3-dilaurin content was obtained after 3-h reaction at 50°C, with 5 wt% of Lipozyme RM IM (based on reactants) amount. Of the lipases studied, both Lipozyme RM IM and Novozym 435 exhibited good performance in terms of lauric acid conversion. Lipozyme TL IM, however, showed low activity. Lipozyme RM IM showed good operational stability in this operation protocol, 80.2% of the original catalytic activity remained after 10 consecutive batch applications. Some other 1, 3-DAG were prepared and high content was obtained after purification: 98.5% for 1, 3-dicaprylin, 99.2% for 1, 3-dicaprin, 99.1% for 1, 3-dilaurin, 99.5 for 1, 3-dipalmitin and 99.4% for 1, 3-disterin.ConclusionThe established vacuum-driven air bubbling operation protocol had been demonstrated to be a simple-operating, cost-effective, application practical and efficient methodology for 1, 3-DAG preparation.

No abstract

Monoacylglycerols (MAG) are nonionic emulsifiers, widely used in food, pharmaceutical, and cosmetic industries. Besides the bulk applications in food and dairy industries, pure MAG are also of great interest in synthetic organic chemistry where they are used as synthetic intermediates and as chiral building blocks. Reaction routes for MAG production including direct esterification of glycerol and fatty acids, interesterification between glycerol and fatty acid esters, glycerolysis of TAG and glycerol, partial hydrolysis of TAG, as well as alcoholysis of TAG. During the past few years, extensive efforts have been made for high yield of MAG from the reaction systems, using either chemical or enzyme as catalysts. And strategies have been developed aiming at the increase of MAG selectivity. An overview is given for such strategies targeting on the increase of MAG yield from the reaction systems. In particular, the mesoporous siliceous framework porosity and the surface hydrophilicity of the heterogeneous catalysts, as well as the solvation within the reaction systems caused by reaction medium, are discussed carefully to clearly highlight how catalysts and reaction medium can help to increase the MAG selectivity (MAG selectivity in the present paper means selectivity to form MAG instead of DAG).

No abstract