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BACKGROUND: Medium‐chain monoglycerides (MGs) are a group of 1‐monoglycerides of medium‐chain fatty acids with strong antibacterial activity, which may influence the gut microbiota in the diet of broilers. The present study evaluated the effects of mixed MGs on the community and function of gut microbiota in broilers. A total of 528 newly hatched male yellow feathered broiler chicks were weighed and randomly assigned into four groups, including a basal diet (CON), a basal diet containing 300 mg kg−1 MG (MG300), 450 mg kg−1 MG (MG450), or 600 mg kg−1 MG (MG600). RESULTS: The cecal acetic acid, propionic acid, butyric acid, isobutyric acid, isovaleric acid and total short‐chain fatty acid of broilers in the MG‐containing groups were notably increased compared with the CON group. Dietary MG selectively increased the relative abundance of Bifidobacteriaceae, Bacteroides and an unclassified genus of Lachnospiraceae family, but decreased the proportion of an unclassified genus of Barnesiellaceae and a norank genus of Flavobacteriaceae family in the cecum of broilers. Functional prediction revealed that MG supplementation enriched the microbial gene abundance of amino acid metabolism and carbohydrate metabolism, while depleted the gene abundance of fat metabolism and energy metabolism. Moreover, the modulation of gut microbiota by MG supplementation was closely correlated with the alteration of muscle amino acids. CONCLUSION: Dietary MGs altered the gut microbiota community structure and metabolites, and modulated the gene abundance of microbial metabolism pathways in the cecum of broilers, which may further influence the growth performance, nutrient utilization and meat quality of the host. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND: Fermentation is a traditional food‐preserving technique. It is an effective process, widely used to enrich the nutrients diversity and bioactivity of the fermented foods since ancient times. This study aimed at investigating the effects of various fermentation starters on the physicochemical, antioxidant, antimicrobial, and antidiabetic properties of blueberry juices. The blueberry juices were fermented by natural fermentation (NFBJ), self‐made starters fermentation (SFBJ), and commercial starters fermentation (CFBJ); fresh blueberry juice (BBJ) was processed without fermentation for comparison. RESULTS: Probiotics‐fermented blueberry juices (SFBJ and CFBJ) showed less total and reducing sugars, higher titratable acidity, and a wider variety and higher amounts of organic acids than non‐fermented blueberry juice (BBJ) did. All the fermented blueberry juices (NFBJ, SFBJ, and CFBJ) showed significantly (P < 0.05) higher antioxidant potentials than that of BBJ measured by 2,2′‐azino‐bis‐3‐ethylbenzothiazoline‐6‐sulfonic acid, cupric‐reducing antioxidant capacity, and ferric‐reducing ability power assays. The SFBJ exhibited the highest antibacterial activities against Escherichia coli, Staphylococcus aureus, and Salmonella Typhimurium, with inhibition zone diameters of 38.84 ± 1.74 mm, 34.91 ± 1.53 mm, and 36.18 ± 3.16 mm respectively. Compared with BBJ, the α‐glucosidase inhibitory activity of the SFBJ and CFBJ increased by two‑to threefold. The α‐amylase inhibitory activity of the SFBJ and CFBJ increased by 600%, whereas the spontaneous fermentation showed no improvement. The SFBJ and CFBJ promoted glucose consumption of HepG2 cell lines, indicating the promising potential for a higher glucose bio‐utilization. CONCLUSIONS: The SFBJ and CFBJ showed remarkable improvements in the antioxidant, antimicrobial, and antidiabetic activities compared with non‐fermented and spontaneous fermented juices, indicating their promising potentials as an antihyperglycemic agent. © 2021 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

BACKGROUND Understanding the interactions between feed additives and the functional properties of egg white protein (EWP) may offer novel insights into the effects of feed additives on laying hens and may provide an alternative for modification of the functional properties of EWP by using laying hens as bioreactors. Glycerol monolaurate (GML) is widely used in the food industry as an effective antibacterial emulsifier. In this work, the effects of three doses of dietary GML supplementation (150, 300, and 450 mg kg−1 hen) on the functional properties of EWP were investigated. RESULTS: The hardness of EWP gels was significantly improved by 300 and 450 mg kg−1 GML supplementation. Foaming capacity (FC) and foaming stability (FS) were increased after GML treatment; 450 mg kg−1 GML supplementation showed the most significant improvements, with 44.82% in FC and 23.39% in FS. Stabilization of EWP‐oil emulsions was also improved, supported by a slowed creaming process and the formation of smaller oil droplets. The heat denaturation temperature and rheological properties were also modified by dietary GML supplementation, implying improved thermal stability. CONCLUSION: Our study demonstrated that GML supplementation has the potential to modify the functional properties of EWP, broadening the application of GML and providing a new perspective for evaluation of the efficacy of feed additives. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Dioleoyl; palmitoyl-rich triacylglycerols (OPO-rich TAG) were synthesized through Aspergillus oryzae lipase (AOL)-catalyzed acidolysis of palm stearin with commercial oleic acid by a one-step process in a stirred tank reactor and continuous packed bed reactor to evaluate the feasibility of using immobilized AOL. AOL was found to be valuable for the synthesis of OPO-rich TAG when compared with commercial lipase from Thermomyces lanuginose (Lipozyme TL IM; Novozymes A/S, Bagsvaerd, Denmark). The C52 (triglycerides with a carbon number of 52, stands for OPO, OPL, LPL and their isomers) content of AOL was higher (45.65 %), and the intensity of treatment (IOT: lipase amount × reaction time/TAG amount) of AOL was just 6.25 % of that of Lipozyme TL IM under similar reaction conditions in the stirred tank reactor. Response surface methodology were used to optimize the reaction conditions of the AOL-catalyzed acidolysis is reaction in the packed bed reactor. The optimal point for the set of experimental conditions generated were as follows: residence time 3.0 h; temperature 62.09 °C; substrate molar ratio 7.13 mol/mol. The highest C52 content obtained was 48.60 ± 2.36 %, with 57.46 ± 1.72 % total palmitic acid at the sn-2 position and 74.21 ± 2.45 % oleic acid at the sn-1,3 positions. The half-life of AOL was 24 h in the stirred tank reactor and 140 h in the packed bed reactor. The immobilized AOL achieved similar conversion and selectivity to commercial lipases for the catalyzed synthesis of OPO-rich TAG and may offer a cheaper alternative. [ABSTRACT FROM AUTHOR]

The enzymatic interesterification of a solvent-free, equimolar mixture of trilaurin and 1,3-palmitin-2-olein was studied using three immobilized lipase preparations as catalysts. Analysis of triacylglycerol (TAG) content and fatty acid (FA) distribution monitored the lipase-catalyzed interesterification in sn-1,3 positions and FA exchange in the sn-2 position caused by acyl migration. Lipase from Rhizopus oryzae immobilized on polypropylene showed high sn-1,3 regioselectivity, and minimal exchange in the sn-2 position. With lipase from Thermomyces lanuginosus on silica (Lipozyme® TL IM), completely randomized FA distribution was obtained in 24 h. T. lanuginosus lipase on polypropylene caused a moderate rate of FA exchange in the sn-2 position. Thus, the T. lanuginosus lipase and silica promoted randomization of FA distribution, whereas the R. oryzae lipase and polypropylene did not. Higher water activity promoted hydrolysis and thereby increased concentrations of partial acylglycerols, but at the same time a decrease in the acyl migration rate of these intermediates was also observed. The net result was that at a certain degree of interesterification, there was no significant effect of water activity on the degree of exchange in the sn-2 position. On the other hand, a low water activity had the major advantage of giving a high yield of TAG. Practical applications: Both the type and the position of FA affect the properties of TAG. In TAG interesterification, there are thus different requirements for regiospecificity in FA exchange, depending on which product is desired. According to our results, lipase-based catalysts can be used for TAG interesterification either to achieve unchanged FA composition in sn-2 position or fast FA randomization in all positions. This helps to broaden the application of lipases in interesterification. The production of TAG can be tailor-made for lipid mixtures with particular TAG composition and FA distribution using proper lipases, support materials, water activity, and reaction time. The enzymatic LLL-POP model reaction was used to investigate effects of lipase, support material, and water activity on acyl migration. (Fig. A): effect of Lipozyme® TL IM, TLPP and ROPP at aw 0.26, (Fig. B): effect of aw between 0.15 and 0.80 using Lipozyme® TL IM as the example. [ABSTRACT FROM AUTHOR]

BACKGROUND Sugar medium-chain fatty acid esters are a new type of biodegradable, non-toxic, non-irritant and non-ionic surfactant with proven antimicrobial activity. Various sugar medium-chain fatty monoesters were prepared enzymatically using Lipozyme TLIM in organic solvent. Properties such as surface tension, antimicrobial activity, and ability to foam, emulsify and stabilize emulsions at room temperature were evaluated to conduct systematic studies on the structure-function relationships of these compounds. RESULTS Results showed that all monoesters displayed good surface activity properties. In particular, sucrose monolaurate was the most excellent surfactant among 12 monoesters. Sugar monoesters containing C8 to C12 alkyl chains showed a broad spectrum of increasing antimicrobial activity. All tested monoesters were more effective against Staphylococcus aureus (Gram-positive bacterium) than Escherichia coli O157:H7 (Gram-negative bacterium). Methyl α- d-glycoside monoesters were the most effective, whereas raffinose monoesters possessed poor antimicrobial activity. CONCLUSIONS Generally, the length of fatty acid chain (hydrophobic group) and sugar groups (hydrophilic group) for sugar medium-chain fatty acid monoesters both affected the surface properties and antimicrobial activities. © 2014 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The DNA microarray was employed in this study to investigate the gene expression profiles of E scherichia coli treated by oil in water (o/w) microemulsion in order to better understand the antimicrobial mechanism of the microemulsion as a promising food-grade antimicrobial system. Among 5,440 open reading frames of E . coli, a total of 634 and 501 were highly induced and repressed, respectively. According to the annotation and analysis in the Gene Ontology ( GO) and Kyoto Encyclopedia of Genes and Genomes ( KEGG) databases, it was found that the differently expressed genes were mainly involved in the biosynthesis of cell wall components and membranes, phosphate-related metabolism and some other biosynthetic pathways, suggesting that the main antibacterial mechanisms of the o/w microemulsion were the attacks to the cell surface structure, especially the cell wall, and its influences on the metabolism of phosphate of the E . coli cells through phosphate absorption inhibition. Practical Applications In the panorama of the increasing need to search for novel strategies in order to prevent foodborne outbreaks, microemulsion systems have been of great interest to researchers for their broad antimicrobial properties. In our group, a series of food-grade or pharmaceutical microemulsion systems based on glycerol monolaurate have been established for antimicrobial applications. It was found that the prepared microemulsions possessed excellent broad-spectrum antimicrobial activities due to the disruption and dysfunction of biological membranes and cell walls, as suggested by the transmission electron microscopy observations and membrane permeability experiments. The antimicrobial mechanisms analysis of the microemulsion mediated by DNA microarray in this work will be of great importance in exploring the structure-activity relationship of the o/w microemulsion at molecular biological levels in future work, in order to provide a guideline in designing food-grade antimicrobial microemulsions. [ABSTRACT FROM AUTHOR]

The antibacterial activities of a food‐grade dilution‐stable microemulsion, which has an oil phase of glycerol monolaurate (5% w/w), propionic acid (15%) and a surfactant phase of Tween 80 (21%), sodium benzoate (21%), have been studied in this work. By broth dilution method, the minimum bactericidal concentrations (MBC) of the microemulsion against Escherichia coli, Staphylococcus aureus and Bacillus subtilis were achieved at 250, 500 and 250 ppm, respectively. The bactericidal kinetic results showed that over 90% viable bacterial cells were killed within 5 min by the microemulsion at the concentrations determined by MBC; a nearly 4 log reduction in S. aureus or B. subtilis titer was obtained while a complete loss of viability was achieved against E. coli in 60 min. The fast‐killing kinetics of the microemulsion was in good agreement with the cell surface hydrophobicity, membrane permeability experiments and the observation of transmission electron microscopy. PRACTICAL APPLICATIONS: This work suggests the potential use of food‐grade fully dilutable microemulsions for antimicrobial purposes in food products. [ABSTRACT FROM AUTHOR]

Food grade monolaurin (the glycerol monoester of lauric acid) microemulsions (MMEs) based on multicomponent mixtures and the effects of MMEs on the shelf life of fresh noodles were studied. A microemulsion system consisting of monolaurin (M), surfactants (Tween 20 and Tween 80, Wenzhou Qingming Chemical Engineering Company, Wenzhou, Zhejiang, China ) and cosurfactant (pentanol and dodecanol) dispersed in distilled water was used. The influence of surfactants on the phase behavior was studied in this article. Subsequently, two MMEs with large oil in water regions have demonstrated the enhanced antimicrobial activities against Bacillus subtilis, Escherichia coli, Aspergillus niger and Penicillium digitatum, compared to monolaurin (M) alone. In addition, the shelf life of fresh noodles prepared with monolaurin (M) alone was about 4 days, whereas MMEs extended shelf life by 10 days at least when stored at 37C. PRACTICAL APPLICATIONS The effect of monolaurin microemulsion (MME) as antimicrobial agents in foods, especially those neutral foods such as noodles, is obvious, and MME has demonstrated a much longer shelf life of fresh noodles than M alone. In addition, for those neutral foods other than fresh noodles, the application of MMEs can also be studied. [ABSTRACT FROM AUTHOR]

In this study, we fabricated ethyl cellulose (EC)–gelatin (G) composite films by solvent casting and electrospinning. The characterization of the cast and electrospun films was performed by scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, X‐ray diffraction, Fourier transform infrared spectroscopy, X‐ray photoelectron spectrometry, and water contact angle measurements. The results showed that the blending of EC with G improved the spinnability of the composite films with higher thermal stability. Compared with solvent casting, electrospinning induced a helix‐to‐coil transition of G and provided more hydrogen‐forming sites for EC to form a compatible network. Interestingly, the electrospun composite film had a hydrophobic surface with a water contact angle of 113.8°, whereas the cast composite film showed a hydrophilic surface at 67.5°. The confocal laser scanning microscopy observations suggested that after water immersion, the cast composite film collapsed into aggregates, whereas the electrospun composite film maintained the nanofibrous structures well; this indicated an improved water resistance. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46824. [ABSTRACT FROM AUTHOR]

Camellia oil one of the most important vegetable oils in China. Fatty acid composition and positional distribution analyzed by GC and GC-MS in this study reveals that camellia oil is rich in oleic acid (around 78% in TAG and 85% at sn-2 position of TAG). Camellia oil has a potential as an edible oil which provides oleic acid or for use as a feedstock in designing oleic acid-enriched structured lipids. Camellia oil - a high oleic-vegetable oil. [ABSTRACT FROM AUTHOR]