Complete kinetic model for esterification reaction of lauric acid with glycerol to synthesize glycerol monolaurate

Glycerol monolaurate(GML)is a widely used industrial chemical with excellent emulsification and antibacterial effect.The direct esterification of glycerol with lauric acid is the main method to synthesize GML.In this work,the kinetic process of direct esterification was systematically studied using p-toluenesulfonic acid as catalyst.A complete kinetic model of consecutive esterification reaction has been established,and the kinetic equation of acid catalysis was deduced.The isomerization reactions of GML and glycerol dilaurate were investigated.It was found that the reaction was an equilibrium reaction and the reaction rate was faster than the esterification reaction.The kinetic equations of the consecutive esterification reaction were obtained by experiments as k_(1)=(276+92261Xcat)exp(-37720/RT)and k_(2)=(80+4413Xcat)exp(-32240/RT).The kinetic results are beneficial to the optimization of operating conditions and reactor design in GML production process.

Glycerol monolaurate improves intestinal morphology and antioxidant status by suppressing inflammatory responses and nuclear factor kappa-B signaling in lipopolysaccharide-exposed chicken embryos

Medium-chain fatty acids and their derivatives are natural ingredients that support immunological functions in animals.The effects of glycerol monolaurate(GML)on intestinal innate immunity and associated molecular mechanisms were investigated using a chicken embryo model.Sixty-four Arbor Acres broiler embryos were randomly allocated into four groups.On embryonic day 17.5,the broiler embryos were administered with 9 mg of GML,which was followed by a 12-h incubation period and a12-h challenge with 32μg of lipopolysaccharide(LPS).On embryonic day 18.5,the jejunum and ileum were harvested.Results indicated that GML reversed the LPS-induced decline in villus height and upregulated the expression of mucin 2(P<0.05).GML decreased LPS-induced malondialdehyde production and boosted antioxidant enzyme activity(P<0.05).GML alleviated LPS-stimulated intestinal secretion of interleukin(IL)-1β,IL-6,and tumor necrosis factor-a(TNF-a)(P<0.05).GML also normalized LPS-induced changes in the gene expression of Toll-like receptor 4,nuclear factor kappa-B p65(NF-κB p65),cyclooxygenase-2,NOD-like receptor protein 3,IL-18,zonula occludens 1,and occludin(P<0.05).GML enhanced as well the expression of AMP-activated protein kinase a1 and claudin 1(P<0.05).In conclusion,GML improved intestinal morphology and antioxidant status by alleviating inflammatory responses and modulating NF-κB signaling in LPS-challenged broiler embryos.

Effects of dietary glycerol monolaurate on productive performance, egg quality, serum biochemical indices, and intestinal morphology of laying hens

Glycerol mono laurate(GML)has been widely used as an effective antibacterial emulsifier in the food in?dustry.A total of 360 44-week-old Hy-Line brown laying hens were randomly distributed into four groups each with six replicates of 15 birds,and fed with com-soybean-meal-based diets supplemented with 0,0.15,0.30,and 0.45 g/kg GML,respectively.Our results showed that 0.15,0.30,and 0.45 g/kg GML treatments significantly decreased feed conversion ratios(FCRs)by 2.65%,7.08%,and 3.54%,respectively,and significantly increased the laying rates and average egg weights.For egg quality,GML drastically in creased albume n height and Haugh units,and enhanced yolk color.Notably,GML increased the concentrations of polyunsaturated and monounsaturated fatty acids and reduced the concentration of total saturated fatty acids in the yolk.The albumen composition was also significantly modified,with an increase of 1.02%in total protein content,and increased 8ntents of His(4.55%)and Glu(2.02%)under the 0.30 g/kg GML treatment.Additionally,GML treatments had positive effects on the lipid metabolism of laying hens,including lowering the serum triglyceride and total cholesterol levels and reducing fat deposit!on in abdominal adipose tissue.Intestinal morphology was also improved by GML treatment,with increased villus length and villus height to crypt depth ratio.Our data demonstrated that GML supplementation of laying hens could have beneficial effects on both their productivity and physiological properties,which indicates the potential application of GML as a functional feed additive and gives us a new in sight into this traditional food additive.

Glycerol monolaurate attenuated immunological stress and intestinal mucosal injury by regulating the gut microbiota and activating AMPK/ Nrf2 signaling pathway in lipopolysaccharide-challenged broilers

This study was conducted to investigate the effects of glycerol monolaurate(GML)on lipopolysaccharide(LPS)-induced immunological stress and intestinal mucosal injury in broilers and its underlying mechanisms.A total of 144 one-d-old Arbor Acres broilers were allocated to a 22 factorial arrangement involving dietary treatment(0 or 1,200 mg/kg dietary GML)and LPS challenge(injected with saline or Escherichia coli LPS on d 16,18,and 20).Samples were collected on d 21.The results revealed that dietary GML augmented serum immunoglobulin A(P=0.009)and immunoglobulin G(P<0.001)levels in challenged birds.Dietary GML normalized LPS-induced variations in serum interleukin-6,interferongamma,and LPS levels(P<0.05),jejunal villus height(P=0.030),and gene expression of interleukin-6,macrophage inflammatory protein-3 alpha,Toll-like receptor 4,nuclear factor kappa-B,caspase-1,tight junction proteins,adenosine monophosphate-activated protein kinase alpha 1(AMPKa1),nuclear factorerythroid 2-related factor 2(Nrf2),and superoxide dismutase-1(P<0.05).GML supplementation ameliorated LPS-induced peroxidation by reducing malondialdehyde content and increasing antioxidant enzyme activity(P<0.05).Dietary GML enhanced the abundances of Anaerostipes,Pseudoflavonifractor,and Gordonibacter and reduced the proportion of Phascolarctobacterium in challenged birds.Dietary GML was positively correlated with alterations in antioxidant enzyme activities and AMPKa1,Nrf2,and zonula occludens-1 expressions.The genera Anaerostipes,Lachnospira,Gordonibacter,Lachnospira,Marvinbryantia,Peptococcus,and Pseudoflavonifractor were linked to attenuated inflammation and improved antioxidant capacity of challenged birds.In conclusion,dietary GML alleviated LPS-induced immunological stress and intestinal injury of broilers by suppressing inflammation and oxidative stress.Dietary GML regulated cecal microbiota and activated the AMPK/Nrf2 pathway in LPS-challenged broilers.