Anti-Obesity Effects of Dietary d-Allulose and Medium-Chain Triglycerides in High-Fat Diet-Fed Rats

d-Allulose, a rare sugar, exerts anti-obesity effects by inhibiting hepatic lipogenesis and promoting energy expenditure. Medium-chain triglycerides (MCTs) consist of three medium-chain fatty acids connected by glycerol. MCTs have been extensively investigated for their ability to reduce body fat accumulation. We previously investigated the anti-obesity effects of a combination of dietary d-allulose and MCT (5% - 13%) in rats;however, we could not confirm the anti-obesity effects of MCT or observed synergetic effects between d-allulose and MCT on body fat loss. We speculated that our previous studies were influenced by the excessive amount of MCT in the diets. Therefore, in this study, we aimed to investigate the anti-obesity effects of the simultaneous intake of d-allulose and MCT in rats fed an obesity-inducing high-fat diet with a low amount of MCTs (2%). Thirty-two male Wistar rats (3-week-old) were randomly divided into four groups: control, d-allulose, MCT, and d-allulose + MCT groups. Rats in each group were fed ad libitum on a control (no d-Allulose or MCT), 5% d-allulose, 2% MCT, or 5% d-allulose + 2% MCT diets for 16 weeks. Abdominal adipose tissue weights were significantly lower in the d-allulose diet group than in the control group, whereas no differences were observed between results of the MCT-supplemented groups. The total body fat mass was significantly lower in the d-allulose and MCT diet groups than in the control group, but no differences were observed between the MCT-supplemented groups. These results suggested that anti-obesity effects of dietary d-allulose were observed, and the effects of dietary MCTs were weaker than those of d-allulose. Moreover, we confirmed the interaction between dietary d-allulose and MCT on indicators of obesity. Interestingly, their effects were not synergistic, as MCT supplementation offset the anti-obesity effects of dietary d-allulose. However, the specific mechanisms underlying those effects remain unknown, warranting further investigation.

Medium-Chain Triglyceride Activated Brown Adipose Tissue and Induced Reduction of Fat Mass in C57BL/6J Mice Fed High-fat Diet

Objective To investigate activation of brown adipose tissue （BAT） stimulated by medium-chain triglyceride （MCT）. Methods 30 Male C57BL/6J obese mice induced by fed high fat diet （HFD） were divided into 2 groups, and fed another HFD with 2% MCT or long-chain triglyceride （LCT） respectively for 12 weeks. Body weight, blood biochemical variables, interscapular brown fat tissue （IBAT） mass, expressions of mRNA and protein of beta 3-adrenergic receptors （β3-AR）, uncoupling protein-1 （UCP1）, hormone sensitive lipase （HSL）, protein kinase A （PKA）, and adipose triglyceride lipase （ATGL） in IBAT were measured. Results Significant decrease in body weight and body fat mass was observed in MCT group as compared with LCT group （P〈O.05） after 12 weeks. Greater increases in IBAT mass was observed in MCT group than in LCT group （P〈O.05）. Blood TG, TC, LDL-C in MCT group were decreased significantly, meanwhile blood HDL-C, ratio of HDL-C/LDL-C and norepinephrine were increased markedly. Expressions of mRNA and protein of β3-AR, UCP1, PKA, HSL, ATGL in BAT were greater in MCT group than in LCT group （P〈O.05）. Conclusion Our results suggest that MCT stimulated the activation of BAT, possible via norepinephrine pathway, which might partially contribute to reduction of the body fat mass in obese mice fed high fat diet.

Medium-chain fatty acids and monoglycerides as feed additives for pig production:towards gut health improvement and feed pathogen mitigation

Ongoing challenges in the swine industry,such as reduced access to antibiotics and virus outbreaks(e.g.,porcine epidemic diarrhea virus,African swine fever virus),have prompted calls for innovative feed additives to support pig production.Medium-chain fatty acids(MCFAs)and monoglycerides have emerged as a potential option due to key molecular features and versatile functions,including inhibitory activity against viral and bacterial pathogens.In this review,we summarize recent studies examining the potential of MCFAs and monoglycerides as feed additives to improve pig gut health and to mitigate feed pathogens.The molecular properties and biological functions of MCFAs and monoglycerides are first introduced along with an overview of intervention needs at different stages of pig production.The latest progress in testing MCFAs and monoglycerides as feed additives in pig diets is then presented,and their effects on a wide range of production issues,such as growth performance,pathogenic infections,and gut health,are covered.The utilization of MCFAs and monoglycerides together with other feed additives such as organic acids and probiotics is also described,along with advances in molecular encapsulation and delivery strategies.Finally,we discuss how MCFAs and monoglycerides demonstrate potential for feed pathogen mitigation to curb disease transmission.Looking forward,we envision that MCFAs and monoglycerides may become an important class of feed additives in pig production for gut health improvement and feed pathogen mitigation.

Synthesis and Evaluation of Glyceride Prodrugs of Naproxen

The glyceride ester derivatives 6a and 6b were prepared by reacting 1,2,3-trihydroxy propane 1,3-dipalmitate/stearate with (S)-naproxen as potential prodrugs. The synthesis was achieved successfully with the aid of N,N’-dicyclohexyl- carbodiimide. These prodrugs were evaluated for anti inflammatory, analgesic and gastroprotective activity. It was found that prodrugs 6a and 6b showed less irritation to gastric mucosa as indicated by ulcer index. The synthesized glyceride esters were found to possess good pharmacological profile as shown by results of anti inflammatory and analgesic activity. The aqueous studies were performed in order to ensure the release of prodrugs. Both prodrugs were found to stable at acidic pH while undergoes hydrolysis at pH 7.4. These findings suggest that the glyceride prodrugs 6a and 6b might be used as potential biolabile derivatives.

Triglycerides Isolated from <i>Streptomyces</i>sp. ZZ035 and Their Nuclear Magnetic Resonance Spectroscopic Characters

Streptomyces sp. ZZ035 isolated from a folk medicinal soil sample in China showed remarkable antimicrobial activities. During the isolation of secondary metabolites, a white crystal powder (1) was isolated from the broth of this strain. Its nuclear magnetic resonance (NMR) and infrared (IR) spectra indicated that it was a complex composed of triglycerides. Next, six C15-17 long- chain fatty acids derived from these triglycerides were respectively identified as n-pentadecanoyl, 12-methyltetradecanoyl, 14-methyl pentadecanoyl, palmitoyl, 15-methyl hexadecanoyl and 14-methyl hexadecanoyl using the gas chromatography-mass spectroscopy (GC-MS) technology. Finally, the 13C and 1H assignments of 1 were achieved through the analyses of NMR data. Based on above, their detailed NMR spectroscopic elucidation and meticulous 13C, 1H assignments, especially the split peaks and coupling correlation of protons attached on the glycerol carbons, were performed for distinguishing triglycerides from other glycerides and for the identification of the long-chain fatty acids, and which would be helpful to the qualitative and quantitative analyses of tri-, di-and mono-glycerides.

Efficacy and safety of modified medium-chain triglyceride ketogenic diet in patients with drug-resistant epilepsy

Background Medium-chain triglyceride ketogenic diet(MCTKD)is previously less commonly used in China.This study was aimed to assess the efficacy and safety of the modified MCTKD in the treatment of drug-resistant epilepsy in Chinese patients.Methods Patients with drug-resistant epilepsy were enrolled to receive treatment with modified MCTKD in Guangdong Sanjiu Brain Hospital during December 2020 and September 2022.The modified MCTKD contained fat that provided 50–70%of the total energy,as well as proteins and carbohydrates that provided 20–30%and 20%of energy,respectively.The fat component was composed of 20–30%medium-chain triglycerides(MCTs)and 30–40%long-chain triglycerides.The efficacy and safety of the diet were assessed at 1,3 and 6 months.Results A total of 123 patients aged 2.5 to 65 years,were included in this study.The response rates at 1,3 and 6 months were 49.6%,43.1%,and 30.9%,respectively.The seizure freedom rates at 1,3 and 6 months were 12.2%,10.6%,and 6.5%,respectively.The retention rates at 1,3 and 6 months were 98.4%,65.0%and 33.3%respectively.Side effects occurred in 21.14%of patients,which were predominantly gastrointestinal symptoms such as abdominal pain,diarrhea,vomiting,and constipation,and most of them resolved after dietary adjustments.A total of 82 patients(66.7%)discontinued the treatment with the reason of refusing to eat(8.1%),poor efficacy(35.0%),poor compliance(4.9%),and inability to follow-up(9.8%).Only 4 patients(3.3%)withdrew the diet due to side effects.Conclusions The modified MCTKD with MCTs providing 20–30%of energy has a good safety in patients with drug-resistant epilepsy,but its effectiveness needs to be enhanced.Further modifications of MCTKD with an optimal energy ratio are required to achieve a better efficacy and safety.

Efficacy of medium-chain fatty acid salts distilled from coconut oil against two enteric pathogen challenges in weanling piglets

Background:The search for alternatives to antibiotics in pig production has increased the interest in natural resources with antimicrobial properties,such as medium-chain fatty acids(MCFA)as in-feed additives.This study evaluated the potential of a novel blend of MCFA salts(DIC)from distilled coconut oil with a lauric acid content to reduce enteropathogens and control intestinal diseases around weaning.Two experimental disease models were implemented in early-weaned piglets,consisting of two oral challenges:Salmonella Typhimurium(1.2×10~8 CFU)or enterotoxigenic Escherichia coli(ETEC)F4(1.5×10~9 CFU).The parameters assessed were:animal performance,clinical signs,pathogen excretion,intestinal fermentation,immune-inflammatory response,and intestinal morphology.Results:The Salmonella challenge promoted an acute course of diarrhea,with most of the parameters responding to the challenge,whereas the ETEC F4 challenge promoted a mild clinical course.A consistent antipathogenic effect of DIC was observed in both trials in the hindgut,with reductions in Salmonella spp.plate counts in the cecum(P=0.03)on d 8 post-inoculation(PI)(Salmonella trial),and of enterobacteria and total coliform counts in the ileum and colon(P<0.10)on d 8 PI(ETEC F4 trial).When analyzing the entire colonic microbiota(16 S rRNA gene sequencing),this additive tended(P=0.13)to reduce the Firmicutes/Bacteroidetes ratio and enriched Fibrobacteres after the Salmonella challenge.In the ETEC F4 challenge,DIC prompted structural changes in the ecosystem with increases in Dialister,and a trend(P=0.14)to increase the Veillonellaceae family.Other parameters such as the intestinal fermentation products or serum pro-inflammatory mediators were not modified by DIC supplementation,nor were the histological parameters.Only the intraepithelial lymphocyte(IEL)counts were lowered by DIC in animals challenged with Salmonella(P=0.07).With ETEC F4,the IEL counts were higher with DIC on d 8 PI(P=0.08).Conclusions:This study confirms the potential activity of this MCFA salts mixture to reduce intestinal colonization by opportunistic pathogens such as Salmonella or E.coli and its ability to modulate colonic microbiota.These changes could explain to some extent the local immune cell response at the ileal level.

Inhibition of African swine fever virus in liquid and feed by medium-chain fatty acids and glycerol monolaurate

Background:The ongoing African swine fever virus(ASFv)epidemic has had a major impact on pig production globally and biosecurity efforts to curb ASFv infectivity and transmission are a high priority.It has been recently identified that feed and feed ingredients,along with drinking water,can serve as transmission vehicles and might facilitate transboundary spread of ASFv.Thus,it is important to test the antiviral activity of regulatory compatible,antiviral feed additives that might inhibit ASFv infectivity in feed.One promising group of feed additive candidates includes medium-chain fatty acids(MCFA)and monoglyceride derivatives,which are known to disrupt the lipid membrane surrounding certain enveloped viruses and bacteria.Results:The antiviral activities of selected MCFA,namely caprylic,capric,and lauric acids,and a related monoglyceride,glycerol monolaurate(GML),to inhibit ASFv in liquid and feed conditions were investigated and suitable compounds and inclusion rates were identified that might be useful for mitigating ASFv in feed environments.Antiviral assays showed that all tested MCFA and GML inhibit ASFv.GML was more potent than MCFA because it worked at a lower concentration and inhibited ASFv due to direct virucidal activity along with one or more other antiviral mechanisms.Dose-dependent feed experiments further showed that sufficiently high GML doses can significantly reduce ASFv infectivity in feed in a linear manner in periods as short as 30 min,as determined by infectious viral titer measurements.Enzyme-linked immunosorbent assay(ELISA)experiments revealed that GML treatment also hinders antibody recognition of the membrane-associated ASFv p72 structural protein,which likely relates to protein conformational changes arising from viral membrane disruption.Conclusion:Together,the findings in this study indicate that MCFA and GML inhibit ASFv in liquid conditions and that GML is also able to reduce ASFv infectivity in feed,which may help to curb disease transmission.

Lipase Catalyzed Synthesis of Medium-chain Biodiesel from Cinnamonum camphora Seed Oil

The non-edible camphor tree seed oil was extracted and catalyzed by immobilized lipase for biodiesel production. The oil yield from camphor tree seeds reached 35.2% of seed weight by twice microwave-assisted extractions. Gas chromatography showed that free fatty acid content in camphor tree seed oil was 1.88%, and the main fatty acids were capric acid(53.4%) and lauric acid(38.7%). With immobilized lipase Candida sp. 99–125as catalyst, several important factors for reaction conditions were examined through orthogonal experiments.The optimum conditions were obtained: water content and enzyme loading were both 15% with a molar ratio of 1:3.5(oil/ethanol), and the process of alcoholysis was in nine steps at 40 °C for 24 h, with agitation at170 r·min-1. As a result, the medium-chain biodiesel yield was 93.5%. The immobilized lipase was stable when it was used repeatedly for 210 h.

基于脂质组学对5种常见禽蛋蛋黄脂质差异的研究

为研究鸭蛋、鹅蛋、鹌鹑蛋、鸽蛋及鸡蛋蛋黄所含脂质的差异,采用超高效液相色谱串联质谱对5种禽蛋黄进行脂质组学分析。结果显示,共检测到6类、26个亚类的1303种脂类。鸭与鸽的蛋黄、鸡与鹌鹑的蛋黄脂质成分相近,鹅蛋与其他蛋黄脂质成分差异最大。鸡蛋黄鞘脂含量最丰富,鹌鹑蛋黄的甘油磷脂含量最高,鸽蛋黄甘油酯含量最低,鸭蛋黄及鸽蛋黄的甘油二酯与甘油三酯含量比值最高,鸭蛋黄及鸽蛋黄中ω-3多不饱和脂肪酸含量较高。与鸡蛋黄相比,其他禽蛋有33个脂质存在极显著差异(P<0.05、VIP≥1并且FC≥10或FC≤0.1)。研究表明,不同禽蛋黄含有的脂质存在显著差异,当对比甘油酯比例及ω-3多不饱和脂肪酸含量时,鸭蛋黄和鸽蛋黄较鸡蛋黄、鹅蛋黄、鹌鹑蛋黄有优势。

“三丁酸甘油酯+二甲酸钾+植物精油”复合制剂对商品肉兔生产性能、养分表观消化率及血清生化和免疫指标的影响

本试验旨在研究饲粮中添加不同剂量的“三丁酸甘油酯+二甲酸钾+植物精油”复合制剂对商品肉兔生产性能、养分表观消化率及血清生化和免疫指标的影响。选取300只健康断奶伊拉商品肉兔,随机分为5个组,每组60个重复,每个重复1只肉兔。A组为空白对照组,饲喂基础饲粮;B组为抗生素对照组,饲喂基础饲粮+20 g/t恩拉霉素+52.5 g/t金霉素;C、D、E组为试验组,分别饲喂基础饲粮+1.0 kg/t三丁酸甘油酯+0.6%二甲酸钾+200 g/t植物精油、基础饲粮+1.5 kg/t三丁酸甘油酯+0.8%二甲酸钾+300g/t植物精油、基础饲粮+2.0 kg/t三丁酸甘油酯+1.0%二甲酸钾+400 g/t植物精油。预试期5 d,正试期30 d。结果表明:1)E组的末重、平均日增重、半净膛屠宰率、全净膛屠宰率、腿肌率与A组相比均有显著提高(P<0.05),与B组相比无显著差异(P>0.05);各试验组的料重比与B组差异不显著(P>0.05),但E组的料重比显著低于A组(P<0.05);各试验组之间,随着复合制剂添加量的增加,试验兔腹泻率和死亡率有降低的趋势,其中以E组最低。2)各试验组的粗蛋白质、粗脂肪表观消化率与B组相比差异不显著(P>0.05),但均显著高于A组(P<0.05)。3)胸腺指数和圆小囊指数均以E组最高,与A组相比差异显著或极显著(P<0.05或P<0.01),与B组相比差异不显著(P>0.05)。4)E组的血清免疫球蛋白A(IgA)、免疫球蛋白G(IgG)、免疫球蛋白M(IgM)、白细胞介素-10(IL-10)、白蛋白(ALB)含量与总抗氧化能力(T-AOC)显著或极显著高于A组(P<0.05),与B组差异不显著(P>0.05);血清谷丙转氨酶(ALT)、谷草转氨酶(AST)活性以E组最低,显著低于A组(P<0.05)。综上所述,本试验条件下,肉兔饲粮中复合制剂的适宜添加量为2.0 kg/t三丁酸甘油酯+1.0%二甲酸钾+400 g/t植物精油。

植物源甘油酯对荔枝蒂蛀虫的防控效果评价

荔枝蒂蛀虫(Conopomorphasinensis)是危害荔枝和龙眼的重要害虫之一。目前,主要通过使用化学农药来防治荔枝蒂蛀虫,这种防治方法存在环境污染、增加害虫的抗药性等问题。因此,寻找新型防控措施防治荔枝蒂蛀虫,是近年来的研究热点之一。植物源甘油酯是一种新开发的农用喷洒油,其杀虫效果与矿物油乳剂相当,且害虫不易产生抗药性。本研究采用喷雾法测定植物源甘油酯对荔枝蒂蛀虫卵、蛹及成虫的触杀及产卵拒避作用,并对其田间防控效果进行评价。结果表明:植物源甘油酯对蒂蛀虫的卵、蛹和成虫均有一定的触杀作用,在植物源甘油酯浓度为4.55 g/L时,对1日龄卵的孵化抑制率达40%以上,蛹羽化率在20%以下,成虫死亡率可达100%,且对雌虫产卵具有一定的拒避作用。此外,田间试验结果表明,使用浓度为4.55 g/L植物源甘油酯后果园内荔枝蛀果率显著降低,与农药混配可使农药使用量减半,且蛀果率降至1%。以上结果表明,植物源甘油酯可用于果园荔枝蒂蛀虫的防控,同时能够降低果园化学农药的使用,显著提高荔枝蒂蛀虫的防治效果,为荔枝产业的健康可持续发展提供研究基础。

Effect of medium-chain triglycerides on growth performance, nutrient digestibility,plasma metabolites and antioxidant capacity in weanling pigs

The aim of this study was to investigate the effect of medium-chain triglycerides(MCTs) on growth performance, nutrient digestibility, plasma metabolites and antioxidant capacity in weanling pigs. A total of 160 weanling(Duroc × Landrace x Yorkshire) pigs(age: 21 ± 1 d; body weight: 7.50 ± 0.28 kg) were randomly allotted to 4 treatments, receiving the following diets for 28 d: control diet [containing 3.5%soybean oil(SO)], MCT1 diet(containing 0.7% MCTs and 2.8% SO), MCT2 diet(containing 1.4% MCTs and2.1% SO) and MCT3 diet(containing 2.1% MCTs and 1.4% SO). Dietary inclusion of MCTs improved the average daily gain and feed efficiency(FE) of pigs compared with the control during the first 2 weeks post-weaning(P < 0.05). A similar positive effect was also observed for the overall FE in MCT2 group(P < 0.05). Compared with the control, apparent total tract digestibility(ATTD) of ether extract was improved by MCT2 and MCT3 treatment from day 12-14 post-weaning(P < 0.05). In addition, MCT2 treatment also exerted a beneficial effect on the ATTD of dry matter(P < 0.05). The increased total protein concentration and decreased urea nitrogen and malondialdehyde levels of plasma were observed in both MCT2 and MCT3 groups on day 14 post-weaning(P < 0.05). In conclusion, MCTs could improve growth performance, nutrients utilization, and antioxidant ability of weanling piglets.

中链甘油酯复合物对保育猪生长性能、免疫功能及粪便微生物菌群的影响

为研究中链甘油酯(MCG)复合物对保育猪生产性能、免疫功能及粪便微生物的影响,选取45头体重(13.96±1.10)kg的杜长大保育猪,随机分为3组(A、B、C组),每组3个重复,每个重复5头猪。A组为对照组饲喂基础日粮,B组在基础日粮中添加2 kg/t泰万菌素,C组在基础日粮中添加3 kg/t中链脂肪酸甘油酯复合物。预试期3 d,试验期28 d。结果表明:(1)与A组相比,C组保育猪末均重提高16.53%、平均日增重提高32.21%,料重比降低12.44%(P <0.05),各组间平均日采食量差异不显著;B组、C组腹泻率比A组分别降低了57.61%、83.08%(P>0.05)。(2)与A组、B组相比,C组试验猪血液白细胞数(WBC)分别增加24.84%、31.98%(P <0.05),与B组相比,C组红细胞数(RBC)增加12.07%(P <0.05),C组试验猪血清IgG水平分别较A组、B组提高9.70%、22.56%(P <0.05),各组间IgA、IgM水平无显著性差异。(3)与B组相比,C组血清过氧化氢酶(CAT)、超氧化物歧化酶(SOD)活性分别上升17.44%、21.32%(P <0.05),与A组、B组相比,C组血清谷胱甘肽过氧化物酶(GSH-Px)活力分别显增强17.01%、20.65%(P <0.01)。C组猪血清丙二醛(MDA)含量低于B组24.83%(P <0.01),低于A组14.83%(P <0.05)。(4)试验结束后,相较于A组、B组,C组粪便大肠杆菌数分别减少25.81%、29.47%(P <0.05)。研究表明,饲粮中添加MCG复合物可促进保育猪生长,增强免疫功能,提高保育猪抗氧化能力,减少粪便有害菌数量。

气相色谱法测定氢化棕榈油甘油酯的脂肪酸组成

目的:构建一种利用气相色谱法的氢化棕榈油甘油酯脂肪酸组成分析体系,为药用辅料氢化棕榈油甘油酯的质量标准制定提供参考依据。方法:选用DB-WAX(30 m×0.53 mm,1.0μm)强极性气相色谱柱,进样体积1μL,分流比为120:1,起始柱温70℃,维持2 min,以每分钟5℃的速率升温至230℃,维持10 min,进样口温度250℃,检测器温度为250℃。结果:本实验成功建立了一种气相色谱方法来测定氢化棕榈油甘油酯的脂肪酸组成,验证结果显示该方法具有良好的系统适用性、专属性和精密度,RSD(%)满足要求,确定了9种脂肪酸甲酯的检测限和定量限,并成功对7批样品进行脂肪酸成分考察。结论:本试验开发的气相色谱法,适用于氢化棕榈油甘油酯中脂肪酸组成的分析测定,能够为该药用辅料的质量控制和质量标准的设立提供参考依据。

Effects of excessive body fat on colostrum lipid patterns: overweight/obese vs. normal weight mothers

Prenatal overweight/obesity(OW/OB)can alter colostrum lipid patterns,thereby affecting the lipid metabolism and even the cognitive and healthy development of infants.However,studies on changes in colostrum lipids in the context of OW/OB are limited,particularly for glycerides and polar lipids.Therefore,this study investigated the infl uence of maternal prenatal weight on colostrum in lipid subclasses and molecular species.The concentration of triacylglycerols(TAGs)in the colostrum of the OW/OB group(35894.43 mg/L)was higher than that of the normal weight(NW)group(26639.20 mg/L),suggesting that colostrum from OW/OB mothers could provide more energy to their infants.Further analysis of the fatty acid composition of TAGs revealed that elevated maternal body weight enhanced the concentration of TAGs containing saturated or n-6 fatty acids and shortened the carbon number of TAGs.Docosahexaenoic acid(DHA)/arachidonic acid(AA)/choline-containing lipids,such as DHA-containing TAGs,AA/DHA-containing phosphatidylethanolamine,and choline-containing phospholipids,were present in higher levels in the colostrum of OW/OB mothers than NW mothers.However,the concentrations of palmitic acid-containing TAGs,linoleic acid-containing TAGs,dihomo-γ-linolenic acid-containing TAGs,and polar lipids and the ratio of TAGs containing n-6 fatty acid/n-3 fatty acid were signifi cantly higher in the colostrum of OW/OB mothers than in that of NW mothers.The fatty acid composition and sphingoid bases of sphingolipids were also altered due to elevated body weight.In conclusion,OW/OB affects colostrum lipids with respect to composition,concentration,and percentage.Although the colostrum of healthy OW/OB mothers can provide suffi cient DHA/AA/choline-containing lipids to their infants,normalization of body weight and fat reserves should be considered as a strategy for highquality human milk lipids.

Evaluation of dynamic effects of dietary medium-chain monoglycerides on performance,intestinal development and gut microbiota of broilers in large-scale production

Medium-chain monoglycerides(MG)have been reported to affect the productive performance,gut microbiota and health of broiler chickens reared in ideal experimental conditions at home and abroad.However,the effects of MG on performance,intestinal development and gut microbiota of chickens in large-scale farms during different feed stages remain unknown.The present study was conducted on a modern farm with a total of 12,000 yellow feathered broiler chicks that were randomly allotted to 2groups(1000 chicks/replicate,6 replicates/group)for a 70-day trial.The control group(CON group)received a basal diet,and the treated group(MG group)was fed a basal diet containing 300 mg/kg mixed MG.The results revealed that dietary MG significantly(P<0.05)increased the body weight and average feed intake,but notably reduced the feed conversion and mortality of chickens in large-scale production during the starter phase.The villus height of the duodenum in the MG group at 1,2 and 7 wk of age increased notably,and the villus height to crypt depth ratio at 1,2,5 and 10 wk of age was improved.Dietary MG decreased the serum insulin content of chickens at 5,7 and 10 wk of age,and decreased the serum lipopolysaccharide at 3 and 7 wk of age.The triglyceride level of chickens at 3,5 and 10 wk of age and the low-density lipoprotein cholesterol level of chickens at 7 and 10 wk of age in the MG group decreased notably,while the high-density lipoprotein cholesterol increased significantly.Moreover,MG supplementation selectively increased the relative abundance of genus Bacteroides(family Bacteroidaceae)and Lachnospiraceae_NK4A136_group,but decreased the content of genus Rikenellaceae_RC9_gut_group,Collinsella and family Barnesiellaceae in the cecum of chickens at 3,7 and 10 wk of age.Conclusively,these findings showed that dietary MG notably enhanced chicken performance,health and feed nutrient utilization at early ages by regulating gut microbiota,intestinal development and serum biochemical indices.

电感耦合等离子体质谱法测定松香甘油酯和氢化松香甘油酯中的铅

建立了电感耦合等离子体质谱法测定松香甘油酯和氢化松香甘油酯中铅含量的分析方法。样品经微波消解赶酸后进行分析,应用碰撞/反应池技术有效地消除了多种原子离子对铅元素的干扰,并选用Bi、Rh元素为内标混合液校正基体干扰和漂移。结果表明:本法具有检出限低,灵敏度高、线性范围宽、快速等优点,能确保实验数据的准确性和稳定性,满足松香甘油酯和氢化松香甘油酯中铅含量的分析要求。

偏甘油酯脂肪酶的研究进展及应用现状

相较于甘油三酯脂肪酶,偏甘油酯脂肪酶因其独特的底物选择性和催化高效性,逐渐成为相关领域的研究热点。旨在为偏甘油酯脂肪酶在油脂加工、脂质分子的定向合成等领域的研究提供理论和技术参考,并为挖掘新型的偏甘油酯脂肪酶打下基础,首先对偏甘油酯脂肪酶的来源和分类进行介绍,随后阐述了偏甘油酯脂肪酶的结构特征和催化特性,最后对其应用现状进行了总结归纳和展望。偏甘油酯脂肪酶有动物来源、植物来源和微生物来源,分为甘油单酯脂肪酶和甘油单酯-甘油二酯脂肪酶;偏甘油酯脂肪酶有帽区、催化三联体和氧负离子洞穴等结构,具有底物特异性和位置特异性;偏甘油酯脂肪酶在食品、有机合成、医疗等领域有着广泛的应用和独特的发展潜力。

脂肪酶Lipozyme TL IM水解金枪鱼油工艺优化及其脂质分析

旨在为Lipozyme TL IM在鱼油脂质改性及相关功能性产品的研发和应用提供参考,以金枪鱼油为原料,采用固定化脂肪酶Lipozyme TL IM对其进行水解,并分离改性水解甘油酯。采用单因素试验研究了pH、水油比(质量比)、水解温度和水解时间对金枪鱼油水解度的影响,确定了适宜的水解工艺参数,并分析了不同水解度下(20%~50%)改性水解甘油酯的脂肪酸组成、结构、热稳定性和氧化稳定性。结果表明:Lipozyme TL IM水解金枪鱼油的适宜工艺参数为pH 6.0、水油比3∶1、水解温度40℃、酶添加量5%(以鱼油质量计),在此条件下水解30、60、80、120 min可分别得到水解度为20%、30%、40%和50%的改性水解甘油酯;随着水解度的增加,所得改性水解甘油酯的多不饱和脂肪酸含量增多,饱和脂肪酸含量减少,结构改变,热稳定性和氧化稳定性变差。综上,可采用Lipozyme TL IM对金枪鱼油进行水解以富集多不饱和脂肪酸,为后续产品开发提供特异性底物。