The aim of this study was to obtain polysaccharides from Hovenia dulcis fruit pedicels, and further evaluate its ability to scavenge free radicals and inhibit the oxidation of biological macromolecules (proteins, lipids, DNA). On the basis of a single-factor experiment, the hot water extraction process of polysaccharides from Hovenia dulcis fruit pedicels was optimized using orthogonal test combined with an analysis of variance. The ability of the extracted polysaccharides to scavenge DPPH and ABTS+ free radicals was determined. In addition, Cu2+/H2O2, FeSO4 and APPH were used to induce the oxidation of bovine serum albumin, linoleic acid and herring sperm DNA, respectively, to construct in vitro protein, lipid and DNA oxidation models and the ability of the extracted polysaccharides to inhibit biological macromolecule oxidation in vitro was evaluated. The results showed that the volume fraction of ethanol precipitation had a significant effect on the yield of polysaccharides from Hovenia dulcis fruit pedicels (P<0.05). The optimal hot water extraction conditions were as follows: solid-liquid ratio, 1:25 g/mL, extraction temperature 85 ℃, extraction time 1 h, ethanol precipitation volume fraction 80%, with the polysaccharide yield of 3.06%±0.181%. With the increase in the concentration, the effects of the extracted polysaccharides in scavenging free radicals and inhibiting the oxidation of biological macromolecules were gradually improved. The IC50 for scavenging DPPH and ABTS+ free radicals were 1.687 and 1.824 mg/mL, and the IC50 for inhibiting bovine serum albumin carbonylation, linoleic acid peroxidation and herring sperm DNA oxidation were 13.84, 10.88 and 74.70 mg/mL, respectively. The results can provide a reference for the extraction of polysaccharides from Hovenia dulcis fruit pedicels and its application in functional food.
肉毒梭菌,又称肉毒杆菌,为革兰氏阳性菌,是危害性极强的食源性致病菌.其食物中毒在罐装和腌制食品较为常见,毒素被人体吸收后,主要破坏神经系统.因此,找到快速检测食品中肉毒梭菌的方法显得十分重要,这对国内外食品安全的监管以及人民的身体健康都有着重要意义.目前市面常见的检测法有传统检测、分子生物学、免疫学等方法,为进一步提高检测效率、特异性和灵敏性,文章主要针对多重PCR技术、胶体金免疫层析法、光谱法等快速检测法进行介绍,旨在为食品中的肉毒梭菌快速检测研究提供新的发展方向与科学依据.
Objective:To investigate the hypolipidemic and hypoglycemic effects of sorghum rice bran flavonoid extract(SRBFT)on high-fat diet-induced obese mice.Method:Twenty-one male C57BL/6 mice were selected and randomly divided into three groups:control group(CON),high-fat model group(HF)and experimental group(SRBFT).Results:The results showed that SRBFT significantly reduced body weight and adipose tissue weight,decreased serum total cholesterol(TC),triglyceride(TG)and low-density lipoprotein cholesterol(LDL-C)levels,and increased high-density lipoprotein cholesterol(HDL-C)levels in mice.In addition,SRBFT significantly reduced fasting blood glucose(FBG),glycated hemoglobin A1c(HbA1c)and insulin levels(INS).In addition,SRBFT significantly decreased the levels of leptin and fatty acid synthase(FAS)and increased the levels of high molecular lipocalin.Conclusion:SRBFT could inhibit lipid accumulation and significantly improve hyperglycemia,insulin resistance and leptin resistance in obese mice.It showed that SRBFT could achieve hypolipidemic and hypoglycemic effects on C57BL/6 mice by promoting lipolysis and regulating energy metabolism.
This artide investigated the effects of Perilla frutescens seed antioxidant peptides on lipid metabolism and oxidative stress in mice fed high-fat diet.Six week old male C57BL/6 mice were randomly divided into four groups:control group,high-fat group,high-fat diet+low dose Perilla frutescens seeds antioxidant peptide groups,and high-fat diet+high dose Perilla frutescens seeds antioxidant peptide groups.After 10 weeks of testing,body weight,serum biochemical indicators,liver triglyceride(TG),total cholesterol(TC),and key genes for lipid metabolism and intestinal tight junction proteins were measured in mice.Perilla frutescens seeds antioxidant peptides significantly reduced body weight and liver index in hyperlipidemic mice,significantly reduced serum aspartate transaminase(AST),alanine aminotransferase(ALT),TG,TC,low density lipoprotein(LDL-C),D-lactic acid(D-LA),diamine oxidase(DAO),and blood sugar level,significantly increased serum high-density lipoprotein(HDL-C)levels in mice,reduced the level of reactive oxygen species(ROS)in the liver and intestines;It increased the activities of superoxide dismutase(SOD),peroxidase(CAT),and glutathione peroxidase(GSH-Px)in the liver,and decreased the level of malondialdehyde(MDA)in the liver.In addition,Perilla frutescens seeds antioxidant peptides increased the expression of zonula occludens-1(ZO-1)and occlusin mRNA in the intestine of mice fed high-fat diet,and reduce tumor necrosis factor α(TNF-α)mRNA expression,and also increased the expression of fatty acid synthase(FAS),a fatty acid production related gene,and promoted the expression of carnitine palmitoyl transferase-1(CPT-1),lipoprotein lipase(LPL),and cytochrome P450 family member 7A1(CYP7A1).Perilla frutescens seed antioxidant peptides can significantly alleviate obesity,reduce lipid deposition and abnormal lipid metabolism in mice on high-fat diet,reduce intestinal oxidative stress,maintain intestinal barrier integrity,and improve the antioxidant capacity of the mice liver,preventing the occurrence of fatty liver in mice on a high fat diet.
In order to explore the optimal process conditions for ultrasonic assisted alkaline enzymatic extraction of chondroitin sulfate(CS)from sturgeon.Using sturgeon cartilage as the raw material,the process was optimized through single factor experiments and the response surface design;the free radical scavenging capacity of sturgeon CS in vitro was determined,and its structure was analyzed by fourier transform infrared spectroscopy(FTIR),high-performance gel permeation chromatography(HPGPC),and high-performance liquid chromatography(HPLC).The optimal extraction process conditions for sturgeon CS were obtained as follows:alkaline protease was used as extraction enzyme,liquid ratio 1∶30(g/mL),extraction time 122 minutes,pH 9.9 and 45 ℃.Under these conditions,the yield of sturgeon CS was 17.06％,the purity was 90.16％,and the response surface model was well fitted;the obtained sturgeon CS has a high scavenging rate for DPPH free radicals,and the IC50 was 15.04 mg/mL;the FTIR characteristic absorption peak of sturgeon CS conforms to the main characteristics of CS,and the molecular weight of the main component is 37 ku,and the monosaccharide composition is composed of glucosamine,glucuronic acid,galactosamine,glucose,galactose,etc.,and is basically consistent with the monosaccharide composition of the standard product.The result shows that the method for extracting sturgeon CS has high yield and purity and can effectively maintain the intact natural structure of sturgeon CS.
