为推动闽北锥栗精深加工技术的发展,提高锥栗脆球的干燥效率和品质,以干基含水率、干基失水速率和感官质量评分为指标,探索微波强度、装载量及初始微波功率密度(微波功率与装载量的比值,Mp0)对蒸煮熟化锥栗球脱水规律的影响.结果表明,微波功率和装载量均对干燥时间有显著影响,Mp0越大,干燥速率越快,其中恒速阶段随着Mp0增大而缩短,而且Mp0对熟化锥栗质地结构的影响更显著,Mp0在5.5W/g时锥栗脆球感官评分最高(80),膨化率最大(2.92),脆度(3.51 N)最佳,孔隙率为61.4％,水分活度低于0.3.然后通过Matlab建立锥栗脆球水分比与时间的动力学模型,发现Page模型拟合度很高(0.99),可以阐明锥栗脆球微波脱水各阶段对其干燥速率的影响;干燥后样品的颗粒含水量随机分布符合六次多项式分布,与平均含水量一致.说明根据锥栗脆球微波干燥的动力学规律,可以通过分段变功率的方式进一步优化锥栗脆球干燥制品的干燥参数.

研究茶膏包埋型泡腾片制备工艺并对其进行品质分析,以武夷岩茶茶膏为包材,以泡腾片pH、崩解时限和硬度为指标,利用正交试验优化混合酸、碳酸氢钠和聚乙烯吡咯烷酮(PVP)的质量分数,并考察泡腾片成品pH、崩解时限、硬度、发泡量和茶多酚含量.结果得出,泡腾片最佳配方组成为;柠檬酸7.5％、酒石酸10％,碳酸氢钠30％,PVP质量分数5％,利用武夷岩茶茶膏包埋粉末后直接压片即可.最优工艺所得泡腾片呈弱酸性,发泡量为26.2mL/g,荼多酚含量为6.43％,外观良好,崩解迅速,溶解后溶液呈红棕色澄清透明、酸甜可口、茶香浓郁.

Using the microwave drying technology,this paper took moisture content,misture loss rate and sensory score as evalution indexs standard,and made a single factor experiment to define the suitable microwave power and material load witch to affect the drying properties of ginkgo fruit.Resuh showed that the ratio of microwave pow er to material load(microwave power density),higher microwave power density carried out to shorter drying time.Microwave power density of ＞ 10 W·g-1 or ＜6 W · g-1,the microwave drying subsection process of ginkgo fruit was contained two stages:speed-up and speed-down,while microwave power density in the 4.71 ～9.19 W·g-1,the microwave drying subsection process of ginkgo fruit was contained three stages:speed-up,constant-speed and speed-down.Material load 60.0 g,microwave power 385 W (microwave power density 6.42 W·g-1),the best sensory quality score of dried products was 7.A kinetic model of moisture content and action time of microwave drying of ginkgo was established by Matlab based on experimental data and test of fit was carried out for the model.Results showed that model of page could accurately describe the microwave drying process of ginkgo fruit,coefficients of models were above 0.999 and the moisture content and drying rate at each period could be described by the equation obtained.

本研究用分离自西藏、新疆、云南地区牦牛奶酪的39株乳酸菌作为供试菌株,制备细菌素粗提液,用琼脂井法分析粗提液对9株致病菌(蜡样芽孢杆菌、金黄色葡萄球菌、埃希氏大肠杆菌O157:H7、单增李斯特菌、费氏柠檬酸杆菌、鼠伤寒沙门氏菌、阴沟肠杆菌、产气荚膜梭菌、宋内志贺菌)和2株非致病菌(无害李斯特菌、嗜热链球菌)指示菌株的抑菌作用.测定结果表明有30株菌的细菌素粗提液对指示菌株有抑菌作用,筛选出Y13、X29和X30这3株抑菌谱较宽的细菌素产生菌.

目的:以实验室提取的甘薯糖蛋白-1 (sweet potato glycoprotein-1,SPG-1)为原料,研究不同加工处理对其蛋白免疫调节和降胆固醇功能的影响.方法:研究热处理、酸碱处理、紫外光照射、微波处理对甘薯糖蛋白SPG-1的免疫调节作用(包括巨噬细胞吞噬功能、细胞吞噬功能和血清溶血素含量)和降血清总胆固醇作用的影响.结果:热处理温度和pH值对甘薯糖蛋白SPG-1的免疫调节和降胆固醇作用的影响较大,热处理温度超过100℃、pH＜3.5或＞7.5时,糖蛋白处理组的吞噬指数(k)、酸性α-醋酸萘酯酶阳性率、半数溶血值(HC50)和血清胆固醇下降率(△TC)均显著性降低(P＜0.05或P＜0.01);糖蛋白处理组的吞噬指数(k)和血清胆固醇下降率(△TC)在紫外光照射条件下与对照组相比差异不显著(P＞0.05),而微波处理60 s以上时,与对照组相比有显著性或极显著性差异(P＜0.05或P＜0.01).结论:甘薯糖蛋白SPG-1加工处理过程中应避免70℃以上的高温,选择合适的pH值范围(3.5～7.5),避免较长时间(＞60 s)的微波处理.

Effects of sweet potato proteoglycans (SPG) in rats fed high lipid diets were investigated. Serum lipid indices for SPG were evaluated. SPG had hypolipidemic effects that were correlated with dosage. There were no significant (p > 0.05) differences in hypolipidemic effects between SPG varieties of different molecular weights. SPG-1 (Mw value: 508.3 kDa) significantly (p < 0.05) reduced serum total cholesterol (TC), triacylglyceride (TAG), low density lipoprotein cholesterol (LDL-C), and apolipoprotein (Apo) B levels, and the arteriosclerosis index (AI), and induced serum high density lipoprotein cholesterol (HDL-C), ApoA-I, lecithin cholesterol acyltransferase (LCAT), and liver lipoprotein lipase (LPL) activities, compared with controls. The whole blood viscosity and red blood cell (RBC) membrane microviscosity were also decreased. Hypolipidemic effects were mediated via elevation of the serum HDL-C concentration by induction of LACT activity, an increased ApoA-I concentration, and a reduction in the serum lipid concentration due to regulation of LPL activity.

Objective: The antibiotic susceptibility of 39 lactic acid bacterial strains isolated from yak milk cheese was evaluated in this study. Methods: Disc diffusion method was employed to test antibiotic susceptibility of these isolates to eight most widely used antibiotics, including ampicillin, chloramphenicol, erythromycin, neomycin, nalidixic acid, streptomycin, tetracycline and vancomycin. Results: These strains primarily presented resistance to four antimicrobial agents: vancomycin, neomycin, streptomycin and nalidixic acid. The number of resistant strains was 36(92.3%), 32(82.1%), 38(97.4%) and 39(100%), respectively. There was variation in susceptibility between the species. Multidrug resistance was identified in most isolates. Conclusion: This study provides valuable data on these isolates for the consideration of application as probiotic bacteria or fermentation starters.

SCOPE:This study investigated the interaction of dietary capsaicinoids with the mRNA and protein expressions of key receptors and enzymes involved in cholesterol metabolism in ovariectomized (OVX) rats. METHODS AND RESULTS:Female Sprague-Dawley rats were subjected to sham operation or ovariectomy. The sham group and OVX control group were fed with high-cholesterol diets, whereas the treatment group (control diet containing 0.01% capsaicinoids) was fed with high-cholesterol plus 0.01% capsaicinoids diet for 21 days. Capsaicinoids significantly decreased the body weight gain, plasma total cholesterol, LDL cholesterol, and triacylglycerol without affecting the high-density lipoprotein cholesterol in the OVX rats. The change in plasma lipoprotein profile was accompanied by a greater excretion of total bile acid in feces and small intestinal contents. Western blot and real-time PCR analyses revealed that capsaicinoids significantly enhanced the expressions of hepatic cholesterol 7α-hydroxylase and transient receptor potential vanilloid type-1 but did not affect the expression of 3-hydroxy-3-methylglutaryl-CoA reductase in the OVX rats. CONCLUSION:Capsaicinoids have cholesterol-lowering effects in OVX rats. The hypocholesterolemic activity of capsaicinoids is caused by the stimulating conversion of cholesterol to bile acids by upregulation of cholesterol 7α-hydroxylase expression and the increase in fecal total bile acid excretion.

Objective: Fourteen strains of lactic acid bacteria were identified by a series of taxonomic methods based on 16S rDNA sequence.Methods: Genomic DNAs were extracted from 14 strains.PCR amplification with Lactobacillus genus-specific primers was employed to select Lactobacillus strains.Homology analysis of 16S rDNA sequence,speciesspecific PCR and NEBcutter analysis were combined to indentify 14 strains to species level.Results: Except 123-2 and 23-3 all strains were identified to be Lactobacillus strains by Lactobacillus genus-specific PCR amplification.Through homology analysis of 16S rDNA sequence,strains 11-2,13-3,14-3,16-4,23-3,24-3,26-1,122-1 and 123-4 were assigned to Lactobacillus casei or Lactobacillus paracasei,17-5,20-2 and 28-1 to Lactobacillus plantarum,123-2 to Leuconostoc mesenteroides,125-2 to Lactobacillus parabuchneri.Except for 23-3,the results from homology analysis corresponded well with those obtained from genus-specific PCR.Stains 11-2,13-3,14-3,16-4,23-3,24-3,26-1,122-1 and 123-4 were further confirmed to be Lactobacillus paracasei by species-specific PCR.Finally,these results were verified by NEBcutter.Conclusion: Rapid and accurate identification of natural lactic acid bacteria to species level can be obtained by the combinatorial application of taxonomic methods presented in this study.

Objective: To explore the application value of randomly amplified polymorphic DNA(RAPD)-PCR for the genotype evaluation of lactic acid bacteria isolated from yak milk cheeses.Methods: In order to establish a reliable RAPD protocol with primer M13,factors such as annealing temperature,Mg2+ concentration,primer amount,Taq polymerase and DNA template for affecting the quality and reproducibility of RAPD profiles were investigated.The optimal PCR procedure and reaction reagent concentration were employed for RAPD amplification of 39 isolates from yak milk cheese on the basis of previous identification of 16S rRNA sequence analysis.The electrophoretic profiles were analyzed using NTsys2.10e software,genetic similarity coefficients were calculated and a cluster dendrogram was plotted.Results: Genetic similarity coefficients of 39 strains ranged from 0.47 to 0.98.The cluster dendrogram showed that 39 isolates were classified into 10 groups using the similarity coefficient of 0.78 as a cut-off point.The discrimination of groups was consistent with the assignment of the species based on 16S rRNA sequence analysis,except for strains X23,Y36 and Y37.Conclusion: RAPD technique is useful in taxonomy of lactic acid bacteria isolated from yak milk cheese.The accuracy of species identification can be improved by the combination of RAPD with other kinds of genotypic methods.

Objective To determine the potential hypocholesterolemic effect of capsaicinoids in Sprague-Dawley rats fed different diets and its mechanism.Methods Thirty-two rats were randomly divided into 4 groups and received one of the following diets: control diet(C);control diet with capsaicinoids(10 mg/kg·bw)(CAP);high-fat diet(HF) and high-fat diet with capsaicinoids(10 mg/kg·bw)(HF+CAP),After 4 w,all mice were anesthetized.Serum and hepatic lipids,the concentration of bile acids in small intestine and feces were determined.The genes expression involved in cholesterol metabolism were determined by real-time PCR methods.Results The concentration of cholesterol in plasma and lipid accumulation in liver of CAP and C+HF+CAP group rats were significantly reduced.The hypocholesterolemic effect of capsaicinoids in HF+CAP group was more obvious than that in CAP group.The mRNA levels of 3-hydroxyl-3-methylglutaryl CoA reductase(HMG-CoA R) and cholesterol 7α-hydroxylase(CYP7A1) were significantly down-regulated while the mRNA levels of transient receptor potential vanilloid type-1(TRPV1),farnesoid X receptor(FXR),ileum bile acid binding protein(IBABP) and ileal apical sodium-dependent bile acid transporter(ASBT) were significantly up-regulated by capsaicinoids in basic and high-fat diet group rats.The concentration of bile acids in small intestine and feces was significantly decreased by capsaicinoids in basic diet group rats.Conclusion It is conceivable that the cholesterol-lowering action of capsaicinoids in rats fed basal diet and high-fat diet may be due to inhibited synthesis of hepatic cholesterol.

The potential mechanism of the hypocholesterolemic effect of capsaicinoids in rats fed with cholesterol-enriched and cholesterol-free diets was determined. Capsaicinoids favorably modified the lipoprotein profile of rats. Capsaicinoids consumption down-regulated the mRNA levels of hepatic 3-hydroxyl-3-methylglutaryl CoA (HMG-CoA) reductase by 0.55-fold and hepatic cholesterol-7α-hydroxylase (CYP7A1) by 0.53-fold in the cholesterol-free diet group (P < 0.05) but up-regulated the CYP7A1 level by 1.38-fold in the cholesterol-enriched diet group (P < 0.05). It also increased the expression levels of ileal bile acid binding protein and apical sodium-dependent bile acid transporter in the ileum, as well as transient receptor potential vanilloid type-1 in the liver and ileum in the different groups. Capsaicinoids reduced the amount of bile acids in feces by -15.97% and contents of the small intestine by -9.64% in the cholesterol-free diet group (P < 0.05) but increased both by 13.06% and 10.20%, respectively, in the cholesterol-enriched diet group. The cholesterol-lowering action of capsaicinoids in the cholesterol-free diet group was attributed to the inhibition of hepatic cholesterol synthesis, whereas that in the cholesterol-enriched diet group was attributed to the stimulation of the conversion of cholesterol to bile acids and the increasing excretions of bile acids in feces.

The changes in chemical components of highland barley wine during fermentation with multi-strain starter were studied and compared with those of traditional fermented highland barley wine.The results showed that the dynamic change patterns of chemical components during fermentation with multi-strain starter and traditional starter were similar.pH value decreased rapidly at first and then kept stable at pH 4.0-4.3,the measured total acidity showed an increasing trend.Fermentation temperature increased first and then dropped gradually with the highest value of about 36.2 ℃.Saccharifying enzyme activity and reducing sugar content increased significantly during 0-24 h,and then decreased till the end of fermentation.Total sugar content kept decreasing throughout the whole process.The alcohol concentration fermented by multi-strain starter was 10.30% which indicated a significant(P 0.05) increase by 57.73% compared with that obtained using traditional starter.Both ammonia-N content and acid proteinase activity increased in the early stages of fermentation followed by a slow decrease.Total free amino acid(FAA) in the final product fermented by multi-strain starter was 80.923 mg/100 mL and no methionine was detected in it.Sensory evaluation showed that the optimal fermentation duration was 60-72 h for highland barley wine production by multi-strain starter.Under this condition,the product was acceptable and maintained the major flavor of wine fermented by traditional starter as evaluated by sensory evaluation.

The purified Gastrodia elata Blume polysaccharide (PGEB-3H), was found to be a glucan with a molecular weight of 28.8 kDa and specific rotation of +206.3 (ca.0.003, H2O). The structural characterics of PGEB was investigated by chemical methods (partial hydrolysis with acid, methylation reaction, periodate oxidation, and Smith degradation) and instrument analysis (IR and NMR). PGEB-3H was mainly composed by glucose, and had a (1→4)-α-D-glucan main chain occasionally branched with α-1,6 glycosidic linkage. PGEB-3H exhibited potential lipid-lowering effects in hyperlipidemia rats.^p

Objective: To investigate the effect of pectin from Ficus pumila L.seeds on mineral absorption in ovariectomized rats.Methods: Thirty SD female rats were divided into five groups.The mice in four of them were double ovariectomized and one week later assigned as model control group and high,medium and low dose groups of Ficus pumila L.pectin.The mice in the fifth group were sham-ovariectomized as sham control.All rats were sacrificed after 4 weeks of feeding to assay pH values and short-chain fatty acids in cecum contents,calcium and phosphorus in bone,and apparent absorption rate of minerals.Results: Compared to the sham control group,the apparent absorption rates of calcium,magnesium,phosphorus,zinc and iron,calcium and phosphorus in bone significantly decreased in OVX rats(P0.05).Pectin from Ficus pumila L.seeds drastically increased the concentration of short-chain fatty acids in cecum content and the area of cecum,decreased the pH of cecum contents,and inhibited the absorption of calcium,magnesium,phosphorus,zinc and iron in ovariectomized rats.Conclusions: Ficus pumila L.seed pectin had a negative effect on mineral absorption in ovariectomized rats.

To investigate deacidification effect of sea buckthorn juice by anion exchange resins.The results showed that titratable acid of sea buckthorn juice reduce and color value and transmittance increase by D941 anion exchange resins.D941 anion exchange resins have weak adsorption capacity for ascorbic acid,superficial adsorption capacity for titratable acid reach 2.70 mg/100 mL,adsorption equilibrium time is 3 h,optimum work flow is 4 BV/h,NaOH regenerant suitable concentration is 0.2% and regeneration cycle is 4 times.D941 anion exchange resins can be used for deacidification of sea buckthorn juice.

Pork longissimus dorsi muscles of normal and PSE quality were sampled to investigate the effects of solution conditions such as pH as well as NaCI and sodium tripolyphosphate (TPP) concentration on the solubility and heat-induced gel strength of porcine myofibrillar proteins by the analyses of absorbance, textural properties and SDS-PAGE profile. Results showed that pH, NaCl and polyphosphate concentration all had a significant effect on the above parameters of porcine myofibrillar proteins (P < 0.05), and high protein solubility achieved by the adjustment of solution conditions favored the improvement of functional properties of PSE porcine myofibrillar protein.

In this study,the effect of a polysaccharide fraction from fruit bodies of Morchella esculenta (L.) Pers,named PMEP-1 on short-chain fatty acids in the intestinal tract of rats was investigated. SD rats were orally administered PMEP-1 at high dosage (400 mg/kg bw·d),medium dosage (200 mg/kg bw·d) and low dosage (100 mg/kg bw·d) for a period of four weeks. Rat feces were collected periodically during the trial. Short-chain fatty acids in intestinal tract of rats were determined by gas chromatography. The results indicated that PMEP-1 had an obvious effect on the production of acetic acid,propionic acid,isobutyric acid,butyric acid,valeric acid and caproic acid,but had no obvious effect on the production of heptanoic acid and isovaleric acid. PMEP-1 at various dosages exhibited considerably different effects on short-chain fatty acids. An obvious effect of medium and low dosages of PMEP-1 on short-chain fatty acids was observed. The highest productivity of short-chain fatty acids in intestinal tract of rats in each dose group appeared at 7-14 days.

The preparation parameters of porous starch were optimized by single-factor, partial-factor and response surface experiments. Results indicated that the optimal preparation parameters were reaction temperature of 51.92 ℃, reaction time of 13.15 h, enzyme addition amount of 4.20%, starch concentration (V/V) 14.24%, reaction pH of 4.4 and glucoamylase-amylase ratio of 4:1. Under these optimal conditions, the water-absorbing capacity of porous starch was 156.01%.

Objective: To investigate the effect of PGEB-3-H,a soluble polysaccharide from Gastrodia elata Blume,on scopolamine-induced learning and memory disorders in mice.Methods: Learning and memory ability in mice were evaluated by Morris water maze.Acetylcholine and malondialdehyde(MDA) content were measured in brain tissues of mice.Results: Compared with model group,the time for passing water maze of mice treated with PGEB-3-H at doses of 100,200 mg/kg bw.d and 400 mg/kg bw.d(namely,PGEB-3-H low-,medium-and high-dose groups,respectively) was obviously shorter in a dose-dependent mode,and there was an extremely significant difference between PGEB-3-H high-dose group and model group(P 0.01).Moreover,PGEB-3-H high-dose group exhibited higher acetylcholine content in brain tissues when compared to normal saline group or positive control group.In addition,MDA content in brain tissues of PGEB-3-H medium-dose group exhibited a significant decrease(P 0.05).Conclusion: PGEB-3-H can improve scopolamine-induced learning and memory disorders in mice,and its mechanism may be due to the increase of acetylcholine content in brain tissues.