黑果枸杞花青素提取物的初步毒性评价

该文评价了黑果枸杞花青素提取物（Anthocyanins extract of Lycium ruthenicum,AEL）的急性毒性和亚急性毒性。采用固定剂量法一次灌胃AEL 8 000 mg/kg进行经口急性毒性试验,观察小鼠毒性反应,记录14 d内一般状态。选取SD大鼠进行30 d喂养试验,记录大鼠体质量和体征变化,实验结束时进行尿液生化指标、血液学指标、血清生化指标检查,并观察脏器形态变化,计算脏体系数和脏脑系数。研究发现：急性毒性试验中,小鼠无不良反应,体质量正常增长,解剖脏器未见明显异常;连续灌胃30 d后,各组大鼠体质量正常增长,未见明显中毒反应;与对照组比较,高剂量组雌性大鼠单核细胞百分比（M%）显著升高（P<0.05）,AST/ALT的比值显著降低（P<0.05）;高剂量组雄性大鼠血清Cl-、脾脏系数高于对照组（P<0.05）。实验组大鼠其余尿液生化指标、血液学指标、血清生化指标、脏体系数和脏脑系数无明显异常。结果表明：小鼠对AEL的单次灌胃最大耐受剂量不低于8 000 mg/kg;连续灌胃30 d,大鼠未见明显中毒反应,AEL在该实验条件下无急性、亚急性毒性,具有较高的安全性。     

Effects of plant extracts on microbial growth, color change, and lipid oxidation in cooked beef

The effects of butylated hydroxyanisole/butylated hydroxytoluene (BHA/BHT), grape seed extract (ActiVin), pine bark extract (Pycnogenol), and oleoresin rosemary (Herbalox) on microbial growth, color change, and lipid oxidation were investigated in cooked ground beef. When compared to the control, 1.0% ActiVin and Pycnogenol) effectively reduced the numbers of Escherichia coli O157:H7 and Salmonella Typhimurium, and retarded the growth of Listeria monocytogenes and Aeromonas hydrophila. Pycnogenol resulted in reductions of 1.7, 2.0, 0.8, and 0.4 log CFU/g, respectively, in numbers of E. coli O157:H7, L. monocytogenes, S. Typhimurium, and A. hydrophila, respectively, after 9 days of refrigerated storage. The color of cooked beef treated with ActiVin was less light (L*), more red (a*), and less yellow (b*) than those treated with BHA/BHT, Pycnogenol, and Herbalox. ActiVin and Pycnogenol effectively retained the redness in cooked beef during storage. The control showed significantly higher thiobarbituric acid-reactive substances (TBARS) and hexanal content over storage. BHA/BHT, ActiVin, Pycnogenol, and Herbalox retarded the formation of TBARS by 75%, 92%, 94%, and 92%, respectively, after 9 days, and significantly lowered the hexanal content throughout the storage period. Results of this work show that ActiVin and Pycnogenol are promising additives for maintaining the quality and safety of cooked beef.     

Identification and characterization of yeast isolated from the elaboration of seasoned green table olives

The purpose of this study was to investigate the yeast population during the processing of green table olives. In the fresh olives, yeast were found at concentrations of around 3.0 log cfu/g, with Cryptococcus spp. being predominant. In the brine, the yeast concentrations were greater than 4.9 log cfu/ml, with Pichia anomala, Kluyveromyces marxianus, and Saccharomyces cerevisiae being the predominant species. Unlike the yeast isolated from the fresh olives, the strains obtained from the olive brine mostly showed low pectolytic but high catalase activities. Some of these strains also exhibited other biochemical desirable properties for the fermentation of green table olives, including their lipolytic activities and their assimilation or production of organic acids in the brine. Seven strains in particular of P. anomala, K. marxianus, S. cerevisiae, and Candida maris showed the best properties for use in trials as starter culture in pilot fermenters.     

胡椒中天然防腐剂的提取方法及其抑菌作用研究

研究了胡椒中天然防腐剂的提取方法和抑菌作用,结果表明,用食用乙醇提取胡椒中防腐物质的最佳提取工艺参数为:固液比1∶25、浸提温度70℃、浸提时间为20h。胡椒醇提取物对实验用常见食品污染菌有较强的抑制作用,对枯草芽孢杆菌的最低抑菌浓度(MIC)为6.25mg/mL,对大肠杆菌为12.5mg/mL,对金黄色葡萄球菌和汉逊氏酵母菌均为25mg/mL,对黑曲霉及青霉等均为50mg/mL,对金黄色葡萄球菌、枯草芽孢杆菌和汉逊氏酵母菌的抑菌活性pH范围均为4~6,对大肠杆菌为4~5。     

樱桃李果实提取物对小鼠高脂膳食诱导肥胖的预防作用

探讨樱桃李果实提取物对小鼠高脂膳食诱导肥胖的预防作用.通过水提法获得果实粗提物,采用福林酚法测定多酚含量,DPPH法测定体外抗氧化活性.小鼠被饲喂高脂饲料的同时,喂食樱桃李果实提取物,每周测定小鼠体重,10周后测定小鼠血清、肝脏中的有关生化指标,采用荧光定量PCR测定肝脏脂代谢相关基因的表达.试验结果表明,樱桃李果实提...     

银杏叶提取液结合异抗坏血酸钠对鲜切砀山梨贮藏品质的影响

目的:研究银杏叶提取液结合异抗坏血酸钠对鲜切梨的保鲜效果。方法:以鲜切砀山梨为材料,探究总黄酮含量分别为0.25(处理1)、0.50(处理2)、0.75 mg/m L(处理3)的银杏叶提取液结合1%的异抗坏血酸钠(D-sodium ascorbate,D-VCNa)溶液对鲜切砀山梨在4℃条件下贮藏品质的影响。采用SPSS软件分析了贮藏期间鲜切梨的呼吸强度、质量损失率、色差、VC含量、硬度、可溶性固形物含量(soluble solid content,SSC)、过氧化物酶(peroxidase,POD)活力、相对电导率及pH值的变化等。结果:不同质量浓度黄酮的银杏叶提取液结合D-VCNa溶液都可以在不同程度上减缓鲜切梨的呼吸强度、质量损失率、色差的增加,减缓VC含量、硬度、SSC的下降速率,延迟褐变发生、POD活力高峰的出现时间,抑制果实pH值和相对电导率的上升。结论:银杏叶提取液结合D-VCNa对鲜切砀山梨的贮藏品质有一定的保鲜作用,其中以总黄酮含量为0.50 mg/m L银杏叶提取液结合1%的D-VCNa溶液处理的鲜切梨保鲜效果最好。     

长裙竹荪3 部分石油醚提取物的对比

目的：通过黔产长裙竹荪鲜品的菌盖、子实体、菌托3 部分石油醚提取物的比较研究,为寻找黔产长裙竹荪菌盖、菌托的利用价值、拓展黔产长裙竹荪的合理利用提供科学依据。方法：常温下用石油醚分别对黔产长裙竹荪的3 部分进行萃取,应用气质联用仪对萃取的化学成分进行研究,气相色谱柱为HP-Innowax极性柱分离。结果：3 部分的石油醚提取物检出69 种成分,其中32 种成分从竹荪属中检出。菌盖、子实体、菌托3 部分的石油醚提取物分别检测出了36、46、31 种成分,脂肪酸分别占检出总量的86.15%、84.03%、86.42%,不饱和脂肪酸分别占脂肪酸总检出量的56.00%、65.79%、63.40%。结论：从竹荪属菌盖、子实体的提取物中检出全顺式-10,12-十六碳二烯醛、从竹荪属菌盖的提取物中检出全顺式-9,12,15-十八碳三烯酸。     

Mathematical modeling of batch bioethanol generation from carob extract in the suspended-cell stirred-tank bioreactor

In this study, various functions were evaluated and utilized to forecast observed values and kinetic parameters of the batch ethanol fabrication from carob extract in the suspended-cell stirred tank reactor (SCSTR). The best model was detected with the model comparison parameters (root-mean-square-error [RMSE], mean-absolute-error [MAE], and R²). The results indicated that the model Stannard (ST) successfully predicted biomass production data (RMSE = 0.26 g L⁻¹, MAE = 0.18 g L⁻¹, and R² = 0.9910), ethanol fabrication data (RMSE = 2.44 g L⁻¹, MAE = 1.88 g L⁻¹, and R² = 0.9809), and sugar depletion data (RMSE = 2.82 g L⁻¹, MAE = 2.17 g L⁻¹ and R² = 0.9938). Nevertheless, the lowest value of the objective function (Φ-factor) was also yielded as 0.041 using the model ST. Additionally, in the estimation of the kinetic data, the model ST also gave well-directed results. Besides, when an independent set of the observed values was utilized to confirm the mathematical functions, the satisfactory consequences were achieved in terms of both the experimental and kinetic values. Consequently, the model ST can work as a universal function in predicting observed values and kinetics of batch ethanol generation from carob extract in an SCSTR.     

低温鞣制用栲胶的制备及其性能研究

在高温和添加含氮化合物条件下，对杨梅栲胶进行亚硫酸化改性，制备低温鞣制用的栲胶。测试结果表明，改性后栲胶的粘度值和盐析值均明显下降，收敛性缓和。定量分析和鞣制试验结果表明，相对于原栲胶，改性后栲胶的渗透性和结合能力受鞣制温度影响较小，渗透速度明显增加。