二元芳香族化合物对酪蝇成虫的引诱效果

室内采用Y型嗅觉仪分别测定苯乙醛与苯甲醛、水杨醛、水杨酸甲酯按不同配比(32:1、16:1、8:1、4:1、2:1,体积比)混配后得到的二元混配物对酪蝇成虫的引诱效果.结果显示:苯乙醛与水杨醛混配,各配比混配物对雌、雄虫均有明显的引诱效果,随着水杨醛比例的增加,混配物对雄虫的引诱效果逐渐增强,但对雌虫的引诱效果之间没有显著差异;苯乙醛与苯甲醛混配,混配比为32:1～8:1时,混配物对雌虫有明显的引诱效果,混配比为8:1时的混配物对雄虫有明显的引诱效果;苯乙醛与水杨酸甲酯混配后则显著降低苯乙醛对雄虫的引诱效果,而两者的混配比为8:1～4:1时,混配液对雌虫有明显的引诱效果.     

加速溶剂萃取(ASE)技术提取海南萝芙木活性成分

考察了加速溶剂萃取(ASE)技术对海南萝芙木抗氧化活性成分的提取效果。以提取物对DPPH自由基的清除率为指标,确定水-丙酮混合溶剂为最佳溶媒,通过正交实验确定了最佳提取条件,即样品经质量分数1%的盐酸预处理30 m in后,以V(丙酮)∶V(水)=1∶1为溶媒,在125℃用加速溶剂萃取仪提取,所得提取物对DPPH自由基的清除率为89.378%,而索式提取法仅为68.45%。表明加速溶剂萃取技术可以作为萝芙木中活性成分的一种高效提取手段。     

用卤虫(Artemia salina L.)评价杀虫活性

[目的]以卤虫(Artemia salina L.)为模式生物对化合物的药理活性进行初步评价.对10种不同作用机制的14种杀虫剂进行了生物筛选试验.[结果]14种供试杀虫剂中有13种对卤虫有显著的毒杀效果,作用于以γ-氨基丁酸为神经递质传导系统的化合物及蜕皮激素类似物效果最为显著.[结论]用卤虫筛选杀虫剂活性的方法简便,对多种作用机制的杀虫剂灵敏.     

槐花α-葡萄糖苷酶抑制活性研究

用体外α-葡萄糖苷酶抑制模型,对槐花乙酸乙酯、石油醚、正丁醇、丙酮水总提取物进行活性筛选,对提取物浓度与抑制活性关系进行了研究,并对强活性的3种浸膏进行了抑制动力学研究。槐花总提取物(IC50=50.56 mg.L-1)、乙酸乙酯部位(IC50=1.25 mg.L-1)、正丁醇部位(IC50=16.14 mg.L-1)。活性远高于对照Acarbose(IC50=1 081.27 mg.L-1);并全部属于非竞争性抑制类型(Ki值分别为4.53、652.5 mg.L-1和62.38mg.L-1);从乙酸乙酯部位得到活性成分槲皮素(IC50=8.86 mg.L-1)和山奈酚(IC50=73.69 mg.L-1)。结果表明,槐花乙酸乙酯部位可作为降血糖活性部位进行体内研究。该文报道的新颖性已为河南大学图书馆2009年6月24日出具的第CX200906242号《科技查新报告》所证实。     

白杨透翅蛾性诱剂的新合成法

白杨透翅蛾(Paranthrene tabaniformis Rott.)是杨树的重要蛀干害虫,以幼虫为害枝干和顶芽,造成林木秃头断梢,林相不整。该虫在我国发生普遍,为害严重。1981年经中国科学院上海昆虫研究所和我所协作证明E-3,Z-13-十八碳二烯醇对雄蛾具有强烈的引诱作用。     

黄花蒿(Artemisia annua L.)提取物对两种病原真菌的生物活性

以石油醚Ⅰ(30℃～60℃)、石油醚Ⅱ(60℃～90℃)、乙醇和丙酮等4种溶剂对黄花蒿的根、茎、叶进行初步提取,采用生长速率法测定不同提取物对玉米小斑病菌、棉花枯萎病菌的抑菌活性。结果表明,黄花蒿提取物对玉米小斑病菌的生物活性好于棉花枯萎病菌;黄花蒿叶的提取物抑菌效果最好,根的抑菌效果最差;叶的石油醚(60℃～90℃)提取物对玉米小斑病菌EC50为156.32mg/L;而叶的丙酮提取物对玉米小斑病菌的EC50为82.37mg/L。     

黑荆树皮中抗氧化性物质化学成分研究初探

用乙酸乙酯-水和丙酮-水为溶剂,石油醚为沉淀剂从黑荆树皮中提取抗氧化活性物质。实验表明:提取物具有较好的抗氧化活性。通过化学预示法对提取物中的化学成分进行了鉴定。     

紫花地丁不同方式提取物抑菌效果研究

采用索式提取和微波2种方式分别对紫花地丁进行提取,并运用生长速率法测定了各提取物对植物病原真菌的抑制作用。实验结果表明:在4.0 g/L时,微波提取物的抑菌活性(最高86.9%)明显高于索式提取物的活性(最高64.7%)。丙酮提取物对棉花枯萎病菌、柑橘炭疽病菌和小麦全蚀病菌的EC50分别是3.04,2.90,2.78 g/L。     

中药翻白草黄酮类化学成分及其降糖活性研究

以翻白草为材料,探究黄酮类化学成分及其降糖活性降糖活性。采用系统溶剂法、柱色谱分离法对翻白草的化学成分进行分离,并鉴定化合物结构。基于HepG2细胞,筛选出具有降糖活性的化合物;采用胰岛素抵抗模型,筛选具有改善胰岛素抵抗的化合物。从翻白草乙醇提取物中分离得到13个化合物,分别鉴定为芹菜素(1)、木犀草素(2)、山柰酚(3)、山柰酚-3-O-β-D-吡喃葡萄糖苷(4)、山柰酚-3-O-β-D-葡萄糖醛酸苷(5)、山柰酚-3-O-β-D-半乳糖苷(6)、山柰酚-3-O-ɑ-L-阿拉伯糖苷(7)、槲皮苷(8)、槲皮素-3-O-β-D-吡喃葡萄糖苷(9)、槲皮素-7-O-β-D-吡喃葡萄糖苷(10)、槲皮素-3-O-β-D-葡萄糖醛酸苷(11)、异鼠李素(12)、异鼠李素-3-O-β-D-葡萄糖醛酸苷(13)。正常HepG2细胞实验中,化合物3、4、11、12、13组葡萄糖含量显著下降(P0.05);胰岛素耐受细胞实验中,化合物3、9、11、13组葡萄糖含量显著下降(P0.05),化合物3、13组的PPARγ蛋白表达显著上升(P0.05)。化合物3、4、11、12、13能够促进正常的HepG2细胞葡萄糖消耗,化合物3、9、11、13能够改善胰岛素抵抗的HepG2细胞葡萄糖消耗。     

紫菀提取物油脂抗氧化效果研究

对紫菀（Aster tataricus.L.f.）乙酸乙酯提取物（EAE）、丙酮提取物（AE）和乙醇提取物（EE）的油脂抗氧化活性进行研究,用碘量法进行抗氧化性的测定。结果表明,EAE对油脂具有较好的抗氧化作用,在一定范围内,抗氧化效果随添加量的增加而增强,而丙酮及乙醇提取物抗氧化效果不明显。此外,EAE与Vc在花生油中有很好的协同增效作用,表明紫苑具有开发天然抗氧化剂的潜在价值。     

全棉筒子纱氧漂工艺的生产实践

为提高漂白全棉筒子纱的白度、强力、毛效等指标,在生产中探讨了水质、过氧化氢用量、漂液pH值、氧漂温度、氧漂时间对筒子纱性能的影响,得出了全棉筒子纱的最佳氧漂工艺。其中27%双氧水浓度12～13 g/L,pH值10.5～11.5之间,氧漂温度与时间控制98±2℃,55分钟。在此工艺下,全棉筒子纱的白度、强力、毛效获得最佳协同效果,可满足客户要求。     

中药祛痘膏的制备与应用

研制了一种以中药组方作为祛痘功效成分的祛痘膏,用于治疗痤疮。确定了祛痘膏的制备工艺和质量标准,同时抽选门诊患者进行治疗,观察临床疗效。结果证实,所得制剂制备工艺简单,性质稳定,疗效确切。治疗组100例,总有效率91％,对照组50例,总有效率80％,治疗组疗效优于对照组（P〈0．05）。     

Physical and Thermal Stability of Spray-Dried Swiss Cheese Bioaroma Powder

The effect of water content on the glass transition temperature of Swiss cheese bioaroma microencapsulated with a spray dryer was determined using differential scanning calorimetry (DSC) while mass loss was determined by thermogravimetric analysis (TGA). The sorption isotherm behavior was assessed at 15–45°C. Data were fitted with different sorption models. The bioaroma microparticles were produced via spray drying in a matrix with a 1:1 ratio (w/w) of maltodextrin 20DE and modified corn starch (Capsul). The isotherms displayed Type II behavior, and the best fit was obtained by the Guggenheim–Anderson–de Boer (GAB) model (coefficient of determination R² ≥ 0.98). The DSC analysis showed that the increased equilibrium moisture content caused a significant reduction in the T_g of the microparticles. The samples stored at intermediate humidity showed thermal stability and the samples with equilibrium moisture content of 17.92% showed a lower mass loss.     

Directed Recovery and Molecular Characterization of Antibiotic Resistance Plasmids from Cheese Bacteria

Resistance to antimicrobials is a growing problem of worldwide concern. Plasmids are thought to be major drivers of antibiotic resistance spread. The present work reports a simple way to recover replicative plasmids conferring antibiotic resistance from the bacteria in cheese. Purified plasmid DNA from colonies grown in the presence of tetracycline and erythromycin was introduced into plasmid-free strains of Lactococcus lactis, Lactiplantibacillus plantarum and Lacticaseibacillus casei. Following antibiotic selection, the plasmids from resistant transformants were isolated, analyzed by restriction enzyme digestion, and sequenced. Seven patterns were obtained for the tetracycline-resistant colonies, five from L. lactis, and one each from the lactobacilli strains, as well as a single digestion profile for the erythromycin-resistant transformants obtained in L. lactis. Sequence analysis respectively identified tet(S) and ermB in the tetracycline- and erythromycin-resistance plasmids from L. lactis. No dedicated resistance genes were detected in plasmids conferring tetracycline resistance to L. casei and L. plantarum. The present results highlight the usefulness of the proposed methodology for isolating functional plasmids that confer antibiotic resistance to LAB species, widen our knowledge of antibiotic resistance in the bacteria that inhabit cheese, and emphasize the leading role of plasmids in the spread of resistance genes via the food chain.     

Oxidative Stability of Rice Bran Wax Oleogels and an Oleogel Cream Cheese Product

Recently, a number of publications demonstrated the successful applications of oleogels (OG) (liquid oils gelled through organogelators) in food products. Although many highlighted the health benefits of OG, potential negative impacts of thermal processing during oleogelation on nutrition and flavor quality of the OG‐based food are not fully studied. Hence, in this study, an oleogel‐cream‐cheese (OCC) product was formulated and the effects of OG processing on the oil's oxidative stability and the tocopherol content were investigated. The OG system used in the cheese product was prepared with high‐oleic soybean oil (HOSO) and rice bran wax. An ungelled cream‐cheese sample (UGCC) and two commercial cream‐cheese products were used as controls. Although high‐performance liquid chromatography data analysis showed a lower total tocopherol content in OG samples compared to HOSO, the samples’ α‐tocopherol content remained comparable. No significant differences were observed between the total tocopherol contents of OCC and UGCC cheese products, and the amount of all three‐tocopherol isomers remained constant during 14 days of storage. Although oxidation analysis showed more volatile compounds in OG samples compared to HOSO, there was only a minor difference in the volatile content between the OCC and UGCC samples. The results show minimal degradation of vegetable OG due to the thermal processing and storage that may help their potential application in dairy products.     

Scaling up the Bioconversion of Cheese Whey Permeate into Fungal Oil by Mucor circinelloides

The bioconversion of hydrolyzed whey permeate into an oil-rich biomass by Mucor circinelloides was scaled up from 250 mL to 4 L with the use of an aerated stirred tank bioreactor. Biomass production and oil accumulation were strongly influenced by agitation speed (99–451 rpm) and aeration rate (0.29–1.70 vvm). Higher agitation and aeration rates (e.g., >400 rpm, >1 vvm), resulted in significantly higher biomass yield due to increased oxygen transfer capabilities and better mixing. Additionally, oil accumulation in the fungal biomass was related to high agitation (>400 rpm), while aeration (0.5–1.5 vvm) had no significant effect within the range evaluated. The predictive model was validated at the optimal conditions of 450 rpm and 1 vvm. Maximum biomass yield of 10.7 g L⁻¹ and lipid content of 32% dry biomass were achieved during 120 hours of fermentation. Simultaneous optimization of agitation and aeration in a bioreactor was found to not only improve fungal growth but also lipid content (24% vs. 32%), lipid yield (2.2 vs. 3.1 g L⁻¹) and γ-linoleic production (73–464 mg L⁻¹) compared to that of shake-flask. This study resulted in a scaled-up and optimized fermentation process that increased production of M. circinelloides biomass for subsequent use as raw material for food, feed, and fuel applications. This signifies a starting point for further studies aimed at assessing the development of a fully functioning fungi-to-food/fuel system on an industrial scale for several agricultural streams.     

Dairy Lecithin from Cheese Whey Fat Globule Membrane: Its Extraction, Composition, Oxidative Stability, and Emulsifying Properties

An ethanol extraction method was studied for the production of dairy lecithin from cheese whey-derived milk fat globule membrane (MFGM). A two-step ethanol extraction of MFGM involving first extraction at pH 6.5, followed by second extraction at pH 4.5 yielded 17.2 % lipids. The extracted material contained about 90 % lipids, 4.5 % ash, and 1.2 % moisture. The phospholipid content of the ethanol extract was 31 % and the remainder was mostly neutral lipids. The phospholipid fraction contained 34 % sphingomyelin, 31 % phosphatidylcholine, 27 % phosphatidylethanolamine, 4.6 % phosphatidylserine, and 3.1 % phosphatidylinositol. Since the ethanol extract contained 31 % phospholipids, it can be technically termed as dairy lecithin. The major fatty acid components were linoleic acid (5.1 %), myristic acid (8.3 %), palmitic acid (29 %), stearic acid (14 %), oleic acid (25 %), and the remainder was minor fatty acids with chain length ranging from C4:0 to C22:5. The dairy lecithin was semi-solid at room temperature and exhibited a major phase transition at about 35 °C. Owing to its low polyunsaturated fatty acid content, the dairy lecithin was reasonably stable to oxidation as measured by the rate and extent of hexanal production during 35 days of storage at 45 °C. Oil-in-water emulsions made with less than 2 % dairy lecithin (relative to the total emulsion weight) were unstable; however, emulsions made with greater than 4 % dairy lecithin were very stable for more than 60 days at room temperature. The results of this study indicated that a highly functional dairy lecithin can be commercially produced using cheese whey-derived MFGM as the starting material.