复方铁皮石斛叶超微粉改善高脂血症小鼠的脂质代谢作用

观察复方铁皮石斛叶超微粉不同配比对高脂高糖致高脂血症模型小鼠的影响。采用高脂高糖饲料喂养制备高脂血症模型小鼠,造模成功后灌胃给予复方铁皮石斛叶超微粉(铁皮石斛叶超微粉和山楂精提物不同配比依次为1:1、1:2、1:4、2:1、4:1)连续9周。检测血清中胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-c)、低密度脂蛋白胆固醇(LDL-c)、谷草转氨酶(ALT)和谷丙转氨酶(AST)水平;末次给药后,检测血清超氧化物歧化酶(SOD)、丙二醛(MDA)和氧化低密度脂蛋白(Ox-LDL)水平;检测肝脏中胆固醇(TC);HE染色观察小鼠肝脏组织形态学。结果表明,复方铁皮石斛叶超微粉(4:1)能有效缓解高脂血症,降低血清TC、LDL-c、MDA、Ox-LDL水平,下降幅度分别为40.84%、36.67%、5.69%、8.22%(p<0.01),血清SOD活性提高5.48%(p<0.01);肝脏TC水平下降14.10%(p<0.05);肝脏重量降低31.35%(p<0.01),能改善肝脏中脂肪沉积。上述结果明确了复方铁皮石斛叶超微粉(4:1)给药组效果较好,可以改善高脂高糖致小鼠血脂异常、肝脏病变。     

板栗叶总黄酮提取工艺的优化及其抗氧化活性

采用响应面法优化板栗叶总黄酮的加压溶剂提取工艺,并考察其抗氧化活性。通过单因素试验考察循环次数、提取温度、提取时间、乙醇体积分数4个因素对板栗叶总黄酮提取率的影响,并采用Box-Behnken设计对提取工艺进行优化,通过DPPH自由基和ABTS+自由基清除以及总抗氧化能力研究其抗氧化活性。结果表明,循环次数为2次,提取温度为73℃,提取时间为7.3 min,乙醇体积分数为40%时总黄酮提取率达到最大值,为(5.18±0.06)%,与预测值(5.20±0.10)%稳合良好。在所设最大板栗叶黄酮提取液浓度下,DPPH自由基清除率为88.44%,ABTS+自由基清除率为82.76%,总抗氧化能力为980.3μmol/L,表明具有很好的抗氧化活性。     

腰果叶多酚超声波辅助提取工艺及其抗氧化能力测定

以腰果叶为原料,采用超声波辅助手段对腰果叶多酚进行提取。在单因素试验基础上,通过响应面法优化腰果叶多酚提取工艺条件。1.0 g腰果叶粉末,所得到最优提取工艺条件为:丙酮体积分数60%、提取温度60℃、提取时间90 min,实测得率为10.29%,接近预测值10.33%。通过腰果叶多酚提取物对DPPH自由基清除能力,ABTS+自由基清除能力,铁离子还原能力,得出腰果叶多酚提取物具有抗氧化能力,相同浓度下腰果叶多酚提取物抗氧化性高于天然抗氧化剂VC。     

竹叶保鲜剂的提取及抑菌效果初探

研究了竹叶保鲜剂的提取工艺和抑菌效果。结果表明,竹叶提取物对多种致病菌有明显的抑菌活性。     

黄刺玫叶片中黄酮物质的提取和分析

介绍了从黄刺玫叶片中提取和分析黄酮类物质的方法。试验结果表明 ,该叶片中总黄酮含量为4 88mg g,其中主要成分是芦丁。本方法操作简便 ,重现性好 ,平均回收率为 97 8% ,相对标准差为 5 1 6%。     

玉米弯孢菌叶斑病菌毒素的生物活性测定及对玉米叶片超微结构的影响

玉米弯孢菌叶斑病（Curvularialunata）是目前玉米生产上的一个主要病害,该病菌可以产生毒素。本文对玉米弯孢菌叶斑病菌产生的毒素进行了生物学测定,并观察了毒素对寄主叶片超微结构的破坏作用。证明玉米弯孢菌叶斑病菌产生的毒素是其致病因子之一,研究发现该毒素不是蛋白质。     

茶多酚和银杏叶有效成分的抗辐射作用研究

将72只昆明种雄性小白鼠随机均分为 6 组,以 150 mg/kg 体重的药物量连续灌服 20d 后,用 Co γ射 60线全身照射,吸收剂量为 9 Gy,继续灌服药物 13d。与对照组相比,茶多酚组、银杏黄酮组、银杏内酯组、茶多酚＋银杏内酯组和茶多酚＋银杏黄酮组的存活率分别提高 66.6%、41.6%、75%、66.6%、75%。平均存活天数分别提高 2.9（P<0.01）、1.8（P<0.05）、3.2（P<0.01）、3.1（P<0.01）、3.1（P<0.01）。实验结果表明：茶多酚和银杏叶有效成分具有抗辐射作用,茶多酚的多酚性羟基和银杏内酯的多羟基以及内酯键并存可能是辐射保护作用的结构基础,不同物质所含结构相同或具有类似官能团是具有复合协同增效作用的前提。     

甘薯叶保鲜及加工利用研究进展

甘薯是我国重要粮食作物,其茎叶及叶柄（一般统称为甘薯叶）含有丰富的营养成分,具有抗氧化、降血脂、降胆固醇、降血糖、抗肿瘤及抑菌等生理功能。因此,对甘薯叶资源进行开发和利用,有助于其价值的发挥。主要综述及展望对甘薯叶目前常用的保鲜方法与加工利用现状,对我国甘薯叶保鲜和加工中存在的主要问题及解决对策进行探讨,旨在为甘薯叶资源的充分利用与相关产业发展提供一定参考。     

Fatty acid profile,physiochemical properties and oxidative stability of ewe’s sausage as affected by distillated myrtle (Myrtus communis) leaves’ intake

The effects of distilled myrtle leaves (DML) intake on physiochemical traits, fatty acid profile and lipid oxidation of ewe’s sausage (Merguez) were investigated. Twenty-seven ewes were divided into three homogenous groups. Ewes were fed hay and concentrate for control group (C). They received concentrate and M-Hay pellets, containing 87% DML, as substitute to hay in MH group; for MC group, ewes received hay, concentrate and M-Conc pellets having 30% DML in partial substitution to concentrate. They were slaughtered at the end of trial (90 days) with an average body weight of 42 kg. DML did not affect the physicochemical and sensory properties (P > 0.05) of Merguez; whereas, it increased lipid oxidative stability (P < 0.05). MH group showed the highest values of α-tocopherol content, C18:2-n6 fatty acid and polyunsaturated fatty acids. DML could be used in animal feeding to obtain higher meat product quality with better fatty acids content and antioxidant potential.     

Effect of Premna microphylla turcz leaves’ extract addition on physicochemical and antioxidant properties of packed tofu by lactic fermentation

In the present study, Premna microphylla turcz leaves (PMTLs) containing rich pectin and isoflavones were introduced to prepare packed tofu coagulated by lactic fermentation, in order to promote its physicochemical and functional properties. Results showed that the final storage (G′) moduli of packed tofu added with PMTL extracts range from 195.2 ± 5.6 Pa to 420.6 ± 10.3 Pa, which were significantly higher (P < 0.05) than the control (PMTL-free, 99.5 ± 8.3 Pa). The hardness, gumminess and chewiness of packed tofu added with 0.8% (w/w) PMTL extracts were 1.43–1.49 times higher than the control without decreasing its water-holding capacity and exhibited the highest scores of overall acceptability, which was recommended as the most acceptable concentration. The total phenolic and flavonoid contents of 0.8%-PMTL supplementation in packed tofu were 1.20 and 1.65 times higher than the control and showed enhanced antioxidant properties in DPPH radical-scavenging capacity, FRAP and RP.