不同贮藏期对蕨麻中淀粉与还原糖含量的影响

测定不同贮藏期青海人工种植蕨麻和野生蕨麻中直链淀粉、支链淀粉和还原糖的含量,分析了含量变化及其相互关系。结果表明,人工栽培蕨麻和野生蕨麻淀粉和还原糖含量没有变化;蕨麻中直链淀粉含量比例较高;不同温度下蕨麻中淀粉和糖之间遵循"低温糖化"和"高温逆转"规律;蕨麻可干藏和鲜藏。     

全谱直读电感耦合等离子体发射光谱法测定青海蕨麻中矿质元素

采用HNO3/H2O2湿法微波消解制样,利用全谱直读电感耦合等离子体原子发射光谱法(ICP-OES),全面详细地分析测定了蕨麻中的矿质元素。共检出17种,分析结果相对标准偏差(RSD,n=9)在0.33%～10.8%之间,其中15种元素在5%以内;加标回收率在92.7%～108.5%之间,其中11种元素在(100±5)%范围内。蕨麻中所含的P、K、S、Mg、Ca、Na等人体常量元素的质量分数分别为0.94%、0.86%、0.45%、0.20%、0.14%和0.006%;人体必需微量元素Fe、Zn、Cu、Cr等的含量分别为25.8、1.84、0.32、0.086mg/100g;人体可能必需元素Si、Mn、B的含量分别为87.9、1.27、1.15mg/100g;此外还含有36.7mg/100g的Al以及微量的Sr、Ti、Ba等元素。     

蕨麻蛋白的提取与功能特性的研究

利用碱溶酸沉法和盐析法提取蕨麻蛋白,分析了蕨麻蛋白的氨基酸种类、含量以及保水性、吸油性、起泡性、乳化性、凝胶形成性等功能特性。结果表明,盐析法提取蕨麻蛋白得率高于碱溶酸沉法;蕨麻蛋白中精氨酸的含量显著高于其蛋白中其他种类氨基酸的含量,占氨基酸总量的21.4%;在不同pH的环境中,蕨麻蛋白的保水性差异较大;蕨麻蛋白的吸油性随着温度的降低而略有升高;随着蛋白浓度的增大,蕨麻蛋白的起泡性能和泡沫稳定性均明显升高;浓度高的蛋白质溶液具有较高的乳化能力。     

Endogenous skeletal muscle antioxidants

Skeletal muscle is susceptible to oxidative deterioration due to a combination of lipid oxidation catalysts and membrane lipid systems that are high in unsaturated fatty acids. To prevent or delay oxidation reactions, several endogenous antioxidant systems are found in muscle tissue. These include α‐tocopherol, histidine‐containing dipeptides, and antioxidant enzymes such as glutathione peroxidase, superoxide dismutase, and catalase. The contribution of α‐tocopherol to the oxidative stability of skeletal muscle is largely influenced by diet. Dietary supplementation of tocopherol has been shown to increase muscle α‐tocopherol concentrations and inhibit both lipid oxidation and color deterioration. Dietary selenium supplementation has also been shown to increase the oxidative stability of muscle presumably by increasing the activity of glutathione peroxidase. The oxidative stability of skeletal muscle is also influenced by the histidine‐containing dipeptides, carnosine and anserine. Whereas carnosine and anserine are affected by diet less than α‐tocopherol and glutathione peroxidase, their concentrations vary widely with species and muscle type. In pigs, beef, and turkey muscle, carnosine concentrations are greater than anserine, while the opposite is true in rabbit, salmon, and chicken muscle. Anserine and carnosine are found in greater concentrations in muscle high in white fibers, with chicken white muscle containing over fivefold more anserine and carnosine than red muscle. Anserine and carnosine are thought to inhibit lipid oxidation by a combination of free radical scavenging and metal chelation.     

蕨麻的化学成分及药理活性研究进展

蕨麻是蔷薇科委陵菜属植物鹅绒委陵菜(Potentilla anserine L.)的根,主要分布于北半球的温带、寒带和高寒地区,在我国主要分布于青海、西藏等地。蕨麻主要含有甾类、三萜类、黄酮类、酚酸类和香豆素类化合物等多种化学成分。中医学研究表明,蕨麻具有健胃补脾、生津解渴、益气补血等功能。生物活性研究结果显示,蕨麻提取物具有耐缺氧、抗疲劳、抗应激、保肝、抗病毒、提高机体免疫力、抗氧化、补血和保护心肌细胞等活性。本文主要从蕨麻的化学成分和药理活性方面综述其研究进展,提出应在现代医药理论指导下,科学开发利用传统药用植物的观点,同时对蕨麻中有效化学成分、活性成分、药理作用及其代谢机制进行系统而深入的探索,并按照合理的本草疗法进行规范化的临床实验,为进一步开发利用该植物做好基础研究。     

An evaluation of a method to differentiate the species of origin of meats on the basis of the contents of anserine,balenine and carnosine in skeletal muscle

The high performance liquid chromatographic method proposed by Carnegie for determining the species of origin of meats in cooked products has been evaluated. The dipeptides anserine, balenine (ophidine) and carnosine have been extracted from the skeletal muscle of animals in New Zealand and compared with results obtained in Australia. The presence of significant quantities of balenine in red deer meat is reported for the first time. Limitations of the method are discussed.