水产品可食部章鱼胺含量的研究

目的测定各种淡水和海水水产品可食部中β3-肾上腺素能受体激动剂章鱼胺的含量,为水产品中章鱼胺的开发利用提供根据。方法取鱼、甲壳类、头足类可食部位匀浆后超声处理,用HPLC测定离心后上清液的章鱼胺含量。结果8种淡水鱼肉章鱼胺含量在30～130μg.g-1之间,其中,背肉普遍比腹肉中含量高。海水鱼以及淡水甲壳类的章鱼胺含量与淡水鱼大致相似。海水甲壳类中章鱼胺含量特别高,是淡水和海水鱼以及淡水甲壳类的几十倍,甚至千百倍。头足类的章鱼胺含量也比较高,在海洋藻类中未检测出章鱼胺。结论海洋贝类等是水产品中章鱼胺最丰富的来源,是减肥者与糖尿病人的理想食品。     

氨基酸结构类似物的合成 1.S-乙基-D,L-高半胱氨酸与 S-氨乙基半胱氨酸的合成

本文介绍以蛋氨酸为原料合成 S-乙基-D,L-高半胱氨酸和以胱氨酸为原料合成S-氨乙基-L-半胱氨酸的简便方法。这二种氨基酸结构类似物可作为蛋氨酸、赖氨酸、苏氨酸以及异亮氨酸等菌种选育的代谢拮抗剂应用,以解除目的酸生物合成过程中关键酶的反馈抑制,从而达到提高这些氨基酸菌株的产酸率,增加氨基酸的产量。     

赖氨酸的营养价值和临床应用

由氨基酸组成的蛋白质是人体生长并维持其生命活动的重要营养物质之一,组成人体蛋白质的氨基酸是由食物中的蛋白质在消化道中经各种蛋白质水解酶的作用分解产生而提供的.各种食物蛋白质的营养价值的高低取决于所含氨基酸的种类、含量     

规范化种植的太子参氨基酸成分分析

目的 分析规范化种植的太子参营养价值.方法 采用柱后衍生氨基酸自动分析仪分析法,分析太子参的氨基酸组成和含量.结果 从太子参块根中共检出18种氨基酸,总氨基酸含量为7.77%,必需氨基酸占总量的32.6%(E/T=O.326),其中精氨酸(Arg)含量高达2.08%,γ-氨基丁酸含量1.65%.结论 太子参具有潜在的营...     

鳀鱼的营养分析与评价

目的分析鳀鱼的营养成分,评价其营养价值,为鳀鱼研究开发提供参考。方法采用通用的方法分析并评价鳀鱼干品的营养成分。结果鳀鱼干品粗蛋白、粗脂肪、总糖及多糖含量分别为59.4%、16.0%、1.34%和0.24%;含17种氨基酸,总量为61.45%,其中7种人体必需氨基酸含量为23.77%,占氨基酸总量的38.68%;必需氨基酸指数为40.25,必需氨基酸的构成比例基本符合FAO/WHO的标准;鲜味氨基酸含量为28.77%,占氨基酸总量的46.81%。鳀鱼干品中含13种饱和脂肪酸(SFA),8种单不饱和脂肪酸(MUFA),6种多不饱和脂肪酸(PUFA),分别占总脂肪酸的60.0%,34.35%和5.83%。含Na、K、P、Mg、Fe、Zn、A1、Mn、B、Cu、Pb、Sn、Cr等矿物元素,微量元素Fe、Zn含量较高。结论鳀鱼是一种营养美味的鱼类,具有一定的食用和保健价值。     

云南产松口蘑17种氨基酸的含量测定及评价

目的：测定云南松口蘑中17种氨基酸的含量，并对其进行营养评价。方法：采用氨基酸分析仪测定松口蘑中17种氨基酸的组成。结果：松口蘑样品经酸水解处理，含有苏氨酸、缬氨酸、蛋氨酸、苯丙氨酸、异亮氨酸、亮氨酸和赖氨酸等17种氨基酸，总氨基酸质量分数为24．73％，其中包含人体必需的8种氨基酸，配比合理：E／（E＋N）=0．35，E／N=0．53，与WHO／FAO提出的E／（E＋N）应为0．4左右，E／N应为0．6左右的参考蛋白质模式接近。结论：说明松口蘑在医学和营养学上都有很高的研究价值，值得大力开发利用。     

僵蚕抗凝活性提取液的氨基酸分析

目的：研究僵蚕中具有抗凝活性的提取液中蛋白质的氨基酸残基种类与含量，为僵蚕抗凝活性作用物质基础研究提供依据。方法：将样品用盐酸水解后采用柱前衍生化高效液相色谱法（HPLC法）测定15种氨基酸的种类与含量。结果：僵蚕提取物中含有所测的15种氨基酸残基，其总量为174．99g·L^-1，其中谷氨酸Glu最高，其次为精氨酸Arg、丙氨酸Ala和甘氨酸Gly。而蛋氨酸Met含量最低。结论：该定量方法准确、可控，可用于僵蚕样品中氨基酸的分析。     

柱前衍生RP-HPLC法测定桑叶中16种游离氨基酸的含量

目的:建立柱前衍生法测定桑叶中游离氨基酸的含量。方法:以水超声提取桑叶中的氨基酸,以异硫氰酸苯酯柱前衍生,采用反相高效液相色谱法测定氨基酸的含量。结果:桑叶中含有苏氨酸、缬氨酸、脯氨酸、蛋氨酸、谷氨酸、甘氨酸、亮氨酸、苯丙氨酸、酪氨酸、天门冬氨酸、γ-氨基丁酸、丙氨酸、组氨酸、胱氨酸、色氨酸、异亮氨酸等16种游离氨基酸;其中人体必需氨基酸有7种,人体半必需氨基酸有1种,含量占氨基酸总量的20%左右。结论:本法不需要专门的氨基酸分析仪,操作简便、灵敏度高,结果准确、可靠。桑叶中氨基酸的种类齐全、含量丰富,具有很高的开发利用价值。     

国内蛋氨酸市场行情火爆——舶来品一统天下，国产品难以匹敌

蛋氨酸属于人或动物维持正常生理活动所必须的8种“必须氨基酸”之一。它是合成蛋白质和胱氨酸的基本原料。蛋氨酸在医药业主要用于生产复合氨基酸输液的原料之一，它本身即具有防治急慢性肝炎、肝硬化和解毒等效果。我国在上世纪50年代初开始研究化学合成蛋氨酸的工艺，最初是为了满足国内医药制剂业的需要（因为蛋氨酸是各种复合蛋氨酸的重要原料）。1959年天津河北制药厂率先建成国内首条药用级蛋氨酸生产线（年产能力为200吨，实际产量仅60～70吨）。     

蓝桉果实中氨基酸成分的含量测定

目的研究蓝桉果实中氨基酸的种类并测定其含量。方法采用氨基酸分析仪测定蓝桉果实中总氨基酸和游离氨基酸的含量。结果蓝桉果实总氨基酸含量为4.76g,其中人体必需氨基酸为2.11g(44.3%);游离氨基酸含量为25.29mg,其中人体必需氨基酸为9.3mg(36.7%)。结论蓝桉果实中含有丰富的氨基酸,具有较高的营养价值。     

Differential effects of Co(2+) and Ni(2+) on protein metabolism in Scenedesmus obliquus and Nitzschia perminuta

Growth, morphological changes, amino acid composition, total soluble protein, and protein electrophoretic pattern were monitored for Scenedesmus obliquus and Nitzschia perminuta grown in the presence of different concentrations of Co²⁺ and Ni²⁺. Lower concentrations of cobalt stimulated the dry mass production and total soluble protein content of the two algae, whereas higher concentrations were inhibitory. Generally, N. perminuta showed more tolerance to the phytotoxicity of the two metals than S. obliquus and more tolerance to nickel than cobalt. However, S. obliquus seems to be more tolerant to cobalt than nickel. Cobalt and nickel have induced an increase in cell volume, change and disorder in cell shape. The increase in cell volume was much observed in Ni²⁺ treated cells. At the same time, the two metals did not induce any distinct morphological abnormalities in N. perminuta. Co²⁺ has stimulated the biosynthesis of all free amino acids in S. obliquus, except aspartic acid and phenylalanine, whereas Ni²⁺ caused 22% inhibition in the content of total free amino acids, except cystine and arginine. On the other hand, Co²⁺ has reduced the content of free amino acids in N. perminuta, except cystine, methionine, valine, and lysine. On the other hand, Ni²⁺ stimulated the biosynthesis of glycine, alanine and histidine and highly stimulated valine and sulphur containing amino acids (cystine and methionine) in N. perminuta. High cobalt concentration (4 ppm) resulted in the disappearance of 28.7 kDa protein, 3.5 ppm Ni²⁺ stimulated the appearance of 18 and 20 kDa proteins in S. Obliquus, while 37 kDa proteins disappeared from N. perminuta treated with high doses of Co²⁺ and Ni²⁺.     

Determination of essential elements (copper,manganese, selenium and zinc) in fish and shellfish samples. Risk and nutritional assessment and mercury–selenium balance

Fish and shellfish are an important source not only of toxic heavy metals, but also of essential elements in the diet. In this study, levels of Cu, Mn, Se and Zn have been determined in fresh, canned and frozen fish and shellfish products. A total of 485 samples of the 43 most frequently consumed fish and shellfish species in Andalusia (Southern Spain) were analyzed for essential elements content. The potential human health risks for the consumers and the nutritional value of the products analyzed were assessed. Furthermore, the mercury-selenium ratios and the selenium health benefit value (Se-HBVs) were calculated. The highest concentrations of Cu were found in crustaceans species (shrimp and prawn) as they have hemocyanin (a copper-containing protein) that functions as an oxygen–transport molecule. Mn levels were higher in canned bivalve molluscs, such as cockle and clam, and in fresh common sole. Concerning Se, two fresh predatory fish species (tuna and swordfish) presented the most remarkable concentrations of this element. The highest concentration of the essential metals analysed was found for Zn, especially in fresh and canned mussels. All the species analyzed showed beneficial Hg:Se ratios and Se-HBVs, except for the shark species (blue shark and cat shark) and gilt-head bream because of their high Hg levels and low Se content, respectively. Nevertheless, the biomagnification usually observed in hazardous metals such as Hg would not occur for the essential elements measured in predatory species. The estimated daily intakes of the elements studied represented very low percentages of their reference values, ranging from 0.1% (Se) to 3.9% (Cu) for person weighting 60 kg, so the intake of these elements through fish and shellfish would not pose any risk for the average consumer. Moreover, the contribution of fish and shellfish products to the recommended daily allowances and adequate intakes of these mineral elements ranges from 2.5% (Mn) to 25.4% (Se).     

Amino-acid composition and nootropic properties of polynoophyt

The nootropic activity of the complex plant preparation polynoophyt (polynoofyt) has been established in animal experiments. The amino-acid composition of the phytopreparation has been studied. A total of 19 amino acids including seven essential ones was identified. The most significant concentrations were found for aspargic acid, asparagine, glutamic acid, glutamine, proline, cystine, methionine, leucine, γ-aminobutyric acid, alanine, and arginine.     

Brain glutathione as a target for aetiological factors in neurolathyrism and konzo

Both neurolathyrism and konzo are associated with the nutritional dependence of human populations on a single plant food. These diseases express themselves as chronic disorders of upper motor neurones, leading to signs and symptoms that characterise amyotrophic lateral sclerosis (motor neurone disease). The plant food associated with neurolathyrism is grass pea, which contains the neurotoxic β-N-oxalyl-α,β-diaminopropionic acid (β-ODAP). The plant food associated with konzo is cassava, which may contain significant concentrations of cyanogenic glycosides and their degradation products. A monotonous diet of grass pea is likely to generate nutritional deficiencies; it is proposed that one of these, plasma methionine deficiency, may predispose neurones to the neurotoxic effects of β-ODAP. Subjects suffering from konzo also have low concentrations of plasma methionine as a result of a dietary deficiency of this amino acid. However, the plasma cystine concentration is also compromised because cyanide released from cyanogenic glycosides in cassava probably reacts with plasma cystine non-enzymatically. The product of this reaction is 2-imino-4-thiazolidine carboxylic acid. Since both plasma methionine and cystine are used for glutathione synthesis it seems likely that one common feature that leads to motor neurone death in neurolathyrism and konzo is the depletion of glutathione in the central nervous system.     

A survey of arsenic species in Chinese seafood.

In the present report, thirty different types of Chinese edible seafood, including brown algae, red algae, fish, crab, shrimp, mussels, oysters, and clams, which are very popular foodstuffs in the Chinese kitchen, were examined for their total content of As as well as its different species. Total arsenic concentration in algae samples was 1.7-38.7 microg/g (dry weight), and 0.086-7.54 microg/g in fish and shellfish (wet weight), respectively. The arsenic species in seafood extracts were determined by using anion and cation exchange high performance liquid chromatography (HPLC) coupled to inductively coupled plasma mass spectrometry (ICPMS). Arsenosugars were detected in all of the extracted algae samples (1.5-33.8 microg/g dry weight) and fish samples (0.018-0.78 microg/g wet weight). Arsenobetaine was detected in all of the extracted fish and shellfish samples (0.025-6.604 microg/g wet weight). In contrast, inorganic arsenic in fish and shellfish samples occurred at levels below 2% of the total arsenic. No inorganic arsenic was detected in the algae samples. This study provides information about the distribution pattern of arsenic species in seafood products. Since the major share of arsenic components in seafood is organic arsenic with a low toxicity, we can conclude that arsenic in seafood does not pose any risk to human health.     

昆仑雪菊中氨基酸的含量分析

目的 研究昆仑雪菊中氨基酸的含量及种类. 方法利用氨基酸自动分析仪测定昆仑雪菊中的氨基酸. 结果 昆仑雪菊中含有17种氨基酸,其中8 种为人体必需氨基酸,游离氨基酸总量达到10.81%. 结论 昆仑雪菊具有较好的营养保健价值和开发前景.     

Amino acid composition and zinc content of milk-clotting protease from Bacillus mesentericus strain 76

The milk-clotting protease from Bacillus mesentericus strain 76 is free of carbohydrate and lacks cysteine and cystine. The amino acid composition indicates a single peptide chain with 304 residues. Five amino acids - aspartic acid, threonine, serine, glycine and alanine - represent one-half of the total residues. The enzyme contains 35 aromatic amino acids and 103 ionic amino acids. The observed constant value of the ratio M_enzyme:A_Zinc is 1:1 for active and acid denatured enzyme preparations, indicating that 0.1 M acetic acid causes denaturation of the enzyme but it can not eliminate the zinc ions.     

氨基酸分析法测定复方骨肽注射液中多肽含量

目的建立复方骨肽注射液中多肽含量的氨基酸分析法。方法氨基酸水解方法:6mol.L-1盐酸110℃水解22h;氨基酸衍生方法:异硫氰酸苯酯(PITC)法;HPLC条件:Agilent Eclipse AAA色谱柱;流动相A:0.1mol.L-1乙酸钠(用冰醋酸调至pH 6.5)-乙腈(97∶3);流动相B:乙腈-水(4∶1);流速:1.0mL.min-1;检测波长:254nm。结果 18种氨基酸的线性、精密度及稳定性良好;除水解样品中的胱氨酸与色氨酸外,其他氨基酸的回收率均达到定量要求。结论方法准确、专属性强,可作为复方骨肽注射液中多肽的定量分析方法。     

鱼油中高度不饱和脂肪酸工业化提取技术的研究

研究了以国产工业化生产设备对鱼油进行多级分子蒸馏,从而提取高度不饱和脂肪酸的方法。分析了不同级别蒸馏所得豆油的碘价、过氧化值、酸价以及色值和气味,并以气相色谱－质谱仪（ＧＣ—ＭＳ）分析了不饱和脂肪酸的成分组成及变化规律。     

家蚕氨基酸、微量元素及总黄酮含量测定分析

目的测定分析全蚕粉中营养成分及总黄酮含量,为家蚕保健食品和药物研究开发提供实验数据。方法采用高效液相色谱（HPLC）法,6-氨基喹啉-N-羟基琥珀酰亚氨基甲酸酯（AQC）为衍生剂,测定氨基酸含量。凯氏自动定氮仪测定蛋白质含量。索氏提取法提取蚕粉中总脂肪酸。原子吸收光谱法测定微量元素含量。紫外分光光度法测定总黄酮含量。结果全蚕粉含16种氨基酸,蛋白质含量高达60％,脂肪酸含量2％,微量元素含量较为丰富。总黄酮含量约为18mg／g。结论HPLC法测定氨基酸操作简便、衍生化反应彻底。家蚕营养成分、总黄酮含量高,确为药食两用佳品。