组培苗鲜罗汉果与干罗汉果营养成分的分析和比较

对组培苗鲜罗汉果与干罗汉果提取物的营养成分进行分析和比较研究,分别测定了蛋白质、脂肪、总糖、碳水化合物、灰分、矿质元素、维生素E和氨基酸含量。结果表明:组培苗鲜罗汉果和干罗汉果蛋白质含量分别为22.23%、19.8%,氨基酸总量分别为12.51%、8.36%,其中人体必需氨基酸占氨基酸总量分别为38.13%、36.36%,矿质元素含量分别为1081mg/100g、1089mg/100g,维生素E含量分别为0.183mg/100g、0.589mg/100g。组培苗鲜罗汉果的蛋白质、氨基酸含量比组培苗干罗汉果分别高2.43%、4.15%,碳水化合物、维生素E含量组培苗干罗汉果比组培苗鲜罗汉果分别高2.44%、0.406mg/100g,矿质元素、粗脂肪、总糖、灰分等含量两者不存在明显差异。     

金藜麦耐盐性分析及营养评价

对我国沿海地区新收集种质资源金藜麦(Chenopodium quinoa Willd.)进行了耐盐性及营养品质评价。结果表明:金藜麦在对盐胁迫相对敏感的芽期和苗期表现出相对较高的耐盐性;子粒蛋白质含量为14.2%,蛋白营养价值优于牛奶以及小麦、水稻、玉米、大豆等作物;子粒中富含维生素B、E等以及钙、锰、铁、铜、锌等矿质元素,特别是钙含量高达190.16 mg/100g,是小米钙含量的35倍;且金藜麦子粒含有丰富的必需脂肪酸,如亚油酸(3.58 g/100g)和亚麻酸(0.44 g/100g),天然抗氧化剂维生素E含量为7.66 mg/100g。这些研究结果表明,新收集的金藜麦种质资源具有较高的营养价值和耐盐性,将为我国藜麦研究和种植提供重要的种质资源。     

五指山参营养成分分析

目的:测定和分析五指山参(箭叶秋葵根茎)的主要营养成分。方法:105℃常压干燥恒重法,微量凯氏定氮法,氨基酸分析仪分析法,索氏抽提法,气相色谱法,DNS法,蒽酮法,重量法,原子吸收分光光度法。结果:五指山参水分含量(14.97±0.37)%;粗蛋白含量(9.22±0.09)%,水解样氨基酸(含色氨酸)含量6.18%;粗脂肪含量(17.57±0.11)%,其中饱和脂肪酸、不饱和脂肪酸、未知脂肪酸占总脂肪酸含量分别为33.16%、42.24%、24.59%;总糖含量(55.75±0.80)%,可溶性糖含量(4.41±0.23)%,还原糖含量(2.08±0.06)%,粗纤维含量(4.35±0.19)%;钙、铁、锌、锰、铜、钾、镁含量分别为4.0mg/g、0.12mg/g、53.5μg/g、14.0μg/g、11.5μg/g、3.4mg/g、1.3mg/g。结论:五指山参营养结构较优,矿物质元素含量相对较高,尤其是钙、铁和锌,值得进一步开发和利用。     

Nutritional Analysis of Abelmoschus sagittifolius

目的:测定和分析五指山参(箭叶秋葵根茎)的主要营养成分.方法:105℃常压干燥恒重法,微量凯氏定氮法,氨基酸分析仪分析法,索氏抽提法,气相色谱法,DNS法,蒽酮法,重量法,原子吸收分光光度法.结果:五指山参水分含量(14.97±0.37) ％;粗蛋白含量(9.22±0.09)％,水解样氨基酸(含色氨酸)含量6.18％;粗脂肪含量(17.57±0.11)％,其中饱和脂肪酸、不饱和脂肪酸、未知脂肪酸占总脂肪酸含量分别为33.16％、42.24％、24.59％;总糖含量(55.75±0.80)％,可溶性糖含量(4.41±0.23)％,还原糖含量(2.08±0.06)％,粗纤维含量(4.35±0.19)％;钙、铁、锌、锰、铜、钾、镁含量分别为4.0mg/g、0.12 mg/g、53.5 μg/g、14.0 μg/g、11.5 μg/g、3.4 mg/g、1.3mg/g.结论:五指山参营养结构较优,矿物质元素含量相对较高,尤其是钙、铁和锌,值得进一步开发和利用.     

金银花尺蠖幼虫、蛹和成虫的营养成分分析

【目的】了解金银花尺蠖Heterolocha jinyinhuaphaga Chu幼虫、蛹和成虫的主要营养成分,评价其营养价值,为金银花尺蠖的食用开发提供理论依据。【方法】采用国家标准检测方法,测定金银花尺蠖幼虫、蛹和成虫的水分、蛋白质、脂肪、总糖、氨基酸、脂肪酸、微量元素和维生素的含量,分析金银花尺蠖幼虫、蛹和成虫的氨基酸分、必需氨基酸指数、必需氨基酸与非必需氨基酸的比值、不饱和脂肪酸与饱和脂肪酸的比值,并与常见食物进行比较分析。【结果】结果表明,金银花尺蠖幼虫、蛹和成虫的水分含量分别为72.93%、64.92%和56.16%;蛋白质含量分别为50.64%、60.12%和48.38%;脂肪含量分别为21.98%、23.84%和20.60%;总糖含量分别为3.32%、5.35%和2.79%;总氨基酸含量分别为394.31、413.54和356.09 mg/g;必需氨基酸总含量分别为158.80、166.83、132.67 mg/g;必需氨基酸占总氨基酸的比例分别为40.27%、40.34%和37.26%;必需氨基酸与非必需氨基酸的比值分别为67.43%、67.62%和59.38%;必需氨基酸指数分别为1.02、1.07和0.87;不饱和脂肪酸的含量分别为68.45%、69.09%和66.29%,其P/S值分别为2.17、2.24和1.95;必需脂肪酸含量分别为34.35%、34.77%和32.71%;微量元素Zen的含量分别为11.29、98.42、66.98 mg/100 g,Fe的含量分别为32.31、19.84、13.04 mg/100 g,幼虫中Cu的含量为18.54 mg/100 g,蛹和成虫中均不含Cu;维生素以B6的含量最高,分别为7.93、25.82、26.21 mg/100 g。【结论】金银花尺蠖具有较高的营养价值和食用价值,具有极大的开发潜力。     

梵净山薇菜营养成分分析

目的：分析梵净山薇菜的营养成分,为梵净山薇菜的开发利用提供科学依据。方法：参照国标的方法测定梵净山薇菜的蛋白质、维生素C、总糖、还原糖、粗纤维、氨基酸、矿质元素等营养成分,并对其进行分析与评价。结果：梵净山薇菜蛋白质、粗纤维和维生素C含量较高,脂肪含量较低,氨基酸总量达22194g/100g,必需氨基酸（EAA）/氨基酸总量（TAA）为44769%,EAA/非必需氨基酸（NEAA）为93200%,必需氨基酸指数（EAAI）为8624,必需氨基酸种类齐全、比例均衡,第一限制氨基酸为甲硫氨酸、半胱氨酸,矿物质元素含量丰富,以钾和铁的含量最高,分别为3 74180、71990mg/kg。结论：梵净山薇菜是一种蛋白质含量高、脂肪含量低、必需氨基酸种类齐全且比例均衡、矿物质元素丰富、营养价值较高的野菜,具有很好的开发应用前景。     

玉米黑粉菌孢子粉的无机元素和氨基酸含量测定

对玉米黑粉菌(Ustilago maydisDC.Corola.)孢子粉的无机元素和氨基酸含量进行了测定。结果表明:玉米黑粉菌孢子粉含有丰富的无机元素,其中铁、钙、镁、磷、锌、锰含量分别为100μg/g、3 561μg/g、1 382μg/g3、500μg/g、101μg/g和24μg/g;同时含有8种必须由食物蛋白质提供的氨基酸,以苏氨酸含量最多,为340.18 mg/100 g。     

河套地区小麦粉营养品质分析及小麦粉营养化发展对策

目的：了解我国河套地区小麦粉营养品质。方法：选取当地2个不同季节生产的特色面粉6种,对其维生素和矿物质进行分析。结果：12个样品维生素E含量为0.061~0.404 mg/100 g,维生素B1、维生素B2、烟酸含量分别为0.139~0.230 mg/100 g、1.380~1.900 mg/100 g、3.425~4.350 mg/100 g,维生素B2和烟酸含量远高于我国小麦粉平均水平。铁、钙、磷、镁含量偏低,但硒含量为0.043~0.250 mg/kg,已达到富硒农产品标准。结论：河套地区小麦粉含有丰富的维生素B2、烟酸、硒,本研究就小麦粉的营养化发展提出对策建议。     

青海玉树沙棘不同部位营养成分分析与营养价值评价

为全面了解青海玉树沙棘的营养价值,选取青海玉树5个不同地区的沙棘,对其不同部位(果实、枝、叶、籽)的营养成分进行分析和营养价值的评价,为玉树沙棘再加工产品的开发和利用提供重要依据。分别用亚临界流体丁烷和1,1,1,2-四氟乙烷(R134a)萃取出沙棘不同部位中的粗脂肪和黄酮类成分,采用快速溶剂萃取法(ASE)提取沙棘中的糖分,然后分别测定了各部位脂肪、黄酮类成分、总糖、多糖、类胡萝卜素、总酸、维生素C、原花青素、沙棘籽中脂肪酸含量,同时还测定了各部位主要常规营养成分、氨基酸和各种矿物质元素含量等。结果表明,玉树沙棘果实中含有丰富的氨基酸(以干计,6.89%)、可溶性糖(7.56%)、类胡萝卜素(34.1 mg/100g)、维生素C(1430 mg/100 g)和总矿物质元素(226.4 mg/100 g);玉树沙棘叶中含有丰富的蛋白质(17.5%)、总黄酮(2.10%)、氨基酸(以干计,15.41%)、总矿物质元素(748.1 mg/100 g);玉树沙棘枝中含有丰富的蛋白质(13.5%)、粗纤维(21.1%)、熊果酸(144.1 mg/100 g)、氨基酸(以干计,11.62%)、总矿物质元素(376.9 mg/100 g);玉树沙棘籽中含有丰富的蛋白质(21.4%)、原花青素(3.27%)、氨基酸(以干计,18.63%)、不饱和脂肪酸(548.6 mg/g)。上述数据表明,青海玉树沙棘不同部位具有良好的营养价值和开发前景,可为青海玉树沙棘的质量控制提供依据。     

蝉拟青霉菌丝体与天然蝉花中化学成分的比较分析

以天然蝉花Cordyceps cicadae做对比,对一株蝉拟青霉Paecilomyces cicadae菌株发酵菌丝体的化学成分进行了分析,包括粗成分、生物活性成分、无机元素、氨基酸、脂肪酸等。结果表明:蝉拟青霉菌丝体中虫草多糖的含量为33.2mg/g,甘露醇的含量为78.9mg/g,麦角甾醇的含量为0.6256mg/g,腺苷的含量为1.0620mg/g,钙、铁、锌、硒和锰微量元素的含量分别为5187.59μg/g、207.23μg/g、41.93μg/g、0.087μg/g和28.24μg/g,18种氨基酸齐全,不饱和脂肪酸是优势脂肪酸,以亚麻油酸、油酸为主,其相对含量分别为53.91%和20.63%,与天然蝉花相比,发酵菌丝体中虫草多糖、甘露醇、麦角甾醇、腺苷、氨基酸总量、必需氨基酸总量和不饱和脂肪酸的含量明显高于后者,其它化学成分和天然蝉花中相应成分基本一致。     

Separation and simultaneous determination of nalidixic acid, hydroxynalidixic acid and carboxynalidixic acid in serum and urine by micellar electrokinetic capillary chromatography

Separation in capillary electrophoresis is governed by various factors, including buffer type, buffer concentration, pH, temperature, voltage and micelles. Through proper adjustment of these parameters, nalidixic acid and its two major metabolites, 7-hydroxynalidixic and 7-carboxynalidixic, could be separated by micellar electrokinetic capillary chromatography using an electrophoretic electrolyte consisting of 50 mM borate buffer (pH 9) containing 25 mM sodium dodecyl sulphate and 10% acetonitrile. A linear relationship between concentration and peak area for each compound was obtained in the concentration range 0.15–100 μg ml⁻¹, with a correlation coefficient greater than 0.999 and detection limits in the 0.2–0.7 ng ml⁻¹ range. Intra- and inter-day precision values of about 0.8–1.2% RSD (n=11) and 1.3–2.0% RSD (n=30), respectively, were obtained. The method has been applied to the analysis of nalidixic acid and its two major metabolites in serum and urine with limits of sensitivity lower than 0.8 ng ml⁻¹.     

酚酸类物质对三七幼苗的化感影响

该文研究了不同浓度的阿魏酸、对香豆酸、丁香酸、对羟基苯甲酸、香草酸5种酚酸类物质对三七幼苗生长和生理的影响。结果表明:处理后,三七幼苗的苗高、根长、可溶性蛋白质含量、根系活力、CAT以及POD活性均有所降低。其中,阿魏酸各处理组幼苗的苗高及POD活性均显著降低,50、100 mg·L~(-1)的对香豆酸以及100 mg·L~(-1)的香草酸处理组幼苗苗高也分别比对照显著降低16.19%、16.67%和29.29%;对香豆酸、丁香酸以及对羟基苯甲酸各处理组幼苗根长均显著低于对照;香草酸处理组幼苗的根系活力也显著低于对照,且幼苗的CAT活性在10、50、100 mg·L~(-1)丁香酸、对羟基苯甲酸以及香草酸处理下也达到了显著降低水平。此外,1 mg·L~(-1)阿魏酸以及100 mg·L~(-1)香草酸处理组幼苗的叶绿素含量也均显著降低;中高浓度的阿魏酸、对香豆酸、丁香酸、对羟基苯甲酸增加了三七幼苗的MDA含量,而香草酸在0.1、1、10、100 mg·L~(-1)浓度下显著降低幼苗的MDA含量;丁香酸、香草酸、对羟基苯甲酸以及中高浓度的对香豆酸增加了三七幼苗的SOD活性,且香草酸各处理组均达到了显著性水平。综上结果表明,5种酚酸类物质对三七幼苗均具有一定的化感抑制作用,但各酚酸物质的作用方式及强度并不完全一致,阿魏酸的化感影响较大,这为进一步研究三七的化感自毒作用提供了一定的理论参考。     

Comparative acid stress response of Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella Typhimurium after habituation at different pH conditions

AIMS: The aim of the study was to evaluate the effect of habituation at different pH conditions on the acid resistance of Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella enterica serotype Typhimurium, and to identify potential differences between the adaptive responses of the three pathogens. METHODS: Stationary phase cells of L. monocytogenes, E. coli O157:H7 and S. Typhimurium, grown in glucose-free media, were exposed to pH 3.5 broth directly or after habituation for 90 min at various pH conditions from 4.0 to 6.0. Survivors at pH 3.5 were determined by plating on tryptic soy agar and incubating at 30 degrees C for 48 h. The kinetics (death rate) of the pathogens at pH 3.5 was calculated by fitting the data to an exponential model. RESULTS: Habituation to acidic environments provided protection of the pathogens against lethal acid conditions. This acid protection, however, was found to be pH dependent. For example, for E. coli O157:H7 an increased acid resistance was observed after habituation at a pH range from 4.0 to 5.5, while the maximum acid tolerance was induced at pH 5.0. Furthermore, the effect of low pH habituation was different among pathogens. For L. monocytogenes, E. coli O157:H7 and S. Typhimurium, the pH range within which habituation resulted to increased acid resistance was 5.0-6.0, 4.0-5.5 and 4.0-5.0, respectively, while the maximum acid tolerance was induced after habituation at pH 5.5, 5.0 and 4.5, respectively. SIGNIFICANCE: Acid stress conditions are common within current food processing technologies. The information on adaptive responses of L. monocytogenes, E. coli O157:H7 and S. Typhimurium after habituation to different pH environments provided in the present study, could lead to a more realistic evaluation of food safety concerns and to a better selection of processes in order to avoid adaptation phenomena and to minimize the potential for food safety risks.     

氨基酸分析仪测定饲料添加剂——叶酸的方法

用６ｍｏｌ／Ｌ盐酸于１１０℃条件下水解饲料添加剂——叶酸,使之游离出谷氨酸,用氢氧化钠中和调节ｐＨ到２,氨基酸分析仪测定谷氨酸含量,经与标准叶酸水解样品比较,计算出叶酸的纯度。该方法重现性好,变异系数ＣＶ＝０．０８％,平均回收率为９８．３４％,浓度与峰面积呈线性相关,相关系数ｒ＝０．９９８７,可随氨基酸分析同时进行,不需改变任何分析条件。     

Triterpene acids from Salvia and Teucrium species

The pentacyclic triterpene acids ursolic acid, oleanolic acid, micromeric acid, maslinic acid and 3-epi-maslinic acid have been isolated from several Salvia and Teucrium species.     

Temperature regulates tuber-inducing lipoxygenase-derived metabolites in potato (Solanum tuberosum)

Temperature is one of the major environmental factors affecting potato tuberization. It has been suggested that lipoxygenase (LOX) mediates between temperature and tuber induction. In this study, the contents of the LOX-derived metabolites hydroperoxylinolenic acid (HPOT), jasmonic acid (JA), tuberonic acid (TA) and tuberonic acid glucoside (TAG) were analyzed in leaves of potatoes growing at different temperatures. At low, tuber-inducing temperature, endogenous levels of JA, TA and TAG rise, indicating their crucial role in tuber induction. The concentration of 13(S)-HPOT seems not to be directly affected by temperature. Instead, the molecule has only a short half-life in leaves and is readily metabolized.     

Characterization of Transgenic Rice Plants Expressing an Arabidopsis FAD7

Fatty acid -3 desaturase (FAD) is the key enzyme catalyzing the formation of trienoic fatty acids. We utilized an Arabidopsis FAD7 gene and the seven independent transgenic rice plants harbouring 1 to 3 copies of this gene were generated. The expression of FAD7 mRNA was different among independent transgenic lines regardless of the copy number. The total linolenic acid (18:3) contents reduced by about 7 – 32 % in transgenic rice plants but the linoleic acid (18:2) content increased accordingly. With or without wounding treatments, the jasmonate content was higher in transgenic lines than in wild-type rice plant. The transgenic lines overproducing jasmonate also showed increased expression of PR1b mRNA and allene oxide synthase inresponse to wounding.