新疆地产葡萄酒和果酒总酚与其抗氧化活性的相关性研究

采用葡萄酒总酚指数(I280)法和p H示差法分别测定了新疆地产23种葡萄酒、果酒的总酚和花青素含量,以β-胡萝卜素-亚油酸体系和磷钼酸体系考察了上述样品的抗氧化活性,并采用防晒系数计算了稀释30倍后各果酒样品的防晒指数(SPF值)。结果表明,干红葡萄酒无论是总酚和花青素的含量还是抗氧化、抗紫外线的活性总体上好于其他各类酒,而葡萄蒸馏酒中仅含少量的酚类,且未检测到花青素。19#甜葡萄酒样品与21#桑葚酒的样品各项指标均与干红葡萄酒相当,表现出很强的活性。对23个葡萄酒和果酒样品中的酚类成分与抗氧化活性的相关性分析结果表明,样品中总酚的含量与其抗氧化和抗紫外线活性有较好的正相关性,相关系数R2分别为0.7928(β-胡萝卜素-亚油酸体系)、0.9132(磷钼酸体系)和0.8268(SPF值);而花青素含量则与样品的抗氧化活性的相关性较弱,相关系数R2分别为0.5426、0.2613和0.3427。     

不同产区赤霞珠葡萄酒酚类物质特征性分析

目的 探究赤霞珠葡萄酒酚类物质的产区差异性。方法 利用高效液相色谱,分析了新疆天山北麓产区、焉耆盆地产区与山东半岛产区赤霞珠葡萄酒中酚类物质组成与含量,结合多元统计方法进行评价。结果 新疆天山北麓产区、焉耆盆地产区与山东半岛产区赤霞珠葡萄酒的酚类物质含量差异较大,其中新疆两产区的原花青素B1、儿茶素、表儿茶素、对香豆酸、总黄烷醇类、总黄酮醇类、总类黄酮及总酚含量显着高于山东半岛产区(P<0.05),焉耆盆地产区芦丁、槲皮苷、白藜芦醇含量显着高于山东半岛产区(P<0.05)。基于酚类物质的聚类分析结果显示,当欧氏距离超过15时,山东半岛产区样品聚为一类,新疆两个产区葡萄酒样品聚在一起;基于酚类物质的Fisher判别分析能区分山东半岛产区样品,对新疆两个产区个别样品有误判,回代检验与交叉验证合计正确率分别为91.30%和86.96%。结论 新疆天山北麓、焉耆盆地与山东半岛产区赤霞珠葡萄酒酚类物质具有明显的产地差异性。     

不同产区赤霞珠干红葡萄酒非挥发风味物质的差异性分析

以宁夏贺兰山东麓、河北怀来、新疆焉耆产区的2016年份15款赤霞珠干红葡萄酒为研究对象,检测其理化指标,采用高效液相色谱法（HPLC）检测供试酒样中非挥发风味物质（糖类、醇类、酸类及酚类等）含量,并对结果进行主成分分析（PCA）及层次聚类分析（HCA）。结果表明,不同产区赤霞珠干红葡萄酒的总酚、总原花青素、黄烷醇、原花青素B1、表棓儿茶素、儿茶素、原花青素B2含量存在极显著差异（P＜0.01）,酒石酸、表儿茶素没食子酸酯存在显著差异（P＜0.05）。经主成分分析得出,供试酒样前2个主成分分别占方差贡献率的33.66%和27.07%;经层次聚类分析得出,新疆焉耆产区酒样与其他产区酒样可以明显归为两类,宁夏贺兰山东麓产区与河北怀来产区酒样也得到了很好的区分。结果表明,产区是影响其风味差异的重要因素。     

新疆四大优势产区葡萄酒中生物胺含量的测定

该研究利用高效液相色谱（HPLC）法对新疆天山北麓、焉耆盆地、吐哈盆地及伊犁河谷四大优势产区中60个葡萄酒样品中的总生物胺含量及8种生物胺组分的含量进行检测分析。结果表明,不同产区葡萄酒中生物胺总含量有所差异,生物胺总含量最高可达到226.13 mg/L,而最低仅有9.15 mg/L,伊犁河谷产区葡萄酒中生物胺总含量低于其他产区葡萄酒中生物胺总含量;同一产区中,各葡萄酒样品中生物胺总含量也有所差异,其中吐哈盆地产区中生物胺总含量（9.66～226.13 mg/L）差异较大;不同品种葡萄酒间生物胺总含量也不同。在四大产区的葡萄酒中,精胺含量（0.90～154.60 mg/L）较高;苯乙胺含量（0.33～4.50 mg/L）较低;组胺含量均＜15.34 mg/L;各产区葡萄酒中腐胺和尸胺含量相对平稳;部分样品中亚精胺未检出。     

德钦、沙城、烟台3个产地赤霞珠干红葡萄酒的品质分析

以云南省德钦县、河北省沙城镇和山东省烟台市3个产地的赤霞珠葡萄为原料酿造干红葡萄酒。分析了3个产地赤霞珠干红葡萄酒的滴定酸、p H值、酒精度、总酚、单宁、花青素、5种花色苷单体和11种单体酚。结果表明:3个产地赤霞珠干红葡萄酒的品质指标间存在显著性差异。就酒精度、总酚和单宁而言,烟台德钦沙城酒样;而聚合指数和色调也表现出相同的趋势。德钦产地葡萄酒中5种花色苷单体总量及各单体含量(矢车菊素葡萄糖苷除外)均显著高于其他2个产地。德钦和沙城两产地赤霞珠干红葡萄酒中总单体酚含量无显著性差异,但均显著高于烟台产地葡萄酒中的含量。     

不同方法测定干红葡萄酒抗氧化性的比较分析

为分析干红葡萄酒酚类物质的抗氧化活性,本研究以新疆、宁夏、烟台产区的干红葡萄酒为实验材料,测定其酚类物质含量和抗氧化活性以及分析不同方法下的酚类物质和抗氧化活性的相关性。结果表明,不同产区的干红葡萄酒中的酚类物质的含量差异较大,与葡萄酒所在产区密切相关。其中,在新疆产区的西拉葡萄酒的总酚含量最高,为384.20 mg·L^-1,赤霞珠葡萄酒抗氧化能力为298.33 U·mL^-1;宁夏产区的赤霞珠葡萄酒总酚含量最高,为266.32 mg·L^-1;烟台产区中西拉葡萄酒总抗氧化能力最高,为263.23 U·mL^-1。同一年份,不同品种葡萄酒中西拉葡萄酒总酚含量、总类黄酮含量、总抗氧化能力和抗超氧阴离子能力最高,分别为310.87 mg·L^-1、549.78 mg·L^-1、239.96 U·mL^-1和1 782.18 U·L^-1。抗超氧阴离子能力主要由总酚、总类黄酮含量决定;不同品种和产区的葡萄酒的总抗氧化能力的大小和酚类...     

基于正交偏最小二乘法判别分析宁夏和河北产区市售马瑟兰葡萄酒理化特征和抗氧化能力

随着中国葡萄酒产业的不断发展，产区之间的同质化问题日趋严重。马瑟兰是近年来在我国各个产区均得到较好表现的优质品种。为解析宁夏和河北产区马瑟兰市售干红葡萄酒特征与差异，进而揭示马瑟兰在不同产区间的不同风格质量表现，对宁夏和河北产区共27款市售酒的理化性质、有机酸、花色苷和其他酚类物质含量及抗氧化能力进行检测，并结合正交偏最小二乘法判别分析(orthogonal partial least squares-discriminant analysis, OPLS-DA)和相关性分析等方法进行分析。结果显示，两地区样品检测中除总酸含量外，其他基础理化指标含量都具有显著差异。有机酸中，琥珀酸是两地区含量差异最大的有机酸；河北地区马瑟兰酒样花青素-3-O-葡萄糖苷含量较高(0.001 1 g/L),而二甲花翠素-3-O葡萄糖苷比宁夏地区酒样低0.033 g/L。基于单体酚含量建立的OPLS-DA模型区分效果最佳，其中11种单体酚对该模型的建立起关键作用。抗氧化能力与相关性分析的结果显示，河北地区马瑟兰酒样抗氧化能力显著高于宁夏地区，且总酚和单体酚类物质对此有重要贡献，特别是表儿茶酸没食子酸酯和龙胆...     

草莓、黑莓、蓝莓中多酚类物质及其抗氧化活性研究

研究草莓、黑莓、蓝莓3种小浆果的总酚、总黄酮、原花青素含量及其总抗氧化能力。结果表明:蓝莓全果的总酚、总黄酮、原花青素含量在所测3种浆果全果中最高,分别为9.44mg没食子酸/g干质量、36.08mg芦丁/g干质量、24.38mg儿茶素/g干质量;其总抗氧化能力也最强,达14.98mmol Trolox/100g干质量。草莓的总酚、总黄酮、原花青素含量则最低,抗氧化能力也最弱。此外,3种浆果果渣中的总酚、总黄酮、原花青素含量以及总抗氧化能力均高于全果和果汁,即果渣>全果>果汁。总酚含量、总黄酮含量以及原花青素含量与总抗氧化能力之间的相关性分析表明,总酚含量与总抗氧化能力之间存在显著线性相关,相关系数r达到0.9704,表明酚类物质是其抗氧化作用的主要物质基础。     

新疆7种桑葚理化品质的比较分析

为了解新疆几种主栽桑葚果实的品质差异,筛选适合深加工的桑葚品种,选择南疆地区7个主栽桑葚品种为材料,对供试样品的水分、pH值、总糖、总酸、还原糖、总酚、总黄酮、原花青素等指标进行分析。结果表明：7种桑葚果实的理化成分存在显著差异（P＜0.05）,其中紫玉一号的水分含量最高89.62%;药桑的总酸含量最高1.86%;大白桑总糖、还原糖含量最高,分别为17.39%、8.58%;小黑桑的VC、粗脂肪、粗蛋白含量最高,分别为0.35 mg/g DW、2.83%和1.93%;而紫玉一号的总酚、总黄酮、原花青素含量最高,分别为17.09 mg GAE/g DW、12.46 mg RE/g DW和3.47 mg/g DW。综上所述,7个果桑品种营养成分丰富,其中大白桑的总糖含量最高,适合加工桑葚酒;小黑桑的粗脂肪粗蛋白含量最高,适用于膳食补充剂;紫玉一号总酚、总黄酮和原花青素含量最高,适合开发功能性食品。     

不同产地冷榨亚麻籽油的脂质组成比较

以来自不同产地的2种中国冷榨亚麻籽油、3种加拿大冷榨亚麻籽油和1种新西兰冷榨亚麻籽油产品作为实验样品,分析比较不同产地冷榨亚麻籽油的脂质组成。研究表明:6种不同产地冷榨亚麻籽油的脂肪酸组成差异不大,主要脂肪酸均为α-亚麻酸、亚油酸、油酸、硬脂酸和棕榈酸;6种不同产地冷榨亚麻籽油的微量营养成分差异显著,总酚、植物甾醇和生育酚含量最高的均为加拿大样品,含量分别为38.06 mg GAE/kg(样品2)、3 671.16 mg/kg(样品2)和536.62 mg/kg(样品3)。     

Purification and characterization of X-prolyl-dipeptidyl-aminopeptidase from Lactobacillus lactis and from Streptococcus thermophilus

X-Prolyl-dipeptidyl-aminopeptidase recently was found in several lactic acid bacteria. This article describes the purification of the enzymes from Lactobacillus lactis and Streptococcus thermophilus and compares their characteristics. Enzymes from both strains are serine-peptidases. They both have a molecular weight of about 165,000 daltons, an isoelectric point near 4.5, and are constituted of two subunits. The pH optimum of the enzyme isolated from L. lactis is 7.0, whereas the enzyme from S. thermophilus possesses a broad pH optimum between 6.5 and 8.2 with glycyl-L-prolyl-aminomethylcoumarin as substrate. Below pH 5, both enzymes are unstable; however, that from S. thermophilus is more rapidly denatured. The enzyme from S. thermophilus is more sensitive to heat than the corresponding enzyme from L. lactis. Enzymes from the both strains have different specificities towards various substrates and are differently effected by metals, chelators, and other inhibitors. The importance of this enzyme for the metabolism of lactic acid bacteria is discussed.     

Isolation and Properties of Starch from Wild Yam from Zimbabwe

Wild Yam (Dioscorea dumetorum) was collected during the wet as well as dry season in the bush of Zimbabwe. Starch from its tubers was isolated in behavioral conditions and properties were determined such as size of granules, content of water, amylose, phosphorus, proteins and lipids, characteristics of gelation of its gels and thermal properties (TG, DTG, DTA).     

Prevalence and antibiotic-resistance of Salmonella isolated from beef sampled from the slaughterhouse and from retailers in Dakar (Senegal)

A study was made of Salmonella contamination in beef sampled from a slaughterhouse and from retailers in Dakar, Senegal. The serotypes as well as antibiotic-resistance patterns of the Salmonella isolates were determined. A total of 435 meat samples (236 from the slaughterhouse, 199 from retailers) were tested. Among them, 275 (63%) were positive for Salmonella, 43% (101/236) from the slaughterhouse and 87% (174/199) from the retailers. Furthermore, 97% of the investigated retailers had at least one beef sample contaminated by Salmonella. The 286 Salmonella isolates were divided into 51 serotypes. The most prevalent serotypes were Salmonella bredeney (25%), S. muenster (8%), S. waycross (7%), S. corvallis (4%) and S. kentucky (4%). About 62% of the isolates were resistant to nitrofurans. Resistance rates were lower to streptomycin (22%), sulfamethoxazole (15%), spectinomycin (1%), chloramphenicol (1%), and tetracycline (0,4%) while low-level resistance to quinolones was detected. About 16% of the Salmonella strains were multiresistant to two or more antibiotic families. Finally, ten resistance profiles have been identified. This study shows the huge spread of Salmonella in the beef production chain in Dakar, Senegal. Finally, this study provides the very first data about Salmonella prevalence in sub-saharian Africa.     

仙人掌多糖提取与多糖胶囊的制备

本研究以仙人掌浓缩清汁为原料,进行仙人掌多糖提取的单因素及正交提取试验,并将提取的仙人掌多糖制备成多糖胶囊。正交提取试验结果表明,仙人掌汁浓缩5倍,乙醇与仙人掌汁的比例为1:3,醇析温度为-18℃时,仙人掌多糖的提取得率最高;仙人掌多糖胶囊制备方法:以95%乙醇作为仙人掌多糖的粘合剂制粒,6%～8%HPMC溶于60%乙醇中作包衣液,在35～40℃下包衣,干燥2h后装胶囊,可获得品质较好的仙人掌多糖胶囊。     

Rheological properties of mustard mucilage isolated from raw and from processed mustard

Mucilage of yellow mustard (Sinapis alba L.) exhibits completely different rheological behaviour, depending on where it has been extracted from. Whereas mucilage isolated from intact mustard seeds or from separated brans acts like many hydrocolloids (e.g. increasing viscosity significantly at low concentrations) these and related properties (i. e. shear thinning behaviour) are lost, once mustard seeds are processed. Mucilage extracted from processed mustard only raises viscosity slightly. Although the supernatant of processed mustard consists of 3-5% mucilage (dry matter), it exhibits Newtonian flow. Changes of rheological properties of mustard mucilage were attributed to a change of molecular shape from an extended to a globular state due to processing. Chemical analysis has shown a significant raise of nitrogen content of mucilage after processing and during storage, indicating some chemical reaction taking place, possibly involving proteins.     

Phytate content of some foods from plant origin from Vietnam and Hungary

For the estimation of phytate-ion the iron content of FeIII-phytate complex was determined by spectrophotometry with o-phenanthroline. In most cases phytate-phosphorus was also evaluated. In different food samples iron to phosphorus ratio in phytate generally deviated significantly from the theoretical 1.20 value. Wheat flour products, maize, rice, beans, peas, lentil and soy from Vietnam and Hungary, furthermore several bakery products from Hungary and some imported soy products were analysed for phytate content. The effect of heat and fermentation on phytate content was also checked in breads and other foods. It was concluded that the processes often used in food industry, namely fermentation and thermal load, have relatively slight effect on the phytate content of plant foods. Cooking losses for phytates ranged 1-60% in cereals and legumes according to the usual kitchen technique in Vietnam.     

不同地区黑木耳多酚提取及抗氧化活性的研究

对云南、福建、黑龙江3个不同地区的黑木耳(Auricularia auricula)进行多酚提取,并比较其抗氧化活性。研究结果显示:黑龙江黑木耳多酚粗提物的还原能力、对DPPH·的清除能力(IC50=4.12 mg/L)及对O2-·的清除能力(IC50=15.17 mg/L)最强,云南黑木耳多酚粗提物则在对羟自由基的清除能力(IC50=302.52 mg/L)和抗脂质过氧化的能力(IC50=23.67 mg/L)最强。总体来说,黑龙江和云南的黑木耳抗氧化活性要高于福建黑木耳,这可能与不同地区黑木耳的多酚成分有关。     

Antioxidant capacity and mineral content of pulp and peel from commercial cultivars of citrus from Brazil

Four Citrus species (C. sinensis, cvs. Pera and Lima; C. latifolia Tanaka cv. Tahiti; C. limettioides Tanaka cv. Sweet lime and C. reticulate, cv. Ponkan) grown in Brazil were characterised in relation to contents of minerals, ascorbic acid, total polyphenols and antioxidant capacity of pulps and peels. In general, the peels demonstrated significantly higher contents of all compounds than the pulps (p < 0.05), with the exception of the Pera orange pulp that presented the highest acid ascorbic content (68 mg/100 ml), while the Tahiti lime peel presented the lowest (8 mg/100 g). Citrus showed high levels of potassium, calcium and magnesium, and the peels were considered sources of these minerals. The Ponkan mandarin peel presented the highest antioxidant capacity. The antioxidant capacity of citrus was correlated both to vitamin C and phenolics. Aside from citrus pulps, the peels are also good sources of bioactive compounds and minerals, and can be explored for their health promoting values in food products.     

竞争中寻求差异差异中寻求认同如何提升珠宝首饰品牌竞争力

伴随着珠宝首饰业的迅猛发展，行业竞争不断激烈，首饰业中的批发，加盟连锁，加工等业务均不同程度地在发生转变，企业中传统的“商标”意识逐渐向“品牌”意识转型已成为市场发展的规律。     

Heat Inactivation of Catalase from Cod Muscle and from Some Psychrophilic Bacteria

Catalase from Pseudomonas sp. and Micrococcus sp. bacteria is inactivated at 93°C and 73°C, respectively, while cod muscle catalase is inactivated at 41°C. This implies that a suitable thermal treatment of a mixture of cod muscle and bacterial catalases will destroy only the cod catalase and leave the bacterial catalase unaltered. The activity of the remaining bacterial catalase is then measured using the disc flotation method.