基于SYBR-Green熔解曲线快速鉴别挪威三文鱼及其制品的方法

挪威三文鱼(学名大西洋鲑)和虹鳟的鱼肉颜色和纹理相似。在市场上常存在将一些挪威三文鱼片错贴标签或以虹鳟冒充挪威三文鱼的现象。为了鉴别挪威三文鱼制品的真伪,以COI基因为靶基因,设计2对鲑科鱼类的通用引物,优化退火温度和两对引物的浓度比值,然后做稳定性试验,建立基于SYBR-Green实时荧光定量PCR熔解曲线快速鉴别大西洋鲑的方法。试验结果显示,当鲑科鱼类DNA模板100 ng,两对通用引物的浓度比值1∶1、退火温度50℃时,大西洋鲑和虹鳟鱼的Tm值分别为(86.29±0.172),(83.50±0.201)℃,且3个检验批次的Tm值没有显著性的差异(P=0.772),表明大西洋鲑和虹鳟可通过实时荧光定量PCR熔解曲线法进行鉴别。该方法可用于大西洋鲑与红鲑、银鲑以及大马哈鱼及其制品的鉴别,具有快速、操作方便、成本低廉、准确度高和重复性好的特点。     

DNA条形码技术在鲑科鱼类真伪鉴别中的应用

本研究建立了基于DNA条形码技术的鲑科鱼类特异性检测方法,并用此方法对17种市售鲑科鱼进行物种检测。先从样品中扩增得到DNA细胞色素C氧化酶I(COI)和16S核糖体RNA(16S rRNA)的基因片段,然后进行一代测序,对测序结果进行比对,验证样品的真实属性。结果表明,以COI为靶标、16S r RNA为辅助靶标,可实现对由单一物种组成的鲑鱼制品的物种鉴定。本研究结果证实DNA条形码技术可用于鲑科鱼类的物种鉴别,为鲑科鱼的市场监管提供技术支撑。     

矿物元素和有机成分指纹组合判别芸豆产地

分析不同地域来源芸豆中矿物元素和有机成分组成特征及含量差异,探讨矿物元素和有机成分指纹组合分析技术对芸豆产地鉴别的可行性。检测来自依安、拜泉县2个主产区54份芸豆样品中31种矿物元素和3项有机成分含量,对数据进行方差分析和判别分析。研究表明,矿物元素指纹对芸豆产地交叉检验的整体正确判别率为94.1%;有机成分指纹对芸豆产地交叉检验的整体正确判别率为83.3%;矿物元素和有机成分指纹组合对芸豆产地的正确判别率显著提高,交叉检验的整体正确判别率达到100.0%。因此,矿物元素和有机成分指纹组合分析结合多元统计学是用于芸豆产地溯源的一种有效技术。     

东海经济鱼类的多元素分析及产地判别

采用电感耦合等离子体质谱和原子吸收光谱测定东海4种经济鱼类中25种矿物元素,用多元统计分析元素组成,判断经济鱼类的地理起源。结果显示,主成分分析可以判别鱼类的产地,揭示在地理多样性中起重要作用的元素。用偏最小二乘判别分析和概率神经网络建立的判别模型,可准确地判别鱼类的产地。进一步分析显示,偏最小二乘判别分析和概率神经网络建立的判别模型在不考虑鱼种的情况下,准确率分别达到97.92%和100%。基于矿物元素指纹信息的产地判别技术可应用于近海3个产地的4种经济鱼类的产地判别。     

不同产地三文鱼的稳定同位素指纹特征及原产地溯源

本研究从深圳口岸获取我国三文鱼主要进口国（法罗群岛、挪威、智利、加拿大以及澳大利亚）的三文鱼样品共16?份,并采集中国产三文鱼（虹鳟）样品2?份,分析三文鱼肌肉、表皮、鳞片以及骨骼中的碳、氮、氢、氧、硫稳定同位素比值,比较不同产地以及不同部位同位素分布差异,采用判别分析对不同产地进行判别。三文鱼的碳、硫以及氢、氧稳定同位素具有显著的产地差异。不同组织之间同位素呈现明显的同位素分馏效应。鳞片以及表皮同位素比值对产地的指示效果优于肌肉和骨骼,结果表明采用稳定同位素能完全将以上产地的样品区分开,且还能将中国的虹鳟与进口的三文鱼进行区分。对市场随机购买的6?份三文鱼样品的产地鉴别结果表明,稳定同位素技术能有效鉴别市场中三文鱼的产地造假行为,可用于对市场上三文鱼的产地追溯,以期为我国食品安全提供技术保障。     

基于ICP-MS/MS分析矿物元素的江西茶叶产地溯源

目的 分析江西不同产区茶叶中矿物元素含量的差异,并结合多元统计方法分析矿物元素指纹特征,构建江西茶叶不同产地鉴别的判别模型。方法 采用电感耦合等离子体串联质谱法(ICP-MS/MS)对采集于3个江西代表县的150个茶叶样品中的15种矿物元素进行测定,获得其中的元素成分信息,结合主成分分析技术(PCA)和判别分析技术(DA),分析不同产地茶叶的特征元素变量,研究筛选元素特征指纹。结果 江西不同产地的茶叶中的常量元素、微量元素和重金属含量差异较大,可以成为指纹分析技术的有效产地溯源指标。主成分分析以提取特征值>1.0,可以将15个矿物元素提取2个主成分,总方差贡献率达63.00%,基本保留了原变量的大部分信息。以2个主成分为原始变量,建立判别典型函数,利用判别典型函数可以对三个不同产地的150个茶叶进行99.3%正确判别。结论 矿物元素指纹图谱可以用于江西茶叶的产地溯源判别,为今后江西各种知名茶叶品牌的原产地保护提供技术支撑。     

不同产地进口三文鱼挥发风味物质组成特征研究

目的初步探索不同产地三文鱼中挥发性风味物质种类和含量组成特征,区分三文鱼的产地。方法采用固相微萃取-气相色谱质谱检测出不同产地进口三文鱼中的挥发性风味成分,通过组成特征分析各成分在三文鱼产地差异分析中的作用。结果检出法罗群岛、挪威、澳大利亚、智利、英格兰、加拿大各含有56、51、53、53、43、43种挥发性成分。醛类化合物和碳氢类化合物是三文鱼挥发性风味成分的主要组成。智利三文鱼含有醛类相对百分含量最高,挪威三文鱼含有醛类相对百分含量最低。反式-2-癸烯醛、2,4-辛二烯醛仅在智利的三文鱼中检出。2,4-十二碳二烯醛和十七醛仅在澳大利亚三文鱼中有检出。2,3-辛二酮仅法罗群岛三文鱼中有检出。1-羟基-2-甲基-1-苯基-3-戊酮仅在澳大利亚三文鱼中检出。2,6-双(1,1-二甲基乙基)-2,5-环己二烯-1,4-二酮和5-十二烷基二氢-2(3H)-呋喃酮仅在加拿大三文鱼中检出。丁酸1-丙基戊酯仅在英格兰三文鱼中检出。2,2-二甲基癸烷仅在挪威三文鱼中被检出。正二十烷仅在挪威三文鱼中检出28.13%(匹配度93%),3-十二炔仅在法罗群岛检出5.64%(86%)。结论特征性的挥发性风味成分可作为特征指标对三文鱼产地进行区分。     

基于矿物元素指纹图谱技术的芸豆产地溯源研究

探讨矿物元素指纹分析技术对芸豆产地溯源的可行性,筛选出判别芸豆产地溯源的有效指标。利用电感耦合等离子体质谱仪(ICP-MS)测定来自依安县和拜泉县2个地域54份芸豆样品中31种矿物元素的含量,对数据进行方差分析、主成分分析、聚类分析和判别分析。研究表明,芸豆中25种矿物元素含量在地域间存在显著性差异,通过逐步判别分析筛选出Ca、As、Mg和Pt 4项元素指标建立芸豆产地判别模型,所建立的模型对芸豆产地整体交叉检验判别率为94.4%。因此,矿物元素指纹图谱技术可用于判别芸豆产地来源。     

DNA条形码序列对药食两用品花椒的品种鉴定

目的:利用DNA条形码鉴定技术,快速、准确的鉴别中药花椒,区别中药花椒及其市售香料花椒的品种来源差异。方法:采用植物DNA试剂盒提取花椒及其混伪品基因组DNA,对全部收集样品的ITS2序列进行扩增和测序,计算物种种间种内Kimura2-parameter(K2P)遗传距离。采用Blast、最近距离法及基于ITS2序列构建Neighbor-joining(NJ)系统聚类树进行鉴别分析。结果:中药花椒及香料花椒的序列长度为224~227 bp,中药花椒种间平均K2P遗传距离明显大于香料花椒种内平均K2P遗传距离;ITS2分子系统树显示,中药花椒及香料花椒均聚为一单系分枝。结论:ITS2序列作为DNA条形码能准确鉴别中药花椒及其香料花椒,为中药花椒及其香料花椒的鉴别提供了依据。     

基于近红外光谱与矿物元素指纹信息融合对绿豆产地判别模型比较分析

为提高模型对绿豆产地的鉴别率,通过近红外光谱指纹信息和矿物元素指纹信息融合技术分析来自黑龙江省杜尔伯特蒙古自治县、吉林省白城市、黑龙江省泰来县、山东省泗水县绿豆样品中近红外光谱吸收强度和矿物元素含量,结合偏最小二乘判别分析(PLS-DA)法建立融合这两种指纹信息的鉴别方法。结果表明,信息融合模型的绿豆产地鉴别准确率为100%,与单一光谱指纹信息模型(90.0%)和矿物元素指纹信息模型(96.7%)相比,分别提高了10.0%和3.3%。因此,采用PLS-DA法信息融合模型对绿豆产地进行鉴别是可行的,近红外光谱指纹信息和矿物元素指纹信息融合技术可以提高绿豆产地的鉴别效果。     

Probiotics and prebiotics--perspectives and challenges

Owing to their health benefits, probiotics and prebiotics are nowadays widely used in yogurts and fermented milks, which are leader products of functional foods worldwide. The world market for functional foods has grown rapidly in the last three decades, with an estimated size in 2003 of ca US$ 33 billion, while the European market estimation exceeded US$ 2 billion in the same year. However, the production of probiotics and prebiotics at industrial scale faces several challenges, including the search for economical and abundant raw materials for prebiotic production, the low-cost production of probiotics and the improvement of probiotic viability after storage or during the manufacturing process of the functional food. In this review, functional foods based on probiotics and prebiotics are introduced as a key biotechnological field with tremendous potential for innovation. A concise state of the art addressing the fundamentals and challenges for the development of new probiotic- and prebiotic-based foods is presented, the niches for future research being clearly identified and discussed.     

常用消毒灭菌法及其机理与应用

介绍了采用消毒灭菌方法,有加热消毒法,紫外线辐射法和化学药剂消毒法。常用化学药剂有醛类、含氯消毒剂、醇类消毒剂以及高锰酸钾、生石灰等,阐释了消毒与灭菌两个概念的区别。     

益生素、益生菌与结肠癌

介绍了益生素和益生菌及其作用机理。在动物模型中，有大量的数据证实益生素和益生菌能够预防癌症．而在人体内还没有直接实验证据。它们抑制癌症的确切机理目前尚不清楚，其抑制机理可能是：肠道菌群代谢活动的改变，肠道理化环境的改变，潜在的致癌物质的黏附和降解，肠道菌群的改变、抗癌或抗诱变物质的形成、提高宿主的免疫应答、影响宿主的生理活动以及发酵不能被消化的食物并形成有益代谢产物。     

节能节水型印染助剂和设备的现状

从节能、节水、缩短工艺流程和环保的角度出发，介绍了国内外研制开发的一系列新型节能、节水型印染助剂和染整设备。     

European citizen and consumer attitudes and preferences regarding beef and pork

This paper presents the combined mid-term findings of the consumer research components of two EU Sixth Framework Programme integrated projects concerning meat, ProSafeBeef and Q-PorkChains. The consumer pillar of ProSafeBeef carried out eight focus group discussions in May 2008, in France, Germany, Spain and the UK. Q-PorkChains conducted a large-scale, web-based, consumer survey in January 2008 in Belgium, Denmark, Germany, Greece and Poland. The first project provides a set of qualitative data from a small cohort of focus groups and the second a set of quantitative data from a larger consumer sample. This paper draws together the main findings of both projects and provides a comprehensive overview of European citizens’ and consumers’ attitudes towards and preferences regarding beef and pork. In general, consumers consider meat to be a healthy and important component of the diet. Consumers support the development of technologies that can improve the health attributes of meat products and guarantee eating quality, but they have a negative view of what they see to be excessive manipulation and lack of naturalness in the production and processing of beef products. In the Q-PorkChains study consumer and citizen segments are identified and profiled. Consumer segments were built upon the frequency and variety of pork consumption. The citizen segments were built upon their attitudes towards pig production systems. Overall, the relationship between individuals’ views as citizens and their behaviour as consumers was found to be quite weak and did not appear to greatly or systematically influence meat-buying habits. Future studies in both projects will concentrate on consumers’ acceptance of innovative meat product concepts and products, with the aim of boosting consumer trust and invigorating the European beef and pork industries.     

Heritability and correlations for body condition score and dairy form within and across lactation and age

The objectives of the current study were to investigate the relationship between body condition score (BCS) and dairy form and changes in genetic parameters for BCS and dairy form within and across lactations and age. Body condition score and dairy form were obtained from the Holstein Association USA, Inc. Records were edited to include those cows classified between 24 and 60 mo of age and between 0 and 335 d in milk (DIM). A minimum of 20 daughters per sire and 15 cows per herd-classification visit were required. The dataset consisted of 135,178 records from 119,215 cows. Repeatability, multiple trait, and random regression models were used to analyze the data. All models included fixed effects for herd-classification visit, age within lactations 1, 2, and 3 or higher, and 5th-order polynomials for DIM. Random effects included sire and permanent environment for all models. Random regression models included age at classification nested within sire or DIM and lactation number nested within sire. Genetic variance for both BCS and dairy form was lowest in early lactation and highest in midlactation. Genetic correlations within and across lactations were high. The genetic correlation between DIM 0 in lactation 1 and DIM 305 in lactation 3 was estimated to be 0.77 for BCS and 0.60 for dairy form. The genetic correlation estimate between 30 mo of age at classification and 50 mo of age at classification was 0.94 for both dairy form and BCS. The repeatability models appeared to generate accurate evaluations for BCS or dairy form at all ages and stages of lactation.     

原花色素及其开发应用

对原花色素的结构、化学特性、制备、分析方法、应用前景作一综述,并重点讨论其生理功能,为在功能性食品、药物、化妆品等领域的深入研究和开发提供参考。     

组学技术与果蔬采后质量和安全控制

果蔬可以提供营养, 有利于人类健康, 而果蔬的后熟及其与环境的相互作用会影响果蔬采后的质量和安全。对果蔬生物学过程的了解和掌握是减少果蔬采后损失和保障果蔬采后质量和安全的关键。在过去的10多年, 基于组学技术的系统生物学在了解果蔬后熟及其与环境相互作用的分子机制方面得到了越来越多的应用。本文对此做了细致的总结, 指出了存在的不足, 并提出了未来的发展方向。     

毛霉型低盐速成豆豉工业化生产工艺与设备

本文介绍了毛霉型低盐速成豆豉的工业化生产工艺及生产线的关键设备。     

Dioxins and PCBs in ostrich meat and eggs: levels and implications

ABSTRACT

Although consumption of eggs is an essential part of our diet, limited information is available for table eggs other than those laid by hens. The aim of our study was to determine concentrations of polychlorinated dibenzofurans (PCDD/Fs), dioxin-like (DL-) and non-dioxin-like (NDL) polychlorinated biphenyls (PCBs) in ostrich eggs and meat available on the Polish market, in order to obtain baseline information on the current status of these pollutants in comparison to poultry products. Obtained data were compared with the binding EU limits set for chicken eggs and meat. The levels of individual PCDD/Fs and PCBs congeners varied considerably. The percentage share of total WHO toxic equivalency factor (WHO-TEQ) content indicates the dominant role of PCDD/Fs. High concentrations of PCDD/F and DL-PCBs, in the range of 0.85–74.48 pg WHO-TEQ g^?1 fat, were found in ostrich eggs; this exceeds the maximum level permitted for chicken eggs by a factor of up to 15. Eight of the 11 egg samples exceeded the action level for hen eggs. Although the ostrich meat concentrations of PCDD/Fs do not exceed the limit established for poultry muscle (1.75 pg g^?1 fat), average contents of PCDD/Fs exceeded almost four times the levels in chicken and turkey muscle. Human exposure was evaluated and the resulting risk was characterised. Taking into account the low average consumption of ostrich eggs, the resulting exposure to dioxins for the general population can be considered as negligibly low. However, the individuals who frequently consume such eggs may be at risk of elevated exposure. Although ostrich products are not consumed frequently, such data are nevertheless useful for food safety purposes.