北京产干黄酱中挥发性风味成分分析

以北京地区5种知名品牌的干黄酱为原料,采用同时蒸馏萃取法提取并结合气相色谱-质谱联用技术 (gas chromatography-mass spectrometer,GC-MS)对其挥发性风味成分进行分析。结果共鉴定出69种物质,其主要是酸类(9种)、酯类(22种)、醛类(8种)、酮类(4种)、酚类(3种)、杂环化合物(13种)、含硫化合物(3种)和其他化合物(7种)等;5种干黄酱中共有的成分是乙酸乙酯、棕榈酸乙酯、十八烯酸乙酯、亚油酸乙酯、亚麻酸乙酯、异戊醛、苯乙醛、4-乙烯基愈创木酚、糠醛、2-乙酰基吡咯、3-甲硫基丙醛等,这些物质共同形成了该5种干黄酱的相同风味,而其中不同的成分又使得该5种干黄酱香气各有特色。     

固相微萃取结合气-质联用确定北京干黄酱中关键香气成分

为了确定北京干黄酱中的关键香气成分,采用固相微萃取对其中的挥发性成分进行了提取,提取物经气相色谱-质谱-嗅觉检测器联用进行分离与鉴定。采用质谱、保留指数、标准品和香气进行定性,共鉴定出53种挥发性成分,其中具有香气活性的化合物有20种;采用2-辛醇为内标进行了定量,计算了在总离子流图上有响应信号的香气活性物质的香气活性值,确定出了北京干黄酱中的7种关键香气物质,分别是3-甲基丁醛、二甲基三硫、2-甲氧基苯酚、苯乙醛、丁酸乙酯、壬醛和3-甲基丁酸。     

同时蒸馏萃取/GC-MS分析干黄酱的挥发性成分

通过同时蒸馏萃取的方法提取干黄酱的挥发性成分,经过气质联机分析,共分析出73种物质,鉴定出3-甲基丁醛(13·36%)、亚油酸乙酯(10·49%)、2-甲基丁醛(7·00%)、(反,反)-9,12-十八碳二烯酸(6·97%)、油酸乙酯(5·97%)、十六酸(5·05%)、苯乙醛(4·28%)、糠醛(3·51%)、1-(1H-吡咯基-2-)-乙酮(3·01%)、糠醇(1·96%)、3-甲基-1-丁醇(1·32%)、5-羟甲基糠醛(0·97%)、3-甲硫基丙醛(0·84%)、2-甲氧基-4-乙烯基苯酚(0·82%)、2,5-二甲基-4-羟基-3(2H)-呋喃酮(0·27%)、3,4-二甲氧基苯酚(0·26%)等33种物质,总相对百分含量为76·84%。经过调配实验,确认了对干黄酱特征香气起主要作用的香料。     

茅台酱香型酒糟香气成分分析

采用水蒸气蒸馏法提取茅台酱香型酒糟的香气成分,并采用气相色谱-质谱法(GC-MS)对其分离和鉴定,鉴定出32种成分,其中糠醛、亚油酸乙酯、棕榈酸乙酯、油酸乙酯、5-甲基-2-糠醛、苯乙醇、吡咯-2-甲醛、苯甲醛、苯乙醛、2-乙酰呋喃、糠醇、2,3,5,6-四甲基吡嗪、9-十五碳烯酸乙酯、2-羟基-3-苯基丙酸乙酯、硬脂酸乙酯、3-乙酰基吡咯、植烷等是构成茅台酱香型酒糟香气的主要成分,占香气成分的93.9%。     

不同萃取方式分析美拉德反应产物挥发性成分

为明确美拉德反应产物挥发性成分及不同前处理方法对挥发性成分种类及含量的影响,以果糖和3种氨基酸的美拉德反应产物为研究对象,通过同时蒸馏萃取、溶剂萃取、固相微萃取3种萃取方式,对美拉德反应产物进行前处理,利用GC-MS技术对挥发性成分进行分析鉴定。结果表明:(1)3种萃取方式检测出的挥发性成分共有75种。同时蒸馏萃取法检测出52种香味物质,对酯类和含氮杂环类有较好的萃取效果;溶剂萃取法检测出20种香味物质,对酮类物质、含氧杂环类及含氮杂环物质有较好的萃取效果;固相微萃取法共检测出27种香味物质,对酯类及烷烃类物质有较好的萃取效果。(2)利用主成分分析法,得出的主要挥发性成分有甲基吡嗪、糠醛、糠醇、戊酸乙酯、2,6-二甲基吡嗪、5-甲基糠醇、5-甲基糠醛、己酸乙酯、4-羟基-2,5-二甲基-3(2H)呋喃酮、2,3-二氢-3,5-二羟基-6-甲基-4H-吡喃-4-酮等。     

固相微萃取结合气-质分析东北大酱的挥发性成分

采用固相微萃取结合气-质联用分析东北大酱的挥发性成分,并考察了提取时间和提取温度对挥发性成分提取效果的影响。结果表明,提取时间为40 min、提取温度为60 ℃时对东北大酱的挥发性成分提取效果较好。从东北大酱中共鉴定出28种挥发性成分,相对含量占总流出物的89.02%,包括酮类3种（相对含量为53.57%）、酸类3种（相对含量13.36%）、醇类2种（相对含量13.20%）、酯类8种（相对含量3.57%）、酚类2种（相对含量2.44%）、醛类5种（相对含量1.55%）、其他类5种（相对含量1.33%）。其中苯乙醛、3-辛酮、2,3,5,6-四甲基吡嗪、愈创木酚、4-乙烯基-2-甲氧基苯酚等挥发性成分对东北大酱整体香气贡献较大。     

4种市售香米中挥发性成分提取与分析

分析香米中的挥发性成分。采用水蒸气蒸馏的方法对北京市场上销售的4种香米中的挥发性成分进行提取。提取物经气相色谱-质谱联用仪分析,结合计算分离出的成分保留指数。结果共鉴定出51种成分,其中烃类31种、酯类6种、含氮化合物5种、有机酸类5种、醛类2种、缩醛类和醚类各1种;采用面积归一化法确定其相对含量;4种香米中均鉴定出的挥发性成分有19种,分别是2,3-二甲基-2-丁烯、乙酸乙酯、3-甲基-2-戊烯、甲基环戊烷、乙基异丁基醚、2,3-二甲基-1-戊烯、苯、2-甲基己烷、2,3-二甲基戊烷、3-甲基己烷、环己烯、三氯乙烯、己醛、N,N-二甲基苯胺、苯并噻唑、十四酸、十六酸、亚油酸、油酸;在4种香米中未鉴定出香米的特征香成分2-乙酰基吡咯啉。     

GC-MS分析自制豆豉中挥发性风味化合物的研究

采用水蒸气蒸馏法提取自制豆豉的挥发性风味化合物,并采用气相色谱-质谱法(GC-MS)鉴定其组成成分.通过GC-MS分析共鉴定出41个挥发性化合物,包括醇(6),酚(7),醛(2),酮(3),酸(8),含N,S化合物(13),烃(2)等7类.结果显示豆豉中主要挥发性风味化合物有:吲哚、四甲基吡嗪、油酸、三甲基吡嗪、二十一烷、棕桐酸、笨甲醛、亚油酸、4-乙烯基-2-甲氧基笨酚、笨甲酸、愈创木酚、苯酚、硬脂酸、2-呋喃甲醇,12-甲基十四烷酸、十五酸、4-甲基-2,6-二叔丁基笨酚,3-乙基-2,5-二甲基吡嗪、笨甲醇、4-乙烯基苯酚、苯乙醇,2,5-二甲基吡嗪,4-甲基-2,6-二叔丁基-4-羟基-环己二烯-1-酮、肉豆蔻酸等24种,占挥发性化合物总量的92.9%.其中对豆豉的风味起重要作用的吡嗪类含量最高.     

顶空固相微萃取-气质联用分析哈尔滨风干肠中的挥发性风味化合物

为了解哈尔滨风干肠这种中式传统肉制品的挥发性风味成分,使用顶空-固相微萃取技术提取挥发性化合物,之后通过毛细管气相色谱-质量色谱联用对挥发性化合物进行分离鉴定。在本实验条件下鉴定出28种挥发性风味化合物。包括14种烃、5种醛、4种酯、2种酚、2种醚和1种醇。这些挥发性化合物的生成可能归因于添加的酒、香辛料、脂肪氧化、氨基酸代谢、微生物活动及这些因素之间的相互作用。本实验所检测的哈尔滨风干肠样品中最主要的风味化合物是己酸乙酯,其次是乙醇、己醛和丁酸乙酯。同时还检测并鉴定出一些支链醛包括苯甲醛、3-甲基丁醛、2-甲基丁醛。     

烘焙时间对云南小粒咖啡挥发性成分影响的研究

本文研究了云南小粒咖啡在烘焙过程中挥发性成分及含量的变化。在230℃烘焙温度条件下,对不同烘焙时间的小粒咖啡采样,采用两种方法对样品进行分析:一、同时蒸馏萃取法提取挥发性成分,采用了气相色谱-质谱联用仪对云南小粒咖啡中的挥发性成分进行了分析检测;二、顶空直接进样,气相色谱-质谱联用仪进行分析检测。对数据进行了定性定量分析、以及聚类分析。方法一分析了160种挥发性化合物,方法二分析了15种挥发性化合物。从数据可以看出,咖啡在此温度条件下,烘焙6 min后,咖啡的主要挥发性成分已经产生,如:2-甲基吡嗪、糠醇、5-甲基呋喃醛、2-乙基-5-甲基吡嗪等。随着烘焙时间增加,咖啡中的挥发性成分种类及含量变化明显。经过聚类分析可以看出,可以分为4类,可以作为判别咖啡烘焙程度一个方法。     

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。     

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.     

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。     

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。     

天然香精香料与生物技术

天然香精香料是高价值的精细化工产品和食品添加剂,但原料来源有限且提取成本高。利用生物技术生产这类产品具有广阔的前景。简述了发酵工程、酶工程、细胞工程和基因工程在香精香料中的应用,并探讨了生物技术在香精香料中的应用前景。     

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。     

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。     

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.