气相色谱-串联质谱正离子模式测定食品中氟虫腈和溴虫腈残留

建立食品中氟虫腈和溴虫腈残留的气相色谱-串联质谱(GC-MS/MS)分析方法。方法 试样经乙腈提取, N-丙基乙二胺(PSA)固相萃取柱(SPE)净化,采用GC-MS/MS以正离子模式多反应监测(MRM)定性、定量测定氟虫腈和溴虫腈。结果 该方法在5～50μg/L浓度范围内呈线性,相关系数r均大于0.998。氟虫腈和溴虫腈的添加回收率分别为78.2%～102.5%和77.0%～104.1%,RSD分别为6.8%～15.2%和6.9%～17.1%,二者的检出限(LOD)均为5μg/kg,定量限(LOQ)均为10μg/kg。结论 气相色谱-串联质谱法正离子模式是简便、快速、准确测定食品中氟虫腈和溴虫腈残留分析方法。     

气相色谱三重四极杆串联质谱法测定鸡蛋和鸡肉中氟虫腈及其代谢物残留量的研究

目的建立一种鸡蛋和鸡肉组织中氟虫腈及其代谢物残留的气相色谱三重四极杆串联质谱法(GC-MS/MS)检测方法。方法样品经乙腈提取液,Bond Elut EMR-Lipids法净化,去除鸡肉和鸡蛋组织中的脂类和蛋白质。质谱采用多反应监测模式(multiple reaction monitoring,MRM)对氟虫腈及其代谢物的定量离子和定性离子进行监测。结果本方法中氟虫腈及其代谢物在20.0~1000μg/L的浓度范围内,线性良好,相关系数r~2大于0.994,在10、20、50μg/L水平上的平均回收率在91%~114.32%之间,相对标准偏差(relative standard deviation,RSD)为0.4%~7.8%(n=6),氟虫腈及其代谢物的检出限(S/N=3)为2.0~3.5μg/kg,定量限(S/N=10)为6.0~10.5μg/kg。结论该方法具有前处理简便快捷、净化效果佳、灵敏度高、成本低等特点,适用于鸡蛋和鸡肉中氟虫腈的快速确认及定量检测。     

2018年深圳市售蔬菜和鸡蛋中氟虫腈及其代谢物的检测分析

目的 建立超高效液相色谱-串联质谱法同时测定蔬菜和鸡蛋中氟虫腈及其代谢物(氟甲腈、氟虫腈砜和氟虫腈亚砜), 并对深圳市售的蔬菜和鸡蛋中氟虫腈及其代谢物残留状况进行抽样检测。方法 采用QuEChERS前处理方法, 以C18色谱柱为分离柱, 以乙腈和10 mmol甲酸+6 mmol甲酸铵水溶液为流动相进行梯度洗脱, 用超高效液相色谱-串联质谱(ultra performance liquid chromatography-mass spectrometry/mass spectrometry, UPLC-MS/MS), 电喷雾电离(electrospray ionization, ESI), 多反应监测(multiple reaction monitoring, MRM)模式检测, 外标法同时定量测定氟虫腈及其代谢物。结果 方法的线性范围为0.1~2.0 μg/L, 线性相关系数均大于0.9994, 检出限0.0005 mg/kg, 定量限0.001 mg/kg; 蔬菜中3个水平的平均加标回收率88.0%~101.2%, 相对标准偏差(relative standard deviation, RSD)均小于8.5%; 鸡蛋中3个水平的平均加标回收率86.1%~104.8%, 相对标准偏差(RSD)均小于9.2%。结论 该方法具有操作简单、干扰少、快速、准确可靠等特点, 可适用于蔬菜鸡蛋中氟虫腈及其代谢物的检测。     

气相色谱法快速测定蛋中氟虫腈及其代谢物

目的建立气相色谱法同时快速测定蛋中氟虫腈及其代谢物残留量的分析方法。方法鸡蛋中的氟虫腈及其代谢物氟甲腈、氟虫腈硫醚、氟虫腈砜残留经乙腈提取,盐析,固相萃取小柱净化,采用气相色谱电子捕获检测器进行分离和测定,外标法定量。结果氟虫腈及其代谢物氟甲腈、氟虫腈硫醚、氟虫腈砜的检出限为0.2μg/kg,在0.2~200μg/kg范围内,线性相关系数大于0.9995。在所添加3个质量浓度水平下,方法的回收率在75.1%~102.0%,相对标准偏差为4.3%~6.4%。结论该方法简便、准确、重现性好,适合对蛋中氟虫腈及其代谢物进行有效监测。     

气相色谱-负化学源质谱法测定牛奶中氟虫腈及其代谢物残留

建立了气相色谱-负化学源质谱(GC-NCI-MS)测定牛奶中氟虫腈及其3种代谢物残留量的分析方法。牛奶经乙腈提取后,分散固相萃取技术QuEChERS(Quick,Easy,Cheap,Effective,Rugged,Safe)净化,HP-5MS分离,气相色谱-负化学源质谱进行测定,外标法定量。在质量浓度为2.5～100μg/L范围内,氟虫腈及其3种代谢物均有良好的线性关系,所有目标物的定量限(LQD)(S/N=10)均在0.03～0.15μg/kg范围内。样品加标质量分数为0.01,0.02 mg/kg和0.05 mg/kg时,氟虫腈及其3种代谢物的平均回收率为85.6%～102.4%,相对标准偏差(RSD)为3.6%～6.1%。该方法样品前处理简单,分析时间短,回收率和精密度等均符合氟虫腈及其3种代谢物检测技术的要求,适用于牛奶中氟虫腈及其3种代谢物残留的检测。     

液相色谱-串联质谱法测定鸡蛋中氟虫腈及其代谢物的残留量

建立一种采用液相色谱-三重四级杆质谱测定鸡蛋中氟虫腈及其代谢物(氟甲腈、氟虫腈砜和氟虫腈硫醚)的快速筛查方法。鸡蛋样品经乙腈和正己烷提取,C18固相萃取柱净化,Shim-pack XR-ODSⅢ色谱柱(2.0 mm i.D×150 mm,2.1μm)分离,以乙腈-5 mmol/L乙酸铵(0.02%甲酸)水溶液为流动相,梯度洗脱,外标法定量。采用液相色谱-三重四级杆串联质谱动态多反应监测模式,以负离子采集进行定性筛查和定量分析。结果表明,氟虫腈及其代谢物在0～50μg/L质量浓度范围内线性关系良好,相关系数R2均大于0.999。以10倍信噪比确定各药物的定量限(LOQ),氟虫腈及其代谢物的定量限为0.3～0.6μg/kg。在0.5、5.0和10.0μg/kg添加水平下,氟虫腈及其代谢物的平均回收率为92.3%～105.1%,相对标准偏差(RSD)为1.2%～8.6%。该方法简便、快速、灵敏,适用于鸡蛋中氟虫腈及其代谢物的快速筛查和定量检测。     

固相萃取-高效液相色谱-串联质谱法测定茶叶中啶虫脒、吡虫啉和氟虫腈残留量

目的建立茶叶中吡虫啉、啶虫脒和氟虫腈三种农药残留的固相萃取-高效液相色谱-串联质谱测定方法。方法样品用水浸泡,乙腈提取,经石墨化碳-氨基复合固相萃取小柱净化,采用Agilent Eclipse AAA色谱柱分离,以0.1%乙酸水溶液和乙腈为流动相梯度洗脱,正、负离子切换扫描,多反应监测(MRM)模式检测,外标法定量。结果在3个添加水平下,吡虫啉、啶虫脒和氟虫腈的平均回收率分别为78.8%~91.5%,81.3%~92.8%,和72.8%~90.0%;相对标准偏差分别为2.6%~10.6%,3.7%~6.6%和3.6%~7.4%。啶虫脒、吡虫啉和氟虫腈的检出限均为0.5μg/kg,定量限为2μg/kg。结论建立的方法简便、快速,灵敏度高,可满足出口茶叶中吡虫啉、啶虫脒和氟虫腈残留同时检测的要求。     

气相色谱-三重四极杆质谱法快速测定糙米中氟虫腈及其代谢物残留

目的建立气相色谱-三重四极杆质谱(gas chromatography-triple quadrupole mass spectrometry,GC-MS/MS)测定糙米中氟虫腈及其代谢产物氟甲腈、氟虫腈砜、氟虫腈硫醚残留的的分析方法。方法糙米加水涡旋混匀后乙腈提取,通过N-丙基乙二胺(primary secondary amine,PSA)、C_(18)粉末、石墨化炭黑(graphitized carbon black,GCB)粉末净化提取液,气相色谱-三重四极杆质谱多重反应离子监测模式(multiple reaction monitoring,MRM)检测,以外标法定量。结果在1～50μg/L范围下,氟虫腈及其代谢物具有良好的线性关系,相关系数(r)均大于0.99,在2、10、20μg/kg 3个添加水平下,氟虫腈及其代谢物的平均回收率为91.6%～109.9%,相对标准偏差(relative standard deviation,RSD)为4.3%～6.3%。氟虫腈及其代谢物在糙米中的定量限为0.2～0.5μg/kg,定量限添加回收率在85.0%～108.0%,RSD为5.9%～6.9%。结论该方法操作简单快速、试剂耗材消耗少、灵敏度高,适用于快速处理大批量糙米中氟虫腈及其代谢产物的残留量检测。     

QuEChERS-高效液相色谱-串联质谱法快速测定鸡肉中氟虫腈及其代谢物

建立一种QuEChERS-高效液相色谱-串联质谱法,快速测定鸡肉中氟虫腈及其3种代谢产物(氟甲腈、氟虫腈砜及氟虫腈亚砜)的方法。鸡肉样品经乙腈分散,DisQuE提取管提取和DisQuE净化管净化后,采用液相色谱-串联质谱定量测定,选择性多反应监测模式检测。在0.5~20ng/mL线性范围内,氟虫腈及其代谢产物的回归方程均呈良好的线性关系,R2>0.999,在添加水平为1.0、5.0、10.0μg/kg时,平均回收率为75.2%~89.9%,相对标准偏差(RSD)为0.8%~9.2%,方法检出限为0.5μg/kg,定量限为1.0μg/kg。该方法简便快捷,灵敏度和准确度均较高,精密度较好,适用于鸡肉中氟虫腈及其代谢产物残留量的检测。     

QuEChERS-液相色谱-串联质谱法测定南瓜中噻虫胺和氟啶虫胺腈的残留量

该研究建立了QuEChERS-液相色谱-串联质谱法同时测定南瓜中噻虫胺和氟啶虫胺腈残留量的分析方法。样品中的噻虫胺和氟啶虫胺腈经乙腈均质提取和基质分散萃取法净化,净化后的样液经0.22μm滤膜过滤后,采用液相色谱-串联质谱法测定。采用C18色谱柱分离,电喷雾离子化、正离子扫描方式和动态多反应监测模式检测,基质匹配标准溶液外标法定量。噻虫胺在2.5～100μg/L(氟啶虫胺腈在0.5～20μg/L)的范围内线性关系良好,相关系数分别为0.9994和0.9988。噻虫胺在5、10和50μg/kg(氟啶虫胺腈在1、2和10μg/kg)的3个添加水平的平均回收率在88.5%～111.2%之间,相对标准偏差(RSD,n=6)在1.12%～6.92%。噻虫胺和氟啶虫胺腈的方法定量限分别为1.0μg/kg和5.0μg/kg。该方法快速简便、灵敏度高、重现性好,可满足南瓜中噻虫胺和氟啶虫胺腈的残留检测要求。     

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。     

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.     

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。     

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。     

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。     

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。     

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。     

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。     

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.