我国调味品安全标准存在的主要问题分析

概述我国调味品标准的基本现状。从完善我国调味品标准体系的角度,分析了我国当前调味品安全标准在体系构建、重要安全标准和检测标准等方面存在的问题。     

国标法和纸片法对食品中大肠菌群检测比较

介绍了用国标发酵法(下简称国标法)和快速检测纸片法(下简称纸片法)对进出口食品中大肠菌群的检测结果采集进出口冷冻饮品、果汁、淀粉、奶粉、乳清粉等各类食品268份,用国标法与纸片法进行了对比检测试验两种方法对大肠菌群检测结果相符的260份,符合率97.1％;两种方法对268份样品检验的合格率相同,合格符合率100％纸片法简便、快速,能代替国标法准确测定各类食品中的大肠菌群     

酿造调味品保管相关知识(上)

仓储管理是现代物流管理的主要内容之一。仓储活动除以商品入库验收,储存保管和出库供应为主外,还包括包装、流通加工、分拣、配送和运输等。将《食品质量安全市场准入制度》,酿造调味品的国家标准,行业标准中对仓储管理的有关规定归纳介绍,以提高酿造调味品行业仓储管理工作水平。     

鱼露的加工制作方法

为传承传统工艺，该文介绍了鱼露的生产工艺及操作要点，主要是原料的选择、腌制、发酵酶解、过滤、浸提和调配等，并提出了鱼露的质量标准。     

米粉(米线)原料标准的研究

本文主要对米粉所用原料大米的糊化特性、品质特性进行了分析，并且对大米的可加工性与糊化数据、直链淀粉含量之间的相关性进行了分析。结果表明：当原料中直链淀粉含量高于27％，最低粘度600～800UV，最终粘度大于1300UV，回老值高于660UV时，加工出的米粉质量较好。大米中直链淀粉含量、最低粘度、最终粘度、回老值与可加工性呈极显著相关。     

Development of a quantitative method for headspace analysis of methylsulfanyl-volatiles from kiwifruit tissue

Minor fruit volatiles are likely to be missed using sampling techniques optimized for the extraction of major compounds. This can be a disadvantage if these minor compounds contribute to characteristic fruit flavors. In this comparative study, headspace solid-phase microextraction (HS-SPME) and dynamic headspace sampling (DHS) parameters were systematically optimized to ensure highest extraction yields of methylsulfanyl-volatiles from kiwifruit tissue samples. A significant “salting-out” effect from the fruit matrix was observed using both sampling techniques after (NH₄)₂SO₄ saturation. HS-SPME at optimized conditions (polydimethylsiloxane-divinylbenzene-coated fiber, (NH₄)₂SO₄ saturation, 5 min equilibration and 20 min sampling at 40 °C) was faster and more convenient to use than DHS for qualitative purposes. Despite this, the qualitative and quantitative methylsulfanyl-volatile profile was improved using optimized DHS ((NH₄)₂SO₄ saturation; sampling time 20 h; flow rate 30 mL min^− 1) compared with HS-SPME, making this the more sensitive and preferred method for quantitative studies. The optimization strategies for increasing headspace extraction yields of trace compounds presented in this study can easily be applied to tissue samples from other fruit.     

国内外纺织品技术标准的现状、发展趋势及对我国纺织品出口的影响

2004年我国纺织行业各项主要经济指标均创良好业绩,同比增长幅度都在20%左右。但出口纺织品服装的平均单价与1997年相比,下降幅度却超过60%。究其原因,除我国纺织业创新能力不足之外,纺织业标准化水平不高和标准体系结构不合理是不可回避的重要原因。文章分析了当今国内外纺织品技术标准现状、发展趋势及其对我国纺织品出口的影响,呼吁改革我国现有的纺织品标准化体系、建立与国际接轨的纺织产品标准体系,以全面提升我国纺织产品品质。     

我国现制饮料微生物污染状况研究

目的 了解我国目前现制饮料中微生物的污染状况。方法 使用随机抽样原则在我国具有代表性的饭店、饮品店、快餐店、集体学校食堂等采集现制饮料和食用冰,共计3 583份,采用国标方法检测菌落总数、大肠菌群、金黄色葡萄球菌、沙门菌。结果 菌落总数>10⁵ CFU/mL所占比例为8.42%,大肠菌群>10² MPN/mL所占比例为19.32%,金黄色葡萄球菌检出率为2.56%,沙门菌检出率为0.09%,计数结果均<10² MPN/mL。蛋白类饮品污染状况最严重,菌落总数与大肠菌群检出比例最高,菌落总数>10⁵ CFU/mL和大肠菌群>10² MPN/mL所占比例分别为21.35%和32.97%。3—5月现制饮料的卫生状况最差,菌落总数>10⁵ CFU/mL所占比例最高,为14.80%。不同采样地点中饭店、酒店的金黄色葡萄球菌检出率最高为5.24%。结论 我国现制饮料的食品安全状况总体较好,但相关部门也应加强加工场所卫生状况的监督抽查。     

Variations in the leaf standard,chemical composition and quality of black tea (Camellia sinensis) due to plucking intervals

Green leaf standard, chemical composition and quality of black tea (Camellia sinensis (L) O Kuntze) change with plucking intervals. Long plucking intervals lead to poor leaf standard with a lot of mature leaves and lower theaflavins, the sum of volatile flavour compounds imparting a sweet flowery aroma (group II volatile flavour compounds), caffeine contents and tasters' evaluations of black tea. The sum of volatile flavour compounds imparting inferior, grassy, green flavour (group I volatile flavour compounds) to tea, however, increases with long plucking intervals.     

Development and application of a heterologous internal standard for polymerase-chain-reaction-based detection of Campylobacter jejuni and Campylobacter coli in foods

 A heterologous internal standard, termed "mimic", was developed for the polymerase chain reaction (PCR)-based detection of Campylobacter jejuni and Campylobacter coli in food. Mimic was designed to contain a heterologous DNA fragment of plasmid pUC18, flanked by a primer binding site, identical to the bacterial target DNA. Application of mimic in the PCR permitted its co-amplification together with the bacterial DNA with similar efficiency. As the length of the amplified products differed, they were easily detectable by agarose gel electrophoresis. The presence or absence of the mimic PCR product was indicative of the efficacy of the PCR. The use of approximately 60 mimic molecules per reaction was optimal for determining the reliability of the diagnostic PCR assays without decreasing the detection limit. This system for the detection of the two species of Campylobacter was successfully applied in routine food surveillance. Received: 4 January 1999