Content of zinc, iron, calcium and their absorption inhibitors in foods commonly consumed in Ethiopia

The zinc, iron, calcium, phosphorus, phytate, tannin and moisture content of 36 foods consumed in rural Ethiopia were analysed. The foods analysed included those based on cereals, starchy tubers and roots, and legumes and vegetables as well as some fruits. Although many foods were relatively rich in zinc and iron, many also contained high levels of phytic acid and tannins, which impair bioavailability of zinc and iron. The phytate:zinc molar ratios were >20 for non-fermented cereal foods, >15 for legumes, and <12 for fermented cereals, starchy tubers and roots. Ratios >15 are associated with low bioavailability of zinc. Given the high iron content and the relatively favourable phytate:iron molar ratio, tef enjera was the best source of bioavailable iron of all foods analysed. Foods prepared from tef, enset and kale are rich sources of calcium. The consumption of diets based on cereals and legumes but poor in animal products can lead to deficiencies of zinc and iron. However, since fermentation can decrease the phytate content by a factor of 3–4, traditional household practices such as fermentation need to be encouraged to address the problem of zinc deficiency, which is particularly prevalent in Ethiopia.     

反相停留流动注射-催化光度法测定自来水及食品中微量亚硝酸盐含量

目的：测定自来水及食品中微量NO2ˉ的含量。方法：利用硫酸介质中NO2ˉ对溴酸钾氧化结晶紫的催化作用，建立室温下反相停留流动注射催化动力学光度法。结果：测得自来水中的N02含量为0．013μ／ml，相对标准偏差为3．8％（n=15），加标平均回收率为99．7％；测得火腿肠和榨菜中的NO2ˉ含量分别为7．5mg／kg和5．2mg／kg，测定值与产品的标称值基本相符。实验还考察了停留时间、硫酸和溴酸钾的浓度以及流速等条件对测量的影响并进行优化。方法的检出限为0．75μg／L，在0．01-0．1μ/ml范围内呈线性关系。结论：方法准确、可靠、简便，试剂消耗量少，适用于饮用水及其它食品中微量NO2ˉ含量的测定。     

Disease risks from foods, England and Wales, 1996-2000

Data from population-based studies and national surveillance systems were collated and analyzed to estimate the impact of disease and risks associated with eating different foods in England and Wales. From 1996 to 2000, an estimated 1,724,315 cases of indigenous foodborne disease per year resulted in 21,997 hospitalizations and 687 deaths. The greatest impact on the healthcare sector arose from foodborne Campylobacter infection (160,788 primary care visits and 15,918 hospitalizations), while salmonellosis caused the most deaths (209). The most important cause of indigenous foodborne disease was contaminated chicken (398,420 cases, risk [cases/million servings] = 111; case-fatality rate [deaths/100,000 cases] = 35, deaths = 141). Red meat (beef, lamb, and pork) contributed heavily to deaths, despite lower levels of risk (287,485 cases, risk = 24, case-fatality rate = 57, deaths = 164). Reducing the impact of indigenous foodborne disease is mainly dependent on controlling the contamination of chicken.     

食源性金黄色葡萄球菌流行特征、产肠毒素特性及耐药性研究

目的：了解食源性金黄色葡萄球菌流行特点及产肠毒素特性及其耐药性，为制定HACCP以防止金黄色葡萄球菌的食源性疾病提供依据。方法：采集8类食品1243件分离金黄色葡萄球菌并进行产肠毒素A—E试验及药物敏感试验。结果：从生肉、熟食、生奶、及水产品中分别分离出40株（10．96％）、12株（3．13％）、34株（16．27％）及1株（1．12％）金黄色葡萄球菌，相应的产肠毒素率分别达到52．50％、58．33％、61．76％、0．oo％；对青霉素、四环素、凝固酶阴性苯唑西林耐药率分别高达93．10％、49．43％、37．93％；79．31％菌株对2种以上的药物多重耐药，最多耐药种类达7种，表现出30种耐药谱。结论：扬州市食品中存在着较严重的金黄色葡萄球菌潜在的危害，主要来源于生肉、生奶及熟食；食源性金黄色葡萄球菌产毒素能力较强。金黄色葡萄球菌对多种药物的耐药性提示安全应用治疗药物的重要性。     

液-质联用法同时测定食品中罗丹明B和苏丹红染料

目的:建立同时测定食品中非法添加的罗丹明B和苏丹红工业染料的液相色谱-串联离子阱质谱法。方法:样品经正己烷提取、中性氧化铝固相萃取柱净化后,以甲醇(A)和1%甲酸(B)为流动相经BioBasic-18 PIONEER柱(150 mm×2.1 mm,5μm)梯度洗脱分离,串联离子阱质谱在电喷雾电离正离子(ESI+)-全扫描(full)-二级质谱(MS/MS)模式下测定罗丹明B和苏丹红含量。结果:方法的线性范围:罗丹明B0 ng/ml～20 ng/ml,苏丹红0 ng/ml～100 ng/ml,r≥0.992。方法的定性检出限为:罗丹明B与苏丹红I、II、III、IV分别为0.1μg/kg、0.5μg/kg、5.0μg/kg、2.0μg/kg、2.0μg/kg。罗丹明B与苏丹红在3种基质高、低两个浓度水平的加标回收率85.2%～109.5%,精密度<20%。结论:本方法灵敏、准确,可用于食品中罗丹明B和苏丹红等非法添加的工业染料的同时测定及确证。     

Contamination of aflatoxins in different kinds of foods in China

Objective To study the contamination of total aflatoxins （AFs） in different kinds of foods including corn, peanut, rice, walnut, and pine nut in six provinces and two municipalities in China. Methods A total of 283 samples of corn, peanut, rice, walnut and pine nut were randomly collected from local markets in Fujian, Guangdong, Guangxi, Hubei, Jiangsu, and Zhejiang provinces, as well as in Shanghai and Chongqing municipalities. The samples were ground to which acetonitrile/water solution was added. After filtering, the extract was transferred into a MycoSepTM purifying column and was pressed slowly. Then the purified liquid was derivatized with trifluoroacetic acid （TFA） and assayed using high performance liquid chromatography （HPLC）. Results AFs were detected in 70.27% of corn samples, with a mean level of 27.44 μg/kg and the highest level of 1098.36 μg/kg. In peanut, the AFs detection rate was 23.08%, with a mean level of 0.82 μg/kg and the highest level of 28.39 μg/kg. Very few rice samples with AFs were detected. The AFs levels were very low in walnut and pine nut. Conclusion Corn is the food most seriously contaminated with AFs in China. AFBI is the main aflatoxin which is found as a contaminant in foods.     

Putting the Nutrient-Rich Foods Index into Practice

With approximately 2 out of 3 Americans currently overweight or obese, many continue to come up short on recommendations for certain nutrients such as calcium, magnesium, potassium, vitamin A, vitamin C, vitamin E, and fiber in their diet. Numerous attempts have been made to provide consumers with nutrient-profiling tools, such as manufacturer-specific symbols, to improve dietary selections, but many of the tools have focused on assisting consumers in making single food selections and do not provide guidance about planning total diets. In response to the 2005 Dietary Guidelines Advisory Committee's recommendation for research to define nutrient density, the Nutrient Rich Foods Coalition (NRFC) embarked on the development of a scientifically valid definition of nutrient density and consumer-driven educational tools to communicate the concept of nutrient-rich foods (NRF) to consumers. The science-based, consumer-driven NRF approach to eating may help Americans make multiple small changes in their diet that ultimately lead to better diet quality and significant improvements in public health.     

液相色谱-串联质谱法测定常见食品中磺胺及喹诺酮

[目的]本试验研究建立常见17种磺胺和15种喹诺酮类药物残留量的液相色谱-电喷雾串联离子阱质谱测定方法。[方法]以稳定同位素氘代磺胺邻二甲氧嘧啶、氘代磺胺间二甲氧嘧啶作为内标,采用多反应监测定量。样品经过匀浆、超声波提取、甲醇溶液涡旋溶解残留物、正己烷涡旋混合离心后进行液相色谱-质谱分析。采用C18柱,MGⅡ色谱柱,以均含0.1%甲酸的水和甲醇、乙腈为流动相进行梯度洗脱。[结果]17种磺胺和15种喹诺酮类药物的线性范围为2.0~50μg/kg,相关系数r>0.995,平均回收率为83.3%~109.9%(添加水平为2.5~10μg/kg),相对标准偏差为2.1%~8.1%。本方法最低检出限均为2.0μg/kg,最低定量限均为4.0μg/kg。[结论]所建方法简便、快速、干扰少、特异性强,是磺胺和喹喏酮残留检测的理想方法。