食品保鲜膜对烹饪蔬菜中维生素C含量的影响

了解使用和不使用食品保鲜膜的烹调蔬菜中维生素C含量的差异。 [方法 ]　模拟家庭中蔬菜的烹饪和储存过程 ,采用 2 ,4-二硝基苯肼法测定其中维生素C的含量。 [结果 ]　食品保鲜膜在 6小时储存时对 9种烹饪蔬菜中维生素C有保护作用 (P <0 .0 1) ;在 2 4小时储存由于各种因素对烹饪蔬菜中的维生素C不能都起到保护作用 ;在菜肴未冷却时加盖食品保鲜膜反而会导致烹饪蔬菜中维生素C含量的下降。 [结论 ]　这些研究结果对正确合理地使用和推广食品保鲜膜具有一定的经济效益和社会意义。     

根菜类腌制过程中亚硝酸盐含量变化规律研究

目的研究根类蔬菜在腌制过程中亚硝酸盐含量的变化规律。方法本试验以白萝卜等3种根菜为原料,采用家庭腌制法,应用(GB5009.33-2010)盐酸萘乙二胺比色法对其腌制过程中亚硝酸盐含量进行检测。结果根类蔬菜在腌制的第12 d左右出现亚硝酸盐含量达2.815 mg/kg的峰值,之后缓慢下降,在第20 d达到稳定值。结论本次研究确定了腌制根菜的最佳食用时间,为人们合理安全食用提供依据,避免由此造成的疾病和损失。     

不同储存方式对蔬菜中亚硝酸盐含量的影响及胃酸条件下维生素E对其的体外抑制作用研究

目的研究不同的储存利用方式对蔬菜中亚硝酸盐含量的影响及胃酸条件下维生素E对其的体外抑制作用。方法用菠菜、空心菜、油菜为原材料,分别研究新鲜时期和经清炒加工之后各4种不同储存方式(25℃袋装、25℃普通、4℃袋装、4℃普通)对亚硝酸盐含量的影响,同时研究胃酸条件下维生素E对亚硝酸盐的抑制作用。结果新鲜蔬菜的全部4种储存方式在储存过程中随储存时间的延长亚硝酸盐的含量先升后降,4种储存方式中亚硝酸盐含量的变化幅度有如下趋势:25℃袋装>25℃普通>4℃普通>4℃袋装;经清炒加工后的4种储存方式的熟菜,菜体中亚硝酸盐含量随时间延长而增加,12 h内差异无统计学意义(P>0.05),24 h达到峰值,25℃袋装条件下24 h时亚硝酸盐含量变化最高。胃酸条件下维生素E和维生素C均有抑制蔬菜中亚硝酸盐生成的作用,蔬菜加工后12小时以内二者与对照组比较差异均无统计学意义(P>0.05),12 h后差异有统计学意义(P<0.05)。结论在购买蔬菜和食用时,应尽量选择新鲜蔬菜,加工后蔬菜应放冷藏袋装储存并在12小时内食用,加工后蔬菜中添加维生素E对亚硝酸盐的抑制作用显著,适合作为补充营养素来抑制蔬菜中亚硝酸盐在体内的生成。     

蔬菜维生素B_1、维生素B_2保留因子的研究

目的通过比较不同蔬菜、不同烹调方法间维生素B1、维生素B2保留因子(RF)的差异,探讨影响蔬菜维生素B1、维生素B2保留因子的因素。方法选取了常见的12种蔬菜,以炒、炖、炸、蒸、焯、盐腌的方法进行烹调,分别记录烹调前后的重量,采用GB/T5009.84-2003荧光法、GB/T5009.85-2003荧光法分别测定烹调前后维生素B1、维生素B2含量,计算出相应的重量保留因子(保留率)和维生素B1、维生素B2保留因子(保留率)。结果鲜豆类蔬菜,维生素B1的保留率大多在66%~75%之间,维生素B2的保留率在85%~90%之间。焯不论对于根茎类还是叶菜类都会造成维生素B1的较大损失,损失率为50%。对于叶菜类,焯同样会造成维生素B2较大损失,RF的均值为50,明显低于炒青菜(P<0.05)。根茎类和茄果类蔬菜在炒的烹调方式下维生素B2的RF值在77~79之间。结论焯会造成较大的维生素B1、维生素B2损失,炒的维生素B1、维生素B2保留率较高;烹调方法、蔬菜的品种是影响维生素保留因子的重要因素。     

The B vitamin content of hospital meals and potential low intake by elderly inpatients

The content of thiamin, riboflavin, vitamin B6 (pyridoxamine, pyridoxal, pyridoxine), niacin and total folate were determined in the meal choices comprising a typical day's menu in a teaching hospital. Thiamine, riboflavine, and B6 were measured by HPLC analysis, folate by microbiological assay, and niacin content was calculated from food tables.
The results were compared with UK Recommended Daily Amounts (RDA) whenever possible (thiamine, riboflavine and niacin). Vitamin B6 and folate results were compared with the US Recommended Daily Dietary Amount (RDDA) as no British recommendation was available.
Elderly inpatients selected meals which, even if completely consumed, provided half the current recommendation for vitamin B6 and one-third of the recommendation for folate. More than half the meal selections provided less than recommended amounts of riboflavine, and in a quarter of cases less than the recommended amount of thiamine.     

Mineral content of traditional leafy vegetables from western Kenya

Socio-economic changes that have taken place in Africa have influenced people's eating habits in both rural and urban set-ups. Most people prefer introduced foods to traditional foods, including plant foods whose consumption is widely regarded as a primitive culture manifesting poor lifestyles. However, recent studies on traditional plant foods have shown that some are highly nutritious; containing high levels of both vitamins and minerals. They also have potential as a remedy to counter food insecurity since most are well adapted to the local environment, enabling them to resist pests, drought and diseases. This paper describes the mineral (calcium, iron and zinc) contents in some 54 traditional vegetable species collected from Nyang'oma area of Bondo district, western Kenya. Atomic absorption spectroscopy was used to determine the mineral content. We found that most traditional leafy vegetables, domesticated and wild, generally contain higher levels of calcium, iron and zinc compared with the introduced varieties such as spinach (Spanacia oleracea), kale (Brassica oleracea var. acephala) and cabbage (Brassica oleracea var. capitata). The results of this study could contribute towards identification, propagation and subsequent domestication and cultivation promotion of nutrient-rich and safe species within the farming systems of the local communities in Kenya, sub-Saharan Africa or elsewhere.     

分光光度法测定蔬菜中铁的含量

用分光光度法直接测定蔬菜中铁的含量,方法简便、快速、准确,对指导人们合理食用蔬菜进行补铁及进一步开发蔬菜产品提供了可靠的理论依据。     

Cholesterol and vitamin D content of eggs in the U.S. retail market

Nationwide sampling in the U.S. of whole large eggs, to update values in the United States Department of Agriculture (USDA) National Nutrient Database for Standard Reference (SR) (http://www.ars.usda.gov/nutrientdata), was conducted in 2000–2001 and in 2010. Retail cartons of large eggs were obtained from 12 supermarket locations using statistical sampling plans based on market share and census data. Cholesterol was analyzed at three laboratories using standard methods involving gas chromatography of the saponified total lipid extract. Vitamin D₃ and 25-OH-vitamin D₃ (2010 samples only) were analyzed by HPLC and UHPLC–MS/MS. Quality control materials were included to validate the accuracy and precision of measurements. The mean cholesterol content decreased 51 mg/100 g (12%; p < 0.0001), from 423 mg/100 g in 2000–2001 to 372 (range 344–405) in 2010. Over the same period, average vitamin D₃ increased by 60%, to 2.05 μg [80 IU]/100 g (range 0.97–12.1). Samples from 2010 contained 0.65 μg 25-OH-D₃/100 g (range 0.43–1.32). The disparate vitamin D (and cholesterol) content of eggs sampled from different locations may reflect industry efforts to modify poultry feed or supplements to affect the nutrient profile of eggs. Cholesterol and vitamin D₃ data from this work were included in SR release 23, and support food consumption surveys, food and nutrition policy, and consumer education.     

Phylloquinone (vitamin K1) content of vegetables

Assessment of vitamin K (VK) dietary intakes has been limited by incomplete VK food composition data for the US food supply. The phylloquinone (VK-1 or vitamin K₁) concentrations of a variety of geographically representative vegetables (n=218) were determined by reversed-phase high performance liquid chromatography with fluorescent detection. Green leafy and flower vegetables including broccoli, broccoli raab, spinach, and certain lettuces, contained >100 μg phylloquinone/100 g vegetable. In contrast, raw tubers and roots contained <10 μg phylloquinone/100 g vegetable. Iceberg lettuce, a primary dietary source of phylloquinone, contained 24.1 μg phylloquinone/100 g vegetable, which is less than previously listed in nutrient databases. Potential factors affecting phylloquinone concentrations include processing and varietal type of leafy vegetables.     

烹调对蔬菜中类黄酮物质含量的影响

目的研究不同烹调方法对蔬菜类黄酮物质含量的影响,为开展类黄酮与健康关系的相关研究提供基础数据。方法以炒、焯、煮、微波四种方法烹调天津市售9种蔬菜,采用高效液相色谱法测定烹调前后以及汤汁中5种类黄酮物质含量。结果炒后类黄酮物质保存率较高,在54.6%~115.6%之间;焯为33.6%~107.8%;煮为31.7%~100.5%,微波保存率为43.1%~109.6%。汤汁中也有部分类黄酮物质存在,不同蔬菜经不同烹调后类黄酮转移率不尽相同,范围在1.4%~55.8%之间。结论烹调对各品种蔬菜类黄酮物质含量均有一定影响,不同烹调方法对不同蔬菜类黄酮物质含量影响不尽相同。     

Preferences for steaming of vegetables

Background:  Steaming retains vitamins and phytochemicals in vegetables better than boiling; thus, it is important to promote this cooking method. The present study aimed to determine what vegetable would be best to use in a campaign to promote steaming.
Methods:  Carrots, broccoli and green cabbage were boiled, steamed or microwave steamed. Untrained assessors ( n  = 50) evaluated the sensory properties of appearance, texture, taste and overall acceptability using a hedonic rating test on a scale from 1–9. Average scores for overall acceptability were calculated for each type of cooking according to the assessors' usual cooking method.
Results:  For all features, steaming and microwave steaming were rated significantly higher than boiling for broccoli (for acceptability 6.2 and 7.1 versus 5.1; P  <   0.001), whereas carrots were similarly considered better for flavour and overall acceptability. Generally, cabbage was rated lower for all features, with no differences amongst the cooking methods (4.9–5.2 for acceptability). Only two of twenty-one subjects who usually boil vegetables preferred the boiled vegetables in the present study.
Conclusions:  Generally, steaming and microwave steaming were preferred for certain vegetables, even by those who normally boil them. Barriers to change need to be considered when planning the promotion of steaming as a regular method of cooking vegetables, although it may be more convincing to use vegetables such as broccoli that are perceived as being most acceptable when steamed.     

市售盐腌菜中亚硝酸盐含量分析

目的调查亚硝酸盐在市售盐腌菜的中含量。方法采用随机方法抽取罗湖区市售的散装、袋装等4种盐腌菜共143份样品，应用GB／T5009．33-2003进行了检测。结果酸菜中的亚硝酸盐平均含量为1.4041mg／kg，高于萝卜干的平均含量1．0218mg／kg；散装成酸菜亚硝酸盐的平均含量为1．4143mg／kg，高于袋装的平均含量1．0387mg／kg，两者都具有显著性差异。结论亚硝酸盐含量与蔬菜种类、腌制方式有关。     

The possible macroeconomic impact on the UK of an influenza pandemic

Little is known about the possible impact of an influenza pandemic on a nation's economy. We applied the UK macroeconomic model ‘COMPACT’ to epidemiological data on previous UK influenza pandemics, and extrapolated a sensitivity analysis to cover more extreme disease scenarios. Analysis suggests that the economic impact of a repeat of the 1957 or 1968 pandemics, allowing for school closures, would be short‐lived, constituting a loss of 3.35 and 0.58% of GDP in the first pandemic quarter and year, respectively. A more severe scenario (with more than 1% of the population dying) could yield impacts of 21 and 4.5%, respectively. The economic shockwave would be gravest when absenteeism (through school closures) increases beyond a few weeks, creating policy repercussions for influenza pandemic planning as the most severe economic impact is due to policies to contain the pandemic rather than the pandemic itself. Accounting for changes in consumption patterns made in an attempt to avoid infection worsens the potential impact. Our mild disease scenario then shows first quarter/first year reductions in GDP of 9.5/2.5%, compared with our severe scenario reductions of 29.5/6%. These results clearly indicate the significance of behavioural change over disease parameters. Copyright © 2009 John Wiley & Sons, Ltd.     

The impact of the business cycle on occupational injuries in the UK

This paper investigates the cyclical fluctuations in rates of workplace injury for the UK from 1986 to 2005. Time series analysis shows that, in aggregate terms, the rate of minor injuries is pro-cyclical whilst the rate of major injury is not affected by the level of economic activity. Analysis by sector reveals that cyclical fluctuations are sharper in the construction and manufacturing sectors. Using panel data, we find that fluctuations in both the rates of minor and major injury are related to the level of new hiring and the ratio of actual to usual hours worked. However, only minor injuries are related to variables that control for workers' bargaining power. The analysis demonstrates the importance of both compositional effects and individual reporting behaviour to understanding cyclical variations in workplace injury rates.     

The role of bread in the UK diet: An update

Bread has been a widely consumed traditional staple food in the UK for centuries, although there has been a decrease in consumption over the past 50 years. This may reflect the increased availability and popularity of other starchy foods such as pasta and rice and potentially negative misconceptions around bread and health (e.g. weight gain and gastrointestinal symptoms). On average, in the UK, bread provides 11–12% of energy, 16–20% of carbohydrate, 10–12% of protein and 17–21% of fibre intakes across all age groups and is a key contributor to micronutrient intakes (9–14% of folate, 15–17% of iron, 12–17% of calcium, 12–13% of magnesium and 10–11% of zinc). White bread is the largest contributor to salt intakes in the UK, though average salt content has been declining, largely as a result of the government reformulation programme with the food industry, including the setting of salt reduction targets. The mandatory fortification of flour with folic acid, a strategy used successfully in >60 other countries as a means of reducing neural tube defects (NTDs), is currently being considered and may be an important public health initiative. The variety of fibre types in bread such as arabinoxylan, oligosaccharides and resistant starch, as well as other bioactives including polyphenols, are an area of emerging interest in relation to nutrition and health. This paper gives an overview of the current contribution of bread to nutrient intakes and considers trends which may change the role of bread in our diet going forward.     

英国全科医生制度发展经验与启示

为了解英国全科医生制度的建立和发展历程、制度现状、发展特点与启示,通过文献法回顾了英国全科医生制度从产生到发展成熟的历程,重点探索了全科医生教育培训、执业方式、服务内容和范围、激励和约束机制等制度方面的演变过程。发现英国国民卫生服务制度和医生对医疗服务体系的控制力、全科医学服务的激励机制和全科医学的发展程度这3个因素相互作用,推动着英国全科医师制度的建立和发展。     

The relationship of socio-economic factors to the use of vitamin supplements in the city of windsor

1,756 completed responses were received to 3,000 health questionnaires that were randomly distributed on a proportional basis to households in the 45 census tracts in the City of Windsor. Answers to questions concerning vitamin use in Windsor households indicate that 59.3% of households used some type of vitamin supplement, and the order of preference was multi-vitamins (34.5% of respondents), single vitamins (14.3% of respondents) and multi-vitamins-minerals (10.5% of respondents). The use of vitamins, and the type of vitamins used, were influenced by age, income, occupation and family size. The effects of age and family size on vitamin use were income dependent.