Chemical studies on some Nigerian carbonated and alcoholic beverages

Carbonated beverages and different brands of lager beer bottled in Nigeria were analysed for carbohydrates, proteins, minerals, vitamins and alcohol, in order to provide basic data for the appraisal of their nutritive value. Seven carbonated beverages and five brands of lager beer were so analysed. The carbohydrate content of the carbonated drinks ranged from $\text{9·52–13·93}\text{g}\text{100}\text{g}$. They all contained sucrose, glucose and fructose. Calcium ranged from $\text{0·97–1·71}\text{mg}\text{100}\text{g}$; potassium, $\text{0·21–0·27}\text{mEq}\text{100}\text{g}$; sodium, $\text{1·58–5·20}\text{mEq}\text{100}\text{g}$. They contained no detectable amount of iron, traces of vitamin C, and negligible amounts of thiamin and riboflavin. The beers contained between 2·56 and $\text{4·17}\text{g carbohydrates}\text{100}\text{g}$. The main sugar was maltose. Alcohol (by weight) ranged from 3·77% to 5·20%. They were poor sources of minerals and vitamins. Some nutritional implications of these data are discussed.     

2000年6月全国食品、饮料及酒类产量一览表

~~2000年6月全国食品、饮料及酒类产量一览表$国家统计局工业交通司     

Moisture sorption isotherms of some Nigerian food grains

A fluidized bed apparatus that can be used to determine moisture sorption isotherms of granular food products is described. This apparatus was used to obtain moisture sorption isotherms for maize, cowpeas, groundnuts and soyabeans at temperatures of 30, 40 and 50°C. Hysteresis was observed in the isotherms for the four products and the equilibrium moisture content was lower for the oily grains (soyabeans and groundnuts) at the same value of relative humidity. The Hailwood and Horrobin equation was used to correlate the experimental data and the values of the correlating constants are tabulated. The Brunauer, Emmett and Teller equation was also used to obtain estimates of the monolayer water content for the four grains.     

Chemical composition and toxic trace element composition of some Nigerian edible wild mushrooms

Two essential amino acids (methionine and tryptophan); anti‐nutritional factors (tannin and trypsin inhibitor) and toxic elements (Pb, Cd, Ni, As, Hg and Cr) were determined spectrophotometrically from five edible wild mushrooms. The tryptophan content was between 1.00 and 1.82 g (100 g)^?1 but methionine was low at 0.26–1.38 g (100 g)^?1. Tannin content was high (30.3–40.0 mg g^?1) but trypsin inhibitor was low (22.0–39.5 TIU g^?1). Trace elements analysis reviled Pb (0.34–5.06 mg kg^?1) to be the highest of all the trace elements. Cd was (0.06–1.70 mg kg^?1), Ni (0.26–2.08 mg kg^?1), As (0.17–0.92 mg kg^?1), Hg (0.01–0.05 mg kg^?1) and Cr (0.04–0.22 mg kg^?1). These mushrooms are nutritious but must be well processed to eliminate or at least reduce the levels of tannin and Pb to improve their nutritional values.     

食品中重金属总量及形态分析研究进展

食品中重金属元素含量超标对人体危害较大,对其中的总量及形态分析的研究工作十分重要,因此近年来成为研究热点本文对重金属总量分析和元素形态分析的方法进行了综述,从前处理方法、分离方法和仪器检测方法三方面进行了归纳总结,就重金属总量分析和元素形态分析的发展方向进行了展望.     

食品中重金属检测与脱除技术研究进展

由于重金属在人体内的累积效应会产生潜在的健康危害,使得食品中的重金属脱除与检测技术越来越受到国内外学者的重视。文章对食品中重金属检测方法的原理及特点进行综述,并介绍几种主要的重金属脱除技术(浸泡法、化学法、吸附法、离子交换法等),同时对食品中重金属脱除技术的未来发展进行展望。     

食品中重金属总量及形态分析研究进展

食品中重金属元素含量超标对人体危害较大,对其中的总量及形态分析的研究工作十分重要,因此近年来成为研究热点。本文对重金属总量分析和元素形态分析的方法进行了综述,从前处理方法、分离方法和仪器检测方法三方面进行了归纳总结,就重金属总量分析和元素形态分析的发展方向进行了展望。      

重金属复合污染对茶叶重金属、主要生化成分含量及冲泡茶汤浸出率的影响研究

通过土壤盆栽实验,研究四种重金属As、Pb、Cr、Cd复合污染对茶叶重金属含量及主要生化成分含量的影响,同时研究了不同冲泡次数下茶汤中四种重金属的浸出率。结果表明:复合污染条件下,茶叶中重金属积累量显著高于对照,其高低顺序为Pb>Cr>Cd>As,其中,Cd在盆栽土壤中的添加量低于As,但在茶叶中的积累量高于Cd,表明Cd在茶树体内的迁移率高于As。复合污染茶叶中的氨基酸和咖啡碱含量均低于对照,酚氨比值高于对照,从而降低了茶叶品质。四种重金属元素在茶汤中的浸出量均随着冲泡次数的增加而减少,Cd、Cr、Pb和As的总浸出率分别为:18.0%~35.7%、14.8%~26.8%、15.4%~31.9%和13.7%~22.1%,Pb和Cd的浸出率大于Cr和As;四种重金属元素之间的络合作用,会影响重金属在茶叶中的累积量和茶汤中的浸出量。      

微胶囊技术及其在果蔬饮料和茶饮料中的应用

介绍了微胶囊技术的概念、功能特性、制备方法,以及它在果蔬饮料和茶饮料中的应用。     

食品中重金属的健康风险评估研究进展

重金属作为受关注的污染物,其毒性具有刺激性、靶器官毒性和致癌性等特点。食品中的重金属是进入人体的主要途径之一。因此,使用精确的方法评估食品对人体的健康风险具有重要意义。重金属的人体生物可利用性可以较为贴近人体重金属暴露的实际情况,通过模拟体外生物可利用性实验模型是现有获取重金属人体生物可利用性数据的通用方法。利用生物可利用性数据评估人体重金属暴露的健康风险相比直接利用食品重金属含量更为准确。本文综述了食品的人体生物可利用性实验方法及现行的重金属健康风险评估方法,分析对比了各种方法的优点和局限性,为科研人员确定不同污染物在食品中的生物可利用性提供思路和方向,以加强食品安全评估和人体重金属暴露评估的准确性。     

核酸适配体检测食品中的重金属研究进展

近些年食品中重金属超标引发很多问题, 严重危害人民群众的生命健康和社会稳定。传统重金属检测方法有原子吸收光谱法, 原子荧光光谱法和X射线荧光光谱法等, 其具有检测灵敏度高, 选择性好, 检测方法成熟等优点, 但是也存在着检测仪器昂贵, 前处理复杂, 检测所需时间长, 不易携带, 不能满足快速、简单、现场测定的实际需要等不足。科研工作者一直在不断探索能够快速, 灵敏, 高效的检测重金属的技术。适配体具有特异性强, 灵敏度高, 稳定性好等优点, 已经成为一种新型识别分子, 被广泛应用于食品中重金属的检测。本文综述了近年来适配体在镉、汞、铅、砷等重金属检测领域的研究, 并对核酸技术在重金属检测方面进行展望。     

食品中重金属检测快速前处理技术研究进展

目前食品中重金属的仪器分析方法大部分时间耗费在前处理步骤上。为提高检测效率,快速前处理技术被不断发展并应用到食品中重金属的检测。食品中重金属常见的快速前处理技术主要包括溶剂提取、微波辅助样品前处理技术、无需前处理的直接进样技术以及其他技术。其中溶剂提取法主要利用酸、碱或有机溶剂选择提取样品中的待测元素;微波技术利用微波电磁能转变为热能,加速样品萃取过程或引燃样品;直接进样技术无需消解处理,可固体直接进样或以悬浮液方式进样。本文对食品中重金属的快速前处理技术进行了综述。展望了食品中重金属快速前处理技术的发展方向,为今后快速前处理方法的开发和标准化提供了思路和借鉴。     

The proximate chemical composition and the amino acid content of some Nigerian oil seeds

Seven samples of some Nigerian oil seeds have been studied with respect to their proximate composition, calcium and phosphorus contents as well as the amino acid composition which was determined by column chromatography. Three of the groundnut samples were processed in the laboratory. These were then compared with a commercial groundnut cake. The African oil bean seeds, the conophor nuts and the soya beans obtained locally were processed in the laboratory. The chemical composition of the oil seed meals were with few exceptions similar to those reported in the literature. The tryptophan and sulphur amino acid contents of the conophor nuts were extremely high compared with the other oil seeds in which the sulphur amino acids were the limiting ones. The lysine contents of the African oil beans and the conophor nuts were exceptionally high compared with others. Glutamic acid followed by aspartic acid and arginine levels were generally high in each of the oil seeds. The implication of these findings are fully discussed.     

药食两用食品中微量元素和重金属含量的测定

建立了微波消解电感耦合等离子体发射光谱法测定药食两用食品中微量元素的方法,并用该法分别测定了14种药食两用食品中Mn、Fe、Zn、Cu、Ni、Cr、Cd和Pb等元素的含量。结果表明,该方法的加标回收率在95.0%~104.0%之间,RSD≤4.35%。药食两用食品中Zn含量高于其它可食性花卉,Fe含量比普通叶菜类蔬菜更高,而其Cu/Zn比值较低,重金属含量普遍较低。此测定结果可为探讨药食两用食品的保健作用与微量元素含量的相关性提供科学数据。      

天然香精系列

<正> 香精是现今食品工业中不可或缺的原料,能够解决天然食品的不足,而且味道与天然食品无异。丹尼斯克科特公司的 NATUROME Essence系列天然香精,主要提取自天然材料,如水果、蔬菜、香辛料,以及草本植物等的天然精华。该香精系列属于水基溶态,不含防腐剂,在低添加量、节省成本的条件下,为食品     

Variation in some heavy metals during the production of white cheese

The lead, cadmium, arsenic and mercury contents in samples of milk, curd and white cheese taken from a production line were investigated. The lead, cadmium and arsenic levels were found to be 12.07±0.06 ng/ml , 1.82±0.01 ng/ml and 0.64±0.03 ng/ml in milk, 219.85±0.46 ng/g , 19.58±0.34 ng/g and 8.80±0.41 ng/g in cheese curd, 250.63±0.53 ng/g , 21.19±0.16 ng/g and 10.85±0.34 ng/g in fresh white cheese preripened in brine salted to 16%, and 260.25±0.51 ng/g , 22.87±0.17 ng/g and 11.35±0.29 ng/g in ripened white cheese, respectively. No detectable levels of mercury were found in any of the samples. Variation in the heavy metal contents of samples taken during the production stages was significant (p <.05). The heavy metal concentrations of the samples were compared with those obtained by other investigators in different countries.     

Study of heavy metals in some cultivated and uncultivated mushrooms of Turkish origin

Twenty-four different species of uncultivated mushrooms of Turkish origin and one cultivated mushroom (Agaricus bisporus) growing in soil composts with 16 different compositions were analysed spectrometrically for their heavy metal (Pb, Cd, Hg, Fe, Cu, Mn, and Zn) contents. The highest Pb levels were 2.35 mg kg⁻¹ for the species Agaricus bitorquis and 7.00 mg kg⁻¹ for the species of Hypholoma fasciculare growing in the vicinity of the road. The highest Cd level was 3.42 mg kg⁻¹ for the species of Hydnum repandum. In the wild mushrooms the highest Fe content was 93.6 mg kg⁻¹ for the species of Bovista plumbea and the highest Cu content was 51.0 mg kg⁻¹ for the species Tricholoma terreum. The highest Mn content was 35.9 mg kg⁻¹ for the species Laccaria laccata and the highest Zn content was 31.6 mg kg⁻¹ for the species of Agaricus bitorquis.     

食品中重金属脱除技术的最新研究进展

食品重金属污染问题屡见不鲜,重金属在人体内积累后,会严重损害人体的神经系统和肝肾功能。如何去除食品重金属污染,已成为当今世界范围内一个重要的食品安全问题。因此,开发食品中重金属脱除技术对于保障食品安全具有重要意义。常见食品中重金属脱除技术根据原理可分为物理处理法、化学浸提法、微生物法和吸附法等。近年来,食品中重金属脱除技术发展较快,尤其是在吸附法中出现了很多高效、绿色和选择性高的吸附材料。本文总结了食品中各类重金属脱除技术,重点介绍各种技术的研究新进展以及其优缺点,为食品中重金属污染物的脱除提供基础参考,同时有助于促进脱除技术的新发展,并为保障食品安全提供新思路。     

Trace elements and heavy metals in mineral and bottled drinking waters on the Iranian market

A survey of Iranian waters, sampled from 2010 to 2013, is presented. A total of 128 water samples from 42 different brands of bottled mineral and drinking water were collected and analysed for contamination levels of lead (Pb), cadmium (Cd), copper (Cu), arsenic (As) and mercury (Hg). Determinations were performed using a graphite furnace atomic absorption spectrophotometer for Pb, Cd and Cu, a hydride vapour generation as well as an Arsenator digital kit (Wagtech WTD, Tyne and Wear, UK) for As and a direct mercury analyser for Hg. Arsenic concentration in six bottled gaseous mineral samples was higher than the related limit. Regardless of these, mean concentrations of Pb, Cd, Cu, As and Hg in all types of water samples were 4.50 ± 0.49, 1.08 ± 0.09, 16.11 ± 2.77, 5.80 ± 1.63 and 0.52 ± 0.03 µg L^?1, respectively. Values obtained for analysed heavy metals in all samples were permissible according to the limits of national and international standards.     

食品稳定剂在饮料中的应用

目的：通过对食品稳定剂在饮料中应用的综述,了解不同稳定剂的特点,为选择稳定剂提供初步的依据。方法：对各种常用稳定剂进行了介绍,并讨论了复合稳定剂的配比问题。结果与结论：在允许的范围内,稳定剂是安全可靠的食品添加剂。在饮料中可加入单一稳定剂亦可加入复合稳定剂。复合稳定剂的配比需要通过实验得到;也有的可通过实验得到一定关系作为理论依据,但不是所有饮料都适用。稳定剂的稳定机制还需进一步探讨。