食品中RS3含量与凝胶性的关系

测定了米线、粉丝、馒头、面包和红薯淀粉中RS3的含量,比较RS3含量与凝胶性的关系。米线中RS3为9.882%,绿豆粉丝为7.902%,水晶粉丝为10.449%,红薯粉丝为10.899%。在冷藏过程中,馒头和面包样品随着RS3含量的增加,凝胶的硬度分别从1031.45g和349.87g增加到4820.10g和851.45g,弹性分别从0.96和0.923下降到0.858和0.9075。红薯淀粉随着加热-冷却处理次数的增加,RS3含量从2.55%增加到6.95%,凝胶的硬度从82.198g增加到497.461g,弹性从0.988下降到0.923。因此,随着RS3含量的增加,凝胶的硬度均显著增加,而弹性变化不大。      

发酵性食品中的氨基甲酸乙酯含量调研

采用SLE(固相支持液/液萃取)结合GC-MS法测定酸奶、酱油、葡萄酒、黄酒及干酪、腐乳中的氨幕甲酸乙酯含量,检测结果显示,黄酒、腐乳中氨基甲酸乙酯含量较高,其次是葡萄酒和酱油,发酵性乳制品和豆豉中均未检出氨基甲酸乙酯.     

花生凝胶食品的研制

本文依据花生蛋白质在一定条件沉凝的特性，采用CaCl2进行了花生凝胶食品的研制。结果表明，产品具有花生特有的风味和良好的烹饪加工性能，维生素E、蛋白质、脂肪收得率分别为81．2％、92．3％和82．1％。     

食品中甲醛的含量与控制

在食品加工过程中,可以通过采取不使用甲醛作为添加剂或甲醛含量高的物质做原料;采用合理的加工工艺;不使用甲醛为材料制造的树脂作为食品包装材料等措施,来有效地控制食品中的甲醛含量。      

食品中吊白块含量的测定

吊白块，学名甲醛合次硫酸氢钠（CH２（OH）SO２Na·２H２O），是工业用增白剂，主要用于染布漂白。若作为食品脱色剂使用，会使食品中残留有害的甲醛，人体摄入甲醛后，可引起食欲减退、厌食、体重减轻、衰弱、失眠等症状。为此，国家早已明文规定，禁止吊白块在食品中使用。但目前在市场上发现，个别小生产者或个体户，他们唯利是图，不惜损害消费者的身体健康，为了吸引消费者，使馒头或粉丝等食品的外观色白漂亮，竟然在这些食品中使用了吊白块。为了维护消费者的利益，保障人民群众的身体健康，严厉打击食品领域的违法行为，有必要…     

大米及其制品中的RS3

测定了英国市场上销售的Basmati(白米,糙米)(长粒米),泰国香米(长粒米),日本大米(短粒米)样品中RS3的含量,比较长粒米和短粒米在熟化过程的稳定性以及不同米制品中含量的差异.结果表明,短粒大米RS3含量高于长粒大米;熟化过程对RS3含量的影响巨大,其中白米米粉在熟化过程中RS3含量下降的程度低于糙米米粉,长粒米米粉、短粒米米粉在熟化过程中RS3含量下降的程度差异不大;保鲜米饭与同品种大米制作熟化大米粉的RS3含量基本相当.     

0～36月龄婴幼儿配方食品及婴幼儿辅助食品中糖含量分析

目的 了解我国市售婴幼儿配方食品（婴儿配方食品、较大婴儿配方食品和幼儿配方食品）及婴幼儿辅助食品（婴幼儿谷类辅助食品和罐装辅助食品）中葡萄糖、半乳糖、果糖、乳糖、蔗糖和麦芽糖的含量,为婴幼儿配方食品及婴幼儿辅助食品相关的食品安全标准管理提供数据支持。方法 根据随机抽样原则,采集国内市场常见的婴幼儿配方食品及婴幼儿辅助食品83例,涵盖婴幼儿配方食品、婴幼儿谷类辅助食品和婴幼儿罐装食品等,利用离子色谱-脉冲安培法对葡萄糖、半乳糖、果糖、乳糖、蔗糖和麦芽糖进行含量检测,并对检测结果进行分析。结果 婴幼儿配方食品中总糖含量的中位数为433.43～476.99 g/kg,其中乳糖占总糖的比均高于95%,乳糖含量由高至低分别为婴儿配方食品、较大婴儿配方食品和幼儿配方食品。婴幼儿谷类辅助食品中总糖检出率为36.8%,含量中位数为0～28.35 g/kg,其乳糖和蔗糖的中位数较高,为84.30和70.17 g/kg,而蔗糖在饼干第三四分位数（Q3）的含量较高,为53.43 g/kg。国产和原装进口配方食品的添加糖含量进行比对,差异没有统计学意义（P>0.05）。结论 我国市售的婴幼儿配方食品中乳...     

黄原胶与魔芋胶的协效凝胶性研究

黄原胶与魔芋胶均为非凝胶多糖,但二者在一定条件下共混可以得到凝胶。当黄原胶与魔芋胶以0.7/0.3的配比共混,多糖总浓度为1%时,二者的协效凝胶性最强,即凝胶强度最大,同时对制备温度和体系盐离子浓度对多糖共混凝胶性的影响作了初步研究,研究表明,当制备温度80℃,盐离子浓度为0.2mol/L,凝胶强度最大。     

不同食品中阿魏酸含量的分析

为比较不同食品中阿魏酸含量,采用高效液相色谱法测定米类、面类、玉米类三类食品共26份试样中的阿魏酸含量。结果表明,三类食品中玉米类食品阿魏酸含量最高,其中冷冻玉米棒阿魏酸含量高达318.4 mg/100 g(以干物质计);阿魏酸含量与食品加工精度和加工方法有关,未经加工的食品和加工精度较低的食品阿魏酸含量较高,加工精度越高,阿魏酸含量越低;一般湿法加工的食品阿魏酸含量要高于干法加工的食品。     

食品成分对淀粉凝胶力学性能的影响

淀粉凝胶的力学性能因糖、无机盐、酸碱、单甘酯等的加入用来改善食品风味和口感的物质而发生变化。这种变化是由于添加物质与淀粉大分子发生作用或是添加物质对淀粉大分子之间的相互作用的产生影响造成的。该研究结果对于生产既具有一定风味又不失良好力学性能的淀粉凝胶类产品提供了必要的依据。     

Saponin content of some Nigerian foods

Saponins have been extracted and purified from millet (Pennisetum typhoideum), beans (Phaseolus vulgaris), guinea-corn (Sorghum vulgare) and groundnut (Arachis hypogaea). Beans were found to contain a considerable amount of saponin—245.0 mg kg^?1, while millet, guinea-corn and groundnut contained 194.7, 72.7 and 48.8 mg kg^?1 dry weight basis respectively.     

Saponin content of food plants and some prepared foods

Quantitative thin layer chromatography was used to estimate the saponin content of 20 common food plants and also of foods prepared from some of them. The food plants found to be richest in saponins were chickpeas (Cicer arietinum), soya beans (Glycine max), lucerne (alfalfa) sprouts (Medicago sativa) and varieties of Phaseolus vulgaris (navy beans, haricot beans, kidney beans). Saponins were not destroyed by processing or cooking. They were present in falafels (prepared from chickpeas), canned baked beans, canned broad beans and protein isolate from faba beans. However, the saponin content of a fermented soya bean product (tempe) was only half that of whole soya beans. Guar meal (Cyamopsis tetragonolobus) contains saponins but only a trace could be detected in samples of guar gum.     

Relation between the molecular structure of some polysaccharides and original properties in sol and gel states

This paper concerns the properties of a few natural polysaccharides investigated in our laboratory. We also present the different techniques used in our group for a long time and their advantages to characterize polysaccharides. In a first part, the behavior of galactomannans with different chemical structures is discussed; the distribution of galactose units along the mannan backbone is very important. Then, xanthan is developed as one of the best thickening polymers due to its high intrinsic stiffness related to the helical conformation stabilized in the presence of excess salt. Gellan under native or deacylated structure is described to demonstrate the role of substituents on the physical properties in solution and especially on the sol–gel transition. The last part concerns the cooperative interaction between xanthan and galactomannan giving in specific conditions two different gels with a gel–sol melting transition around 25°C and 50–60°C, respectively, depending on the galactomannan microstructure.     

Relationship between the antioxidant properties and the phenolic and flavonoid content in traditional balsamic vinegar

The antioxidant properties of traditional balsamic vinegar as regards its phenolic and flavonoid content comparing it to selected vinegars and red wines have been investigated. The polyphenols were separated from interfering compounds utilizing C18 columns. The polyphenolic content was determined utilizing both Folin–Ciocalteu and peroxidase assays. The antioxidant capacity was quantified using both ABTS and FRAP assays. The results show that traditional balsamic vinegar has lower antioxidant activity and phenolic and flavonoid content than Nero d’Avola but higher than the other tested products. The antioxidant capacity of wines and vinegars is highly correlated with their phenolic content, measured by peroxidase assay and it is also highly correlated with their flavonoid content while in traditional balsamic vinegar and balsamic vinegar this correlation diminishes. The study describes a simple and fast method of separating from other compounds and of measuring polyphenols in the analysis of red wines and vinegars with complex composition such as traditional balsamic vinegar.     

Multi-element determination in some foods and beverages using silica gel modified with 1-phenylthiosemicarbazide

ABSTRACT

1-Phenylthiosemicarbazide bonded modified silica gel (PTC-SG) was synthesised and characterised by FTIR, SEM and elemental analysis for a novel separation/preconcentration of multiple elements based on solid phase extraction. The analytical parameters including pH of solutions, amounts of PTC-SG, flow rates of sample, eluent type and sample volume were optimised. The adsorption capacities of PTC-SG were found to be 7.9, 6.4, 6.3, 8.3, 7.2, 8.9 and 6.6 mg/g for Cu(II), Cd(II), Pb(II), Co(II), Cr(III), Ni(II) and Mn(II), respectively. The limit of detection (LOD) was calculated as 3x the standard deviation(s) of the reagent blank (k = 3, N = 21) and the LOD values were obtained to be 0.98 µg L^?1 (Cu), 0.65 µg L^?1 (Cd), 0.57 µg L^?1 (Pb), 1.12 µg L^?1 (Co), 1.82 µL^?1 (Cr), 1.67 µg L^?1 (Ni) and 0.55 µg L^?1 (Mn). Certified reference materials were used to test the validation of the present method. The new solid phase extraction method was successfully applied to determination of the amount of multiple elements in food and beverage samples.     

广西部分食品中铝含量监测及人群膳食暴露评估

目的了解广西部分食品中铝的污染状况,评估居民膳食中铝暴露的风险。方法对2009—2013年广西检测的部分食品中铝含量进行分析,结合2002年广西居民膳食营养调查中的食物消费量数据,计算广西居民膳食中铝暴露量。结果 2009—2013年共检测食品样品10类5 679份,铝含量的平均值为132.17 mg/kg,检出率为73.01%(4 146/5 679),超标率为29.51%(1 676/5 679)。其中以海蜇、紫菜干(海带干)、油条3种食品的检出率和超标率最高,且铝的平均含量也是极高。油条样品中铝含量的均数和中位数均最高,分别超过国家残留量标准的3.8倍和3倍。10类居民膳食中铝平均每周摄入量为0.426 mg/kg BW,低于JECFA制定的每周耐受摄入量(PTWI)。馒头、海蜇、油条和油饼高消费量人群的每周铝摄入量分别是PTWI的3.07、2.40、2.23和1.23倍。结论广西监测的油条、紫菜、海蜇等食品中铝含量超标较严重,居民平均膳食摄入铝的量虽然低于PTWI,但高消费量人群铝的暴露风险较大,仍需要加强对生产经营者科学合理使用含铝添加剂的技术指导,以降低居民膳食中铝的摄入量。     

Phytate content of some foods from plant origin from Vietnam and Hungary

For the estimation of phytate-ion the iron content of FeIII-phytate complex was determined by spectrophotometry with o-phenanthroline. In most cases phytate-phosphorus was also evaluated. In different food samples iron to phosphorus ratio in phytate generally deviated significantly from the theoretical 1.20 value. Wheat flour products, maize, rice, beans, peas, lentil and soy from Vietnam and Hungary, furthermore several bakery products from Hungary and some imported soy products were analysed for phytate content. The effect of heat and fermentation on phytate content was also checked in breads and other foods. It was concluded that the processes often used in food industry, namely fermentation and thermal load, have relatively slight effect on the phytate content of plant foods. Cooking losses for phytates ranged 1-60% in cereals and legumes according to the usual kitchen technique in Vietnam.     

Fluoride content of some common South Indian foods and their contribution to fluorosis

Fluoride contents of 98 food items commonly used in South India were determined with special reference to the feeding habits of remote rural populations in 41 villages of Anantapur District, Andhra Pradesh, India, where dental and skeletal fluorosis is endemic. Fluoride up to 4.5 mg kg^?1 was found in irrigation and drinking water supplies. Thirty-two locally grown food items had generally higher fluoride contents (ranging jiom 0.2 to 11.0 mg kg^?1) with the notable exception of coconut water where even traces of fluoride could not be detected. The combined daily intake of fluoride jiom food and drinking water in the local population was found to range jiom 2.2 mg to 7-3 mg (0.05–0.32 mg kg^?1 BW). The role played by food composition, cooking habits of the local population, general poverty and illiteracy in contributing to the prevalence of fluorosis in schoolchildren in the age group 6–18 years (even in areas with drinking water supplies within the permissible levels as per WHO standards) is discussed.     

2006—2015年广州市部分食品甲醛监测结果分析

了解广州市部分食品甲醛残留情况,为食品安全风险评估及政府监管提供参考依据。方法 在全市12个区的餐饮企业、农贸市场、超级市场、批发点4类采样场所,于不同时间采集1 416份样品进行甲醛项目检测。结果 1 416份样品甲醛检测值范围为2.0～4 500.0 mg/kg,甲醛含量大于100 mg/kg占总样品数的13.21%(187/1 416),其中禽类副产品甲醛含量大于100 mg/kg比例为32.63%(31/95)、畜类副产品甲醛含量大于100 mg/kg比例为31.54%(94/298)、鱼类产品(银鱼、九肚鱼、鱼皮)甲醛含量大于100 mg/kg比例为30.85%(29/94)、甲壳类产品(虾仁)甲醛含量大于100 mg/kg比例为19.35%(24/124);农贸市场与批发点来源样品甲醛含量大于100 mg/kg比例高于超市与餐饮环节;9～11月采集的样品甲醛含量大于100 mg/kg比例高于其他月份,2012—2013年采集的样品甲醛含量大于100 mg/kg比例高于其他年份。结论 广州市甲醛残留量较高的食品主要为畜类副产品的牛百叶、牛心顶,禽类副产品的鹅肠、鸭肠,甲壳类产品的虾仁,鱼类产品的银鱼、九肚鱼、鱼皮等,甲醛残留情况较严重的月份为每年的9～11月,相关部门应加强监管,防范食源性疾病的发生。