饲料添加剂莱克多巴胺最大残留限量标准的争辩

据WTO新闻网消息,2011年6月30日和7月1日,WTO成员国就食品安全规则的科学性基础是否受到消弱这一问题展开了讨论,原因是国际标准制定机构未能在一种饲料添加剂（莱克多巴胺）最大残留限量问题上达成一致。问题讨论的焦点在于,有关莱克多巴胺最大残留限量的不同,     

绿色食品标准中大蒜感官品质及重金属限量问题研究

绿色食品标准内容的设定要体现优质和安全两个要素。普通的食品标准一般都对感官品质要求进行了分级,如一级品、二级品、三级品等。为了体现绿色食品的“优质”,在设定绿色食品标准的感官品质指标时,一般应达到普通食品标准的最高级水平。普通的食品标准一般也对卫生安全品质做一定的要求,而绿色食品标准对安全品质的要求范围更广、指标更严,这也是其特色所在。绿色食品大蒜对安全品质要求主要是农药残留限量和重金属限量两部分。本文论述了绿色食品大蒜标准中感官品质和重金属限量应达到的要求。 一、感官品质要求 绿色食品大蒜的感官…     

国内外婴幼儿食品中重金属限量标准比较分析

重金属是影响婴幼儿食品安全的重要风险因素,也是各国家/组织食品安全关注的焦点,而制定严格的限量标准是控制此类风险的重要措施。本文分析了国际食品法典委员会（CAC）、欧盟、美国、新加坡、澳大利亚和新西兰、加拿大、韩国及我国婴幼儿食品中重金属限量标准状况,比较了国内外限量标准的差异,据此提出了完善我国婴幼儿食品中重金属限量标准的建议,以及进出口婴幼儿食品生产、监管中需要注意的问题。     

中草药饲料添加剂

中草药饲料添加剂安徽马鞍山市光明饲料厂（２４３０４１）熊沈学中草药饲料添加剂是具有我国特色的新型高效饲料添加剂。传统的中草药来源主要有四个方面，即植物、动物、矿物和他们的加工品。虽然中草药含有种种养分，但使用中草药饲料添加剂往往不是为动物提供某些营养...     

紫外分光光度法测定饲料添加剂苯甲酸钠的研究

研究了苯甲酸钠的紫外分光光度法测定,实验证明：该方法可以快速、准确地测定饲料中的苯甲酸钠的含量。样品最小检出量为0.001 4mg/ml,回收率达96%。为饲料工业中快速检测苯甲酸钠提供了一种新的方法。     

饲料添加剂——阿散酸的分光光度法测定

饲料添加剂——阿散酸的分光光度法测定￥广东省农科院畜牧研究所＠刘婕￥广东工业大学化工系＠尚红霞饲料添加剂———阿散酸的分光光度法测定广东省农科院畜牧研究所（５１０６４０）刘婕广东工业大学化工系（５１００９０）尚红霞阿散酸（化学名称：对氨基苯胂酸）作为抑菌...     

酶法检测食品中铅离子的研究

食品中的铅直接对人类健康造成危害,利用脲酶比色法检测松花蛋和番茄酱样品中的铅离子,得到了良好的效果。此方法不需要价格昂贵的大型仪器,适用于中小型食品企业完成食品中铅含量的测定。     

A survey of selected heavy metal concentrations in Wisconsin dairy feeds

Heavy metals such as zinc (Zn), copper (Cu), chromium (Cr), arsenic (As), cadmium (Cd), and lead (Pb) are potential bioaccumulative toxins of the dairy production system. The heavy metal content of dairy feeds, however, remains poorly documented, particularly in the United States. This survey determined the heavy metal content of 203 typical dairy ration components sampled from 54 dairy farms in Wisconsin. Lowest heavy metal concentrations were found in homegrown alfalfa (Medicago sativa L.) hay and haylage, and corn (Zea mays L.) grain and silage. Highest metal concentrations were found in purchased feeds, particularly mineral supplements, and to a lesser extent corn- or soybean-based concentrates. Zinc and Cu were found at the highest concentration in complete dairy (total mixed and aggregated component) rations and reflected the deliberate addition of these metals to meet animal nutrient requirements although more than half the farms fed Cu and Zn above US recommended levels. Concentrations of Cr, As, Cd, and Pb were present in much lower concentrations and decreased in the order Cr > As > Pb > Cd. No complete Wisconsin dairy ration contained heavy metal concentrations above US maximum acceptable concentrations and would be unlikely to induce any toxic effects in dairy cattle. Concentrations of Cd in complete dairy rations were closest to US maximum acceptable concentrations, suggesting the greatest potential long-term risk to exceed US maximum acceptable concentrations if whole farm levels of Cd were to increase in the future. With the exception of Pb, the main sources of Zn, Cu, Cr, As, and Cd in the complete dairy feed ration originated from imported feed. The continued importation of heavy metals in dairy feed is likely to be associated with accumulation of these metals in soils where manure is applied. Although the cycling of many heavy metals through the dairy food chain will be limited by factors such as a soil's cation exchange capacity, pH, salinity, and phytotoxicity of the metal, these may be less limiting for Cd. It is important that sources of Cd in the dairy system are identified and minimized to prevent problems associated with Cd accumulation in the dairy soil system arising over the long-term.     

茶渣蛋白的提取、酶解及其作为饲料添加剂的应用研究

利用碱溶酸沉法从茶渣中提取蛋白,优化了提取工艺,并将茶渣蛋白酶解后作为饲料添加剂添加到猪的基础日粮中。试验结果表明:茶渣蛋白的最佳提取工艺条件为NaOH浓度0.12mol/L、提取温度90℃、提取时间1.5h、液料比30∶1(v/w)、最佳沉淀pH3.5,在此条件下茶渣蛋白的提取率为75.47%;选用风味蛋白酶酶解茶渣蛋白,酶解产物能有效提高猪的生产性能,改善猪的机体免疫能力以及提高胰脏和十二指肠中消化酶的活性。     

蒸馏单甘酯的重金属限量试验改进研究

研究取消饱和硫化氢溶液的蒸馏单甘酯重金属限量试验的最佳方法。分别用硫代乙酰胺、硫化钠和硫化钠-丙三醇进行实验并与饱和硫化氢比较,结果表明,硫化钠-丙三醇法简单、快捷,为最佳方法。     

酿酒废酵母吸附共存重金属离子的研究

为研究酿酒废酵母吸附共存重金属离子的可行性,在单因素试验的基础上,采用响应曲面法探讨酿酒废酵母吸附共存离子Pb2+、Ni 2+、Cu2+的最佳工艺条件。结果表明:酿酒废酵母对共存重金属离子Pb2+、Ni 2+、Cu2+吸附的最佳条件为pH值3.15,吸附温度30℃,吸附时间60min,酵母浓度2.04g/L,离子浓度61.34mg/L,该条件下酿酒废酵母对共存离子的吸附率为62.78%。     

Aflatoxins and heavy metals in animal feed in Iran

The occurrence of aflatoxin (aflatoxin B₁, aflatoxin B₂, aflatoxin G₁ (AFG₁) and aflatoxin G₂ (AFG₂)) and heavy metal (Pb, Cd, As and Hg) contamination was determined in 40 industrially produced animal feed samples which were collected from the southwest of Iran. The results indicated that 75% of samples were contaminated by four aflatoxins and the level of AFB₁ and sum of aflatoxins were higher than the permissible maximum levels in Iran (5 and 20 µg kg^?1, respectively) in all feed samples. A positive correlation was found between four types of aflatoxins in all the tested samples (p < 0.01) and the positive correlation between AFG₁ and AFG₂ was significant (r² = 0.708). All feed samples had lead concentrations lower than the maximum EU limit, while 5%, 17% and 42.5% of feed samples had As, Cd and Hg concentrations higher than the maximum limits, respectively.     

A simple and rapid turbidimetric method for determining catechins in beverages

We have developed a simple and rapid turbidimetric method to determine catechins based on the fact that many polyphenols produce hydrogen peroxide in an alkaline environment and that hydrogen peroxide oxidises cerium to generate cerium oxide precipitates. Four catechins (epicatechin, epigallocatechin, epicatechin gallate, epigallocatechin gallate) aggregated with these precipitates to form massive precipitates with increased turbidity. The catechins solution (0.18 mL) was mixed with 0.02 mL of 1% CeCl₃ solution, and absorbance (650 nm) was measured immediately after agitation for 3 min using a spectrophotometer. Absorbance was strongly correlated (0.99) with the concentration of each catechin compound. For commercially bottled green tea, the estimated catechin content determined using this turbidimetric method showed better correlation with the content determined by high‐performance liquid chromatography than that determined using ferrous tartrate method, which is the official Japanese method for determining the tannin content of green tea.     

雷氏盐重量法测定氯化胆碱含量的不确定度分析

通过建立数学模型,分析不确定度的来源,计算得到氯化胆碱含量的测量扩展不确定度为0.3％.在采用雷氏盐重量法检测氯化胆碱的含量中,测量重复性是影响含量不确定度的主要因素.     

饲料添加剂甲酸钙的合成研究与应用

本文报道了甲酸钙的合成和检测方法,以甲酸和石灰乳及甲酸和碳酸钙为原料合成甲酸钙,具有工艺简单、操作方便、收率高、纯度高等特点,并介绍了甲酸钙作为饮料添加剂的应用及效果。     

不同打顶方式对烤烟吸收重金属的影响

为探讨烤烟重金属的调控措施,采用大田试验方法,研究了在土壤重金属复合污染的条件下,不同打顶方式对烤烟吸收重金属的影响.结果表明,处理B初花打顶正常留叶对叶部Cd、Pb、Cr(下部叶和中部叶)调控效果较好.在重金属复合污染条件下,烟株体内重金属Cd、Pb和Hg含量随叶位的升高而增加,Cr含量随叶位的升高而降低,根部含量最...