富含共轭亚油酸的食用油安全性毒理学试验研究

目的日本已经有富含共轭亚油酸的食用油商品。为了使共轭亚油酸在我国得到广泛的应用,进行富含纯度共轭亚油酸食用油的食品安全性毒理试验研究。方法依据GB15193—94《食品安全性毒理学评价程序和方法》进行急性毒性试验、三项遗传毒性试验和30天喂养试验。结果共轭亚油酸对两种性别的SPF级昆明种小鼠经口毒性,一次灌胃量达20g／kg·bw两周内动物未见明显中毒症状,无动物死亡,按急性毒性分级标准规定,该受试物属无毒级。三项遗传毒性试验（Ames、小鼠骨髓嗜多染红细胞微核试验、小鼠精子畸形试验）结果均为阴性。30天喂养试验结果表明：该受试物O．87、2．20、4.30g／kg.bw剂量（分别相对于推荐人群日摄影入量3．6g/kg.bw的20、50、100倍）对wistar大鼠的临床检查,血液学,生化学,脏器重量和系数以及病理组织多样指标无明显影响,未发现该受试物有明显的毒性作用。结论富含共轭亚油酸的食用油既无毒也无任何副作用。     

Effects of corn silage hybrids and dietary nonforage fiber sources on feed intake, digestibility, ruminal fermentation, and productive performance of lactating Holstein dairy cows

This experiment was conducted to determine the effects of corn silage hybrids and nonforage fiber sources (NFFS) in high forage diets formulated with high dietary proportions of alfalfa hay (AH) and corn silage (CS) on ruminal fermentation and productive performance by early lactating dairy cows. Eight multiparous Holstein cows (4 ruminally fistulated) averaging 36 ± 6.2 d in milk were used in a duplicated 4 × 4 Latin square design experiment with a 2 × 2 factorial arrangement of treatments. Cows were fed 1 of 4 dietary treatments during each of the four 21-d replicates. Treatments were (1) conventional CS (CCS)-based diet without NFFS, (2) CCS-based diet with NFFS, (3) brown midrib CS (BMRCS)-based diet without NFFS, and (4) BMRCS-based diet with NFFS. Diets were isonitrogenous and isocaloric. Sources of NFFS consisted of ground soyhulls and pelleted beet pulp to replace a portion of AH and CS in the diets. In vitro 30-h neutral detergent fiber (NDF) degradability was greater for BMRCS than for CCS (42.3 vs. 31.2%). Neither CS hybrids nor NFFS affected intake of dry matter (DM) and nutrients. Digestibility of N, NDF, and acid detergent fiber tended to be greater for cows consuming CCS-based diets. Milk yield was not influenced by CS hybrids and NFFS. However, a tendency for an interaction between CS hybrids and NFFS occurred, with increased milk yield due to feeding NFFS with the BMRCS-based diet. Yields of milk fat and 3.5% fat-corrected milk decreased when feeding the BMRCS-based diet, and a tendency existed for an interaction between CS hybrids and NFFS because milk fat concentration further decreased by feeding NFFS with BMRCS-based diet. Although feed efficiency (milk/DM intake) was not affected by CS hybrids and NFFS, an interaction was found between CS hybrids and NFFS because feed efficiency increased when NFFS was fed only with BMRCS-based diet. Total volatile fatty acid production and individual molar proportions were not affected by diets. Dietary treatments did not influence ruminal pH profiles, except that duration (h/d) of pH <5.8 decreased when NFFS was fed in a CCS-based diet but not in a BMRCS-based diet, causing a tendency for an interaction between CS hybrids and NFFS. Overall measurements in our study reveal that high forage NDF concentration (20% DM on average) may eliminate potentially positive effects of BMRCS. In the high forage diets, NFFS exerted limited effects on productive performance when they replaced AH and CS. Although the high quality AH provided adequate NDF (38.3% DM) for optimal rumen fermentative function, the low NDF concentration of the AH and the overall forage particle size reduced physically effective fiber and milk fat concentration.     

ICP-AES法测定食品用纸包装容器及材料中可迁移性重金属镉

用4%乙酸溶液,在60℃条件下浸泡食品用纸包装样品2h,用电感耦合等离子体发射光谱法准确测定浸泡中可迁移性重金属Cd的浓度,实验过程操作简便,精密度实验和回收率实验说明该方法检测结果准确可靠。     

Cultivating Smartcities

On 9 April 2009, Michelle Obama planted the first seedlings of onion, lettuce, peas and peppers in the 102-square-metre (1,100-square-foot) White House Kitchen Garden. She may have planted the green shoots for a smartcity. CJ Lim , author of Smartcities + Eco-warriors (Routledge, 2010), describes sustainable urban developments in the form of smartcities – a new urban exuberance reintegrating cultivated land within an urban economic and ecological context system. These verdant edible edifices of urban spatial theatre are aesthetically and culturally engaging. Soliciting an emotional as well as intellectual response they have the potential to connect with the public and involve them in the architectural possibilities of the city. Copyright © 2010 John Wiley & Sons, Ltd.     

基于量纲分析方法的苜蓿干燥特性参数确定

应用量纲分析方法,建立了苜蓿的干燥温度、样品质量、茎秆长度、介质流速和初始含水率与其干燥常数k的经验公式,并得到了温度特性系数n与干燥温度的函数关系,提出了改进苜蓿薄层干燥方程,为分析干燥条件对苜蓿干燥速度的影响提供了理论依据。     

An analytical overview of the composition and characteristics of China's food safety standards

This paper discusses the framework of China's food safety standards and provides a brief overview of the problems and developmental characteristics of food safety in China. The composition and characteristics of China's food safety standards are revealed by an analysis of the changes in China's general food standards, an overview of the characteristics of the hygiene requirements in the production and operation process, and an introduction to food product and test method standards. In conclusion, Chinese food safety standards are still being improved, but they must also be effectively implemented and followed up in real time in order to continuously improve the quality of food and reduce food safety incidents. © 2024 Society of Chemical Industry.     

食品包装与食品安全

食品包装与食品安全有密切的关系,食品包装必须保证被包装食品的卫生安全,才能成为放心食品。国家对食品包装有哪些具体规定?食品包装、食品生产企业和消费者应该注意哪些主要方面的问题?最近国家质量监督检验检疫总局在食品安全市场准入制度(QS标志)工作中对原材料、食品添加剂、包装材料和容器有哪些规定,因为只有合格的原材料、食品添加剂、包装材料和容器才能生产出符合质量安全要求的食品。本文从食品包装检验工作者的视角上,谈谈食品包装与食品安全,以帮助人们关注食品安全,增加食品企业的质量意识,提高消费者的鉴别能力。     

干燥性食品塑料包装防湿寿命计算

干燥性食品变质的主要原因之一是吸湿.文中介绍了塑料袋装食品的防湿寿命的计算,在理论和实际上都具有较大的意义.     

基于高频探测信号的金属探测器的研究

运用于食品领域,是金属探测器的一种新用途。与其他领域相比,在食品工业所使用的金属探测器需要有较高的灵敏度。文中从提高探测信号频率的角度,探讨了频率变化对于金属探测器探测灵敏度的影响,论证了采用高频探测信号是提高金属探测器性能的有效途径。     

Yogurt enrichment with functional asparagus fibre. Effect of fibre extraction method on rheological properties, colour, and sensory acceptance

In the asparagus-processing industry, the by-products constitute around 50% of the total weight. These by-products are rich in fibre and bioactive compounds which could be advantageously employed in human nutrition. In the present work, yogurts were enriched with fibre obtained from the non-edible part of asparagus shoots to assess how the method of extraction (water or ethanol) and then drying (oven or lyophilisation) affects its performance. Fibre incorporation increased the consistency of the yogurts (higher η, G′, G″), especially if the fibres had been extracted in ethanol and lyophilised. However, there were no significant changes in the viscoelastic behaviour (tan δ) for any of the fibre types. Fibres diminished the clarity and imparted a yellow-greenish colour to the yogurt, which also varied depending on the method of extraction and drying, the yogurts with water-extracted fibres being more colourful. The sample more liked according to a consumer test was the yogurt containing water-extracted and oven-dried fibre for aroma, taste, texture, and overall acceptance, and ethanol-extracted and lyophilised for colour. The consumer panel scored all the samples around to the neutral point “neither like nor dislike”, demonstrating that fibre obtained by all methods were equally compatible with yoghurt enrichment.