Organic Food: Buying More Safety or Just Peace of Mind? A Critical Review of the Literature

Consumer concern over the quality and safety of conventional food has intensified in recent years, and primarily drives the increasing demand for organically grown food, which is perceived as healthier and safer. Relevant scientific evidence, however, is scarce, while anecdotal reports abound. Although there is an urgent need for information related to health benefits and/or hazards of food products of both origins, generalized conclusions remain tentative in the absence of adequate comparative data. Organic fruits and vegetables can be expected to contain fewer agrochemical residues than conventionally grown alternatives; yet, the significance of this difference is questionable, inasmuch as actual levels of contamination in both types of food are generally well below acceptable limits. Also, some leafy, root, and tuber organic vegetables appear to have lower nitrate content compared with conventional ones, but whether or not dietary nitrate indeed constitutes a threat to human health is a matter of debate. On the other hand, no differences can be identified for environmental contaminants (e.g. cadmium and other heavy metals), which are likely to be present in food from both origins. With respect to other food hazards, such as endogenous plant toxins, biological pesticides and pathogenic microorganisms, available evidence is extremely limited preventing generalized statements. Also, results for mycotoxin contamination in cereal crops are variable and inconclusive; hence, no clear picture emerges. It is difficult, therefore, to weigh the risks, but what should be made clear is that 'organic' does not automatically equal 'safe.' Additional studies in this area of research are warranted. At our present state of knowledge, other factors rather than safety aspects seem to speak in favor of organic food.     

纸浆漂白废水中有机氯化物的排放与控制

本文概述了纸浆漂白废水的特性，以及影响其有机氯化物发生量的因素。     

烤烟国家标准(40级)河南烟叶水浸液pH值、总酸度和总挥发酸含量的研究

测定了河南烤烟（４０级）各等级烟叶的水浸液总酸度、水浸液ｐＨ值、总挥发酸含量。结果表明：各等级烟叶总酸度集中在１２％～１６％之间，水浸液ｐＨ值集中在５．２０～５．３６之间，总挥发酸含量集中在０．３７％～０．７７％之间。进一步分析了上述测定结果与烟叶部位、颜色、等级的关系，找出了规律性，为研究有机酸对烟草品质的影响提供了参考依据。     

磷钼蓝分光光度法测定果蔬中有机磷

将氯化亚锡与亚硫酸钠混合溶液作为磷钼蓝分光光度法中的还原剂,分别测定样品中的总磷和无机磷,从而得到样品中有机磷的含量。该方法的最大吸收波长为740nm,磷在0～30μg范围内符合比耳定律,标准曲线的回归方程为y=0.1972x-0.0234,相关系数R2=0.9955,摩尔吸收系数为1.53×105L.mol-1.cm-1,相对标准偏差为1.85%～4.11%,回收率为96.16%～103.06%。     

MS-HPLC法检测啤酒酵母胞内代谢有机酸的变化

通过啤酒酵母细胞的几种破壁方法比较 ,确定了微波破壁 (MS ,microwave -split)和高效液相色谱(HPLC)联用的方法 ,对通风发酵过程中啤酒酵母细胞胞内六种有机酸含量的动态变化 ,进行了定性定量跟踪检测。本方法具有前处理简单、干扰小、分析速度快等优点 ,便于及时跟踪测定发酵过程中有机酸的动态变化。研究结果表明通风发酵过程中 ,胞内作为经济性碳底物的柠檬酸和琥珀酸含量很低 ,代谢变化调控严格 ;其余四种有机酸在发酵后期阶段有机酸含量变化对K 、Ca2 两种离子响应不同     

有机释酸剂及其应用

测试了多种有机酯类化合物在不同温度下的释酸情况及对酸性染料上染速率的影响，以此为原料制备了两种释酸剂，并对其在酸性染料染色中的应用性能进行了测试。实验结果表明，采用释酸剂代替醋酸作为酸性染料染色的酸剂，可大大减缓染色初期的上染速率，提高染色的均匀性。     

超声波处理凹凸棒土的有机改性研究

采用超声波技术,对凹凸棒土进行有机改性,提高凹凸棒土的吸附性能.比较了不同的阳离子表面活性剂的改性效果,并且通过正交实验得出了超声波改性的最优工艺条件为:十八烷基三甲基氯化铵的添加比例为35 mmol/100g,超声波处理时间10 min,屏极电流0.5 A.在此条件下,苯酚吸附量可达17.0 μg/mg.     

木素制可降解塑料的研究

以木质素、25%的甘油共混造粒,造粒后的木质素与淀粉母料、聚乙烯共混挤出制备55%的木质素基塑料.研究了木素/淀粉/聚乙烯共混物的流变特性、力学性能和降解性.流变特性表明共混物可加工性,添加淀粉母料的共混物的力学性能有所降低而降解性加快.     

新型有机絮凝剂的合成及其应用

介绍了采用正交设计的方法，以魔芋精粉和磷酸盐为主要原料合成新型有机絮凝剂魔芋葡甘聚糖磷酸酯的配方及条件。同时进行了絮凝效果应用研究。     

透析培养法稳定出芽短梗霉摇瓶发酵条件的研究

以出芽短梗霉色素低产株G58-2为生产菌株,研究了其透析培养下的菌体形态,及普鲁兰多糖摇瓶发酵的最佳条件。结果表明,通过透析培养制备的发酵接种液优于普通培养,在其OD600为0.442,接种龄36h,初始pH7.0,装液量50 mL/250 mL,摇床转速200 r/min条件下培养84 h出芽短梗霉G58-2不仅色素含量低,粗多糖产量可达到4.84 g/100 mL,并且实验稳定性有效提高。