Contaminants of food

A scheme has been developed to rank 70 industrial organic chemicals in order of their priority for further study as potential contaminants of food. Numerical scales were developed for the following seven key criteria concerning environmental issues, food and toxicity:

-Production volume

-Pattern of usage

-Possible fate in the environment

-Likelihood of chemical entering the food chain

-Mechanism of entry into the food chain

-Persistence and accumulation in the food chain

-Toxicity.

Each chemical was assigned a score for the above criteria, which were combined to give an overall ranking for the chemicals. This scheme has been endorsed by the MAFF Steering Group on Chemical Aspects of Food Surveillance. It will be used in the assessment of relative priorities for further non-statutory surveillance for these contaminants in the UK food supply.     

餐厨垃圾高温厌氧消化

在中试规模下,研究餐厨垃圾高温厌氧消化试验,通过监测餐厨垃圾厌氧消化过程中产气量、气体组成等产气情况和消化液中pH值、SCOD、NH4+-N、VFAs等化学指标含量变化,确定餐厨垃圾厌氧消化的最大有机负荷,并分析餐厨垃圾高温厌氧消化技术的可行性,结果表明,在工程上餐厨垃圾单独进行高温厌氧消化产甲烷具有技术可行性,但难以保证系统长时间安全稳定运行;餐厨垃圾厌氧消化正常运行时最大有机负荷可达2.551 kg VS/(m3.d);当系统有机负荷为2.551 kg VS/(m3.d)时,每天每千克VS最高可产生甲烷量0.622 m3;氨氮对餐厨垃圾厌氧消化产甲烷影响明显;餐厨垃圾中固有Na+含量对厌氧消化产甲烷影响不明显。     

Survey of selected mycotoxins in food

The contamination of a variety of foods with the mycotoxins aflatoxins B1, B2, G1, M1, ochratoxin A, patulin, and byssochlamic acid was investigated. With the developed methods, the identification was made possible by in situ fluorescence spectral analysis with a far reaching exclusion of substances which simulate sycotoxins. Aflatoxin B1 was detected in 2 samples of 105 spontaneously moulded food specimens and only in 1 of a group of 198 food samples that were obviously not moulded. Aflatoxin M1 was identified in 4 of 60 samples of the so-called wintermilk. Investigated dairy products did not contain aflatoxin M1. Ochratoxin A could be detected twice in 49 spontaneously moulded corn samples, aflatoxin, however, was not found. Further investigations of 50 samples of moulded food revealed ochratoxin A in 2 samples of raw coffee. Food samples obviously not moulded did not contain ochratoxin A. Patulin was detected in 19 of 110 samples of fruit and fruit products, especially in commercial apple juice, in rotten parts of apples, and in moulded fruit products. Byssochlamic acid was not detected in fruit juices or in fruit. The toxicological consequences of mycotoxins in food and possibilities to reduce mycotoxins are discussed.     

The problem of predicting global food production

This paper examines the problem of the development of models capable of predicting the capacity of the global food production system. In particular, it identifies the various factors influencing the food production, and estimates their relative influence and predictability. The paper discusses also the problems connected with coupling of models representing the "driving" forces, the Earth system consisting of the atmosphere, the ocean and land surface, and food production. The overall conclusions drawn are: i) The time is not yet ripe for designing a comprehensive coupled model for predicting the global food production that takes into account all the factors having a significant influence; ii) the main difficulties are the modelling of the driving forces, e.g. socioeconomic and political factors, and iii) despite these problems, it is judged that results obtained with existing models are capable of providing concrete information for implementation of adaptation and mitigation measures.     

Decreasing reliance on mineral nitrogen--yet more food

Higher crop production normally demands higher nutrient application rates and consequently increased mineral nitrogen use. With food demand for 2030 estimated around 2800 mill. tonnes (t) yr-1, the corresponding mineral N consumption figure is 96 mill. t (78 mill. t yr-1 in 1995/1997). Global-level mineral N losses to the environment from mineral fertilizer use are currently 36 mill. t yr-1, worth USD 11,700 mill. and with adverse environmental impacts. However, innovative fertilizer-use efficiency (FUE) technologies enable increased production with a less than a proportionate increase in mineral-N use. Moreover, nitrogen-nutrient supplies can be augmented through improvements in agricultural production systems and in the exploitation of alternative sources such as biological nitrogen fixation (BNF). By 2030, with adequate policy, technology transfer, research and investment support, the on-farm adoption of BNF and FUE technologies could generate savings of 10 mill. t yr-1 of mineral N, worth USD 3300 mill.     

两段式热解厨余垃圾实验研究

通过厨余垃圾的工业分析，发现其挥发分比例较高，适合热解利用；采用热重分析方法分析了不同条件下厨余垃圾的热解特性，提出了厨余垃圾两段式热解转化利用的思路，得出了厨余垃圾热解的合适工艺条件。在自行设计建造的一段回转炉、二段焦化罐中对厨余垃圾热解，并分析了产物的组成和性质。     

Determining dioxin-like compounds in selected Korean food

To measure the levels of dioxin-like compounds, pork, mackerel, cheese and milk were analyzed. The food samples were obtained at three different markets in Seoul. All the samples were animal origin and their lipid contents ranged from 4% to 34%. After extraction, extracts were cleaned up by sulfuric acid impregnated silica gel, purified on a series of silica gel, alumina, carbon column chromatography and then analyzed by high resolution gas chromatography/high resolution mass spectrometry. The levels of polychlorinated dibenzo-p-dioxins/furans for pork, mackerel, cheese and milk were 0.0008, 0.8663, 0.002 and 0.0236 pgTEQ/g wet weight, respectively. In addition, the levels of non-ortho coplanar polychlorinated biphenyls for pork, mackerel, cheese and milk were 0.0041, 1.5781, 0.0259 and 0.0353 pgTEQ/g wet weight, respectively. Among food samples analyzed, pork showed the lowest level of dioxin-like compounds.     

Zinc oxide nanoparticles: potential effects on soil properties,crop production,food processing,and food quality

Environmental Science and Pollution Research - The use of zinc oxide nanoparticles (ZnO NPs) is expected to increase soil fertility, crop productivity, and food quality. However, the potential...     

Organochlorine compounds in a three-step terrestrial food chain

The concentrations of 15 organochlorine chemicals (PCBs and pesticides) were studied in a Central European oak wood food chain system: Great tit (Parus major), caterpillars (Tortrix viridana, Operophtera brumata, Erannis defoliaria), and oak-leaves (Quercus robur). Juvenile tits receive organochlorines from the mother via egg transfer and, eventually to a greater extent, from the caterpillar food source during nestling period. The concentrations of PCB 153 (2,2′,4,4′,5,5′-hexachlorobiphenyl, the most abundant in this study) was found in leaf material at ca. 1 ng/g, in caterpillars 10 ng/g, and in bird eggs 170 ng/g on an average and on a dry mass basis.     

餐厨垃圾厌氧产氢综述

针对餐厨垃圾厌氧产氢过程,从工艺、单组分底物厌氧产氢和过程机理研究阐述了国内外进展,并对未来研究发展方向进行了展望.研究成果表明,餐厨垃圾厌氧发酵产氢过程可行,但影响因素多,系统不稳定,大部分研究停留在实验室小试阶段.尚需针对餐厨垃圾厌氧发酵产氢优势菌种选育、生态因子调控、代谢机理、反应器改进和系统控制模拟等方面开展研究,为该技术的大规模应用提供研究基础.     

Estimating chemical biotransformation rates from food web concentrations

Biotransformation is widely recognized as the most important and most uncertain determinant of bioaccumulation. A step-wise method for estimating organism-specific biotransformation half-lives from field observations and using established food web modeling is developed. As a proof of concept, the method is applied to the case of nine polycyclic aromatic hydrocarbons (PAHs) in a well-studied food web in Bohai Bay, China. The estimated half-lives are in good agreement with the existing literature. The proposed biotransformation estimation method, through data mining, for sufficiently defined ecosystems, may greatly reduce the necessary animal testing involved in chemical assessments by providing useful guidance to experimentalists and regulators.     

国内外餐饮垃圾的管理

餐饮垃圾高含水量和易腐等特性 ,使其成为一类特殊的固体垃圾。餐饮垃圾对于我国城市发展还是个新问题 ,国内外系统报道其管理和处理对策的文献也很少。在分析中 ,介绍了国内外餐饮垃圾的管理政策与治理技术 ,同时 ,针对我国目前现状 ,提出城市餐饮垃圾的管理和治理建议 ,为困扰我国众多城市的餐饮垃圾管理与治理决策提供参考     

Modelling PCB bioaccumulation in a Baltic food web

A steady state model is developed to describe the bioaccumulation of organic contaminants by 14 species in a Baltic food web including pelagic and benthic aquatic organisms. The model is used to study the bioaccumulation of five PCB congeners of different chlorination levels. The model predictions are evaluated against monitoring data for five of the species in the food web. Predicted concentrations are on average within a factor of two of measured concentrations. The model shows that all PCB congeners were biomagnified in the food web, which is consistent with observations. Sensitivity analysis reveals that the single most sensitive parameter is log K(OW). The most sensitive environmental parameter is the annual average temperature. Although not identified amongst the most sensitive input parameters, the dissolved concentration in water is believed to be important because of the uncertainty in its determination. The most sensitive organism-specific input parameters are the fractional respiration of species from the water column and sediment pore water, which are also difficult to determine. Parameters such as feeding rate, growth rate and lipid content of organism are only important at higher trophic levels.     

Fenton试剂法降解餐厨垃圾异味

自行设计Fenton试剂法降解还原性气体异味的反应器,研究了Fenton试剂法处理餐厨垃圾异味主要成分(苯、乙酸乙酯、苯乙烯)的降解效果。以苯为典型代表物,优化得出该实验的最佳反应条件为:pH=3,FeSO4.7H2O投加量为1 g/L液相,30%H2O2投加量为10 mL/L液相,紫外光源辅助。结果证明,Fenton试剂法处理单一异味气体的效果较理想,在前180 min内能达到90%以上,该法在处理气态异味污染物方面具有广阔的应用前景。     

竹叶与餐厨垃圾厌氧共消化工艺

将黄金竹和毛竹的竹叶分别与餐厨垃圾厌氧共消化,通过分析消化过程中的产气量、pH、COD、NH4+-N和VFAs变化,探讨添加不同竹叶对餐厨垃圾厌氧消化效果的影响.实验结果表明,添加毛竹叶显著增强了餐厨垃圾的厌氧消化能力.毛竹叶+餐厨垃圾组的总产气量是餐厨垃圾对照组单独厌氧消化总产气量的3.28倍,甲烷总产量为10.1 L,COD去除率高达83.0％.而添加黄金竹叶对餐厨垃圾厌氧消化的影响则不明显,可能因为黄金竹叶在消化过程中释放了大量挥发性脂肪酸(VFAs),造成体系酸中毒.     

Drivers of food waste generation and best practice towards sustainable food waste management in the hotel sector: a systematic review

Environmental Science and Pollution Research - The growing volumes of food globally are lost or wasted along the entire food chain. However, a high effort in investigating why food waste (FW)...     

Biomagnification of organochlorines along a Barents Sea food chain

To trace the biomagnification of organochlorines in marine food chains near Svalbard, which may lead to the high organochlorine concentrations in top predators from the area, we compared concentrations and patterns of organochlorines in selected taxa. The pelagic crustaceans, Calanus spp. (copepods), Thysanoessa spp. (euphausiids), Parathemisto libellula (amphipod), and the fish species, Boreogadus saida (polar cod) and Gadus morhua (cod) were selected to represent the lower trophic levels in the food web. Four seabird species were chosen at the higher trophic levels, Uria lomvia (Brünnich's guillemot), Cepphus grylle (black guillemot), Rissa tridactyla (black-legged kittiwake) and Larus hyperboreus (glaucous gull). We found low concentrations of the organochlorines sigma hexachlorocyclohexanes (sigma HCHs), hexachlorobenzene (HCB), sigma Chlordanes, sigma DDTs and sigma polychlorinated biphenyls (sigma PCBs) in crustaceans (11-50 ng g-1 lipid wt.) and fish (15-222 ng g-1 lipid wt.). In seabirds, the organochlorine concentrations biomagnified one to three orders of magnitude dependent on species and compound class. Glaucous gulls had the highest concentrations of all organochlorines. The organochlorine levels in all taxa except glaucous gull were comparable to those recorded in similar species in the Canadian Arctic. The organochlorine pattern changed from crustaceans and fish to seabirds. Moving up the food chain, the relative contribution of sigma HCHs, HCB and sigma Chlordanes decreased, and the relative contribution of sigma DDTs, sigma PCBs, persistent compounds and metabolites increased. The results reflected trophic transfer of organochlorines along the food chain as well as different elimination potentials due to direct diffusion in crustaceans and fish, and higher contaminant metabolic activity in seabirds.