利用苦瓜子衣制备食用色素的研究

对苦瓜子衣色素的提取工艺及安全性进行了研究,确定了最佳提取工艺条件为:用乙醚作提取剂,提取剂用量为1∶40g/ml,提取时间为20min,提取温度为20℃,提取次数为2次。毒性试验表明:该色素的毒性很低,主要有毒元素的含量为Pb<2.0ppm、As<2.0ppm、Hg<0.01ppm。     

An Ethical Toolkit for Food Companies: Reflections on its Use

Nowadays many debates are going on that relate to the agricultural and food sector. It looks as if present technological and organizational developments within the agricultural and food sector are badly geared to societal needs and expectations. In this article we briefly present a toolkit for moral communication within the food chain. This toolkit is developed as part of a European research project. Next, we discuss what such a toolkit can bring about, given the characteristics of the present day agricultural and food sector and its wider context. We defend that the toolkit can be seen as one of the mechanisms that can help enterprises in the agricultural and food sector to be accountable. It should, however, be complemented with other mechanisms, first, to empower the wider public and, second, to stimulate a dialogue, on a more equal footing, between public authorities, citizens, and economic actors.     

Is Shennongjia a Suitable Site for Reintroducing Giant Panda: An Appraisal on Food Supply

The giant panda was found on Mount Shennongjia in Central China for thousands of years but vanished in the late 19th century. The possibility for reintroducing the giant panda in Shennongjia is discussed in terms of food availability, carrying capacity, and predicted bamboo flowering. Three species (Fargesia spathacea, F. murielae, and Yushania confusa) are considered the preferred forage bamboos, which could feed 193–223 giant pandas. However, in 1879–1888 these three species synchronously flowered and died back. In the past, such bamboo flowering usually forced the panda to migrate to a new habitat where forage bamboos were available. But since the 19th century, Shennongjia has become separated from other panda habitats by densely populated agricultural zones. Multi-species flowering of the forage bamboo and isolating of the habitat might caused the extinct of the giant panda in Shennongjia. If the flowering cycle of the bamboo is genetically fixed, the next synchronous flowering of two staple food species (F. spathacea and F. murielae) may occur in 2436–2439. It means that the food supply is dependable in Shennongjia for reintroducing the giant panda before 2436.     

Feeling Food: The Rationality of Perception

Regulatory bodies tend to treat people’s emotional responses towards foods as a nuisance for rational opinion-formation and decision-making. This position is thought to be supported by such evidence as: (1) people showing negative emotional responses to the idea of eating meat products from vaccinated livestock; and (2) people showing positive emotional responses to Magnum’s “7 sins” marketing campaign. Such cases are thought to support the idea that regulatory communication about foods should abstract from people’s emotional perceptions and that corporate marketing of foods should show restraint in capitalizing upon these weaknesses of the heart. This paper, on the contrary, argues that people’s emotional perceptions of foods represent valuable sources of knowledge. This argument is developed by making the dominant reception of people’s emotions intelligible by tracing its roots through the history of the Platonic paradigm. Although this paradigm has dominated the philosophical and psychological debate about emotions, the idea that emotions are sources of knowledge has recently gained force. This paper also traces the historical roots of the alternative Aristotelian paradigm. The cases of meat products from vaccinated livestock and Magnum’s 7 sins serve to illustrate this controversy. The paper concludes by showing that a neo-Platonic emphasis on the irrationality of emotions does not contribute to a fruitful discussion about implications of people’s perceptions for agricultural and food politics, whereas a neo-Aristotelian account of rational emotions could enable regulatory bodies to engage people in a fruitful process of opinion-formation and decision-making about food production and consumption. This paper has been written in the context of a research project “Images of Food” co-funded by the Dutch Ministry of Agriculture, Nature and Food Quality and the Social Sciences Group of Wageningen University and Research Centre. I would like to thank my colleagues Hans Dagevos, Sandra van der Kroon, Siet Sijtsema, Cor van der Weele (Wageningen University), and Cindy Wolff, as well as the members of the advisory board for this project, for the inspiring discussions about previous versions of this paper.     

An analysis of the Canadian Research and Development System for Agriculture/Food

The report entitled An Analysis of the Canadian Research and Development System for Agriculture/Food which was presented to the Science Council of Canada in July, 1991 contains many far-reaching recommendations for revisions of the research and educational components of the Agriculture/Food System in Canada. The report calls for research of holistic and interdisciplinary nature. It calls for determination of research priorities by broadly constituted committees which would include reporesentaitves heretofore not included in the process of decisionmaking regarding scientific research. In addition, it calls for restructuring of the agricultural education system. The Co-editors of this Journal, believe that these recommendations should be wildely discussed and, therefore, requested publication of the Executive Summary of this Report.     

Trust,Food, and Health. Questions of Trust at the Interface between Food and Health

The food sector and health sector become more and more intertwined. This raises many possibilities, but also questions. One of them is the question of what the implication is for public trust in food and health issues. In this article, I argue that the products on the interface between food and health entails some serious questions of trust. Trust in food products and medical products is often based upon a long history of rather clear patterns of mutual expectations, yet these expectations are not similar in both sectors. As long as the food sector and health sector remain distinct, these differences will not lead to problems of trust, yet when new products are introduced, like functional foods or personalized dietary advices, trust can be threatened. To prevent this, we need clarity with regard to what we can expect of these new products and of whom to expect what in this situation. This requires not␣only adequate information on operating procedures, but also a profound debate␣on responsibilities and the explication and interpretation of moral values and norms.     

From Food Justice to a Tool of the Status Quo: Three Sub-movements Within Local Food

The local food movement has been touted by some as a profoundly effective way to make our food system become more healthy, just, and sustainable. Others have criticized the movement as being less a challenge to the status quo and more an easily co-opted support offering just another set of choices for affluent consumers. In this paper, we analyze three distinct sub-movements within the local food movement, the individual-focused sub-movement, the systems-focused sub-movement, and the community-focused sub-movement. These movements can be combined within any particular campaign or within the goals of any particular organization or individual activist, but they are nevertheless quite different from each other, and come out of different conceptualizations of what food, people, and locality are. We argue that most of the critiques leveled against local food are actually directed against the individual-focused sub-movement, which is most compatible with the current industrial food system, and perhaps not surprisingly receives the most mainstream attention. Further, we argue that while each movement has its own strengths and weaknesses, it is the community-focused sub-movement that has the most potential to radically transform the global food system.     

飞机草提取物对小菜蛾产卵驱避活性的研究

以干扰作用控制指数作为评价指标,测定了飞机草提取物和乙醇提取物的不同萃取物对小菜蛾产卵驱避作用活性。结果表明,飞机草乙醇提取物及其氯仿萃取物对小菜蛾具有较强的驱避作用,驱避效果达80％以上,对小菜蛾起驱避作用的活性成分主要存在于氯仿萃取物中。     

Effects of elevated atmospheric CO2 on invasive plants: comparison of purple and yellow nutsedge (Cyperus rotundus L. and C. esculentus L.)

The rise in atmospheric CO(2) concentration coupled with its direct, often positive, effect on the growth of plants raises the question of the response of invasive plants to elevated atmospheric CO(2) levels. Response of two invasive weeds [purple nutsedge (Cyperus rotundus L.) and yellow nutsedge (Cyperus esculentus L.)] to CO(2) enrichment was tested. Plants were exposed to ambient (375 micromol mol(-1)) or elevated CO(2) (ambient + 200 micromol mol(-1)) for 71 d in open top chambers. Photosynthetic rate did not differ between CO(2) treatments for either species. Conductance was lower in purple nutsedge and tended to be lower in yellow nutsedge. Purple nutsedge had higher instantaneous water use efficiency; a similar trend was noted for yellow nutsedge. Purple nutsedge had greater leaf area, root length and numbers of tubers and tended to have more tillers under high CO(2). In yellow nutsedge, only tuber number increased under CO(2) enrichment. Leaf dry weight was greater for both species when grown under elevated CO(2). Only purple nutsedge made seed heads; CO(2) level did not change seed head dry weight. Root dry weight increased under the high CO(2) treatment for purple nutsedge only, but tuber dry weight increased for both. Total dry weight of both species increased at elevated CO(2). Purple nutsedge (under elevated CO(2)) tended to increase allocation belowground, which led to greater root-to-shoot ratio (R:S); R:S of yellow nutsedge was unaffected by CO(2) enrichment. Findings suggest both species, purple more than yellow nutsedge, may be more invasive in a future high-CO(2) world.     

日本野漆树在红壤侵蚀区的栽培管理

介绍了日本野漆树的生长习性、栽培历史及现状,并针对红壤侵蚀区的生态环境特点,分析和探讨了其适宜的栽培与管理技术及综合利用价值。