Consumer acceptance of food crops developed by genome editing

One of the major problems regarding consumer acceptance of genetically modified organisms (GMOs) is the possibility that their transgenes could have adverse effects on the environment and/or human health. Genome editing, represented by the CRISPR/Cas9 system, can efficiently achieve transgene-free gene modifications and is anticipated to generate a wide spectrum of plants. However, the public attitude against GMOs suggests that people will initially be unlikely to accept these plants. We herein explored the bottlenecks of consumer acceptance of transgene-free food crops developed by genome editing and made some recommendations. People should not pursue a zero-risk bias regarding such crops. Developers are encouraged to produce cultivars with a trait that would satisfy consumer needs. Moreover, they should carefully investigate off-target mutations in resultant plants and initially refrain from agricultural use of multiplex genome editing for better risk–benefit communication. The government must consider their regulatory status and establish appropriate regulations if necessary. The government also should foster communication between the public and developers. If people are informed of the benefits of genome editing-mediated plant breeding and trust in the relevant regulations, and if careful risk–benefit communication and sincere considerations for the right to know approach are guaranteed, then such transgene-free crops could gradually be integrated into society.     

Seeing group members eating a familiar food enhances the acceptance of novel foods in capuchin monkeys

In primates, social context is one of the factors that increases the acceptance of novel foods. Previous experiments showed that tufted capuchins, Cebus apella, eat significantly more of novel foods when in the presence of group members eating the same novel foods. Several processes may have led to these results. The mere presence of group members may reduce the individual's stress of being alone, or its neophobic response and, consequently, may increase its food consumption. The individual may be influenced by what group members do, and local/stimulus enhancement and/or social facilitation may occur. To investigate the above processes, we assessed whether an individual capuchin monkey's consumption of novel foods is lower when (1) the individual is alone with nobody in the nearby cage than when (2) group members are present in the nearby cage with no food or when (3) they are present and eating a familiar food. We tested 15 subjects with three novel foods, each presented in one condition. In both social conditions, the more group members there were by the food box the more the experimental subject ate. In addition, when group members were present and eating food, there was a significant increase in the acceptance of the three foods, regardless of what group members were eating. We argue that social facilitation of eating is a quicker way to overcome neophobia and only social facilitation of eating what the others are eating can be considered a safe way to learn about a safe diet. Copyright 2000 The Association for the Study of Animal Behaviour.     

Genotoxicity of heat-processed foods

Gene-environment interactions include exposure to genotoxic compounds from our diet and it is no doubt, that humans are regularly exposed to e.g. food toxicants, not least from cooked foods. This paper reviews briefly four classes of cooked food toxicants, e.g. acrylamide, heterocyclic amines, nitrosamines and polyaromatic hydrocarbons. Many of these compounds have been recognised for decades also as environmental pollutants. In addition cigarette smokers and some occupational workers are exposed to them. Their occurrence, formation, metabolic activation, genotoxicity and human cancer risk are briefly presented along with figures on estimated exposure. Several lines of evidence indicate that cooking conditions and dietary habits can contribute to human cancer risk through the ingestion of genotoxic compounds from heat-processed foods. Such compounds cause different types of DNA damage: nucleotide alterations and gross chromosomal aberrations. Most genotoxic compounds begin their action at the DNA level by forming carcinogen-DNA adducts, which result from the covalent binding of a carcinogen or part of a carcinogen to a nucleotide. The genotoxic and carcinogenic potential of these cooked food toxicants have been evaluated regularly by the International Agency for Research on Cancer (IARC), which has come to the conclusion that several of these food-borne toxicants present in cooked foods are possibly (2A) or probably (2B) carcinogenic to humans, based on both high-dose, long-term animal studies and in vitro and in vivo genotoxicity tests. Yet, there is insufficient scientific evidence that these genotoxic compounds really cause human cancer, and no limits have been set for their presence in cooked foods. However, the competent authorities in most Western countries recommend minimising their occurrence, therefore this aspect is also included in this review.     

Prebiotics in foods

A wealth of information has been gathered over the past 15 years on prebiotics through experimental, animal and human studies, with the aim to understand the mechanism of actions and elucidate their beneficial health effects to the human host. Significant amount of evidence exists for their ability to increase the bioavailability of minerals and stimulate the immune system, although there is less clear evidence so far for their prophylactic or therapeutic role in gastrointestinal infections. Moreover, the effect of the food delivery vehicle on the efficacy of prebiotics is an area that has been hardly investigated. Besides their beneficial effects, prebiotics influence the textural and organoleptic properties of the food products, such as dairy and baked products. To do this however, they need to be stable during food processing, in particular under conditions of high temperature and low pH.     

Chitosan-based dietary foods

Chitosan exhibits anticholesterolemic, antiulcer and antiuricemic properties when orally administered, and is potentially suitable for the prevention of the coeliac disease. This set of properties stems from the capacity to bind specifically fatty acids, bile acids, phospholipids, uric acid and the toxic gliadin fraction. Chitosan does not depress the serum iron and hemoglobin, does not overstimulate the 3-hydroxy-3-methylglutaryl CoA reductase; it does not alter the human intestinal microbiota, but lowers the putrefaction metabolites. Its susceptibility to the hydrolytic action of lipases is discussed. For oral administration, chitosan should be supplied with a proper degree of polymerization and chemical form.     

Traditional fermented foods

For centuries, diverse plant and animal materials have been fermented by various bacteria, yeasts, and fungi to make excellent foods. The kinds of micro organisms used in traditional fermentation are restricted to a relatively few genera, including Aspergillus, Rhizopus, Mucor, Actinomucor, Monascus, Saccharomyces, Neurospora, Acetobacler, Bacillus, and Lactobacillus. The two principal advantages of food fermentations over other processes are to add flavor and to prevent spoilage. Fermented fish is a common food in the Orient and may have been the first product made by fermentation. Flavor is especially important in vegetable diets based on bland foods such as rice. Shoyu is the best, known oriental food fermentation, and it is very widely used as a flavoring agent. Be sides this fermentation, there are a large number of additional ones not so well known outside the Orient, whose products serve as seasoning or flavoring agents. Miso and natto are prepared from soybeans in Japan. Sufu is a cheese like product made from soybean milk in China. Tempeh and ontjom are Indonesian foods prepared from soybeans and peanuts, respectively. These food fermentations are discussed with emphasis on how they are produced and the flavor formed.     

生物技术与食品

现代生物技术是以生命科学为基础,利用生物或其组织部份的特性和功能,设计构建具有预期性状的新物种或新品系,以及与工程原理相结合进行加工生产,为社会提供商品和服务的综合性技术体系。生物技术已经被运用了许多个世纪,传统上它曾被集中地用于生产新种类的食品,如面包、奶酪、啤酒、葡萄酒以及酱油、米酒和发酵的奶制品。食品工业在过去几十年里发生了些什么变化?首先,世界范围的人口结构发生了重要变化,老年社会的形成,65岁以上的人口增加了,这些人需要符合营养结构的及可以立即食用的产品。其次,家庭规模的减小意味着对小包装食品的需求…     

Enterococci from foods

Enterococci have recently emerged as nosocomial pathogens. Their ubiquitous nature determines their frequent finding in foods as contaminants. In addition, the notable resistance of enterococci to adverse environmental conditions explains their ability to colonise different ecological niches and their spreading within the food chain through contaminated animals and foods. Enterococci can also contaminate finished products, such as fermented foods and, for this reason, their presence in many foods (such as cheeses and fermented sausages) can only be limited but not completely eliminated using traditional processing technologies. Enterococci are low grade pathogens but their intrinsic resistance to many antibiotics and their acquisition of resistance to the few antibiotics available for treatment in clinical therapy, such as the glycopeptides, have led to difficulties and a search for new drugs and therapeutic options. Enterococci can cause food intoxication through production of biogenic amines and can be a reservoir for worrisome opportunistic infections and for virulence traits. Clearly, there is no consensus on the acceptance of their presence in foodstuffs and their role as primary pathogens is still a question mark. In this review, the following topics will be covered: (i) emergence of the enterococci as human pathogens due to the presence of virulence factors such as the production of adhesins and aggregation substances, or the production of biogenic amines in fermented foods; (ii) their presence in foods; (iii) their involvement in food-borne illnesses; (iv) the presence, selection and spreading of antibiotic-resistant enterococci as opportunistic pathogens in foods, with particular emphasis on vancomycin-resistant enterococci.