共查询到16条相似文献,搜索用时 0 毫秒
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Meyer B 《International journal of food microbiology》2006,112(3):275-279
Numerous reports are available on microbial resistance to antibiotics as well as to biocides. Instances of cross-resistance between these substance groups have been reported. Resistance, which is a genetically determined phenomenon, has to be distinguished from phenotypic adaptation processes, which are not hereditary. Adaptation can be avoided by rigorous cleaning and disinfection, avoiding concentrations of disinfectants below the microbicidal concentration. Resistance phenomena have to be divided into intrinsic and acquired resistance. Intrinsic resistance is the naturally greater resistance of certain microbial species compared to others. The term acquired resistance is used if certain strains of a microbial species differ significantly in their susceptibility to biocides compared to the average of this species. An overview of existing reports of resistance to different biocidal substances is given. In most of these reports, resistance is defined as an elevated minimum inhibitory concentration. The relevance of these data for disinfection processes, where microbicidal concentrations are applied, is discussed. Rotational use of different types of disinfectants, to avoid development of resistance, has been discussed controversially. Because of the unspecific mechanism of action of biocides, and the lack of scientific evidence for its need, rotational use of disinfectants is not recommended. In conclusion the risk of hazards in food production and processing caused by resistance to biocides is regarded as low. 相似文献
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Henle T 《Molecular nutrition & food research》2007,51(9):1075-1078
Physiological consequences resulting from protein-bound Maillard compounds in foods must be discussed carefully. This was the idea behind the debate, which is put for discussion by the papers by Sebekova and Somoza, who argued for the motion that dietary advanced glycation end products (AGEs) are a health risk, and by Ames, who provided evidence against the motion. In this two excellent reviews, numerous arguments based on papers published in high-impact journals are given for each of the opinions. The fact that no final conclusion can be drawn, may reflect the need for a more comprehensive examination of this issue in the future. For a deeper understanding of biological consequences resulting from heated foods, the relationships between well-defined biological effects and well-characterized chemical structures must be studied. Prerequisite for this is profound chemistry--pure compounds, exact concentrations, and unambiguous analytical techniques. A real "risk assessment" is much too complex than to leave it up to one discipline alone. It must be a comprehensive and interdisciplinary approach, joining the resources of biology, medicine, and chemistry. 相似文献
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Does a two-year period of orthokeratology lead to changes in the endothelial morphology of children?
Purpose
To compare changes in endothelial morphology in the central and superior cornea in subjects wearing single-vision spectacles and orthokeratology lenses over two years.Methods
Endothelial images of the two locations of 99 subjects (6–12 years) from completed myopia control studies were analysed. Endothelial cell density (ECD), coefficient of variation in cell size (CV), and hexagonality (HEX) before and two years after treatment were compared between the two groups of subjects.Results
Baseline ECD and CV in the central cornea were slightly lower than those in the superior cornea, but no significant difference in HEX was found in the two corneal locations. After two years, reduction in ECD and increase in CV were only significant in the central cornea, but not in the superior cornea. Reduction in HEX was significant in both corneal locations. Subjects receiving orthokeratology had smaller reduction in ECD in the central cornea compared to the controls (orthokeratology: 56 ± 94 cells/mm2; control: 98 ± 91 cells/mm2, p = 0.024), otherwise, there were no significant differences in the changes in endothelial morphology in the two corneal locations between the two groups of subjects.Conclusions
The current study confirmed that there were differences in endothelial morphology of central and superior cornea of Chinese children aged 6–12 years. The morphological response to normal ageing differed between the two corneal locations as reduction in cell density and polymegathism were found only in the central cornea whilst pleomorphism was found in both locations. Orthokeratology lens wear had minimal effect on the developmental changes in endothelial morphology. 相似文献8.
Chirumbolo S 《Journal of the science of food and agriculture》2012,92(8):1573-1577
Plant phytochemicals represent an exciting opportunity to maintain best health conditions through a balanced and properly administered daily nutrition or dietary supplement and have often been considered a good option for obtaining a few promising, expensive new drugs from plants. Several polyphenolic compounds, such as resveratrol, tea catechins and flavonoids, which are commonly found in vegetables, fruits and plant-derived juices or beverages, exert well-evidenced cardioprotective, neuroprotective, chemopreventive and anti-inflammatory properties, but, nevertheless, further clinical and epidemiological research is required. Most of these botanical byproducts are produced as noxious components by plants, in order to prevent pathogen colonization, insect-mediated damage and also to discourage animals from eating them. An evolutionary theory of stress adaptation would explain how these toxic substances from nature act as protective molecules. A future challenge to achieve a rather complete understanding of these chemical phenol derivatives for human health should deal with the complexity of cellular signalling networks, the epigenetic machinery endowment of the cell and the nonlinear relationship between dose and effectiveness. 相似文献
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Initial assays indicated that lentil is a very poor host for an Asian population of the seed beetle Callosobruchus maculatus (F.). Larval survival was near zero, and females laid few or no eggs on lentil seeds. However, mass selection in the laboratory consistently produced a rapid increase in survival (from <2% to >80% in <20 generations) as well as a moderate increase in host acceptance. We investigated whether adaptation to lentil simultaneously causes cross-adaptation to other grain legumes, particularly those closely related to lentil. After 30 generations of selection, survival in lentil exceeded 90% in the lentil line, but remained near zero in a line maintained on the ancestral host, mung bean. Despite this extreme divergence in performance in lentil, the lines did not differ in their survival on eight other legume hosts, including two hosts (pea and fava bean) that belong to the same tribe (Vicieae) as lentil. Similarly, females from the lentil line laid more than three times as many eggs on lentil as females from the mung bean line did, but the lines exhibited only minor differences in their acceptance of eight alternative hosts. Lentil-line females did not show greater acceptance of artificial seeds (glass balls), as might be expected if increased egg-laying on lentil was simply due to a reduction in the overall threshold for oviposition. We conclude that the changes in larval physiology and adult behavior that permitted rapid colonization of a marginal host were largely specific to that host, and not likely to promote a further expansion of the beetle's host range. 相似文献
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This study provides a quantitative evaluation on the potential impact of the implementation of the Trans-Pacific Partnership (TPP) on the economic interests in the US textile industry, particularly with regard to Japan’s accession to the agreement. By adopting the Global Trade Analysis Project (GTAP) computable general equilibrium model based on the GTAP8 database, results of the study show that: first, trade creation effect of the TPP would result in an increase of the US textile exports to other TPP members; however, with Japan’s accession to the TPP, the potential expansion of the US textile exports would be substantially offset. Second, the TPP would negatively affect the US textile exports to the North American Free Trade Agreement and CAFTA regions, particularly in the case when Japan becomes a TPP member. Third, the TPP would expand the two-way intra-industry trade between the United States and Japan for textiles. Fourth, the TPP would cause an expansion of the trade deficit as well as a decline of domestic production in the US textile industry, particularly in the case when Japan becomes a TPP member. Findings of this study augment our understanding of the Textile and apparel (T&A)-specific sectoral impact of the TPP and provide valuable inputs supporting the T&A sectoral negotiation under the TPP. 相似文献
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《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2013,30(1):9-24
A Total Diet Study (TDS) consists of selecting, collecting and analysing commonly consumed foods to obtain concentration data of different chemical compounds in foods as eaten. A TDS food list summarises the most consumed foods and represents the dietary habits of the general population of the country under study. The work reported here investigated whether TDS food lists that were initially designed for the whole population of the country under study also sufficiently cover the dietary pattern of specific subpopulations that are extra vulnerable for certain contaminants. The work was performed using data of three European countries: the Czech Republic, France and the UK. Each national food consumption database was combined with the corresponding national TDS food list (containing 336, 212 and 119 food items for the Czech Republic, France and the UK, respectively). The data were aggregated on the highest level of hierarchy of FoodEx-1, a pan-European food classification system, including 20 main FoodEx-1 groups. For the group ‘milk and dairy products’, the coverage of the consumption by the food list was investigated for more refined subgroups. For each food group or subgroup and country, the average percentage of coverage of the diet by the national TDS food list was calculated for different subpopulations, including children versus adults, women versus men, vegetarians versus non-vegetarians, and women of child-bearing age versus older women. The average diet of the different subpopulations was sufficiently covered by the food list of the Czech Republic and France. For the UK the average coverage was low due to a different food-coding approach and because food lists were not derived directly from national food consumption data. At the level of the 20 main food groups, differences between the subpopulations with respect to the average coverage of consumption by the TDS food list were minimal. The differences were more pronounced when looking in detail at the coverage of the dairy consumption. TDS food lists based on the mean consumption of the general population are also applicable to study the chemical exposure of different subpopulations, e.g. children, women of child-bearing age and vegetarians. This lowers the effort when performing a TDS. 相似文献
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Berlyne’s theory of hedonic appreciation in experimental esthetics includes complexity as a relevant dimension in the development of preferences. However, the soundness of this theory in the field of food and beverages has been challenged. The work reported here investigates the influence of perceived complexity on consumers’ preferences for some dairy desserts. Given the limits on sensory complexity reported in the literature, we (i) controlled for consumers’ level of familiarity with the products, (ii) used enough products to be able to test a quadratic model, (iii) evaluated sensory complexity with consumers, and (iv) analyzed data after clustering. Seven gourmet dairy desserts were tested by 145 French consumers, unfamiliar with this type of product, in a quantitative study. Products were also sensory-characterized by a panel using an adaptation of Sequential Profiling. We distinguished four groups of consumers with different perceptions of sensory complexity. For one group, the influence of complexity on preference was in line with Berlyne’s theory. Individual differences were also underlined between groups as the self-reported eating style and the level of familiarity with dairy products. Finally, our results confirm the importance of a dynamic evaluation to understand sensory complexity. Indeed, our findings show the influence of the number of sensations and their temporal evolution on sensory complexity. For the first time, we underline the potential effect of texture and flavor sensations on perceived complexity. 相似文献
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Trung D. Vo Barry S. Lynch Ashley Roberts 《Comprehensive Reviews in Food Science and Food Safety》2019,18(1):31-47
Emulsifiers are commonly used in food processing for the technological purpose of altering the flavor or to improve the texture of foods. Due to their ubiquity, these substances are consumed daily at low levels in the human diet. Recently published in vitro and in vivo studies suggest dietary exposure to emulsifiers modulate the gut microbiota and contribute to the increasing prevalence of metabolic disease. A literature search was conducted which identified eight studies investigating the interaction of sodium carboxymethyl cellulose, polysorbate 80, gum arabic, carrageenan, and arabinogalactan with the gut microbiota in murine and in vitro models. Numerous inconsistent changes in various phyla and genera were identified. These studies were conducted at high doses that have no relevance to the current dietary levels consumed in the United States. Subtle changes in gut microbiota composition as a toxicological endpoint is not supported by established internationally recognized toxicology testing guidelines. Therefore, the results of these studies are difficult to interpret and extrapolate to humans and are not supported by previous safety conclusions of international food safety authorities. The current understanding of the gut microbiota is that the structure is highly dynamic and is heavily influenced by the diet. Thus, the results of these studies may not necessarily suggest a safety concern, but rather reflect an adaptive response of the gut microbiota to an external stressor. Future research will need to further elucidate the mechanisms of metabolic disease in rodents and humans and establish clinically relevant and reliable endpoints to assess changes in gut microflora. 相似文献
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Cristina Delgado‐Andrade José A Rufián‐Henares Rosa Nieto José F Aguilera M Pilar Navarro Isabel Seiquer 《Journal of the science of food and agriculture》2010,90(5):898-905
BACKGROUND: The effects of pelleting on the extent of the Maillard reaction (MR) and on calcium, magnesium and zinc solubility and absorption were analysed in a conventional pre‐starter diet for suckling piglets. Development was tested measuring colour, absorbance (280/420 nm), fluorescence, residual free lysine, furosine, hydroxymethylfurfural (HMF) and furfural contents before and after pelleting. Fluorescence, absorbance and mineral solubility were also measured after in vitro digestion of diets. The effects on mineral absorption were tested using Caco‐2 cells. RESULTS: MR indexes confirmed the development of the reaction during the pelleting of this particular diet compared with the meal diet. The CIE‐Lab colour parameters showed a decrease in luminosity (L*) and progress of the colour to the red zone (a*) in the pelleted diet. A 36% decrease in free lysine content was observed. Significant correlations were observed between fluorescence intensity and furosine levels, HMF and furfural. The pelleting process did not modify calcium and magnesium solubility after in vitro digestion, but soluble zinc increased. The efficiency of calcium and zinc transport across Caco‐2 cell monolayers was greater in the pelleted diet. CONCLUSIONS: Evidence of MR development is shown, resulting in various nutritional consequences. Optimisation of pelleting could result in a better formulation of diets for feedstuffs. Copyright © 2010 Society of Chemical Industry 相似文献