926 resultados para Pesticide residues in food


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The closely related multidrug efflux pumps QacA and QacB, from the bacterial pathogen Staphylococcus aureus, both confer resistance to various toxic organic cations but differ in that QacB mediates lower levels of resistance to divalent cations. Cloning and nucleotide sequencing of the qacB gene revealed that qacB differs from qacA by only seven nucleotide substitutions. Random hydroxylamine mutagenesis of qacB was undertaken, selecting for variants that conferred increased resistance to divalent cations. Both QacA and the QacB mutants capable of conferring resistance to divalent cations contain an acidic residue at either amino acid 322 or 323, whereas QacB contains uncharged residues in these positions. Site-directed mutagenesis of qacA confirmed the importance of an acidic residue within this region of QacA in conferring resistance to divalent cations. Membrane topological analysis using alkaline phosphatase and beta-galactosidase fusions indicated that the QacA protein contains 14 transmembrane segments. Thus, QacA represents the first membrane transport protein shown to contain 14 transmembrane segments, and confirms that the major facilitator superfamily contains a family of proteins with 14 transmembrane segments.

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In the course of myosin-catalyzed ATP hydrolysis, certain amino acid residues in myosin interact with counterparts in actin to produce the relational changes that underlie muscle contraction; some of these interactions are ionic, but the stronger interactions are hydrophobic. In an effort to identify myosin residues participating in hydrophobic interactions, myosin (from smooth muscle) fragments with mutations at suspected sites were engineered and compared with wild-type fragments. It was found that the ATPase of doubly mutated (Trp546Ser and Phe547His) fragments was minimally activated by actin and did not decorate actin well to form the regular arrowhead pattern characteristic of myosin binding to actin filaments. Thus, we suggest that Trp546 and Phe547 are important participants in the hydrophobic actin-myosin interaction.

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The main directions in food packaging research are targeted toward improvements in food quality and food safety. For this purpose, food packaging providing longer product shelf-life, as well as the monitoring of safety and quality based upon international standards, is desirable. New active packaging strategies represent a key area of development in new multifunctional materials where the use of natural additives and/or agricultural wastes is getting increasing interest. The development of new materials, and particularly innovative biopolymer formulations, can help to address these requirements and also with other packaging functions such as: food protection and preservation, marketing and smart communication to consumers. The use of biocomposites for active food packaging is one of the most studied approaches in the last years on materials in contact with food. Applications of these innovative biocomposites could help to provide new food packaging materials with improved mechanical, barrier, antioxidant, and antimicrobial properties. From the food industry standpoint, concerns such as the safety and risk associated with these new additives, migration properties and possible human ingestion and regulations need to be considered. The latest innovations in the use of these innovative formulations to obtain biocomposites are reported in this review. Legislative issues related to the use of natural additives and agricultural wastes in food packaging systems are also discussed.

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Tese de doutoramento, Ciências do Ambiente, Universidade de Lisboa, Faculdade de Ciências, 2016

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Pt.1. Food and drug legislation.--Pt.2. Experiences in food and drug enforcement.--Bibliography (p.201)

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Thesis (Master's)--University of Washington, 2016-06

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Microscopic identification of organic residues in situ on the surface of archaeological artefacts is an established procedure. Where soil components morphologically similar to use-residue types exist within the soil, however, there remains the possibility that these components may be misidentified as authentic residues. The present study investigates common soil components known as conidia, fungal spores which may be mistaken for starch grains. Conidia may exhibit the rotating extinction cross under cross-polarised light commonly diagnostic of starch, and may be morphologically indistinguishable from small starch grains, particularly at the limits of microscope resolution. Conidia were observed on stone and ceramic archaeological artefacts from Honduras, Palau and New Caledonia, as well as experimental artefacts from Papua New Guinea. The findings act as a caution that in situ analysis of residues, and especially of those less than 5 mu m in size, may be subject to misidentification. (c) 2005 Elsevier Ltd. All rights reserved.

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In the center of today's continued and rapid technological change and ever competitive environment of the next millennium, manufacturers must realize that unless they are ready to consider and evaluate new technologies brought onto them, they may fail to adequately respond to the challenges that lie ahead of them. This research was designed to determine the consistency of the perceptions of technical and non-technical administrators, in manufacturing environment, towards technological change and group technology as an advanced manufacturing system. This research has included a review of literature with references to technological change, justification and implementation processes, and various manufacturing systems including group technology and its benefits. This research has used the research method of empirical analysis (quantitative) and case studies (qualitative) to research perceptions of technical and non-technical administrators towards technological change and group technology. Sixty-four (64) technical and fifty-one (51) nontechnical administrators from fifty (50) manufacturing organizations in the United States of America responded to the mail survey questionnaire used in this research. Responses were analyzed using the Repeated Measures ANOVA procedure to compare mean responses of each group. Two correlation analyses, Cronback Coefficient Alpha and Pearson Correlation Coefficient, were also performed to determine the reliability of the questionnaire as well as the degree of correlation of perceptions between these two groups. This research, through the empirical analysis, has found that perceptions of the technical and non-technical administrators towards group technology were not consistent. In other words, they did not perceive the benefits of group technology in the same manner to the overall organizational performance. This finding was significant since it provided the first clear and comprehensive view of the technical and non-technical administrators' perception towards group technology and technological change, in Food Equipment Manufacturer Industry, in United States of America. In addition, a number of cases were analyzed and the results have supported those of the quantitative analysis. Therefore, this research not only has provided basic data, which was unavailable prior to this investigation, but it also provided a basis for future studies.

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Humans undergo biological ageing at different rates. This associates with functional decline in a number of physiological systems and increasing incidence of age-related pathologies. The discovery of robust biomarkers of ageing could be used to identify early divergence from a path of healthy ageing towards age-related disease. In the present study, we undertook proteomic analysis of plasma from healthy young men (mean age = 21.4 ± 1.5 years) and healthy mid-life men (mean age = 57.0 ±1.6 years). We identified twelve spots including transferrin, complement C3b and transthyretin that differed in abundance between the age groups. Transferrin spots showed an acidic pI shift in older males. Sandwich ELISAs were used to investigate the changes further. C3b levels were below the level of detection by ELISA and plasma concentrations of total transferrin or transthyretin were not different between the age groups studied here. However, analysis of transferrin N-glycan structures showed an increase in terminal galactose residues in older men, suggesting that the loss of terminal N-acetyl neuraminic acid residues contributes to the more acid pI of transferrin spots observed with age. Terminal galactosylation of transferrin may be a biomarker of healthy ageing and is now under investigation in the MARKAGE study.

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Food allergy affects 6% of children but there is no cure, and strict avoidance of index allergens along with immediate access to rescue medication is the current best management. With specialist care, morbidity from food allergy in children is generally low, and mortality is very rare. However, there is strong evidence that food allergy and food hypersensitivity has an impact on psychological distress and on the quality of life (QoL) of children and adolescents, as well as their families. Until recently, the measurement of QoL in allergic children has proved difficult because of the lack of investigative tools available. New instruments for assessing QoL in food allergic children have recently been developed and validated, which should provide further insights into the problems these children encounter and will enable us to measure the effects of interventions in patients. This review examines the published impact of food allergy on affected children, adolescents and their families. It considers influences such as gender, age, disease severity, co-existing allergies and external influences, and examines how these may impact on allergy-related QoL and psychological distress including anxiety and depression. Implications of the impact are considered alongside avenues for future research.

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In this article the authors explore the performance-related employee behaviors that are the most troublesome in food service. Four subsegments of food service were surveyed and differences in profit and not-for-profit operations analyzed. Significant differences were found between the two groups, with for-profit operations indicating more severe problems in all but one behavior category.

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Lactic acid bacteria expolysaccharides (LAB-EPS), in particular those formed from sucrose have the potential to improve food and beverage rheology and enhance their sensory properties potentially replacing or reducing expensive hydrocolloids currently used as improvers in food and beverage industries. Addition of sucrose not only enables EPS formation but also affects organic acid formation, thus influencing the sensory properties of the resulting food/beverage products. The first part of the study the organoleptic modulation of barley malt derived wort fermented using in situ produced bacterial polysaccharides has been investigated. Weisella cibaria MG1 was capable to produce exopolysaccharides during sucrosesupplemented barley malt derived wort fermentation. Even though the strain dominated the (sucrose-supplemented) wort fermentation, it was found to produce EPS (14.4 g l-1) with lower efficiency than in SucMRS (34.6 g l-1). Higher maltose concentration in wort led to the increased formation of oligosaccharide (OS) at the expense of EPS. Additionally, small amounts of organic acids were formed and ethanol remained below 0.5% (v/v). W. cibaria MG1 fermented worts supplemented with 5 or 10% sucrose displayed a shear-thinning behaviour indicating the formation of polymers. This report showed how novel and nutritious LAB fermented wort-base beverage with prospects for further advancements can be formulated using tailored microbial cultures. In the next step, the impact of exopolysaccharide-producing Weissella cibaria MG1 on the ability to improve rheological properties of fermented plant-based milk substitute plant based soy and quinoa grain was evaluated. W. cibaria MG1 grew well in soy milk, exceeding a cell count of log 8 cfu/g within 6 h of fermentation. The presence of W. cibaria MG1 led to a decrease in gelation and fermentation time. EPS isolated from soy yoghurts supplemented with sucrose were higher in molecular weight (1.1 x 108 g/mol vs 6.6 x 107 g/mol), and resulted in reduced gel stiffness (190 ± 2.89 Pa vs 244 ± 15.9 Pa). Soy yoghurts showed typical biopolymer gels structure and the network structure changed to larger pores and less cross-linking in the presence of sucrose and increasing molecular weight of the EPS. In situ investigation of Weissella cibaria MG1 producing EPS on quinoa-based milk was performed. The production of quinoa milk, starting from wholemeal quinoa flour, was optimised to maximise EPS production. On doing that, enzymatic destructuration of protein and carbohydrate components of quinoa milk was successfully achieved applying alpha-amylase and proteases treatments. Fermented wholemeal quinoa milk using Weissella cibaria MG1 showed high viable cell counts (>109 cfu/mL), a pH of 5.16, and significantly higher water holding capacity (WHC, 100 %), viscosity (> 0. 5 Pa s) and exopolysaccharide (EPS) amount (40 mg/L) than the chemically acidified control. High EPS (dextran) concentration in quinoa milk caused earlier aggregation because more EPS occupy more space, and the chenopodin were forced to interact with each other. Direct observation of microstructure in fermented quinoa milk indicated that the network structures of EPS-protein could improve the texture of fermented quinoa milk. Overall, Weissella cibaria MG1 showed favorable technology properties and great potential for further possible application in the development of high viscosity fermented quinoa milk. The last part of the study investigate the ex-situ LAB-EPS (dextran) application compared to other hydrocolloids as a novel food ingredient to compensate for low protein in biscuit and wholemeal wheat flour. Three hydrocolloids, xanthan gum, dextran and hydroxypropyl methylcellulose, were incorporated into bread recipes based on high-protein flours, low-protein flours and coarse wholemeal flour. Hydrocolloid levels of 0–5 % (flour basis) were used in bread recipes to test the water absorption. The quality parameters of dough (farinograph, extensograph, rheofermentometre) and bread (specific volume, crumb structure and staling profile) were determined. Results showed that xanthan had negative impact on the dough and bread quality characteristics. HPMC and dextran generally improved dough and bread quality and showed dosage dependence. Volume of low-protein flour breads were significantly improved by incorporation of 0.5 % of the latter two hydrocolloids. However, dextran outperformed HPMC regarding initial bread hardness and staling shelf life regardless the flour applied in the formulation.

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Nanotechnology is a multidisciplinary science that is having a boom today, providing new products with attractive physicochemical properties for many applications. In agri/feed/food sector, nanotechnology offers great opportunities for obtaining products and innovative applications for agriculture and livestock, water treatment and the production, processing, storage and packaging of food. To this end, a wide variety of nanomaterials, ranging from metals and inorganic metal oxides to organic nanomaterials carrying bioactive ingredients are applied. This review shows an overview of current and future applications of nanotechnology in the food industry. Food additives and materials in contact with food are now the main applications, while it is expected that in the future are in the field of nano-encapsulated and nanocomposites in applications as novel foods, additives, biocides, pesticides and materials food contact.

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A Minimum Essential Standard of Living (MESL) is derived from a negotiated consensus on what people believe is a minimum standard. It is a standard of living that meets an individual’s or a household’s physical, psychological and social needs. This is calculated by identifying the goods and services required by different household types in order to meet their needs. While an MESL is based on needs, not wants, it is a standard of living below which nobody should be expected to live. This report focuses on food, one of the 16 elements of the Minimum Essential Standard of Living (MESL) data. It is based on a methodology called Consensual Budget Standards (CBS). The report is presented in the context of increasing concerns about the issue of food poverty in the Republic of Ireland (ROI) and an increase in the number of people reporting that they do not have enough money to buy food. Recent data from The Organisation for Economic Co-operation and Development (OECD) have shown that the number of people believing they cannot afford food doubled from 4.2% in 2008 to 9% in 2014. Data from Eurostat show that in 2013, food and non-alcoholic beverage prices in Ireland were 17% higher than the EU average. Moreover, research by Carney and Maitre, using data from the Survey on Income and Living Conditions (SILC), found that one in ten people are living in food poverty in Ireland. Food poverty is defined as the inability to have an adequate and nutritious diet due to issues of affordability and access to food. This has related effects on health, culture and social participation. The 2013 data from the Survey on Income and Living Conditions (SILC) show that 1.4 million people, almost 31% of the population, suffer from deprivation. This means that they are unable to afford two items from a list of 11 very basic items (of which one is not being able to eat a meal with meat, chicken, fish or a vegetarian equivalent every second day). The highest levels of deprivation are experienced by lone parents (63%), unemployed people (55%) and people not at work because of illness or disability (53%). The experience of the Vincentian Partnership for Social Justice (VPSJ) is that expenditure on food tends to be one of the least important considerations when households are dealing with competing demands on an inadequate income. A Minimum Essential Standard of Living (MESL) is derived from a negotiated consensus on what people believe is a minimum standard. It is a standard of living that meets an individual’s or a household’s physical, psychological and social needs. This is calculated by identifying the goods and services required by different household types in order to meet their needs. While an MESL is based on needs, not wants, it is a standard of living below which nobody should be expected to live. This report focuses on food, one of the 16 elements of the Minimum Essential Standard of Living (MESL) data. It is based on a methodology called Consensual Budget Standards (CBS). The report is presented in the context of increasing concerns about the issue of food poverty in the Republic of Ireland (ROI) and an increase in the number of people reporting that they do not have enough money to buy food. Recent data from The Organisation for Economic Co-operation and Development (OECD) have shown that the number of people believing they cannot afford food doubled from 4.2% in 2008 to 9% in 2014. Data from Eurostat show that in 2013, food and non-alcoholic beverage prices in Ireland were 17% higher than the EU average. Moreover, research by Carney and Maitre, using data from the Survey on Income and Living Conditions (SILC), found that one in ten people are living in food poverty in Ireland. Food poverty is defined as the inability to have an adequate and nutritious diet due to issues of affordability and access to food. This has related effects on health, culture and social participation. The 2013 data from the Survey on Income and Living Conditions (SILC) show that 1.4 million people, almost 31% of the population, suffer from deprivation. This means that they are unable to afford two items from a list of 11 very basic items (of which one is not being able to eat a meal with meat, chicken, fish or a vegetarian equivalent every second day). The highest levels of deprivation are experienced by lone parents (63%), unemployed people (55%) and people not at work because of illness or disability (53%). The experience of the Vincentian Partnership for Social Justice (VPSJ) is that expenditure on food tends to be one of the least important considerations when households are dealing with competing demands on an inadequate income. - See more at: http://www.safefood.eu/Publications/Research-reports/The-cost-of-a-healthy-food-basket.aspx#sthash.RiBpj5no.dpuf A Minimum Essential Standard of Living (MESL) is derived from a negotiated consensus on what people believe is a minimum standard. It is a standard of living that meets an individual’s or a household’s physical, psychological and social needs. This is calculated by identifying the goods and services required by different household types in order to meet their needs. While an MESL is based on needs, not wants, it is a standard of living below which nobody should be expected to live. This report focuses on food, one of the 16 elements of the Minimum Essential Standard of Living (MESL) data. It is based on a methodology called Consensual Budget Standards (CBS). The report is presented in the context of increasing concerns about the issue of food poverty in the Republic of Ireland (ROI) and an increase in the number of people reporting that they do not have enough money to buy food. Recent data from The Organisation for Economic Co-operation and Development (OECD) have shown that the number of people believing they cannot afford food doubled from 4.2% in 2008 to 9% in 2014. Data from Eurostat show that in 2013, food and non-alcoholic beverage prices in Ireland were 17% higher than the EU average. Moreover, research by Carney and Maitre, using data from the Survey on Income and Living Conditions (SILC), found that one in ten people are living in food poverty in Ireland. Food poverty is defined as the inability to have an adequate and nutritious diet due to issues of affordability and access to food. This has related effects on health, culture and social participation. The 2013 data from the Survey on Income and Living Conditions (SILC) show that 1.4 million people, almost 31% of the population, suffer from deprivation. This means that they are unable to afford two items from a list of 11 very basic items (of which one is not being able to eat a meal with meat, chicken, fish or a vegetarian equivalent every second day). The highest levels of deprivation are experienced by lone parents (63%), unemployed people (55%) and people not at work because of illness or disability (53%). The experience of the Vincentian Partnership for Social Justice (VPSJ) is that expenditure on food tends to be one of the least important considerations when households are dealing with competing demands on an inadequate income. - See more at: http://www.safefood.eu/Publications/Research-reports/The-cost-of-a-healthy-food-basket.aspx#sthash.RiBpj5no.dpuf A Minimum Essential Standard of Living (MESL) is derived from a negotiated consensus on what people believe is a minimum standard. It is a standard of living that meets an individual’s or a household’s physical, psychological and social needs. This is calculated by identifying the goods and services required by different household types in order to meet their needs. While an MESL is based on needs, not wants, it is a standard of living below which nobody should be expected to live. This report focuses on food, one of the 16 elements of the Minimum Essential Standard of Living (MESL) data. It is based on a methodology called Consensual Budget Standards (CBS). The report is presented in the context of increasing concerns about the issue of food poverty in the Republic of Ireland (ROI) and an increase in the number of people reporting that they do not have enough money to buy food. Recent data from The Organisation for Economic Co-operation and Development (OECD) have shown that the number of people believing they cannot afford food doubled from 4.2% in 2008 to 9% in 2014. Data from Eurostat show that in 2013, food and non-alcoholic beverage prices in Ireland were 17% higher than the EU average. Moreover, research by Carney and Maitre, using data from the Survey on Income and Living Conditions (SILC), found that one in ten people are living in food poverty in Ireland. Food poverty is defined as the inability to have an adequate and nutritious diet due to issues of affordability and access to food. This has related effects on health, culture and social participation. The 2013 data from the Survey on Income and Living Conditions (SILC) show that 1.4 million people, almost 31% of the population, suffer from deprivation. This means that they are unable to afford two items from a list of 11 very basic items (of which one is not being able to eat a meal with meat, chicken, fish or a vegetarian equivalent every second day). The highest levels of deprivation are experienced by lone parents (63%), unemployed people (55%) and people not at work because of illness or disability (53%). The experience of the Vincentian Partnership for Social Justice (VPSJ) is that expenditure on food tends to be one of the least important considerations when households are dealing with competing demands on an inadequate income. - See more at: http://www.safefood.eu/Publications/Research-reports/The-cost-of-a-healthy-food-basket.aspx#sthash.RiBpj5no.dpuf