食品安全

Nutritional and environmental regulation of the synthesis of highly unsaturated fatty acids and of fatty-acid oxidation in Atlantic salmon (Salmo salar L.) enterocytes and hepatocytes Abstract The objective of this work was to determine whether highly unsaturated fatty acid (HUFA) synthesis and fatty-acid oxidation in Atlantic salmon (Salmo salar L.) intestine wasunder environmental and/or seasonal regulation.Triplicate groups of salmon were grown through a full two-year cycle on two diets containing either fish oil (FO) or a diet with 75% of the FO replaced by a vegetable oil (VO) blend containing rapeseed,palm, and linseed oils. At key points in the life cycle fatty acyl desaturation/elongation (HUFA synthesis)and oxidation activity were determined in enterocytes and hepatocytes using [1–14C]18:3n–3 as substrate. As observed previously, HUFA synthesis in hepatocytes reached a peak at seawater transfer and declined thereafter, with activity consistently greater in fish fed the VO diet. In fish fed FO, HUFA synthesis in enterocytes in the freshwater stage was at a level similar to that in hepatocytes. HUFA synthesis in enterocytes increased rapidly after seawater transfer, however,and remained high for some months after transfer before decreasing to levels that were again similar to those observed in hepatocytes. Enterocyte synthesis of HUFA was usually higher in fish fed the VOdiet than in those fedtheFO diet. Oxidation of [1–14C]18:3n–3 in hepatocytes from fish fed FO tended to decrease during the freshwater phase but then increased steeply, peaking just after transfer before decreasing during the remaining seawater phase. At the peak in oxidation activity around seawater transfer, activity was significantly lower in fish fed VO than in fish fed FO. In enterocytes,oxidation of [1–14C]18:3 in fish fed FO reached a peak in activity just before seawater transfer. In fish fed VO, except for high activity at nine months the pattern was similar to that obtained in enterocytes from fish fedFO,with high activity aroundseawater transfer and declining activity in seawater. In conclusion, fatty acid metabolism in intestinal cells seemed to be under dual nutritional and environmental or seasonal regulation. Temporal patterns of oxidation of fatty acids wereusually similar in the two cell types, but HUFA synthesis in enterocytes peaked over the summer seawater phase rather than at transfer, as with hepatocytes, suggesting the possibility of different regulatory cues.Keywords Atlantic salmon Life cycle Enterocytes Hepatocytes PUFA HUFA Desaturation/elongation b-Oxidation Vegetable oilSelenium Health Benefit Values as Seafood Safety Criteria Abstract: Selenium (Se) is absolutely required for activity of 25–30 genetically unique enzymes (selenoenzymes).All forms of life that have nervous systems possess selenoenzymes to protect their brains from oxidative damage. Homeostatic mechanisms normally maintain optimal selenoenzyme activities in brain tissues, but high methylmercury (MeHg) exposures sequester Se and irreversibly inhibit selenoenzyme activities. However,nutritionally relevant amounts of Se can replace the Se sequestered by MeHg and maintain normal selenoenzyme activities, thus preventing oxidative brain damage and other adverse consequences of MeHg toxicity.Findings of studies that seem contradictory from MeHg exposure perspectives are entirely consistent from MeHg:Se molar ratio perspectives. Studies that have reported dose-dependent consequences of maternal MeHg exposures on child development uniformly involved seafoods that contained much more Hg than Se.Meanwhile more typical varieties of ocean fish contain much more Se than Hg. This may explain why maternal MeHg exposure from eating ocean fish is associated with major IQ benefits in children instead of harm. Therefore, instead of being avoided, ocean fish consumption should be encouraged duringpregnancy. However,the safety of freshwater fish consumption is less certain. In freshwater fish, MeHg bioaccumulation and toxicity are both inversely related to Se bioavailability. Their Se can be far lower than their MeHg contents,potentially making them more dangerous than pilot whale meats. Therefore, to provide accurate and appropriate regulatory advice regarding maternal consumption of seafoods and freshwater fish, Hg:Se molar ratios need to be incorporated in food safety criteria. Keywords: brain selenium, seafood fish, mercury toxicity ExtremelyQUALITY ASSURANCE SYSTEMS IN FOOD INDUSTRYAND HEALTH SECURITY OF FOODAbstract.In order to ensure the appropriate food safety and health of consumers, suitable legal requirements and new quality standards are constantly being elaborated. The free trade exchange within the European Union made it necessary to unify food legislation and quality standards within the entire area of the EU. This publication outlines appropriate systems and standards functioning in the food industry as well as the legal basis for their application. Apart from systems which are compulsory in enterprises of the food industry,the article also discusses systems which individual enterprises implement voluntarily as well as informatics systems used to organize and manage the production and product traceability.Key words: GHP, GMP, HACCP, traceability, food safetyDerivation of Vascular Endothelial Cells from Human Embryonic Stem Cells Under GMP-Compliant Conditions: Towards Clinical Studies in Ischaemic DiseaseAbstract Revascularisation of ischaemic tissue remains an area of substantial unmet clinical need in cardiovascular disease.Strategies to induce therapeutic angiogenesis are therefore attractive. Our recent focus has been on human embryonic stem cell (hESC) strategies since hESC can be maintained in a pluripotent state or differentiated into any desired cell type, including endothelial cells (EC), under defined differentiation culture conditions.We recently published a protocol for non-good manufacturing practice (GMP) feeder- and serum-free hESC-EC-directed monolayer differentiation to vascular EC demonstrating the potential to generate hESC-derived EC in aGMP-compliant manner suitable for use in clinical trials. In this study we modified that laboratory protocol to GMP compliance. EC production was confirmed by flow cytometry, qRT-PCR and production of vascular structur es in Matrigel®, yielding approximately 30 % mature VE-cadherin+/PECAM-1+ cells using the GMP-compliant hESC line RC13. In conclusion, we have successfully demonstrated the production of vascular EC underGMPcompliant conditions suitable for clinical evaluation Keywords hESC .GMP . Roslin Cells . Differentiation . Vascular endothelial cells . EC . EPCPOSTIMPLEMENTATION COSTS OF HACCP AND SSOP'S IN GREAT PLAINS MEAT PLANTS'ABSTRACTThe objective of this analysis was to determine the costs of the development and implementation of HACCP, SSOP 's, Salmonella Performance Standards, and Generic E. coli Process Control Testing for small meat and poultry plants. USDA estimated these costs to be $0.0024 per pound with the release of the Pathogen Reduction Ruling. Weighted averages from two other studies estimating implementation costs were $0.0005 and $0.01 39 per pound. To collect data and measure actual implementation costs, phone survtys and personal interviews were conducted with small meat (defined as having I0 or more employees but less than 500) slaughter and processing plants in North Dakota, South Dakota, Nebraska, Kansas, Missouri, and Oklahoma. The analysis suggests that the plants incurred an average of $0.009perpound in development and implementation costs for these regulations.HACCP implementation in the production of fresh-cut fruits and vegetablesAbstractPurpose of the review: This review focuses on the complex task of the final implementation of HACCP by fresh-cut processors. In the face of recent episodes involving safety of produce and fresh-cut products, HACCP has been highly demanded for this industry by regulators, politicians, consumers and the market.Findings: The incidence of illnesses caused by foodborne pathogens associated with produce and fresh-cut fruits and vegetables has increased. A great amount of research continues to be done on interventions and on a hurdle approach to prevent contamination by microbial and other hazards. In the literature the importance of the prerequisite programs: GAPs, GMPs and SSOPs, as part of any quality and safety integrated system wherein HACCP may be the last step, is continuously stressed. Limitations/implications: The adoption of integrated safety systems by the fresh-cut industry is very important. Apart from GMPs (mandatory), specific legislation and guidance for these products is necessary (microbiological criteria, guides for GAPs, SSOPs,HACCP). This may be a problem since the market exertsa lot of pressure on produce and fresh-cut processors, and the system may act functionally as a trade barrier for small and medium size businesses and for developing countries. Implementation of HACCP system should occur in later stages. Directions for future research: The dynamic of the fresh-cut market and the severe safety requirements imposed especially by consumers, will lead and it is already observed in recent literature, to reflections and analysis on food safety management systems and safety strategies using new approaches and philosophies.Keywords:Hazard Analysis Critical Control Points (HACCP); fresh-cut; produce; Good Manufacturing Practices; Good Agricultural Practices; Sanitation Standard Operating Procedures。