Browsing by Subject "Meat"

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  • Leroy, Frédéric; Abraini, Fabien; Beal, Ty; Domínguez-Salas, Paula; Gregorini, Pablo; Manzano, Pablo; Rowntree, Jason; van Vliet, Stephan (2022)
    Animal source foods are evolutionarily appropriate foods for humans. It is therefore remarkable that they are now presented by some as unhealthy, unsustainable, and unethical, particularly in the urban West. The benefits of consuming them are nonetheless substantial, as they offer a wide spectrum of nutrients that are needed for cell and tissue development, function, and survival. They play a role in proper physical and cognitive development of infants, children, and adolescents, and help promote maintenance of physical function with ageing. While high-red meat consumption in the West is associated with several forms of chronic disease, these associations remain uncertain in other cultural contexts or when consumption is part of wholesome diets. Besides health concerns, there is also widespread anxiety about the environmental impacts of animal source foods. Although several production methods are detrimental (intensive cropping for feed, overgrazing, deforestation, water pollution, etc.) and require substantial mitigation, damaging impacts are not intrinsic to animal husbandry. When well-managed, livestock farming contributes to ecosystem management and soil health, while delivering high-quality foodstuffs through the upcycling of resources that are otherwise non-suitable for food production, making use of marginal land and inedible materials (forage, by-products, etc.), integrating livestock and crop farming where possible has the potential to benefit plant food production through enhanced nutrient recycling, while minimising external input needs such as fertilisers and pesticides. Moreover, the impacts on land use, water wastage, and greenhouse gas emissions are highly contextual, and their estimation is often erroneous due to a reductionist use of metrics. Similarly, whether animal husbandry is ethical or not depends on practical specificities, not on the fact that animals are involved. Such discussions also need to factor in that animal husbandry plays an important role in culture, societal well-being, food security, and the provision of livelihoods. We seize this opportunity to argue for less preconceived assumptions about alleged effects of animal source foods on the health of the planet and the humans and animals involved, for less top-down planning based on isolated metrics or (Western) technocratic perspectives, and for more holistic and circumstantial approaches to the food system.
  • Sauvala, Mikaela; Woivalin, Emma; Kivistö, Rauni; Laukkanen-Ninios, Riikka; Laaksonen, Sauli; Stephan, Roger; Fredriksson-Ahomaa, Maria (2021)
    Game birds may carry zoonotic bacteria in their intestines and transmit them to hunters through bird handling or through the handling and consumption of contaminated meat. In this study, the prevalence of foodborne bacteria was screened from game bird faeces and mallard breast meat using PCR. The sampling occurred in southern Finland from August to December during the hunting season. Isolates were characterized by multi-locus sequence typing. Mesophilic aerobic bacteria and Escherichia coli counts were used to assess the microbial contamination of mallard meat. In total, 100 woodpigeon (Columba palumbus), 101 pheasants (Phasianus colchicus), 110 mallards (Anas platyrhynchos), and 30 teals (Anas crecca) were screened during the hunting season. Additionally, 100 mallard breast meat samples were collected. Campylobacter and Listeria were commonly detected in the faeces and Listeria on mallard meat. L. monocytogenes of sequence types associated with human listeriosis were frequently found in game bird faeces and on mallard meat. Good hygiene during game bird handling, storing the game bird meat frozen, and proper heat treatment are important measures to minimize the health risk for hunters and consumers.
  • Zhang, Yuemei; Magro, Arianna; Puolanne, Eero; Zotte, Antonella Dalle; Ertbjerg, Per (2021)
    This study aimed to investigate the effect of storage at -3 ?C on myofibrillar protein in fast or slow frozen pork. Five pork loins at 48 h post-mortem were subjected to either fast (cold metal plate/-80 ?C) or slow freezing (still air/-20 ?C) followed by storage at -3 ?C for 0, 1, 3, and 7 days before thawing. Freezing rate significantly influenced myofibrillar proteins within 3 days at -3 ?C, evidenced by higher thaw loss, higher surface hydrophobicity and reduced water-holding of myofibrils, and accelerated appearance of a myosin-4 fragment (160 kDa) in slow freezing. However, these observed differences disappeared after 7 days of storage at -3 ?C. The meat pH after thawing did not differ between fast and slow freezing rate. However, the pH values after thawing in both groups decreased with extended storage at -3 ?C. Our results suggest that the beneficial effects of fast freezing are gradually lost by holding at -3 ?C due to more extensive protein denaturation.
  • Zhang, Yuemei; Ertbjerg, Per (2019)
    The role of protein denaturation in formation of thaw loss is currently not well understood. This study investigated denaturation of myofibrillar and sarcoplasmic proteins of pork loins caused by freezing-thawing in relation to freezing rate. Compared to fast freezing, slow freezing caused 28% larger thaw loss, decreased water-holding capacity of myofibrils and increased surface hydrophobicity, indicating more pronounced denaturation of myofibrillar proteins. We here propose a model: In slow freezing protons are concentrated in the unfrozen water resulting in reduced pH in proximity of structural proteins causing protein denaturation. In parallel, large ice crystals are formed outside of muscle fibers resulting in transversal shrinkage. In fast freezing small ice crystals trap protons and cause less severe protein denaturation and reduced thaw loss. Differential scanning calorimetry and tryptophan fluorescence spectra indicated sarcoplasmic protein denaturation in drip due to freezing-thawing. However, sarcoplasmic protein denaturation was independent of freezing rate.
  • Zeng, Zhen; Li, Cheng; Ertbjerg, Per (2017)
    The purpose of this study was to increase the knowledge on the relationship between proteolysis of myofibrillar proteins and the water-holding of meat. Myofibrils isolated from porcine longissimus thoracic et lumborum muscle were used as a model system. Myofibrils were incubated with either calpain-2, the proteasome or a lysosomal extract at 25 degrees C for 2 h. All three proteolytic systems improved the relative water-holding and generally there was a larger effect with increasing amount of enzymes in the incubation. The improved water-holding occurred in parallel to degradation of myofibrillar proteins. Desmin was degraded by calpain-2 as well as by lysosomal enzymes and a-actinin was released by the proteasome. We here propose a model in which degradation of proteins in and around the Z-disk allows overall swelling of the filament lattice and more specifically in the I band area. In conclusion, proteolytic degradation of myofibrillar proteins by calpain-2, the proteasome or lysosomal enzymes improves the water-holding of myofibrils.
  • Päivärinta, M.; Latvio, S.; Fredriksson-Ahomaa, M.; Heikinheimo, A. (2020)
    Plasmid-encoded extended-spectrum β-lactamase and AmpC gene-carrying Escherichia coli (ESBL/AmpC E. coli) is an increasing cause of human infections worldwide. Increasing carbapenem and colistin resistance further complicate treatment of these infections. The aim of this study was to assess the occurrence of ESBL/AmpC E. coli in different broiler flocks and farms, as well as in broiler meat, in a country with no antimicrobial usage in broiler production. An additional goal was to assess the genetic characteristics of ESBL/AmpC E. coli isolates by using whole genome sequencing (WGS). Altogether 520 caecal swabs and 85 vacuum-packed broiler meat samples were investigated at the slaughterhouse level. WGS of the bacterial isolates revealed acquired antimicrobial resistance (AMR) genes, multilocus sequence types (MLST) and plasmid sequences. ESBL/AmpC E. coli was identified in 92 (18%) of the caecum and 27 (32%) of the meat samples. ESBL/AmpC E. coli-carrying birds derived from six (33%) out of 18 farms. Of the two blaESBL/AmpC genes detected by PCR, blaCMY-2 (96%) was predominant over blaCTX-M-1 (4%). Furthermore, WGS revealed an additional AMR gene sul2. Carbapenemase, colistin, and other AMR genes were not detected from the isolates of either the caecal or meat samples. Altogether seven MLSTs (ST101, ST117, ST212, ST351, ST373, ST1594 and an unknown ST) and a variety of different plasmid sequences (IncB/O/K/Z, IncI1, IncFII, IncII, IncFIB, IncFIC, IncX1 and an additional set of Col-plasmids) were detected. This is the first study on genomic epidemiology of ESBL/AmpC E. coli on broiler farms and flocks with no antimicrobial usage, by using WGS analysis. Results show that ESBL/AmpC E. coli occurrence is common both in the caecum and in the packaged meat. However, compared to other European countries, the occurrence is low and the presence of AMR genes other than blaCMY-2 and blaCTX-M-1 is rare. More studies are needed to understand the ESBL/AmpC E. coli occurrence in broiler production to prevent the meat from contamination during slaughter and processing, thereby also preventing zoonotic transmission of ESBL/AmpC E. coli. Additionally, more studies are needed to understand the ecology and fitness cost of Enterobacteriaceae plasmids in animal production in order to prevent their acquisition of plasmid-encoded antimicrobial resistance genes such as carbapenem and colistin resistance genes, as this would pose a great hazard to food safety.