Thesis (M.S.)--Montana State University--Bozeman, 2007. / Typescript. Chairperson, Graduate Committee: Gary W. Brester. Includes bibliographical references (leaves 114-120).

Thesis (MScVoedselwet)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: Red meat has a limited shelf-life at refrigerated temperatures, where spoilage is mainly due to the proliferation of bacteria, yeast and moulds, acquired during the dressing process. In addition, almost a fifth of food-borne disease outbreaks, caused by microorganisms such as Escherichia coli 0157:H7, Listeria monocytogenes and Staphylococcus aureus are associated with red meat. To improve the microbiological quality of red meat, systems such as HACCP, GHP and GMP are currently practiced; however, these practices are not able to extend the shelf-life of these products. At present suitable food-grade preservatives are recommended, but the use of some of these preservatives is increasingly being questioned with regard to their impact on human health. Additionally, food service customers demand high quality products that have a relatively long shelf-life, but still prefer the appearance of minimally processed food. All these factors challenge the food manufacturing industry to consider more natural means of preservation. Antimicrobial metabolites of food grade bacteria, especially lactic acid bacteria, are attracting increasing attention as food preservatives. Bacteriocins are antimicrobial peptides (3 to 10 kDa) with variable activity spectra, mode of action, molecular weight, genetic origin and biochemical properties that are bacteriostatic or bactericidal to bacteria closely related and bacteria confined within the same ecological niche. Micro-organisms were isolated from beef, lamb and pork, obtained from four commercial retailers. The number of viable cells three days after the sell-by date at 4ºC ranged from 80 cfu.g-1 to 1.4 × 108 cfu.g-1. Fifty-three percent were Gram-negative bacteria, 35% Gram-positive and 12% yeast. The microbial population of the meat was greatly influenced by the origin, i.e. the retailer. Bacteriocins produced by Enterococcus faecalis BFE 1071, Lactobacillus curvatus DF 38, Lb. plantarum 423, Lb. casei LHS, Lb. salivarius 241 and Pediococcus pentosaceus ATCC 43201 were screened for activity against bacteria isolated from the different meat samples. Sixteen to 21% of the isolates, identified as members of Klebsiella, Shigella, Staphylococcus, Lactobacillus, Lactococcus, Leuconostoc, Enterococcus, Pediococcus, Streptococcus and Bacillus were sensitive to the bacteriocins. Curvacin DF 38, plantaricin 423 and caseicin LHS (2.35 to 3.4 kDa) had the broadest activity range and inhibited species of Lactobacillus, Pediococcus, Enterococcus, Listeria, Bacillus, Clostridium and Propionibacterium. The bacteriocins remained stable at 121ºC for 20 min, in buffers with a pH ranging from 2 to 10 and in NaCl concentrations of between 0.1 and 10% (m/v). Like most peptides, they were sensitive to proteolytic enzymes. Curvacin DF 38 is sensitive to amylase, suggesting that the bacteriocin might be glycosylated. To assess the efficiency of curvacin DF 38, plantaricin 423 and caseicin LHS as meat preservatives, they were partially purified by ammonium sulphate precipitation and separation in a Sep Pak C18 cartridge. The shelf-life of pork may be extended by up to two days. Meat samples treated with bacteriocins were darker than the control (untreated) sample. Descriptive sensory evaluation by a seven-member panel indicated that there were significant differences (P ≤ 0.05) regarding the aroma, sustained juiciness, first bite and metallic taste attributes of the control and the 4 day-treated samples. The control and 2 day-treated samples and the 2 day- and 4 day treated samples did not differ significantly regarding these attributes. There were no significant differences regarding the initial juiciness, residue and pork flavour attributes. Concluded from the results obtained in this study, bacteriocins produced by Lb. curvatus DF 38, Lb. plantarum 423 and Lb. casei LHS effectively extended the shelf-life of pork loins by up to 2 d at refrigerated temperatures with no drastic changes on sensory characteristics. In edition, the stability of these bacteriocins broadens their application as preservatives in many foods. / AFRIKAANSE OPSOMMING: Die rakleeftyd van rooivleis by yskastemperature is beperk, waar bederf hoofsaaklik deur die vermenigvuldiging van bakterieë, giste en swamme veroorsaak word. Die meeste van hierdie kontaminante is afkomstig van die slagtingsproses. Byna ’n vyfde van alle uitbrake van voedselvergiftigings wat deur organismes soos Escherichia coli 0157:H7, Listeria monocytogenes en Staphylococcus aureus veroorsaak word, word met rooivleis geassosieër. Die praktyke HACCP, GMP en GHP word tans toegepas om die mikrobiologies kwaliteit van vleis te handhaaf, maar is egter nie voldoende om die rakleeftyd van rooivleis the verleng nie. Die preserveermiddels wat huidiglik aanbeveel word vir dié doel, word toenemend bevraagteken aangaande die invloed daarvan op die menslike gesondheid. Hierby is daar ’n aanvraag na hoë kwaliteit, ongeprosesseerde produkte met ’n verlengde rakleeftyd. Gevolglik word die voedsel vervaardigings industries aangemoedig om meer natuurlike vorms van preservering the oorweeg. Die aandag word tans op die anti-mikrobiese metaboliete van voedselgraad microbes, veral melksuurbakterieë, gevestig. Bakteriosiene is anti-mikrobiese peptiede (3 tot 10 kDa) met verskeie aktiwiteitsspektra, werkswyse, molekulêre massa, genetiese oorsprong en biochemiese eienskappe. Bakteriosiene is meestal bakterie-dodend of - staties teen taksonomies naby geleë organismes en organismes vanuit dieselfde ekologiese nis. Mikroörganismes is geïsoleer vanuit bees-, skaap- en varkvleis, verkry vanaf vier supermarkte. Die aantal lewensvatbare selle per gram (cfu.g-1) het drie dae na die “verkoop”-datum by 4ºC vanaf 80 cfu.g-1 tot 1.4 × 108 cfu.g-1 gevarieër. Drie en vyftig persent van die isolate is as Gram-negatief, 35% as Gram-positief en 12% as giste geïdentifiseer. Die sensitiwiteit van hierdie isolate teen bakteriosiene wat deur Enterococcus faecalis BFE 1071, Lactobacillus curvatus DF 38, Lb. plantarum 423, Lb. casei LHS, Lb. salivarius 241 en Pediococcus pentosaceus ATCC 43201 geproduseer is, is vervolgens getoets. Tussen 16% en 21% van die isolate was sensitief teen die bacteriosiene en is onder andere as Klebsiella, Shigella, Staphylococcus, Lactobacillus, Lactococcus, Leuconostoc, Enterococcus, Pediococcus, Streptococcus en Bacillus geïdentifiseer. Die bakteriosiene met die wydste aktiwiteitsspektrum, naamlik, curvacin DF 38, plantaricin 423 en caseicin LHS is verder ondersoek. Hierdie antimikrobiese peptiede (2.35 tot 3.4 kDa) toon aktiwiteit teen spesies van Lactobacillus, Pediococcus, Enterococcus, Listeria, Bacillus, Clostridium and Propionibacterium. Die bakteriosiene is stabiel by 121ºC vir 20 min, in buffers met ‘n pH-reeks van tussen 2 en 10 en soutkonsentrasies vanaf 0.1% tot 10%. Soos die geval by meeste peptiede is hierdie bakteriosiene sensitief vir proteolitiese ensieme. Curvacin DF 38 is ook sensitief vir amylase, wat daarop dui dat hierdie bakteriosien moontlik geglikosileer is. Die effektiwiteit van curvacin DF 38, plantaricin 423 en caseicin LHS as preserveermiddel in voedselsisteme is getoets deur dit te suiwer (ammonium sulfaat presipitasie en Sep Pak C18 kolom) en op vark lendestukke aan te wend. Mikrobiese analise het bewys dat die rakleeftyd van vark met sowat 2 dae verleng kan word. Volgens die vleiskleurevaluering was die bakteriosien behandelde vark donkerder as die kontrole. Die aroma-, sappigheid-, tekstuur- en metaalgeur-eienskappe van die kontrole en die 4-dag behandelde monster het volgens ‘n opgeleide sensoriese paneel betekenisvol verskil (P ≤ 0.05). Die kontrole en die 2-dag behandelde en die 2-dag behandelde en die 4-dag behandelde monsters het nie betekenisvol verskil nie. Daar was geen betekenisvolle verskil aangaande die aanvanklike sappigheid-, residu- en varkgeur-eienskappe nie. Hierdie sensoriese eienskappe is belangrik ten opsigte van die verbruiker se aanvaarding van die produk. Vervolgens kan uit hierdie resultate afgelei word dat die bakteriosiene wat deur Lb. curvatus DF 38, Lb. plantarum 423 en Lb. casei LHS geproduseer word voldoende is om die rakleeftyd van vark lendestuk by 4ºC met 2 dae te verleng met min of geen effek op die sensoriese persepsie van die vleis. Hierdie bakteriosiene is ook stabiel onder verskeie kondisies wat die toepassing as preserveermiddel aansienlik verbreed.

Thesis (MSc (Consumer Science)--Stellenbosch University, 2008. / The purpose of this study was to investigate the chemical composition mineral and cholesterol content of the different cuts (breast, drumstick and thigh) of raw guinea fowl meat. The study also aimed at establishing the effect of cooking method on guinea fowl quality attributes by investigating the effect of different cooking methods on the chemical composition and sensory attributes of the different cuts. The effect of injecting a brine solution on the chemical composition and sensory attributes were also investigated. There were no differences in terms of moisture content of the various cuts raw guinea fowl meat The breast had significantly higher protein content when compared to drumstick and thigh (P<0.05). The fat content was similar for all the cuts (P>0.05). Whilst the drumstick had significantly the lowest value for ash content when compared to the thigh. Saturated fatty acids (SFAs) and total unsaturated fatty acids (TUFAs) were not different (P>0.05) in all the cuts. Drumstick had significantly higher monounsaturated fatty acids compared to other cuts (P<0.05), and it had the highest polyunsaturated fatty acids (P<0.05). The breast had the lowest (P<0.05) n-6 fatty acid value (44.25) and had relatively the lowest Polyunsaturated:Saturated (P:S) fatty acid ratio of 1.74 when compared to the other cuts. High n-6:n-3 ratios, ranging from 7.05 to 16.58, were also found in all the cuts. Cholesterol was lowest (P<0.05) in the breast. Seventeen amino acids were found, including the eight of the nine essential amino acids. Significant differences were found in amino acid values for the different cuts. Values of iron were significantly higher in the drumstick and thigh cuts (P<0.05), whilst drumstick had the highest zinc content of all the cuts (P<0.05). On investigating the effect of three cooking methods (baking-bag, foil-wrap, open-roasting at 140ºC for 65 minutes) on the chemical composition, the open-roasting method produced higher moisture content (P<0.05) consistently for all cuts, with the breast having the highest and the drumstick the lowest (P<0.05). The moisture content of the baking-bag method on the other hand was consistently the lowest (P>0.05). This effect was significant for the breast, which had lost the most moisture (P<0.05). The baking-bag method consistently resulted in a higher protein content, which is attributed to the higher moisture loss (P<0.05) in comparison with the other methods, resulting in a more concentrated product. With regard to the fat content no effect resulting from the cooking methods could be observed (P>0.05), but the cuts’ natural fat content was reflected especially in the open–roasting method (P<0.05) giving further support to the understanding that the open-roasting method indeed made the least inroads on the chemical composition of guinea fowl meat under these restraints: controlled for cooking time and temperature, internal temperature not controlled. All the cuts cooked according to all the methods, had the favourable >0.4 Polyunsaturated:Saturated fatty acids (P:S) ratio, ranging from 0.91 to 1.42 between cuts and treatments. The n-6:n-3 ratio was below the recommended beneficial value, namely <4:1, in all the cuts irrespective of all the cooking methods, ranging from 2.47 to 3.08. The study of the effect of the three cooking methods (baking-bag, foil-wrap and open-roast) on the sensory attributes of the breast meat revealed that aroma-intensity of the three cooking treatments did not differ significantly (P>0.05). Foil-wrap produced a more tender and juicier product (P<0.05), while, when using the baking-bag method, values for flavour decreased (P<0.05). It is proposed that a higher internal temperature (which was not controlled) was attained when using the baking-bag method (temperature and time controlled) resulting in loss of volatile flavour components. The effect of the three cooking methods (baking-bag, foil-wrap and open-roast) on the proximate composition (moisture, protein, fat and ash) of raw and cooked breast meat was investigated. As anticipated raw breast meat had higher moisture content (74.55%, P<0.05) than the cooked cuts, with open-roasting showing the highest (68.55%) value and foil-wrap close second (68.12%). These values differed significantly from the baking-bag method (66.06%, P<0.05). An investigation on the effect of brine infusion on the sensory attributes and chemical composition (proximate and fatty acid composition, and mineral content) of breast meat, baked in foil-wrap, was carried out using descriptive sensory analysis with the injected breast and the control as variable. There were no significant differences (P>0.05) between the injected and the control samples for any of the sensory attributes of aroma, tenderness, initial juiciness, sustained juiciness and flavour. Judge:treatment variations were observed for all the attributes, and samples differed for all attributes except for aroma. It is proposed that the use of the hand injector could not effectively distribute the brine solution, hence the recommendation to repeat the experiment using an electronic multineedle-injector. No effect was observed for the proximate composition (P>0.05). Further research pertaining to cooking methods of meat of free-range guinea fowl is recommended to address certain issues that have been highlighted.

Thesis (MSc Food Sc (Food Science))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: Fresh ostrich meat competes in well regulated and competitive international markets; therefore food quality and safety are of the utmost importance. At the same time the production process must be well controlled to be cost effective. Losses in meat yield through bruising and the trimming thereof as well as a high initial microbial load that causes a decrease in shelf-life is thus undesirable. The main objectives of this study were firstly to investigate the expected prevalent microbial growth on ostrich meat as well as possible environmental contaminants to establish which bears the greatest risk. Secondly to establish the best practice of removing bruised areas from carcasses from both a microbiological and meat yield perspective. Lastly to investigate bruises on carcasses to predict the possible causes thereof so as to minimize bruising during transport and handling. From this study it was concluded that the prevalent growth on carcasses was predominantly Grampositive which increased ten fold from post-evisceration to post-chilling, this was also associated with a marked increase in Gram-negative organisms. The most dangerous vector for contamination was found to be standing water containing Gram-negative human pathogens including Shigella, Salmonella and E. coli. Bruises to the necks (52.58% of all bruises) were the most frequent, the high side railings on transport trucks the probable cause thereof. It was indicated that aerobic viable counts decreased after cold trimming, where the opposite occurred on warm trimmed surfaces, while the average loss in meat yield per bird due to bruising was smaller for cold trimming. / AFRIKAANSE OPSOMMING: Vars volstruisvleis kompeteer in goed gereguleerde en kompeterende internasionale markte; dus is voedselkwaliteit en –veiligheid baie belangrik. Terselfdertyd moet die produksieproses goed beheer word en koste effektief wees. Verliese aan vleisopbrengs as gevolg van kneusings en die verwydering daarvan, sowel as ‘n hoë inisiële mikro-organisme lading wat ‘n verkorte rakleeftyd tot gevolg het, is dus ongewens. Die hoofdoelwitte van die studie was eerstens om die verwagte mikro-organisme groei op volstruisvleis en op moontlike omgewings kontaminasie bronne te ondersoek om vas te stel watter bronne die grootste risiko dra vir besmetting. Tweedens om die beste praktyd vir die verwydering van kneusings van die volstruiskarkasse te bepaal uit beide ‘n mikrobiologiese en vleisopbrengs oogpunt. Laastens om die omvang en verspreiding van karkaskneusings te ondersoek om die oorsaak daarvan te probeer aandui en sodoende kneusings tydens vervoer en hantering te verminder. Uit die studie was die volgende duidelik; die mikrobiese groei op karkasses was hoofsaaklik Gram-positief, tellings het tienvoudig toegeneem vanaf ontweiding tot na verkoeling, met ‘n gepaardgaande merkbare toename in Gram-negatiewe organismes. Die gevaarlikste oorsaak van omgewingskontaminasie was staande water wat Gram-negatiewe menslike patogene (insluitend; Shigella, Salmonella en E. coli) bevat het. Nekkneusings (52.58% van all kneusings) was die algemeenste; met die hoogte van die kantreëlings van die volstruistrokke die moontlike oorsaak daarvan. Dit is bewys dat die aerobe mesofiele plaattelings afgeneem het na koue verwydering, maar dat die teenoorgestelde gesien is op warm gesnyde areas; die gemiddelde verlies in vleisopbrengs per volstruis as gevolg van kneusingverwydering is kleiner tydens koue verwydering.

The aim of this thesis was to inform about pig genotypes and sex influencing selected traits of meat quality. Several combinations of the final pig hybrids (CLxCLW)xCLW-sire line, (CLxCLW)x(CLW-sire line x Pn), (CLxCLW)x(DxPn) and (CLxCLW)x(CLW-sire line x D)with balanced sex ratio (barrows : gilts). The highest intramuscular fat content (2,15 %) has been detected in the (CLxCLW)x(CLW-sire line x D) hybrid combination; the barrows (1,78 %) reached a higher ratio compared to gilts (1,42 %). There were detected only small differences in traits pH45 and pH24, there was not even found any difference between the two sexes. The lightest meat (% remission) has been proven by the (CLxCLW)xCLW-sire line combination with no significant difference between sexes. There have been quite similar values between the sexes and even hybrid combinations, concerning the meat lightness (L*). The drip loss was highest in the (CLxCLW)x(DxPn) combination with only fractional difference between sexes. In the shear force has been detected the lowest value in the (CLxCLW)x(CLW-sire line x Pn) combination with a small difference between barrows and gilts. From the genotype aspect were confirmed statistically important differences in the following traits: intramuscular fat content, meat lightness (% remission), drip loss and shear force. From sex aspect, only differences in intramuscular fat content were found.

In this thesis I deal with the influence of storage temperature on reducing the number of microorganisms in meat products. In this work is analyzed cooling and freezing storage of meat and meat products. The next section provides an overview of the major contributors to food-borne illness (Salmonella, Escherichia coli, Campylobacter, Listeria monocytogenes, Bacillus cereus, etc.). At the end of research is the mention of the HACCP system. The research was focused on the refrigerated storage of whole (rod) sausages and vacuum packed sliced meat products, which were further divided into cooked and uncooked meat products. The thesis was evaluated the effect of changes in temperature and storage technology to the number of microorganisms in cooked and uncooked meat products.

My thesis which deals with optimization of durable meat products processing. Research has found that during drying a durable meat product, there has been a gradual water loss and impairment of aw below 0.85. Fat and salt levels were rising. Measured values show that an optimum time to dry durable meat products is 42 days and it should be done gradually. Measurements have shown that the results are strongly influenced by random variations. Only the difference in the average proportion of fat between 7th and 14th day wasn´t proved at the 5% level of significance.

Made available in DSpace on 2014-06-11T19:32:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-07-30Bitstream added on 2014-06-13T21:05:27Z : No. of bitstreams: 1 takahashi_se_dr_botfmvz.pdf: 234326 bytes, checksum: b32a0357c60cf8480511f2b7215fb35f (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Universidade Estadual Paulista (UNESP) / O objetivo do presente estudo foi verificar a ocorrência da carne pálida em diferentes linhagens de frango de corte e também avaliar as demais características de qualidade de carne. Foram utilizados 1440 pintos de corte de um dia, sexados, distribuídos segundo um delineamento inteiramente casualizado em esquema fatorial 3 x 2, com três linhagens (Avian48, Cobb e Hubbard) e dois sexos, com quatro repetições de 60 aves cada, totalizando 24 parcelas experimentais. As aves foram criadas sob as mesmas condições de manejo e alimentação. Aos 35, 42 e 49 dias de idade, foram retiradas 48 aves no total em cada abate para avaliação da ocorrência de carne pálida e determinações das características de qualidade da carne do peito, como pH, cor, desnaturação protéica, perda de exsudato, capacidade de retenção e absorção de água, perdas por cozimento e força de cisalhamento. Os resultados foram submetidos à Análise de Variância e, posteriormente, ao teste de comparação de médias de Tukey para as variáveis com diferença estatística significativa, utilizando o procedimento GLM (General Linear Models) do programa estatístico SAS (SAS Institute, 1996). Nas condições em que foi realizado este experimento, as diferentes linhagens não apresentaram diferenças com relação às características de qualidade de carne. Os machos apresentaram um valor de pH maior em comparação com as fêmeas em todas as idades estudadas. Com relação à coloração da carne, em todas as idades, as carnes de peito não apresentaram valores superiores à L*49,0, que os classificariam como pálidas, ou seja, a cor variou de normal à escura independente da linhagem, indicando, desta forma, que a linhagem não influenciou a ocorrência de carne pálida nem as demais características de qualidade. / The objective of this study was to verify the occurrence of pale meat in different commercial strains of broiler chickens and also to evaluate the other characteristics of meat quality. We used 1440 one day old chicks, male and female, distributed in a completely randomized design in an factorial 3 x 2, with 3 strains (Avian48, Cobb e Hubbard) and 2 genders, with four repetitions of 60 chickens each, in a total of 24 experimental parcels. The chickens were raised under the same handling and feeding conditions. When the chickens were 35, 42 and 49 days old, we removed 48 of them in total in each slaughter for evaluating the occurrence of pale meat and determining the characteristics of their breast meat quality, such as pH, color, protein denaturation, exsudate loss, capacity of water retention and absorption, losses for cooking and shearing strength. The results were submitted to the Variation Analysis and afterwards to the Tukey average comparison test for the variables with significant statistic difference, using the GLM (General Linear Models) procedure of the statistics program SAS (SAS Institute, 1996). Under this experiment's conditions, the different lineages didn't present any differences related to the characteristics of the meat quality. The males presented a higher pH value comparing to the females in all the ages studied. About the meat coloring, in all ages, the breast meat didn't present values higher than L*49,0, which would be considered pale that means that the color changed from normal to dark independently of the lineage, indicating that the lineage didn't influence the occurrence of pale meat and the other quality characteristics.

One of the main drivers influencing consumers in the purchasing of red meat is the level of visible fat, and this is particularly important in lamb, with lamb often being perceived as fatty. Consumer-driven preference for leaner meat, coupled with the meat processing industries preference for a reduction in carcass fat, increasing lean meat yield and reducing waste, have led to continued selection for lean growth and reduced fatness in several meat producing species The perception of lamb being fatty could be directly targeted in isolation by reducing overall fat levels, however there are related effects on meat (eating) quality, and the combined improvement and consistency of meat (eating) quality and the reduction of overall fatness is more complicated. It is apparent that fat content plays a significant role in meat (eating) quality. Generally four major fat depots are recognised in animal carcasses, these are: subcutaneous (under the skin); internal organ associated; intermuscular (between muscles and surrounding muscle groups); and intramuscular (marbling, between muscle fibres), the latter generally regarded as having the greatest association with meat (eating) quality. X-ray computed tomography (CT) can measure fat, muscle and bone in vivo in sheep and CT predictions of carcass composition have been used in commercial UK sheep breeding programmes over the last two decades. Together with ultrasound measures of fat and muscle depth in the loin region, CT measured carcass fat and muscle weights have contributed much to the success of breeding for leaner carcasses and increased lean meat yield. Recently it has also been considered that x-ray computed tomography provides the means to simultaneously estimate IMF and carcass fat in vivo. Thus the aim of this project is to investigate the use of two and three-dimensional x-ray computed tomography techniques in the estimation of meat (eating) quality traits in sheep, and to further investigate the genetic basis of these traits and the possibility of their inclusion into current breeding programmes. The primary approach was the use of two-dimensional x-ray computed tomography, determining the most accurate combination of variables to predict IMF and mechanical shear force in the loin. The prediction of mechanical shear force was poor with accuracies ranging from Adj R2 0.03 – 0.14, however the prediction of IMF in the loin was more promising. CT predicted carcass fat weight accounted for a moderate amount of variation in IMF (R2 =0.51). These accuracies were significantly improved upon by including other information from the CT scans (i.e. fat and muscle densities, Adj R2 >0.65). Average muscle density in a single or multiple scans accounted for a moderate amount of the variation in IMF (Adj R2 = 0.51-0.60), and again accuracies R2 >0.65 were achieved, independent of CT-measured fat areas or predicted fat weights. Similar results were achieved with the use of three-dimensional CT scanning techniques (Adj R2 0.51 – 0.71), however, there was a dramatically increased requirement for image analysis when compared to two-dimensional techniques, and the increase in accuracy was not significant. This suggests that the current method of two-dimensional image capture is sufficient in the estimation of IMF in vivo in sheep. The prediction equations developed as part of this work were applied across divergent breed types (Texel, Scottish Blackface and Texel cross mule), to investigate the transferability of the prediction equations directly across to other breeds of sheep. As part of this study, the IMF levels across the breed types and sexes were also compared and found that IMF was significantly affected by breed type (P<0.001) with Scottish Blackface lambs having higher levels of IMF when compared to Texel cross mule lambs, and the lowest levels of IMF were in the purebred Texel lambs at the same liveweight or similar levels of carcass fatness. Sex also had a significant effect on IMF across breeds (P<0.001) with females having higher levels of IMF at similar levels of both carcass fat and liveweight, and within breed, females had significantly higher levels of IMF in both the purebred Texel and Scottish Blackface lambs, when compared at similar levels of carcass fat and liveweight (P<0.05). Using the models previously developed in purebred Texel to predict IMF in the Scottish Blackface and Texel cross mule, accuracies were found to be R2 = 0.57 – 0.64 and R2 = 0.37 – 0.38 respectively. Providing evidence that the equations are transferable across to some breeds more successfully than others, however, given that there is currently no method of accurately estimating IMF in vivo, accuracies across to both breeds are acceptable. The genetic parameter estimation was unsuccessful using the same research-derived dataset as previously employed in the study. However the ambition was always to investigate the genetic relationships between traits in a large industry dataset, exploiting the wealth of commercial CT information available. These investigations were considerably more successful, and among the first to present genetic parameters of novel CT-derived IMF estimates. The results found moderate heritability estimates of h2 0.31 and 0.36 for the final selected prediction equations, with clear indications that one model not including CT predicted carcass fat or any other fat measures, was more independent of these measures and the two separate prediction methods were highly genetically correlated with each other (rg = 0.89). The results from this study show that not only is it possible to accurately estimate IMF levels in the loin of Texel sheep using CT scanning, but that, until breed specific predictions are developed, the methods developed in this study are transferable across some breed types. The results also show that CT predicted IMF is heritable, independent of overall fatness and has the potential to be included in current breeding programmes. These findings can now be used to develop breeding programmes which enable breeders to make the best use of CT scanning technology to improve carcass composition while maintaining or possibly improving aspects of meat (eating) quality.

Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2015-10-20T13:26:49Z No. of bitstreams: 2 Dissertação - Welman Paixão Silva Oliveira - 2015.pdf: 3359047 bytes, checksum: 482c0dffd55820a44e37332618f5e06d (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Rejected by Luciana Ferreira (lucgeral@gmail.com), reason: on 2015-10-21T10:09:43Z (GMT) / Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2015-10-21T11:11:31Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - Welman Paixão Silva Oliveira - 2015.pdf: 3359047 bytes, checksum: 482c0dffd55820a44e37332618f5e06d (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-10-22T12:20:41Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - Welman Paixão Silva Oliveira - 2015.pdf: 3359047 bytes, checksum: 482c0dffd55820a44e37332618f5e06d (MD5) / Made available in DSpace on 2015-10-22T12:20:41Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - Welman Paixão Silva Oliveira - 2015.pdf: 3359047 bytes, checksum: 482c0dffd55820a44e37332618f5e06d (MD5) Previous issue date: 2015-03-06 / Meat is a food of high nutritional value and easy deterioration. The boning operation if not performed in adequate sanitary conditions, can compromise the microbiological quality of this noble product. This study was the largest to evaluate microbiological characteristics of beef subject to the deboning process at 15 ° C ambient temperature.The inlet temperature of the rooms in dessosa room was considered as the initial temperature (Ti) while the temperature measured in the cuts, bone and corresponding to the same house, as the final temperature (Tf). The difference between Ti and Tf was calculated, as well, was monitored variation in temperature rise of meat cuts, which occurred during the deboning process compared to the ambient temperature (Ta) of the boning room. In the boning room entrance was measured the pH of the muscle Longissimusdorsi between the 12th and the 13th thoracic vertebra and the value found was considered as the initial pH (pHi). After boning the hindquarters, the pH in the commercial courts and figures were considered as the final pH was measured (PHF). The data were submitted to ANOVA and Tukey's test to compare the effect of Ta on the variables: temperature of the meat cuts, pH and the results of bacteriological analyzes. The "t" test was also used to compare the varying temperatures and pH for each treatment at the inlet and the outlet boning room. After analyzing the results, we concluded that the bacteriological quality of rear cattle on the 4th presented is acceptable, given the low contamination levels found; the pH and the inlet temperature to the room boning room were also acceptable, lying within the margins allowed by the specific legislation for industries under Federal Inspection Service (SIF); boning room ambient temperature is quite heterogeneous, existing significant variations depending on the location sampled; the studied meat cuts, the temperature curves in relation to the time spent in the boning room were represented by a linear function with higher coefficients of determination 99%. Regression and determination coefficients were similar for the ribeye, the lizard and the sirloin, indicating that the maximum temperature input in the boning room should not exceed 5.1 ° C when the ambient temperature is 15 ° C and 5 9 ° C to room temperature to 12 ° C; contamination by mesophilic the surface of contrafilés increased significantly during boning, and for the G15 group this increase was more evident. The deboning process of "white bone" contributes to the excessive initial contamination of the tenderloin; the association processes of boning "white blood", and the increase of boning room temperature to 15 ° C for an increase of ten times the surface contamination of the ribeye, which means a higher risk of product deterioration. / A carne é um alimento de alto valor nutricional e fácil deterioração. A operação de desossa, se não for realizada em condições higiênico-sanitárias adequadas, pode comprometer a qualidade microbiológica desse produto nobre. O presente estudo foi realizado com o objetivo maior de avaliar características bacteriológicas da carne bovina submetida ao processo de desossa em temperatura ambiente de 15ºC. A temperatura de entrada dos quartos na sala de dessosa foi considerada como a temperatura inicial (Ti), enquanto a temperatura mensurada nos cortes, desossados e correspondentes aos mesmos quartos, como a temperatura final (Tf). Foi calculada a diferença entre a Ti e a Tf, como também, foi monitorada a variação na elevação de temperatura dos cortes cárneos, ocorrida durante o processo de desossa em relação à temperatura ambiente (Ta) da sala de desossa. Na entrada da sala de desossa foi aferido o pH do músculo Longissimusdorsi entre a 12ª e a 13ª vértebra torácica e o valor encontrado foi considerado como o pH inicial (pHi). Após a desossa do quarto traseiro, foi aferido o pH nos cortes comerciais e os valores encontrados foram considerados como o pH final (pHf). Os dados foram submetidos à análise de variância e teste de Tukey para comparar o efeito da Ta nas variáveis: temperatura dos cortes cárneos, pH e os resultados das análises bacteriológicas. O Teste "t" também foi utilizado para comparar as variáveis de temperaturas e de pH em relação a cada tratamento na entrada e na saída da sala de desossa. Após análise dos resultados, pôde-se concluir que a qualidade bacteriológica dos quartos traseiros bovinos apresentou-se aceitável, tendo em vista os baixos níveis de contaminação encontrados; o pH e a temperatura de entrada à sala de desossa dos quartos também foram aceitáveis, encontrandose dentro das margens permitidas pela legislação específica para indústrias sob Serviço de Inspeção Federal (SIF); a temperatura ambiente da sala de desossa é bastante heterogênea, existindo importantes variações, dependendo do local amostrado; nos cortes cárneos estudados, as curvas de temperatura em relação ao tempo de permanência dentro da sala de desossa foram representadas por uma função linear com coeficientes de determinação superior a 99%. Os coeficientes de regressão e determinação foram semelhantes para o contrafilé, o lagarto e a picanha, indicando que a temperatura máxima de entrada na sala de desossa não deve superar os 5,1°C quando a temperatura ambiente for de 15°C e os 5,9°C para temperatura ambiente a 12°C; a contaminação por mesófilos na superfície dos contrafilés aumentou de forma significativa durante a desossa, sendo que para o grupo G15 esse aumento foi bem mais evidente. O processo de desossa do “osso branco” contribui para a excessiva contaminação inicial do contrafilé; a associação dos processos de desossa do “osso branco” e o aumento da temperatura da sala de desossa para 15 °C determinaram um aumento de dez vezes na contaminação superficial do contrafilé, o que significa um maior risco de deterioração do produto.