Thesis (MScVoedselwet)--University of Stellenbosch, 2003. / ENGLISH ABSTRACT: Two experiments were conducted in order to manipulate the physical and chemical properties and shelf life of ostrich meat. Experiment 1: The effect of dietary fish oil rich in n-3 fatty acids on the organoleptic, fatty acid and physicochemical characteristics of ostrich meat. The diet of four ostrich groups (15 birds per group), approximately 3 months of age (ca. 41 kg live weight) grazing a predominantly oats pasture, was supplemented with a diet containing 6.7% fish oil. The birds received a supplement of either 0 (diet 1), 800 (diet 2), 1600 (diet 3) or 2400 g (diet 4) DM/day resulting in the consumption of 0 (diet 1), 14.5 (diet 2), 29 (diet 3) and 43.5 (diet 4) g fish oil per day. The ostriches were slaughtered at 10 months of age (ca. 70 kg live weight). An increase in the amount of fish oil consumed was found to have had statistically no significant effect on the sensory characteristics of the M. iliofibularis, although there was a tendency towards an increase in ‘fishiness’, for both aroma and flavour. However, increased concentrations of fish oil had a significant effect on the aroma and flavour of the abdominal fat pads. The muscle pHf and muscle lightness (L*) reflected a significant reduction with increased fish oil levels. The increased feed intake, on the other hand, had no effect on the chemical composition (moisture, protein, fat and ash content) of the meat. The fatty acid profile of both fat and meat was affected by the consumption of fish oil. The SFA concentration increased, while the PUFA concentration decreased, with an increase in feed intake. The MUFA concentration remained constant for all four groups. Experiment 2: The effect of dietary vitamin E and the type of packaging on the sensory quality, physicochemical composition and shelf life of ostrich meat. Two groups of ostriches (35 birds per group; ca. 3 months old) were fed diets containing either 40 mg/kg feed vitamin E (control) or 150 mg/kg feed Vitamin E for nine months. The birds were slaughtered at 12 months of age. The effect of different the levels of vitamin E and heat shrink treatment of vacuum packaging material on the shelf life of refrigerated (0°C) ostrich M. flexor cruris lateralis, was evaluated over 81 days. Vitamin E and heat shrink treatments were found to have had no significant effect on the sensory characteristics; off-meat aroma, sourness, juiciness and mealiness. Rancidity was found to be slightly more pronounced (although not statistical significant) in the vitamin E and heat shrink groups than in the feed control and vacuum-packed groups. A significant decrease in the organoleptic quality of the meat, over a 40 day shelf life period, was observed. The pH and muscle tenderness showed a significant reduction with increased storage time. The purge loss in the package increased over time with no change in muscle drip loss. The colour, conjugated dienoic acid and fatty acid content showed no significant changes over time or with regards to treatment. The total viable counts and coliform numbers in the muscle increased over time, with the coliforms being slightly suppressed by the inclusion of vitamin E in the diet. A microbiological safe shelf life of 40 days at 0°C was obtained. / AFRIKAANSE OPSOMMING: Twee eksperimente is uitgevoer om die fisiese en chemiese eienskappe, asook die rakleeftyd van volstruisvleis, te manipuleer. Eksperiment 1: Die effek van visolie, ryk aan n-3 vetsure, op die organoleptiese, vetsuur- en fisies-chemiese eienskappe van volstruisvleis. Die dieet van vier groepe volstruise (15 voëls per groep), ongeveer 3 maande oud (ca. 41 kg lewende massa) wat ‘n hawer weiding bewei het, is aangevul met ‘n byvoedingsmengsel wat 6.7% visolie bevat en in toenemende hoeveelhede vir die groepe volstruise gevoer is. Die voëls het ‘n aanvulling van 0 (dieet 1), 800 (dieet 2), 1600 (dieet 3) of 2400 g (dieet 4) DM/dag ontvang wat gelei het tot ‘n inname van 0 (dieet 1), 14.5 (dieet 2), 29 (dieet 3) en 43.5 (dieet 4) g visolie per dag. Die volstruise is op ‘n ouderdom van 10 maande geslag (ca. 70 kg lewende massa). ‘n Toename in die hoeveelheid visolie ingeneem, het geen statisties betekenisvolle effek op die sensoriese eienskappe van die M. ilifibularis gehad nie, alhoewel daar ‘n tendens was vir ‘n toename tot ‘n ‘visagtige’ aroma en smaak. ‘n Toename in die konsentrasie visolie het egter ‘n betekenisvolle effek op die ‘visagtige’ aroma en smaak van die abdominale vet neerslae gehad. Die spier pHf en spier ligtheid (L*) het ‘n betekenisvolle afname met toename in voer inname getoon. Die verhoogde olie inname het egter geen effek op die chemiese samestelling (vog-, proteïen-, vet- en asinhoud) van die vleis gehad nie. Die vetsuurprofiel van beide die abdominale vet neerslae en die vleis is deur die inname van visolie verander. Die versadigde vetsuurkonsentrasie het verhoog terwyl die poli-onversadigde vetsuurkonsentrasie verlaag het met ‘n toename in rantsoenvlakke. Die mono-onversadigde vetsuurkonsentrasie het egter konstant gebly vir al vier groepe. Eksperiment 2: Die effek van vitamien E en die tipe verpakking op die sensoriese kwaliteit, fisies-chemiese samestelling en rakleeftyd van volstruisvleis. Twee groepe volstruise (35 voëls per groep, ongeveer 3 maande oud) het voere oor ‘n tydperk van nege maande ontvang wat 40 mg vitamien E/kg voer (kontrole) of 150 mg vitamien E/kg voer bevat het. Die voëls is op 12 maande ouderdom geslag. Die effek van die verskillende vlakke van vitamien E en hitte-behandeling van die verpakkings materiaal op die rakleeftyd van verkoelde (0°C) volstruis M. flexor cruris lateralis, is oor 81 dae geëvalueer. Vitamien E en die hitte-behandeling het geen betekenisvolle effek op die organoleptiese eienskappe (af-vleis aroma, suurheid, sappigheid en melerigheid) gehad nie. Galsterigheid was ‘n bietjie meer gedefinieerd (anie-betekenisvol) in die vitamien E en hitte behandelde groepe as in die rantsoen kontrole en vakuum verpakte vleis. ‘n Betekenisvolle afname is waargeneem in die organoleptiese kwaliteit van die vleis oor ‘n 40 dae rakleeftyd periode. Die pH en taaiheid van die spier het betekenisvol afgeneem met ‘n toename in bergingsperiode. Die drup verlies tydens verpakking het ook oor tyd toegeneem, terwyl geen verandering in die analitiese drup verlies van die spier verkry is nie. Die kleur, gekonjugeerde dieensuur en vetsuursamestelling het geen verandering oor tyd of ten opsigte van behandeling getoon nie. Die Totale Lewendig Seltelling en coliforme het toegeneem oor tyd, terwyl die coliforme deur die byvoeging van vitamien E tot ‘n mate onderdruk is. ‘n Mikrobiologies veilige rakleeftyd van 40 dae is verkry.

Thesis (Msc Food Sc (Food Science))--University of Stellenbosch, 2006. / The aim of this study is to determine the effect of crossbreeding Zimbabwean Blue (ZB) and South African Black (SAB) ostriches on the morphological, physical, chemical and sensory quality of the meat. However, it is also necessary to determine the reproductive performance of these genotypes to scientifically support decisions made in the ostrich industry. In relation to reproductive traits and body measurements influencing these traits, results from the study suggested that ZB birds are between 9 and 15% heavier than their SAB contemporaries. Regarding SAB females, egg production was 47% higher, levels of shell deaths were lower, percentage of eggs not incubated was lower (P<0.01) and 84% more (P<0.01) chicks were produced in a season compared to their ZB contemporaries. Mates of SAB males produced a higher (P≤0.05) percentage of eggs not incubated and higher shell death percentages than the mates of ZB males. It has to be conceded that ZB females had a lower reproduction than SAB females, limiting the application of this genotype as a dam line in crossbreeding systems. With regard to morphological properties, the pure Blue genotype in comparison to the pure Black genotype differed significantly (P≤0.05), with 16 kg for live weight, 8.3 kg for carcass weight and 3.5 kg for leg weight. However, when comparing carcass yields (expressed as %) there were no significant differences (P>0.05) between genotypes. The M. gastrocnemius, M. femorotibialis accessorius, M. iliotibialis cranialis, M iliotibialis lateralis, M. iliofibularis and M. iliofemoralis showed significant genotype differences (P≤0.05) for individual muscle weight. When comparing the physical meat quality characteristics between the pure Blue genotype and the pure Black genotype, 70% of the muscles were higher (P≤0.05) in pH24, 50% of the muscles were redder (P≤0.05) and significantly less (P≤0.05) saturated in colour, 67% of the muscles had a lower (P≤0.05) percentage drip loss and 50% of the muscles had a lower (P≤0.05) percentage cooking loss. No significant (P>0.05) genotype differences were observed regarding the sensory quality of the meat. Regarding chemical meat quality characteristics, the percentage of moisture was higher and the percentage of lipid was lower for eight of the ten muscle groups from the pure Blue genotype. No significant differences (P>0.05) were found between genotypes or between muscles regarding the percentage of protein present in the meat. The highest (P>0.05) content of soluble collagen, myoglobin and cholesterol was found in the Blue x Black genotype, whereas the lowest percentage of the latter constituents was found in the pure Blue genotype. For the pure Black genotype the concentration of saturated fatty acids in the meat was lower (P≤0.05), the concentrations of total unsaturated fatty acids and desirable fatty acids in the M. illiofibularis were the highest (P≤0.05), while the concentration of monounsaturated fatty acids was also higher (P≤0.05) in both muscles of this genotype compared to the other two genotypes. Regarding both fat depots, the pure Black genotype had a lower (P≤0.05) concentration of saturated fatty acids, a higher (P≤0.05) concentration of monounsaturated fatty acids and total unsaturated fatty acids and a higher (P≤0.05) polyunsaturated:saturated fatty acid ratio. The percentage of desirable fatty acids in the abdominal fat depot was significantly higher (P≤0.05) for the pure Black and the Blue x Black genotype. In conclusion, crossbreeding between SAB and ZB ostriches seems to be a viable option to produce larger birds with more meat, without negatively affecting the overall quality of the meat.

Em termos globais, existe urna tendência crescente na demanda por alimentos saudáveis e seguros. Visando esta demanda, a carne de avestruz é vista corno uma opção. A indústria sul-africana é a grande abastecedora da União Européia (UE) e o Brasil tenta disputar esse mercado, que é extremamente exigente em regras que garantam a produção de um alimento seguro, o que torna de vital importância um gerenciamento da qualidade em todas as fases de produção. Este estudo analisa o sistema agroindustrial da carne de avestruz, investigando os atributos de qualidade do produto divulgados por meio eletrônico de comunicação em dois países, África do Sul e Brasil, e comparando-os às necessidades de bem-estar do consumidor. Após pesquisa bibliográfica teórica, elaborou-se pesquisa documental, na qual os dados quantitativos do setor foram obtidos em fontes governamentais de cada país e os qualitativos em reportagens divulgadas em meio eletrônico e nos sites das empresas líderes de mercado em cada país, posteriormente submetidos à técnica de análise de conteúdo. Os resultados mostram que a produção sul africana atende às normas de gerenciamento de qualidade exigidas pelo bloco europeu, mas isso não foi suficientes para evitar reincidência de Influenza A em seu rebanho. Por outro lado, o brasileiro ainda não implementou o Plano Nacional de Controle de Resíduos (PNCR), sem o qual não consegue exportar, o que implica na obrigatoriedade de venda para o mercado interno, que possuí baixa demanda. Na comunicação adotada, ambos os países focam, principalmente, a dimensão biológica, seguido pelo bem-estar psicológico: o prazer de comer bem. / In global terms, there is a growing trend in the demand for healthy and safe food. Aiming this demand, ostrich meat is seen as an option. The South African industry is the major supplier of the European Union (EU) and Brazil tries to play this market, which has extremely demanding rules to ensure a safe food production, which makes a vital quality management in all stages of production. This study analyzes the agribusiness system of ostrich meat, investigating the quality attributes of the product disclosed by electronic means of communication in both countries, South Africa and Brazil, and comparing them to the needs of well-being of the consumer. After theoretical literature, was conducted archival research in which quantitative data were obtained from industry sources and government of each country in the qualitative reports electronically and posted on the websites of leading companies in each Country, then submitted to technique of content analysis. The results show that South African production meets quality management standards. required by the European bloc, but this was not sufficient to prevent recurrence of Influenza A in his flock. On the other hand, the Brazilian has yet to implement the National Plan for Waste Management (PNCR), without which it can not export, which implies the obligation to sell to the domestic market, which has low demand, Communication adopted in both countries focus mainly the biological dimension, followed by psychological well-being: the pleasure of eating well.

Magister Scientiae - MSc / The aim of this study was to determine the quality of slaughtered ostrich meat and to evaluate the ostrich slaughter process, to determine whether ostrich meat are contaminated by the in-house slaughtering practices and if prevalence of microorganisms increase with the succession of the slaughter process. Furthermore, the presence of specific foodborne pathogens and spoilage organisms was explored by means of molecular and conventional methods to determine whether ostrich meat is a source of these microorganisms. Data obtained from this study provides some baseline information that could be used in future studies on system contamination and the extent of downstream processing steps in the production of ostrich meat. Antimicrobial resistance has become a growing area of concern in both human and veterinary medicine, it is therefore necessary that another aim of this study was to determine the antibiotic resistant pattern of Staphylococcus aureus in ostrich meat in order to establish whether Staphylococcus aureus strains isolated from ostrich meat samples show resistance to antibiotics. / South Africa

The ostrich meat is being introduced in the market for meat as a healthy alternative when compared with most other meat, because it has low content of total lipids, saturated fatty acids and calories. Despite these benefits reported in the scientific literature on the ostrich meat, there are few jobs in relation to protein quality and effect of the consumption of meat on the metabolism of humans and animals. This study aims to assess the biological and physical chemistry of ostrich meat, its effect on biochemical parameters in rats and compared with most other meat consumed. We performed analysis of proximate composition, fatty acid profile, cholesterol and minerals of ostrich meat, beef, pork and chicken. To test the biological, experimental diets were prepared with casein (control) and diets in which casein was replaced by ostrich meat, beef, chicken and pork. The proximate composition of meat, for moisture, protein and ash, was very similar, but the meat of ostriches showed a lower percentage of lipid (0.58%). Moreover, had a good relationship of polyunsaturated fatty acids / saturated (0.99) n6/n3 ratio (8.32) and greater amount of iron (4.17 mg/100g). By the assay it was found that as well as beef, pork and chicken, beef and ostrich has an excellent quality protein and showed positive results in the biochemical parameters of rats fed with this meat, especially in relation to serum cholesterol of animals that showed a lower concentration. / A carne de avestruz está sendo introduzida no mercado das carnes como uma alternativa mais saudável quando comparada com outras carnes, pois tem baixo teor de lipídios totais, de ácidos graxos saturados e calorias. Apesar desses benefícios relatados na literatura científica sobre a carne de avestruz, existem poucos trabalhos, em relação à qualidade protéica e o efeito do consumo desta carne sobre o metabolismo de humanos e animais. Este trabalho tem como objetivo a avaliação biológica e físico-química da carne de avestruz, seu efeito nos parâmetros bioquímicos em ratos e comparar com outras carnes mais consumidas. Foram realizadas análises da composição centesimal, perfil de ácidos graxos, colesterol e minerais das carnes de avestruz, bovina, suína e frango. Para o ensaio biológico, foram elaboradas dietas experimentais, com caseína (controle) e dietas onde a caseína foi substituída por carne de avestruz, carne bovina, carne de frango e carne suína. A composição centesimal das carnes, em relação à umidade, proteína e cinzas, foi bastante semelhante, porém a carne de avestruz apresentou um percentual de lipídio mais baixo (0,58%). Além disso, apresentou uma boa relação de ácidos graxos poliinsaturados/saturados (0,99), razão n6/n3 (8,32) e maior quantidade de ferro (4,17 mg/100g). Através do ensaio biológico verificou-se que assim como a carne bovina, suína e frango, a carne de avestruz possui uma excelente qualidade protéica e apresentou resultados positivos nos parâmetros bioquímicos de ratos alimentados com esta carne, principalmente em relação ao colesterol sérico dos animais que apresentaram menor concentração.