Thesis (PhD (Food Sc))--Stellenbosch University, 2011. / ENGLISH ABSTRACT: Ostrich meat has become increasingly popular in South Africa and abroad, driven by the health conscious trend and ostrich meat’s natural low intramuscular fat, high polyunsaturated fatty acid and low cholesterol content. This increased demand led to the investigation of novel packaging regimes to improve its attractiveness and shelf-life. Different modified atmospheric packaging regimes were studied for fresh and frozenthawed ostrich M.iIliofibularis steaks stored at ±4°C for 10 days. Oxygen MAP (30 CO2:70 O2) was applied with great success to fresh steaks, and resulted in significantly improved colour stability, decreased drip loss and a 10-day shelf-life. Oxygen MAP of frozen-thawed ostrich steaks was not successful as the colour deteriorated within 3 days, coupled with high lipid and protein oxidation. The microbial shelf-life was not influenced by freezing and thawing. The use of nitrogen MAP (30 CO2:70 N2) as an alternative to vacuum packaging for fresh and frozen-thawed ostrich meat was inconclusive due to trace amounts of residual oxygen in the headspace accelerating myoglobin oxidation by depleting the metmyoglobin reducing activity. The differences in oxidative stability of the fresh and frozen-thawed ostrich meat led to the investigation of the source of these differences and a system that would allow control over the freezing and thawing practice. This was supported by the industry that is under increasing pressure to reduce the excessive (15-20%) thaw weight loss that is continually reported. Subsequently, a mathematical prediction model based on the control volume approach was developed that predicted the rate of freezing and thawing of intact whole vacuum-packed ostrich muscle. The model predicted with greater accuracy than existing models, and can be used successfully by the industry to optimally design, control and operate their systems. Furthermore research was conducted to investigate the effect of different freezing and thawing rates on the ice crystal formation and the quality of ostrich M. femorotibialis stored at ±4°C post freeze/thaw. Five characteristic freezing rates (FR (time from 0°C to -7°C): 1, 2, 4, 8, 24h) were paired with five characteristic thawing rates (TR (time form -7°C to 0°C): 1.5, 3, 6.5, 14, 21h) in a completely randomised block design. Results showed that thawing had no impact on any of the tested quality parameters, including thaw loss. Freezing rate however did influence the ice crystal formation and at a characteristic freezing rate of one hour (FR_1h) only intracellular ice crystals were observed throughout the M. femorotibialis leading to the lowest thaw loss (2.57%) and highest shear force. Freezing rate of 2h, 4h and 8h (FR_2h, FR_4h and FR_8h) were dominated by extracellular ice crystals. FR_2h and FR_8h showed major dehydration of the muscle fibres and excessive distortion of the muscle fibre matrix that led to significantly lower oxidative stability. FR_24h (approximately commercial rates) formed columns of ice from the surface to the centre of the meat resulting in the highest thaw loss (6.24%). FR_4h was judged to deliver the best quality product with moderate thaw (3.93%) and drip loss, low cooking loss, good colour stability and extremely low TBARS. FR_4h is an achievable rate of freezing for the industry and if implemented should decrease the thaw loss problem as well as increase revenue and throughput in the processing facility. / AFRIKAANSE OPSOMMING: ‘n Hedendaagse strewe na ‘n gesonde lewenstyl tesame met die natuurlike lae vetinhoud (d.i. hoë poli-onversadigde vetsure en lae cholesterolvlak) van volstruisvleis het gelei tot ‘n toename in die nasionale en internasionale aanvraag. Hierdie het ook die behoefte laat ontstaan om nuwe verpakkingstegnieke te ondersoek om sodoende die aanvaarbaarheid en rakleeftyd van die produk te verleng. Die invloed van verskeie gewysigde atmosferiese verpakkingsmetodes (GAV) op die kleurstabiliteit, drupverlies en rakleeftyd van vars en bevrore/ontdooide volstruisvleis (spesifiek M. Iliofibularis), gestoor by ±4°C vir 10 dae, is ondersoek. Die suurstof GAV (30 CO2:70 O2) van vars volstruisvleis het ‘n verbetering in kleurstabiliteit, verlaagde drupverlies en 'n verlengde mikrobiese rakleeftyd (10 dae) tot gevolg gehad. Die suurstof GAV van bevrore-ontdooide volstruisvleis het geen voordelige effek op kleurstabiliteit en rakleeftyd getoon nie. Die bevrore/ontdooide monsters het totaal verkleur na 3 dae en ‘n hoë vlak van lipied- en proteïenoksidasie is waargeneem. Die bevriesing en ontdooiing het geen invloed op rakleeftyd gehad nie. Die moontlikheid om stikstof GAV (30 CO2:70 N2) as 'n alternatief tot vakuumverpakking vir vars en bevrore/ontdooide volstruisvleis te gebruik, is beïnvloed deur die teenwoordigheid van oorblywende suurstof in die lugruimte van die GAV, met ‘n gevolglike toename in die tempo van mioglobien oksidasie as gevolg van ‘n afname in die metmioglobien reduksie aktiwiteit. Die verskil in die oksidatiewe stabiliteit van vars en bevrore/ontdooide volstruisvleis het gelei tot ‘n verdere ondersoek na die oorsaak van die verskille en die ontwikkeling van ‘n moontlike protokol om die oksidatiewe stabiliteit en dus rakleeftyd van volstruisvleis, te verbeter en bestuur. Die behoefte aan so ‘n protokol is beklemtoon deur die bedryf wat onder toenemende druk verkeer om buitensporige ontdooiingsverliese (15-20%) te verminder. ‘n Wiskundige voorspellingsmodel, gebaseer op die beheer-volume benadering, is ontwikkel om die tempo van bevriesing en ontdooiing van vakuumverpakte heel volstruisspiere te voorspel. Die model het tempo van bevriesing en ontdooiing met groter akkuraatheid as die bestaande modelle voorspel en kan suksesvol gebruik word in die bestuur van slagpale. Verder navorsing is onderneem om ondersoek in te stel na die effek van die tempo van bevriesing en ontdooiing op die kwaliteit van die bevrore-ontdooide volstruisvleis tydens berging by ±4°C. Die invloed van die kombinasie van vyf bevriesingstempo’s (FR (tydsverloop 0°C tot -7°C): 1, 2, 4, 8, 24 h) met vyf ontdooiingstempo’s (OT (tydsverloop -7°C to 0°C): 1.5, 3, 6.5, 14, 21 h) is ondersoek. Die resultate het getoon dat ontdooiingstempo geen beduidende invloed op enige van die kwaliteit kriteria, insluitend ontdooiingsverlies, gehad het nie. Bevriesingtempo het egter ‘n groot rol ten opsigte van yskristalvorming gespeel. Teen ‘n kenmerkende bevriesingstempo van een uur (FR_1h) was slegs intrasellulêre yskristalle waargeneem dwarsdeur die M. femorotibialis wat gelei het tot die laagste ontdooiingsverlies (2.57 %). Die ander bevriesingstempo’s, d.i. FR_2h, FR_4h en FR_8h, het gelei tot die vorming van meestal ekstrasellulêre yskristalle. Bevriesingstempo’s van FR_2h en FR_8h het beduidende dehidrasie van die spiervesels en vervorming van die spiervesel matriks tot gevolg gehad, wat tot verhoogde oksidasie gelei het. ‘n Bevriesingstempo van FR_24h (d.i. kommersieële tempo), het gelei tot die vorming van yskolomme van die oppervlak na die middelpunt van die spier, wat gevolglik die grootste ontdooiingsverlies (6.24%) tot gevolg gehad het. ‘n Bevriesingstempo van vier ure (FR_4h) is bestempel as die mees geskikte bevriesings tempo as gevolg van ‘n matige ontdooiingsverlies (3.93%), drupverlies, lae kookverlies, goeie kleur stabiliteit en uiters lae lipiedoksidasie te verseker. Die FR_4h bevriesingstempo is haalbare in die bedryf. Indien dit geïmplementeer word, sal dit waarskynlik die deurset van die slagpalesiklus asook die kostedoeltreffendheid van die volstruisbedryf vebeter, deur die vermindering van ontdooiingsverlies en verbetering van die algehele kwalitiet van die vleis.

Thesis (MScAgric)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Although transport and lairage of ostriches are accepted causes of production losses, these losses have not yet been quantified. Transport and lairage regulations focus on the wellbeing of the birds and, by default reduce some losses. This thesis investigated weight losses and meat quality of ostriches as a result of transport density, lairage duration and lairage feed availability (ad libitum). All birds were reared on the same farm and loaded and transported together. They were randomly divided into their respective groups on loading for the transport trial, and on offloading for the lairage trial. Bird grouping was according to density for the transport trial (4 groups, H1, H2: 0.56m2/bird and L1, L2: 0.96m2/bird) and according to time spent in lairage and feed availability for the lairage trial (n=30 birds/group; L0hr and L24hr; n=15 birds/group L48hr and L48hr ad libitum feed). Behavioural observations of the ostriches showed a tendency of the ostriches to lean against objects and to orientate towards forces exerted on it to help keep its balance. Reactions to sound fluctuations were noted, with birds reacting towards changes in sound volume during transport and lairage. Timepoint numbers were allocated for each time the birds were weighed during the trial. Time points 1, 2, 3, 4 and 5 were allocated to loading, arrival, 19 hr in lairage, 31 hr in lairage and 39 hr in lairage respectively for Trial 2. Results showed no differences (P > 0.05) in live weights or meat quality parameters between Groups H1, H2, L1 and L2 during transport. Differences (P < 0.05) were found in cumulative weight losses between L0hr and the rest of the groups for time point 1. Differences between L48hr and L48hr ad libitum were found for time point 4 for cumulative weight loss. L48hr also differed significantly between the other lairage duration groups for dressing percentages as a function of loading weight. Ad libitum feed availability had a significant effect on live body weight changes but not the meat quality parameters for the groups held for 48hr in lairage. The number of birds having bruises (≈50% per group) was similar between groups and lairage had no influence on bruising. Results seem to indicate that the evaluated transport densities had no effect on the weight loss or meat quality of ostriches. However, the results indicate that the lairage period should be studied further with specific reference to weight losses during lairage. Meat quality was unaffected by the lairage parameters reported in this thesis. / AFRIKAASE OPSOMMING: Hoewel vervoer en voorslag hou (“lairage”) aanvaar word as die oorsake van produksieverliese, is hierdie aspekte nog nie gekwantifiseer nie. Regulasies in terme van vervoer en voorslag hou fokus op die welstand van die voëls en gevolglik verminder sommige verliese met hierdie faktore. Konflik tussen boere en sekondêre produsente (abattoirs en verwerkers) oor die kostes verbonde aan hierdie gewigsverliese, is in wese ‘n oorsaak van oorbruggingsfases (vervoer). Daarom is die voorslag hou-parameters van tyd, voerbeskikbaarheid en laai digtheid ondersoek. Twee proewe is geloods; een vir vervoer en een vir voorslag aanhou. Voëls is voor hulle op vragmotors gelaai is, geweeg en op spesifieke tye daarna geweeg. Diere van die laaidigtheidsproef is ingedeel in vier groepe (H1, H2: 0.56m2/voel en L1, L2: 0.96m2/voel). Met aflaai is die eerste toets groep geslag terwyl die tweede toets groep ingedeel is volgens die tyd gespandeer en voer beskikbaarheid in voorslag aanhou (n=30 voëls/groep - Groepe L0u, L24u; n=15 voëls/groep - L48u en L48u ad libitum gevoer). Gedrag van voëls is aangeteken tydens vervoer. Finale gewig was slagpale gewig en elke tyd periode waar die voëls geweeg is, is aangeteken as ‘n tydpunt. Vleiskwaliteit analises is gedoen op die linker boud se fan filet. ‘n Standaard rak leeftyd toets is ook gedoen om kwaliteit parameters te toets oor tyd. pH is gekatorigiseer volgens groepe om moontlike verskille te beklemtoon. Gedrag is opgeteken volgens die oriëntasie en steunings gewoontes van die volstruise gedurende vervoer. Voëls probeer hulle balans te hou deur op voorwerpe en op mekaar te leun, asook om hul liggaam oriëntasie te gebruik. Reaksies tot klank veranderinge is ook opgemerk tydens vervoer en voorslag aanhou. Resultate toon geen betekenisvolle verkille tussen digtheid groepe H1, H2, L1 en L2 nie. Geen gewigsverskille is gevind tussen vervoerdigtheid groepe nie. Vleiskwaliteit-parameters is ook ondersoek en geen verskille is gevind tussen groepe nie. Resultate toon wel betekenisvolle verskille in gewigsverlies-persentasie tussen groepe vir tyd in voorslag aanhou. Groepe L48u en L48u ad libitum, het onder andere betekenisvol verskille getoon vir tydpunt 4. Betekenisvolle verskille in uitslagpersentasie as funksie van begin-gewig tussen 48 uur en die res van die groepe is ook gevind. Verdere vleiskwaliteit-parameters (drupverlies, pH, ens.) tussen groepe het geen betekenisvolle verskille getoon nie. Resultate dui aan dat voer beskikbaarheid het ‘n invloed op gewigsverskille in voorslag aanhou. Regulasies vir voorslag hou, vervoer en welstand van volstruise sal moontlik verder ondersoek moet word met spesiale klem op die nut van voorslag aanhou en die se invloed op gewigsverlies. Vleiskwaliteits-parameters is nie beïnvloed deur die aspekte ondersoek nie.

Thesis (Msc Food Sc (Food Science))--University of Stellenbosch, 2005. / The aim of this study was to investigate the effects of hot-deboning (1 h post-mortem) on the shelf-life and the physical meat quality characteristics, including tenderness, pH, purge (%), cooking loss (%), and raw meat colour of vacuum packed ostrich (Struthio camelus var. domesticus) meat cuts from the M. gastrocnemius, pars interna and the M. iliofibularis during post-mortem refrigerated aging for respectively 21 d at 4ºC and 42 d at -3º to 0ºC.

Thesis (MScAgric)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: This research study consists of three investigations with regard to ostrich (Struthio camelus var. domesticus) production, meat quality and the processing of ostrich meat into a value added meat product. The first study was conducted in order to establish whether the gradual replacement of soybean oilcake meal with cottonseed oilcake meal (CSOCM) as a protein source in the diet of slaughter ostriches would affect ostrich growth performance and meat quality. A total of 105 ostriches were divided into five feeding groups according to the CSOCM inclusion level: Control (0% CSOCM), 3%, 6%, 9% and 12% CSOCM, and fed with experimental diets from 6 to 13 months of age. As a result of feeding CSOCM, the final live weight and the average daily gain significantly increased in the 12% CSOCM group compared to the other treatment diets. The proximate composition, cholesterol content, mineral and fatty acid profile of the meat remained unaffected. Considering all the results, CSOCM may be used as an alternative protein source to soybean oilcake meal in ostrich nutrition, resulting in decreased feed costs. Secondly, a descriptive sensory analysis, together with chemical and physical measurements, was performed to determine whether the manipulation of the fatty acid composition in the fan fillet (Iliofibularis muscle) as a result of feeding CSOCM would be detected on a sensory level. Two levels of CSOCM were investigated; 0% as a control and 9% CSOCM. No significant differences were found for the physical measurements (cooking loss (%) and shear force) as well as for the pH and proximate composition of the raw fan fillet. The Control group presented a higher (P<0.05) mono-unsaturated fatty acid (MUFA) content in the cooked fan fillet whereas the 9% CSOCM group showed a favourable increased (P<0.05) poly-unsaturated fatty acid (PUFA) content when compared to the cooked Control samples. As a result, the poly-unsaturated:saturated fatty acid (PUFA:SFA) ratio in the 9% CSOCM group was also higher (P<0.05). No differences (P>0.05) were found between the treatments for the n-6:n-3 (omega 6 to omega 3) ratio. The 9% CSOCM group had a more intense beef aroma, had a higher level of initial and sustained juiciness as well as increased tenderness (P<0.05). Inclusion of 9% CSOCM resulted in a favourable cooked ostrich fan fillet. Finally, the effect of feeding CSOCM on a processed ostrich meat product was investigated. Fan fillet (Iliofibularis muscle) from 13 month old birds receiving no cottonseed oilcake meal (Control) or 9% cottonseed oilcake meal (9% CSOCM) was used. Olive oil was used as a replacement for pork fat, and warthog (Phacochoerus africanus) meat was used to replace commercial pork meat in the production of a semi dry sausage, cabanossi. Olive oil was included at three levels (0%, 1% and 2%). Six treatments were investigated: Control 0% olive oil, Control 1% olive oil, Control 2% olive oil, 9% CSOCM 1% olive oil, 9% CSOCM 2% olive oil en 9% CSOCM 2% olive oil. The Control and 9% CSOCM ostrich meat did not differ significantly in chemical composition nor fatty acid profile. After smoking and drying the fat content in the cabanossi containing 0%, 1% and 2% olive oil averaged 7.2%, 7.45% and 8.65% respectively. Processed meat products containing less than 10% fat are classified as a low-fat meat product. Olive oil is a mono-unsaturated vegetable oil containing mainly Oleic acid (C18:1n9c), and low quantities of saturated fatty acids and polyunsaturated fatty acids. Total mono unsaturated fatty acids in the cabanossi increased from 47.0% to 73.0% of total fat, whilst total saturated fatty acids and total polyunsaturated fatty acids decreased from 40.6% to 19.9% and 11.6% to 6.6% respectively as olive oil increased from 0% to 2%. The inclusion of olive oil at 2% resulted in cabanossi with increased (P<0.05) tenderness, juiciness and cured red meat colour, all factors that appeal greatly to the consumer. Overall flavour was not adversely affected by the inclusion of olive oil. This investigation indicated that the use of CSOCM had no negative effect on the production performance of ostriches whilst a 9% CSOCM inclusion level resulted in meat that was found to be favourable by a trained sensory panel. Furthermore, the use of CSOCM as a feed component also had no negative effect on a processed product (cabanossi) derived from the meat obtained from the birds fed this feed component. The CSOCM used in this investigation had low levels of gossypol (10 to 20ppm) and more research is required on the effect of the use of CSOCM with higher levels of gossypol on the production performance of ostriches. / AFRIKAANSE OPSOMMING: Die studie het bestaan uit drie ondersoeke met betrekking tot volstruis (Struthio camelus var. domesticus) -produksie, -vleiskwaliteit en die vervaardiging van waarde-toegevoegde geprosesseerde volstruis-vleisprodukte. Die doel van die eerste studie was om vas te stel of die geleidelike vervanging van sojaboonoliekoekmeel met katoensaad-oliekoekmeel (CSOCM) as ‘n proteïenbron in die voeding van volstruise, die groeipersentasie en vleiskwaliteit van die Iliofibiularis spier (fan fillet) sal affekteer. ‘n Totaal van 105 volstruise is verdeel in vyf voedingsgroepe volgens die katoensaad oliekoekmeel insluitingsvlak: Kontrole (0% CSOCM), 3%, 6%, 9% en 12% CSOCM. Die onderskeie voedingsgroepe was van ses tot 13 maande ouderdom op die eksperimentele voere geplaas. Die resultate het aangedui dat die voëls in die 12% CSOCM behandelingsgroep ‘n betekenisvolle (P<0.05) toename in finale lewende massa asook gemiddelde daaglikse toename gehad het. Die proksimale samestelling, cholesterol-inhoud, mineraal- en vetsuursamestelling van die vleis was nie geaffekteer deur die insluiting van CSOCM nie. Die CSOCM kan dus wel as ‘n alternatiewe proteïenbron in die voeding van volstruise gebruik word. Laasgenoemde bevinding kan ook lei tot verlaagde voerkostes, aangesien CSOCM heelwat goedkoper is as sojaboon-oliekoekmeel. Die tweede deel van die studie was van ‘n chemiese asook sensoriese aard. ‘n Beskrywende sensoriese analiese is uitgevoer om vas te stel of die manipulering van die vetsuursamestelling in die volstruis fan fillet as gevolg van die CSOCM sensories waargeneem kan word. Die chemiese en fisiese eienskappe van die vleis is ook ondersoek. Twee vlakke van CSOCM inhoud is ondersoek; 0% (as kontrole) en 9% CSOCM. Geen betekenisvolle verskille is gevind vir die fisiese vleiskwaliteit (kookverliespersentasie en taaiheid), asook vir die proksimale samestelling en pH van die fan fillet nie. Die gekookte fan fillet van die Kontrole behandeling het ‘n betekenisvolle (P<0.05) toename in mono-onversadigde vetsure (MUFA) getoon en die 9% CSOCM het ‘n voordelige toename in poli-onversadigde vetsuur-inhoud (PUFA) gehad. Die poli-onversadigde tot versadigde vetsuurverhouding (PUFA:SFA) was as ‘n gevolg ook betekenisvol hoër. Geen verskille (P>0.05) is opgemerk in die omega-6 tot omega-3 poli-onversadigde vetsuurverhouding (n-6:n-3) nie. Met betrekking tot die sensoriese eienskappe het die 9% CSOCM ‘n meer opvallende beesvleis aroma, hoër vlakke van aanvanklike sappigheid en ook sagter vleis in vergelyking met die kontrole behandeling gehad (P<0.05). Insluiting van 9% CSOCM het gelei tot ‘n gekookte volstruis fan fillet van voornemende kwaliteit. Laastens is daar ondersoek ingestel op die vervanging van varkvet met olyfolie in die vervaardiging van ‘n volstruis cabanossi. Chemiese asook sensoriese analises is uitgevoer op die gedroogde en gerookte volstruis cabanossi. Vir die vervaardiging van laasgenoemde produkte is die fan fillet van 13 maande oue voëls van die Kontrole (0% CSOCM) en 9% CSOCM behandelings gebruik. Addisioneel tot die volstruisvleis is daar ook vlakvarkvleis (Phacochoerus africanus) gebruik om die kommersiële varkvleis te vervang. Olyfolie was ingesluit teen drie vlakke (0%, 1% en 2% van die totale mengsel). Ses behandelings was ondersoek: Kontrole 0% olyfolie, Kontrole 1% olyfolie, Kontrole 2% olyfolie, 9% CSOCM 1% olyfolie, 9% CSOCM 2% olyfolie en 9% CSOCM 2% olyfolie. Daar was geen verskille (P>0.05) in die chemiese en vetsuursamestellings van die Kontrole en 9% CSOCM volstruisvleis nie. Na die droging en rooksiklus was die gemiddelde vet-inhoud van die 0%, 1% en 2% olyfolie cabanossi monsters onderskeidelik 7.2%, 7.45% en 8.65%. Geprosesseerde vleisprodukte met ‘n vet-inhoud van minder as 10% word in die kommersiële vleisindustrie na lae vet vleisprodukte verwys. Olyfolie is baie ryk aan MUFA, veral Oleïensuur (C18:1n9c) en dit bevat ook lae hoeveelhede SFA en PUFA. Die totale MUFA inhoud in die cabanossi het toegeneem van 47.0% tot 73.0% terwyl die totale SFA en PUFA onderskeidelik afgeneem het van 40.6% tot 19.9% en 11.6% tot 6.6%, met ‘n olyfolie toename van 0% tot 2%. Die insluiting van olyfolie teen 2% het gelei tot ‘n sagter cabanossi wat meer sappig was met ‘n meer opvallende rooi gekuurde vleiskleur, wat almal eienskappe is wat dié produk meer aantreklik maak vir die verbruiker. Hierdie studie het aangedui dat CSOCM geen negatiewe effek gehad het op die produksie van volstruise nie. Volstruisvleis van die behandelingsgroep wat CSOCM teen 9% van die dieet ontvang het, het wel vleis geproduseer wat as aanvaarbaar aanskou was deur ‘n opgeleide sensoriese paneel. Die gebruik van CSOCM as ‘n voerbestandeel het ook geen negatiewe effek gehad op ‘n geprosesseerde produk (cabanossi) gemaak van die volstruisvleis nie. Die CSOCM wat in die huidige studie gebruik is, het baie lae vlakke van gossypol (10 – 20dpm) gehad en verdere ondersoek is noodsaaklik om die effek van CSOCM met hoër vlakke van gossypol op die produksie van volstruise te bevestig.

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.

Made available in DSpace on 2015-04-17T14:49:13Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1407033 bytes, checksum: 932b37f811919fe1ee5f9dbb0e27dce4 (MD5) Previous issue date: 2011-08-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Brazil is a developing country in which a significant proportion of the population has limited access to fresh meat, and as a substitutive for this item the alternative is the consume of meat derivated products, so it is high the consumption of products such as sausages and mortadella in Brazil. The aim of this study was to analyze the performance of ostrich meat from the deboned leg, the physical and chemical characteristics and the development and evaluation of smoked sausage from this meat. It was done the proximate composition, instrumental color, pH, water activity (aw), the instrumental texture, emulsification capacity and water absorption capacity of ostrich meat. For the development of smoked mortadella with modified starch and soybean oil was used a complete23 factorial design with 3 central points. It was assessed the stability of the emulsion, microbiological characteristics, proximate composition, instrumental color, pH, water activity (wa), the instrumental texture, capacity to retain water, the juice released from the packaging, weight loss from cooking and sensory evaluation of mortadella. Ostrich meat had presented excellent performance after deboned (87.27%), good percentage of macronutrients, highlighting the low amount of fat, good absorption capacity of oil and water. The mortadella presented a humidity varying from 71,56±0,72 to 68,17±0,52, lipids 10,86±0,31% to 15,84±1,11%, RMF 1,56±0,19% to 1,01±0,02%, protein from 15,23±0,73% to 12,40±0,49% and carbohydrates from 2,36±1,34% to 1,30±0,08%, instrumental texture of 0,13±0,01 the 0,29±0,05 Kgf/cm2, instrumental color for the parameter L * 52,83±0,42 to 60,96±0,58, the * 8,60±0,13 to 12,29±0,28, b * 11,36±0,04 to 13,84±0,16, stability of the emulsion from 48±0,43% to 86,61±0,79%, juice released from the packaging from 4,23±0,20% to 7,47±0,84%, weight loss from cooking from 1,40±0,24% to 10,92±0,00%, capacity of retention of water varied of 0,27±0,02% the 0,37±0,09%, pH in the rate from 6,29±0,00 to 6,52±0,03, 0,97±0,00 water activity of 0,98±0,00, and a good sensorial acceptance and purchase intention. It was possible to observe in this experiment that is feasible the elaboration of sausages with ostrich meat, with modified starch, soy oil and liquid smoking, maintaining the nutritional and technological qualities, which demonstrates the viability of its production. / O Brasil é um país em desenvolvimento e uma parte significativa da população tem restrito acesso a carne in natura, tendo apenas possibilidade de aquisição de derivados cárneos, por isso, é alto o consumo de produtos embutidos no Brasil. O objetivo deste estudo foi analisar o rendimento da carne da perna de avestruz pós-desossada, as características físicas e químicas e o desenvolvimento e avaliação de mortadela defumada. Foi realizada a composição centesimal, a cor instrumental, o pH, a atividade de água (aw), a textura instrumental, a capacidade de emulsificação e a capacidade de absorção de água da carne de avestruz. Para o desenvolvimento das mortadelas defumadas com amido modificado e óleo de soja foi utilizado um planejamento fatorial completo 23 com 3 pontos centrais. Avaliou-se a estabilidade da emulsão, características microbiológicas, a composição centesimal, a cor instrumental, o pH, a atividade de água (aw), a textura instrumental, a capacidade de retenção de água, o suco exsudado da embalagem, a perda de peso por cozimento e análise sensorial das mortadelas. A carne de avestruz apresentou um excelente rendimento pós-dessosa (87,27%), bom percentual de macronutrientes, ressaltando a baixa quantidade de gordura, boa capacidade de absorção de óleo e de água. As mortadelas apresentaram uma umidade variando de 71,56±0,72 a 68,17±0,52, lipídios 10,86±0,31% a 15,84±1,11%, RMF 1,56±0,19% a 1,01±0,02%, proteína de 15,23±0,73% a 12,40±0,49% e carboidratos de 2,36±1,34% a 1,30±0,08%, textura instrumental de 0,13±0,01 a 0,29±0,05 Kgf/cm2, cor instrumental para o parâmetro L* 52,83±0,42 a 60,96±0,58, a* 8,60±0,13 a 12,29±0,28, b* 11,36±0,04 a 13,84±0,16, estabilidade da emulsão de 48±0,43% a 86,61±0,79%, exsudato da embalagem de 4,23±0,20% a 7,47±0,84%, perda de peso por cozimento de 1,40±0,24% a 10,92±0,00%, capacidade de retenção de água variou de 0,27±0,02% a 0,37±0,09%, pH na faixa de 6,29±0,00 a 6,52±0,03, atividade água de 0,97±0,00 a 0,98±0,00, e uma boa aceitação sensorial e intenção de compra. Foi possivel observar neste experimento que é viável a elaboração de mortadelas com carne de avestruz, com amido modificado, óleo de soja e defumação líquida, mantendo as qualidades nutricionais e tecnológicas, o que demonstra a viabilidade de sua produção

Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: The production and export of ostrich meat from southern Africa, to especially the European Union, are increasing rapidly due to the healthy nature of ostrich meat. The European Union has very high standards when importing food products, and it is inevitable that more emphasis is being placed on the production of high quality ostrich meat. Another aspect also of concern to consumers, is the welfare of animals prior to slaughter, and this forces producers to look at ways to decrease stress of animals during the ante-mortem period. Research regarding the effect of stress during the ante-mortem period, and as a result, on meat quality, haematology and weight loss in ostriches, is lacking and thus the purpose of this study was to investigate the effect of various transport distances, travel conditions and different birds on these factors. Ante-mortem stress was measured using serum corticosterone levels (ng/ml), heterophil: lymphocyte (H:L) ratio, white blood cell (WBC) count, aspartate aminotransferase (AST) and creatine kinase (CK), as well as the rate and extent of pH decline in the M. gastrocnemius. Special emphasis was also placed on the meat quality parameters drip loss, cooking loss, colour and Warner-Bratzler shear force (kg/1.27 cm diameter). Live weight losses, as well as carcass weight and weight of bruises cut off from each bird were also recorded during various stages of the trials. The effect of transport distance on the meat quality of ostriches was investigated. Ultimate pHu measurements were taken at 24 hours post-mortem. The muscles of the ostriches from the control group (i.e. birds that were not transported prior to slaughter) had a lower mean pHu (5.77 ± 0.053) than birds that travelled 60 (5.93 ± 0.053) and 600 km (6.11 ± 0.053), respectively. Differences in meat drip loss percentage were also observed between the three treatments. The birds in the control group (0.40 ± 0.07 %) had the lowest meat drip loss percentage compared to the birds that travelled 60 km (treatment C) (1.36 ± 0.07 %) and 600 km (treatment B) (0.97 ± 0.07 %), respectively, to a commcerical ostrich abattoir. Ostriches that were transported for 600 km (8.13 ± 1.16 %) had a greater percentage live weight loss during the antemortem period than birds that travelled a distance of 60 km (2.4 ± 2.185 %) to the abattoir, although both groups were deprived of feed for the same period. When the haematology of the groups that travelled different distances was compared at various time intervals in the ante-mortem period, both groups of birds experienced significant increases in WBC, s-AST and s-CK. An increased H:L ratio from pre-transport to post-transport was only evident in the birds that travelled 600 km (treatment B). However, the birds that travelled 60 km were the only group of birds that had significant elevated serum corticosterone levels during the ante-mortem period. The increase in the various blood parameters indicates severe physical stress, which negatively affected meat quality. Another trial also investigated the effect of various farming systems and transport on meat quality and bruising of ostrich carcasses. Ostriches were raised in three different farming systems, i.e. feedlot -, semiintensive - and free range conditions. Other factors that could maybe impact on stress susceptibility, such as road conditions, floorspace and floor type were also investigated. A significant difference in meat pHu was found between ostriches that were raised in a feedlot (5.95 ± 0.018) and semi-intensive (6.04 ± 0.033) environment. The feedlot birds also had the greatest percentage of carcass weight removed due to bruising. The free range birds were the birds that had the lowest floor density per birds and also had the least amount of bruising on their carcasses. Incidently the other two groups (feedlot and semi intensive) were the birds that travelled on the same type of road (mountain pass) in a truck with rubber flooring whilst the free range birds travelled on a straight road in trucks with metal grid floors.The results indicate that the type of farming system didn’t have a significant influence on meat quality of ostriches, but that factors such as road conditions, flooring and bird density did play a significant role in the incidence of bruises and injuries obtained during transport. / AFRIKAANSE OPSOMMING: Die produksie en uitvoer van volstruisvleis vanuit suidelike Afrika, na veral die Europese Unie, is gedurig aan die toeneem as gevolg van die gesonde aard van volstruisvleis. Die Europese Unie het baie hoë standaarde wanneer dit kom by die invoer van voedselprodukte en dit is onvermydelik dat meer klem op die produksie van hoë gehalte volstruisvleis gelê word. ʼn Ander aspek wat ook kommer wek by verbruikers is die welstand van diere voor slagting en hierdie aspek noodsaak produsente om te kyk na maniere om stres te beperk tydens die periode voor slagting. Navorsing rakende die effek van stres tydens die ante-mortem periode, asook vleiskwaliteit, hematologie en gewigsverlies in volstruise as gevolg van vervoer, ontbreek. Die doel van die studie was dus om die invloed van verskillende vervoerafstande, vervoersomstandighede en tipe produksiesisteme op volstruise se stresrespons te ondersoek. Die omvang van ante-mortem stres is bepaal deur die serum-kortikosteroon vlakke (ng/ml), heterofiel: limfosiet (H:L) ratio, witbloedsel (WBS) telling, aspartaat aminotransferase AST en creatien kinase CK, asook die tempo en vlak van pH-daling in die M. gastrocnemius, te meet. Spesiale klem is gelê op die vleisgehalte parameters kookverlies, drupverlies, kleur en Warner-Bratzler-skeurwaardes (kg/1.27 cm deursnee). Gewigsverlies is aangeteken op verskillende stadiums tydens die proewe. Karkasgewigte en die hoeveelheid gewig afgesny van elke volstruiskarkas a.g.v. kneusings is ook bepaal. Die eerste studie het die invloed van vervoerafstand op vleiskwaliteit van slagvolstruise ondersoek. Vleis kwaliteit parameters soos pH, drip verlies, kook verlies, taaiheid en kleur is ondersoek. Die pHu metings is op 24 uur post-mortem geneem. Slagvolstruise in die kontrole groep (d.i. -volstruise wat nie voor slagting vervoer is nie) het ’n laer vleis pHu (5.77 ± 0.05) gehad as voëls wat onderskeidelik 60 km (5.93 ± 0.05) en 600 km (6.11 ± 0.05) ver vervoer is. Verskille in persentasie dripverlies is gesien tussen die vleis van die voëls wat nie vervoer is nie (0.40 ± 0.07 %) en die voëls wat 60 km (1.36 ± 0.07 %) en 600 km ver (0.97 ± 0.07 %) onderskeidelik vervoer is. Volstruise wat vir 600 km (8.13 ± 1.16 %) vervoer is, het ‘n groter persentasie lewende gewig tydens die ante-mortem periode as voëls wat 60 km (2.4 ± 2.19 %) ver vervoer is na die abattoir, verloor, al was beide groepe weerhou van voer vir dieselfde tydperk. Beide groepe wat vervoer is (60 en 600 km) het merkbare toenames in witbloedsel (WBS) tellings, s-AST’s en s-CK’s getoon tydens die ante-mortem periode. Daar is slegs ʼn toename in H:L ratio (ʼn indikator van stres) van voor vervoer tot na vervoer gesien in die voëls wat 600 km vervoer is. Daarteenoor was die voëls wat slegs 60 km vervoer is die enigste voëls wat ʼn toename in korticosteroon vlakke getoon het gedurende die ante-mortem periode. Die toenames is heel moontlik ‘n aanduiding van erge fisiese stres wat ‘n negatiewe effek op vleiskwaliteit het. Die tweede studie het die effek van verskillende produksiesisteme en die stress respons van die verskillende groepe slagvolstuise op vervoer ondersoek. Vleis kwaliteit parameters soos pH, drip verlies, kook verlies en taaiheid is ondersoek. Die hoeveelheid kneusings per volstruis is ook gemeet. Daar was ‘n beduidende verskil (P = 0.009) tussen die pHu van die voerkraal (5.95 ± 0.018) en semi- intensiewe (6.04 ± 0.033) volstruise. Die voerkraal volstruise se vleis het die grootste drip- en kookverliese gehad in vergelyking met die ander twee groepe (semi-intensiewe en ekstensiewe) terwyl die ekstensiewe volstruise die taaiste vleis gehad het. Die voerkraalvoëls het ook die grootste persentasie karkasgewig verloor a.g.v. kneusings wat afgesny is. Die ekstensiewe voëls het die laagste vloer digtheid per volstruis gehad asook die minste kneusings. Die ander twee groepe (voerkraal en semi intensief) was die groepe wat op dieselfde pad vervoer is (bergpas) in vragmotors wat rubber vloere gehad het terwyl die ekstensiewe voêls op ‘n reguit pad vervoer is in ‘n vragmotor met ‘n metaal oppervlakte. Die resultate van die studie is ‘n aanduiding dat die tipe plaassisteem nie ‘n groot impak op die hoeveelheid akute stres ervaar deur die voëls tydens vervoer gehad het of gevolglik op die vleiskwaliteit van die volstruise nie, maar dat faktore soos pad toestand, tipe vloer en voëldigtheid wel ‘n wesenlike rol speel in die voorkoms van kneusings en beserings opgedoen tydens vervoer.

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.

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

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