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Meat quality characteristics of male and female common eland (Tragelaphus oryx)

dc.contributor.advisorHoffman, Louwrens C.en_ZA
dc.contributor.advisorKotrba, R.en_ZA
dc.contributor.authorLaubser, Johannes Gerhardusen_ZA
dc.contributor.otherStellenbosch University. Faculty of Agrisciences. Dept. of Animal Sciences.en_ZA
dc.date.accessioned2018-02-22T08:47:02Z
dc.date.accessioned2018-04-09T11:46:20Z
dc.date.available2019-02-28T03:00:15Z
dc.date.issued2018-03
dc.identifier.urihttp://hdl.handle.net/10019.1/103871
dc.descriptionThesis (MScAgric)--Stellenbosch University, 2018.en_ZA
dc.description.abstractENGLISH ABSTRACT: This study investigated the factors that determine meat characteristics, composition and overall meat quality of male and female Cape eland (Tragelaphus oryx oryx) muscles (Longissimus thoracis et lumborum, Biceps femoris, Semimembranosus, Semitendinosus, Infraspinatus and Supraspinatus). This was done by gathering data on the chemical composition (moisture, protein, fat and ash contents), physical attributes (pH, drip and cooking loss, colour and tenderness), sensory analysis, fatty acid profile and ageing of the selected muscles. Females (n=6) had a mean live weight of 357.2 kg and males (n=6) 305.4 kg, with cold carcass weights of 162.4 kg and 153.8 kg, respectively. Dressing percentages were calculated from the warm carcass weight and was similar for females and males (48.6 % and 50.8 %, respectively). The LTL (3.99-4.21 kg), BF (3.27-4.04 kg) and SM (3.39-3.75 kg) were the heaviest of the seven muscles removed from the carcass and was on average three to four times the size of the IS (1.15-1.32 kg), SS (0.86-1.15 kg), PS (0.99-1.22 kg) and ST (1.33-1.60 kg). Furthermore eland offer a significant portion (around 26 % of the warm carcass weight, excluding the head) of edible offal due to their large size. The ultimate pH of all the muscles fell within the normal range (5.5-5.9), although the IS (which had the highest pH) displayed physical signs of DFD compared to the other muscles. Most of the physical measurements were normal for red meat, except for the shear force being higher than for other game species with the LTL having the highest shear force (97.6 N). The CIE colour measurements were in line with what is expected from game meat (L* = 32.3-37.5, a* = 12-15.5 and b* = 10.6-12.9). The proximate composition of the muscles did not vary and was in line with the composition of other game species except for having slightly higher moisture contents (75.6-77.8 %) and proportionally lower protein contents (20.3-23.0 %). During the sensory evaluation the overall aroma intensity recorded for eland was quite high (68.3 out of 100) and was strongly correlated (r = 0.926) to beef-like aroma. Unwanted aroma and flavour attributes such as gamey (19.9 and 18.3 out of a 100 for aroma and flavour, respectively), livery (1.3 and 1.2) and metallic (5.1 and 9.6) did not play a significant role in the overall profile of the meat. The discriminant analysis plot showed a clear distinction between male and female LTL’s, while the BF’s were grouped closer together. Overall the BF (72 and 68 for aroma and flavour intensity, respectively) was rated higher for aroma and flavour than the LTL (65.5 and 62.7); this was supported by the variable loadings plot showing a stronger association with the BF than LTL for most of the sensory attributes. The BF also had higher amounts of most fatty acids (17.94 mg/g total fatty acids, compared to 12.36 for the LTL), possibly linked to a higher intramuscular fat. The fatty acid profile for eland is promising since the P:S ratio was between 0.4 and 0.6, with the bulk of the saturated fatty acids made up by stearic acid (around 78 % of the SFA’s). The n-6:n-3 ratio was also lower (1.01-1.77) than recorded before, further supporting the fact that free range game can be considered as a healthier alternative to intensively farmed livestock. An ageing trial was conducted in order to establish the optimum ageing period for the LTL and BF muscles. An increase in tenderness (57.3 N) was witnessed up to day 28 post-mortem of ageing. Both purge and drip losses increased (2.5 and 1.3 % increase, respectively) throughout ageing, while cooking loss decreased (1.3 %). Meat surface colour turned brighter, more red (CIE a* = 15.6 on day 35) and yellow (CIE b* = 12.7 on day 35) with time. Hue-angle values only increased up to day 17 (41.4), whereas chroma continued to increase up to day 35 (20.2). Sex did not affect any of the measurements. Initially the BF was more tender, had less purge loss and higher CIE a* and b* values than the LTL, however as the ageing period progressed the differences between the muscles became less apparent. In conclusion, it was found that the structural, sensory and biochemical properties of the meat of eland are not as strongly influenced by sex as they are by muscle type. Furthermore results compared favourably with previous studies on game animals, as well as domestic animals, paving the way forward for eland domestication and meat production.en_ZA
dc.description.abstractAFRIKAANSE OPSOMMING: Die fokus van hierdie studie was om ondersoek in te stel rakende die faktore wat vleiskwaliteit en -samestelling en gevolglik die algehele kwaliteit beïnvloed van manlike en vroulike Kaapse eland (Tragelaphus oryx oryx) spiere (Longissimus thoracis et lumborum, Biceps femoris, Semimembranosus, Semitendinosus, Infraspinatus and Supraspinatus). Dit was gedoen deur data in te samel rakende die chemiese samestelling (vog, proteïen, vet en as) en fisiese eienskappe (pH, drup- en kookverlies, kleur en taaiheid), asook ‘n sensoriese analise, vetsuur profiel en veroudering van geselkteerde spiere te voltooi. Daar is bevind dat koeie (n=6) se gemiddelde lewendige gewig was 357.2 kg en bulle (n=6) 305.4 kg, met koue karkas gewigte van 162.4 kg and 153.8 kg onderskeidelik. Afslag persentasies was bereken deur gebruik te maak van die warm karkas gewigte en was soortgelyk vir koeie en bulle (48.6 % en 50.8 %, onderskeidelik). Die LTL (3.99-4.21 kg), BF (3.27-4.04 kg) en SM (3.39-3.75 kg) was die swaarste van die sewe spiere wat verwyder is en was gemiddeld drie tot vier keer die grootte van die IS (1.15-1.32 kg), SS (0.86-1.15 kg), PS (0.99-1.22 kg) en ST (1.33-1.60 kg). Elande bied ook ‘n aansienlike porsie afval (rondom 26 % van die warm gewig, uitsluitende die kop) as gevolg van hul grootte. Al die spiere se pH lesings was normaal (5.5-5.9), alhoewel die IS (met die hoogste pH) fisiese tekens van DFD getoon het in vergelyking met ander spiere. Die meerderheid van die fisiese metings was normaal vir rooivleis, behalwe dat die taaiheid hoër was as vir ander wildspesies met die LTL wat die taaiste was (97.6 N). Die CIE kleur metings was ook in lyn met wat verwag word vir wildsvleis (L* = 32.3-37.5, a* = 12-15.5 en b* = 10.6-12.9). Die chemiese samestelling van die spiere het nie baie varieer nie en was ook ooreenstemmend met vorige studies op wildsvleis, behalwe dat die vog inhoud (75.6-77.8 %) effens hoër was en die proteïen inhoud (20.3-23.0 %) proporsioneel laer was met vog inhoud. Gedurende die sensoriese analise was die algehele aromatiese intensiteit van die eland vleis taamlik hoog (68.3 uit ‘n 100) en was daar ‘n sterk korrellasie (r = 0.926) met ‘n beesagtige aroma. Ongewenste aroma en geur eienskappe soos wildagtig (19.9 en 18.3 uit ‘n 100 vir aroma en geur onderskeidelik), lewerig (1.3 en 1.2, onderskeidelik) en metaalagtig (5.1 en 9.6, onderskeidelik) het nie ‘n groot rol in die algehele sensoriese profiel van die vleis gespeel nie. Die diskriminante analitiese plot het ‘n duidelike onderskeid tussen manlike en vroulike LTL’s getoon, terwyl die BF’s nader aan mekaar gegroepeer was. Die BF (72 en 68 uit ‘n 100 vir aroma en geur intensiteit onderskeidelik) is gekenmerk aan ‘n algehele hoër aroma en geur gradering as die LTL (65.5 en 62.7, onderskeidelik), dit is ondersteun deur die veranderlike beladingsplot wat getoon het dat meeste van die sensoriese eienskappe met die BF eerder as die LTL geassosieer het. Die BF het ook hoër hoeveelhede van meeste vetsure bevat (17.94 mg/g totale vetsure, in vergelyking met 12.36 vir die LTL), moontlik gekoppel aan meer intramuskulêre vet in die BF. Die vetsuur profiel van eland vleis was belowend aangesien die P:S ratio tussen 0.4 en 0.6 was met steariensuur wat die meerderheid van die versadigde vetsure opgemaak het (ongeveer 78 %). Die n-6:n-3 ratio was ook laer (1.01-1.77) as voorheen gemeet en dit ondersteun die feit dat vrylopende wild beskou kan word as ‘n gesonde alternatief tot intensief geboerde vee. ‘n Verouderingsproef is uitgevoer om te bepaal wat die optimum verouderingsperiode is vir die LTL en BF spiere. Taaiheid van die vleis het afgeneem (57.3 N) tot en met 28 dae na dood. Beide verouderingsvog en drup verliese het verhoog (2.5 en 1.3 % verhoging, onderskeidelik) gedurende die verouderingstydperk, terwyl kook verlies afgeneem het (1.3 %). Die vleis se oppervlak kleur het helderder, meer rooi (CIE a* = 15.6 op dag 35) en geel (CIE b* = 12.7 op dag 35) geword met tyd. Kleur-hoek waardes het slegs verhoog tot en met dag 17 (41.4), terwyl chroma aanhoudend verhoog het tot en met dag 35 (20.2). Geslag het nie enige van die metings beïnvloed nie. Aanvanklik was die BF sagter, met minder verouderings-vog verlies en hoër CIE a* en b* waardes as die LTL, maar verskille tussen die twee spiere het weggeval soos die verouderingstydperk toegeneem het. Ten slotte word die strukturele -, sensoriese - en biochemiese eienskappe van eland vleis nie soveel deur geslag beïnvloed soos dit deur spiersoort beïnvloed word nie. Verder het resultate goed vergelyk met vorige studies op wildsvleis, sowel as plaasvee, wat belowend is vir die makmaak en vleisproduksie van elande.af_ZA
dc.language.isoen_ZAen_ZA
dc.publisherStellenbosch : Stellenbosch Universityen_ZA
dc.subjectCape eland (Treagelaphys oryx)en_ZA
dc.subjectMeat characteristics of Treagelaphys oryxen_ZA
dc.subjectMeat -- Quality -- Evaluationen_ZA
dc.subjectUCTDen_ZA
dc.titleMeat quality characteristics of male and female common eland (Tragelaphus oryx)en_ZA
dc.typeThesisen_ZA
dc.rights.holderStellenbosch Universityen_ZA
dc.embargo.terms2019-02-28


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