Thesis (MScVoedselwet)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: The objective of this investigation was to evaluate the effects of age (adult, sub-adult and lamb),
gender (male and female) and production region on the morphological characteristics of
springbok (Antidorcas marsupialis). In addition, the effects of the latter on the physical, chemical
and sensory quality of the M. longissimus dorsi (LD) muscle were determined. Where
applicable, correlations within the various physical and chemical attributes of the meat were
verified in the experiments. The sensory ratings of the meat were correlated with the data on the
physical and chemical attributes of the LD muscle, where applicable.
The mean live mass of male and female adult springbok differed significantly (p < 0.05)
and averaged 31.7 ± 0.70 and 28.3 ± 0.60 kg respectively. Gender had no significant effect on
the mean live mass of the sub-adult category. The mean dressing percentage of the males
(58.83 ± 0.53%) was noted to be significantly higher than that of the females (55.79 ± 0.50%).
The lambs (58.98 ± 1.07%) had the highest dressing percentage of all the age categories. An
increase in carcass measurements was noted with an increase in animal age. Gender did not
have a significant (p > 0.05) effect on the carcass measurements.
Inverse correlations were noted between pH24 and drip loss (r = -0.26, p < 0.01) and
cooking loss (r = -0.42, p < 0.0001) of the LD muscle. It was noted that stressed animals had a
significantly (p < 0.05) higher ultimate pH24 (6.30 ± 0.07), as observed in the meat originating
from the Caledon region and this meat consequently had a significantly (p < 0.05) lower cooking
loss (27.18 ± 0.62%) and drip loss (1.79 ± 0.08%). Meat shear force values ranged between
1.67 ± 0.05 and 2.67 ± 0.16 kg. 1.27 cm-1 diameter. Age-related effects on tenderness were
found to be minor in comparison to pH24 effects.
The females (3.13 ± 0.28%) were noted to have a significantly (p < 0.05) higher fat
content than the males (1.35 ± 0.08%). The adult (2.45 ± 0.26%) and sub-adult (2.50 ± 0.28%)
animals had a significantly higher fat content in comparison with the lambs (1.32 ± 0.11%). The
protein content of the springbok meat originating from the four production regions varied
between 18.80 ± 0.35 and 21.16 ± 0.51%. Gender had no significant effect on the protein
content, except for the meat originating from Rustfontein Nature Reserve where the females had
a significantly higher protein content. The two major amino acids noted for springbok LD muscle
were glutamic and aspartic acid. Phosphorous was the predominant mineral, followed by
potassium and calcium. Production region had a significant (p < 0.05) effect on both the amino
acid and mineral content of the meat. The saturated fatty acid (SFA) content of the LD muscle contributed 38.40 to 42.69% of
the total identified fatty acids. The poly-unsaturated fatty acid (PUFA) content (36.34 - 40.98%)
of the meat was very close to this range, meaning that optimal polyunsaturated to saturated
(P:S) ratios (0.96 - 1.18) were present. The effects of age and gender on the fatty acid
composition were minor in comparison with regional effects.
Warner-Bratzler Shear force (kg. 1.27 cm-1 diameter) values were inversely correlated
with the following sensory attributes: tenderness (r = -0.70, p < 0.01), residual tissue (r = -0.68,
p < 0.01) and sustained juiciness (r = -0.43, p < 0.05). Decreased acceptance of the meat was
noted with an increase in ultimate pH (pH24) from 5.4 to 5.8. As the ultimate pH of the meat
increased, the rankings for tenderness (r = -0.46, p < 0.05) and sustained juiciness (r = -0.54, p
< 0.05) decreased significantly. / AFRIKAANSE OPSOMMING: Die doel van hierdie ondersoek was om die invloed van ouderdom, geslag en produksie area op
die morfologiese eienskappe van springbok (Antidorcas marsupialis) te evalueer. Die effek van
laasgenoemde faktore op die fisiese, chemiese en sensoriese kwaliteit van die M. longissimus
dorsi (LD) is ook ondersoek. Korrelasies in die fisiese en chemiese eienskappe van die vleis is
bestudeer. Die resultate van die sintuiglike evaluering van die vleis is gekorreleer met die
fisiese en chemiese data van die LD spier, indien van toepassing.
Die gemiddelde gewig van die manlike (31.7 ± 0.70 kg) en vroulike (28.2 ± 0.60 kg) diere
het betekenisvol (p < 0.05) verskil. Geslag het geen betekenisvolle effek op die gemiddelde
gewig van die sub-volwasse diere getoon nie. Die gemiddelde uitslag persentasie van die
manlike diere (58.83 ± 0.53%) was betekenisvol (p < 0.05) hoër in vergelyking met die vroulike
diere (55.79 ± 0.50%). Met ‘n toename in ouderdom is ‘n toename in karkas metings
waargeneem. Geslag het geen effek op die karkas metings getoon nie.
Negatiewe korrelasies is genoteer tussen die finale pH (pH24) en drupverlies (r = -0.26, p
< 0.05) en tussen pH24 en kookverlies (r = -0.42, p < 0.0001) van die LD spier. Gestresde diere
van die Caledon area het ‘n betekenisvolle (p < 0.05) hoër pH24 (6.30 ± 0.07) getoon en
gevolglik ‘n laer (p < 0.05) kookverlies (27.18 ± 0.62%) en drupverlies (1.79 ± 0.08%). Die
skeurkrag waardes van die LD spier het gewissel van 1.67 ± 0.05 tot 2.67 ± 0.16 kg. 1.27 cm-1
diameter. Die effek van ouderdom op taaiheid was klein in vergelyking met die effek van pH24.
Die vroulike diere (3.13 ± 0.28%) het ‘n hoër (p < 0.05) vetinhoud as die manlike diere
(1.35 ± 0.08%) getoon. Die volwasse (2.45 ± 0.26%) en sub-volwasse (2.50 ± 0.28%) diere se
vetinhoud was hoër as die van die lammers (1.32 ± 0.11%). The proteininhoud het gewissel van
18.80 ± 0.35 tot 21.16 ± 0.51%. Geslag het geen effek (p > 0.05) getoon op die proteieninhoud,
behalwe vir die vleis van die Rustfontein Natuur Reservaat. Glutamien en aspartien suur was
kwantitatief die belangrikste aminosure. Fosfor was die belangrikste mineraal, gevolg deur
kalium en kalsium. Produksie area het ‘n betekenisvolle (p < 0.05) effek op die aminosuur en
mineraalinhoud getoon.
Die versadigde vetsuur (SFA) inhoud het gewissel van 38.40 tot 42.69% van die totale
geïdentifiseerde vetsure. Die poli-onversadigde vetsuur (PUFA) inhoud het gewissel van 36.34
tot 40.98% en daarom is optimale poli-onversadigde tot versadigde (P:S) verhoudings (0.96 -
1.18) genoteer. Die effek van ouderdom en geslag op die vetsuursamestelling was minimaal in vergelyking met
die effek van produksie-area.
Warner-Bratzler skeurkrag (kg. 1.27 cm-1 diameter) waardes was negatief gekorreleer
met die volgende sensoriese eienskappe: taaiheid (r = -0.70, p < 0.01), residuweefsel (r = -0.68,
p < 0.01) en volgehoue sappigheid (r = -0.43, p < 0.05). Daar is ‘n afname in die
aanvaarbaarheid van die vleis waargeneem met ‘n toename in pH24 van 5.4 tot 5.8. Met ‘n
toename in pH24, het die taaiheid (r = -0.46, p < 0.05) en volgehoue sappigheid (r = -0.54, p <
0.05) van die vleis afgeneem
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/16373 |
| Date | 04 1900 |
| Creators | Kroucamp, Mariska |
| Contributors | Hoffman, L.C., Manley, M., University of Stellenbosch. Faculty of Economic and Management Sciences. School of Public Management and Planning. |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
| Format | xii, 121 leaves : ill. |
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