Logistics around the meat supply chain in Kruger National Park : the African savanna buffalo (Syncerus caffer caffer) as model

Van As, Jan Singleton (2019-04)

Thesis (MScFoodSc)--Stellenbosch University, 2019.

Thesis

ENGLISH ABSTRACT: To facilitate a better relationship with adjacent communities, the Kruger National park (KNP) is investigating the possibility of sustainable offtakes of buffalo and using some of the meat as cooked stew as part of targeted environmental education engagement with local schools. Many of such schools form part of the government feeding scheme, which currently does not include any animal protein, except for canned fish occasionally. However, to help finance this scheme, an analysis of the whole supply meat value chain is required to see whether more expensive meat products can be derived from buffalo carcasses that could be sold to the public; the income from this would then be used to subsidise the school engagements. Therefore, the objective of this study was to investigate the meat characteristics, composition and overall meat quality of male and female African savanna buffalo (Syncerus caffer caffer) muscles [Longissimus thoracis et lumborum (LTL), Biceps femoris (BF), Semimembranosus (SM), Semitendinosus (ST), Infraspinatus (IS) and Supraspinatus (SS)] from animals in the Kruger National Park, South Africa. The meat quality was quantified on the physical characteristics (pH, colour, drip and cooking loss, water holding capacity and tenderness), proximate composition (moisture, protein, fat and ash content) and ageing of the selected muscles. For the first trial thirty buffalo were harvested in KNP and divided into adult and sub-adult categories according to sex (male and female). Males (n=17) had a mean “live” weight of 478.6 kg and females (n=13) 451.7 kg. Dressing percentages was very similar 58.3% and 58.9% for males and females, respectively. Of the six muscles, the three heaviest muscles were the BF (5.3-5.7 kg), SM (4.4-4.6 kg) and LTL (3.0 kg). The muscle weights of the selected muscles increased between 24 and 50 percent between sub-adult and adults. Sex did not influence the physical and chemical characteristics. However, muscle type had an influence, with highest tenderness observed for the SS muscle (31.0 N), BF muscle was toughest (45.9 N) and LTL muscle had highest amount of protein (22.7%). Age also had an influence; Sub-adults had a lower muscle ultimate pH, shear force and protein content, with a higher moisture content (p≤0.05) than the adult category. Thus, sub-adult meat samples displayed more desirable physical characteristics. Furthermore, the mean CIELab colour measurements were in accordance with what is expected for game meat (L*=38.54, a*=15.94 an b*=11.75). An ageing trial was conducted to determine a standard protocol for ageing time to achieve optimal tenderness for the LTL, SM and BF muscles. A significant increase in tenderness was noted for both the LTL and SM muscle by 25 days post-mortem, however, a decrease in tenderness was noted for the BF muscle over the ageing period of 32 days. Furthermore, cumulative purge loss increased over the 32 days post-mortem from 4.0% to 9.3%. Cooking loss decreased significantly from day one PM to day five post-mortem and then plateaued over the ageing period with a slight increase from day 13 PM onwards. Furthermore, all the mean colour measurements changed significant over the ageing period. The mean muscle (BF, SM and LTL) surface colour turned lighter (L*=41.3), less red (a*=13.2), and more yellow (b*=12.4) over the 32 days post-mortem. The study found that ageing the LTL and SM muscles up to day 25 gave optimum tenderness, and the BF should be utilised in different value-added products, such as biltong. A biltong production trial was conducted to determine the effect of freezing of measles infected buffalo carcasses on the physico-chemical and textural properties of biltong. Fifteen frozen and fifteen chilled carcasses were utilised and five selected muscles (BF= Biceps femoris; SM: Semimembranosus; ST: Semitendinosus; LTL: Longissimus thoracic et lumborum; RF: Rectus femoris) were removed. Biltong from the frozen-thawed muscles had a higher (p≤0.05) salt, protein and ash content with a lower (p≤0.05) moisture, water activity (aw), pH and fat content. The BF muscle had the lowest salt content as well as the highest pH and fat content. Overall, frozen-thawed biltong had a higher hardness as well as lower springiness compared to fresh muscle tissue. Nonetheless, the study confirms that frozen carcasses detained due to low-level measles infection can therefore be utilised in value added products such as biltong. For the last trial, a standard operating procedure (SOP) was developed, for the management of African savanna buffalo carcasses in Kruger National Park. Grade A and AB (sub-adult) buffalo carcasses should be utilised for aged primal cuts and value-added products. Whereas grade B, C (adult) and detained (frozen) buffalo carcasses are more suited for processed meats and value-added products. The primal cuts, LTL and SM of grade A and AB carcasses should be aged at 0-5oC for 25 days in vacuum bags and sold to restaurants and lodges. The BF is ideal for the production of biltong due to the lack of decrease in shear force over an extended period. The trimming and off-cuts could be utilised for value added products (mince, boerewors and patties). Hides, trophy heads and bone meal could be processed further locally and sold at auctions and local shops.

AFRIKAANSE OPSOMMING: Om ‘n beter verhouding met die aangrensende gemeenskappe te fasiliteer, ondersoek die Nasionale Krugerwildtuin die moontlikheid om buffels te oes en om dan die vleis te gebruik as stowe vleis in ‘n skoolvoedingsprogram. Om hierdie skema te finansier, word ‘n ontleding van die hele vleis voorraad waardeketting vereis om te kan sien of duurder vleis produkte geproduseer kan word van buffelkarkasse wat dan aan die publiek verkoop kan word. Hierdie inkomste sal dan gebruik word om die skoolvoedingsprogram te subsideer. Daarom is die doel van die studie om die vleis eienskappe, samestelling en algehele kwaliteit van manlike en vroulike African savanna buffel (Syncerus caffer caffer) spiere [Longissimus thoracis et lumborum (LTL), Biceps femoris (BF), Semimembranosus (SM), Semitendinosus (ST), Infraspinatus (IS) and Supraspinatus (SS)] te ondersoek, van diere in die Nationale Kruger Wildtuin, Suid Afrika. Die vleiskwaliteit is gekwantifiseer op die fisiese eienskappe (pH, drup- en kookverlies, kleur en taaiheid), chemiese samestelling (vog, proteïen, vet en as) en veroudering van geselekteerde spiere. Vir die eerste proef was dertig buffels geoes in die Nasionale Krugerwildtuin en verdeel in twee ouderdomsgroepe, naamlik volwasse en subvolwasse, en volgens geslag (manlik en vroulik). Manlik (n=17) se gemiddelde “lewendige” gewig was 478.6 kg en vroulik (n=13) was 451.7 kg. Uitslagpersentasie was omtrent dieselfde 58.3% en 58.9% vir manlik en vroulik onderskeidelik. Van die ses spiere, is die drie swaarste spiere die BF (5.3-5.7 kg), SM (4.4-4.6 kg) en LTL (3.0 kg). Die gewigte van die geselekteerde spiere het met 24 tot 50 persent vermeerder tussen subvolwasse en volwasse buffels. Die geslag het geen invloed op die fisiese en chemiese eienskappe gehad nie. Spiertipe het egter ‘n invloed gehad, met die hoogste sagtheid opgemerk vir die SS spier (31.0 N), BF spier was die taaiste (45.9 N) en die LTL spier het die hoogste proteïen inhoud (22.7%). Ouderdom het ook ‘n invloed getoon; subvolwasse buffels het die laagste ultimate pH, taaiheid en proteïen inhoud vertoon, met ‘n hoër voginhoud (p≤0.05) as die volwasse buffels. Dus het subvolwasse buffels meer wenslike fisiese eienskappe. Verder, was die gemiddelede CIELab kleur metings ook in ooreenstemming met vorige studies op wildsvleis (L*=38.54, a*=15.94 an b*=11.75). ‘n Verouderingsproef is uitgevoer om ‘n standaardprotokol vir die verouderingperiode te bepaal om die optimum sagtheid te bepaal vir die LTL, SM en BF spiere. ‘n Beduidende toename in sagtheid is opgemerk vir die LTL en SM spiere 25 dae post-mortem, alhoewel ‘n toename in taaiheid opgemerk is vir die BF spier oor die 32 dae verouderingsperiode. Verder het die kumulatiewe vogverlies vermeerder oor die verloop van die 32 dae post-mortem vanaf 4.0% tot 9.3%. Kookverlies het beduidend afgeneem vanaf dag een tot dag vyf post-mortem waarna ‘n plato oor die verouderingsperiode opgemerk is met ‘n effense toename vanaf dag 13 post-mortem. Verder het al die kleurmetings beduidend verander oor die verouderingsperiode. Die kleur van die vleisoppervlak het ligter geword (L*=41.3), minder rooi (a*=13.2), en meer geel (b*=12.4) oor die verloop van die 32 dae. Die studie het bevind dat die veroudering van die LTL en SM spiere tot 25 dae post-mortem optimale sagtheid gegee het en dat die BF spier in ander waarde toegevoegde produkte soos biltong gebruik moet word. ‘n Biltong produksieproef is gedoen om die effek van 15 gevriesde buffelkarkasse op die fisiese, chemiese en teksturele eienskappe van biltong te bepaal. Vyftien gevriesde en vyftien verkoelde karkasse is gebruik waarvan vyf spiere (BF= Biceps femoris; SM: Semimembranosus; ST: Semitendinosus; LTL: Longissimus thoracic et lumborum; RF: Rectus femoris) uitgehaal is. Biltong van die ontdooïde spiere het ‘n (p≤0.05) hoër sout-, proteïen- en as-inhoud gehad (p≤0.05) met ‘n laer vog, wateraktiwiteit (aw), pH en vetinhoud. Oor die algemeen, het ontdooïde biltong ‘n hoër hardheid sowel as ‘n laer veerkragtigheid in vergelyking met vars biltong gehad. Nietemin, gevriesde karkasse (karkasse met masels “detained”) kan dus gebruik word in waarde toegevoegde produkte soos biltong. Vir die laaste proef is ‘n standaard bewerkings prosedure ontwikkel vir die bestuur van die African savanna buffelkarkasse in die Nasionale Krugerwildtuin. Graad A en AB (subvolwasse) buffelkarkasse moet gebruik word vir verouderde primale snitte en waarde toegevoegde produkte. Graad B en C (volwasse) en gevriesde buffelkarkasse is meer geskik vir geproseseerde vleise en waarde toegevoegde produkte. Die primale snitte, insluitende die LTL en SM, moet vir 25 dae verkoel, vakuumverpak, verouder word en aan restaurante en lodges verkoop word. Die BF is ideaal vir die vervaardiging van biltong as gevolg van die gebrek in afname in skeurkrag oor die verlengde verouderingsperiode. Die oortollige vleis snysels (trimmings) en lae gehalte oortollige vleis snysels (off-cuts) kan gebruik word vir waarde toegevoegde produkte (maalvleis, boerewors en patties). Huide, trofeekoppe en beenmeel kan verder geprosesseer word (deur plaaslike inwoners) en verkoop word by veilings en plaaslike winkels.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/105940
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