Masters Degrees (Food Science)

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Browsing Masters Degrees (Food Science) by Subject "African savanna buffalo -- Meat quality"

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    Logistics around the meat supply chain in Kruger National Park : the African savanna buffalo (Syncerus caffer caffer) as model
    (Stellenbosch : Stellenbosch University, 2019-04) Van As, Jan Singleton; Hoffman, Louwrens C.; Gouws, Pieter Andries; Govender, D.; Stellenbosch University. Faculty of Agrisciences. Dept. of Food Science.
    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.