No abstract

The global meat industry is characterised by a growing interest in natural preservative additives. This study determined the effect of sweet basil (Ocimum basilicum L.) essential oil (SBEO) on colour and lipid oxidation in minced beef. The phytoconstituents of SBEO were analyzed by gas chromatography mass spectrometry. Thereafter, minced beef samples from Nguni and Boran cattle were treated with either no additives (control, C) or SBEO added at 2% (SB2), 4% (SB4), or 6% (SB6). The meat samples were aerobically packaged and stored (4 ± 1°C) for seven days for measurement of lightness (L⁎), redness (a⁎), yellowness (b⁎), hue, chroma, and lipid oxidation (acid-reactive substances, TBARS) on days 0, 4, and 7. Thirty-two bioactive compounds with reported antioxidant and antimicrobial and activities were identified in SBEO, including Estragole (41.40%), 1, 6-Octadien-3-ol, 3,7-dimethyl (29.49%), and trans-.alpha.-Bergamotene (5.32%). On days 0, 4, and 7, SB2, SB4, and SB6 had higher (P < 0.05) L⁎, a⁎, b⁎, hue, and chroma values; and on days 0 and 4 TBARS were lower (P < 0.05) in SB2 and SB4 than C and SB6. The addition of 2% and 4% SBEO improved colour and lipid oxidative stability, demonstrating potential for its use as a natural antioxidant additive in meat.

Animal products (meat, milk, and eggs) represent one of the most frequently consumed foods in human nutrition because of their desirable taste, high nutritional value, availability, and accessibility. Their intake is important for growth, sound health, and smooth functioning of the body. For most countries, animal products are valuable sources of complete protein, including essential amino acids, fatty acids, and many other essential micronutrients, such as iron, zinc, calcium, vitamin A, E, and B1, as well as other bioactive compounds, which are often deficient in other food sources (Schonfeldt, Pretorius, & Hall, 2013). Besides these qualities, animal products are easily susceptible to oxidation and quality deterioration. This deterioration usually begins during the ante-mortem stage and it continues through the post mortem condition (Falowo, Fayemi, & Muchenje, 2014) due to the inability of inherent endogenous antioxidant to combat free radicals that are generated during the process. However, the susceptibility of animal products to oxidation and quality deterioration can be reduced by supplementing them with antioxidants such as vitamin E. It has been revealed that supplementing animals with vitamin E (α-tocopherol) can slow down the oxidation of lipids and improve oxidative stability of muscle and dairy food (Gallardo, Manca, Mantecón, Nudda, & Manso, 2015). Basically, vitamin E is a member of a class known as the fat-soluble vitamins which includes vitamin A, D, E, and K. Vitamin E plays an important antioxidant role by acting as a chain-breaker and free-radical scavenger in muscle cell membranes and tissues while boosting the immune system (Azzi & Zinggl, 2005). Within tissues, vitamin E is mainly concentrated in the unsaturated phospholipid bilayer of the cell membranes where it inhibits lipid oxidation by functioning as a free-radical scavenger

This study aimed to assess the influence of genotype and physiological status on blood metabolites of Nguni (10), Boer (10) and Non-descript (10) goats during late gestation and early lactation periods. Blood samples were collected and analysed using standard methods. The result revealed that, Nguni goat had higher (P Lass Than 0.05) mean values of red cell counts (13.37 x1011/L), haemoglobin (9.07 g/dL) and creatine kinase (269.54 U/L) compared to Boer (9.96 x 1011/L, 7.94 g/ dL and 132.16 U/L) and Non-descript (12.98 x 1011 /L, 7.85 g/ dL and 143.50 U/L) goats, respectively. The Nguni goat also had higher mean values of glucose (3.38 mmol/L) and urea content (5.51 mmol/L) compared to Boer goats (2.96 mmol/L and 4.45 mmol/L) and Non-descript (2.50 mmol/L and 3.90 mmol/L). There was higher mean values of red cell counts (14.44 x 1011 /L), haemoglobin (8.57 g/dL), glucose (3.12 mmol/L), sodium (141.74 mmol/L) and calcium content (2.37 mmol/L) during late gestation compared to early lactation (9.77 x 1011/ L, 8.00 g /dL, 2.77 mmol/L, 137.37 mmol/L and 2.23 mmol/L) period. It was concluded that, genotypes and physiological status had influence on blood metabolites of goats.

This study was conducted to evaluate the yield and composition of milk from 30 indigenous South African goats of different genotypes, namely Nguni, Boer, and non-descript, reared under a free-ranging system. Milk yield and composition (milk fat, protein, lactose, solid non-fat, and minerals) from Nguni (10), Boer (10) and non-descript (10) goats were measured and analysed per week at each stage of lactation. Results showed that Nguni goats produced (1.2 ± 0.09, 1.3 ± 0.11 and 1.2 ± 0.07 L per day) more milk (p < 0.05) at early, mid-, and late stages of lactation than Boer (0.6 ± 0.10, 1.0 ± 0.17, and 0.6 ± 0.09 L per day) and non-descript (0.3 ± 0.10, 0.3 ± 0.12, and 0.3 ± 0.09 L per day) goats, respectively. The mean value of milk fat, protein, and lactose content from Nguni goats was 3.98, 3.54, and 5.31; Boer goats, 2.9, 3.59, and 5.04 and non-descript goats, 4.05, 3.39, and 5.02, respectively. There was a significant effect (p < 0.05) of genotypes on milk fat, milk magnesium, and sodium contents of Nguni, Boer, and non-descript goats. It could be concluded that Nguni goats produced more milk than Boer and non-descript goats, but the non-descript goat had a higher mean percentage of milk fat compared to Nguni and Boer goats.

This study aimed to determine and compare the fatty acid composition and atherogenecity index of milk fat from Nguni, Boer and non-descript at two different sampling periods. The goats (n = 10 for each goat genotypes) were raised under an extensive system of husbandry. Milk samples were collected from each individual goat to determine fatty acids, as methyl esters, using gas chromatography. The result revealed significant differences (P < 0.05) in fatty acid profiles among the three goat genotypes for butyric, caproic, myristic, palmitic, stearic, vaccenic, linoleic, conjugated linoleic, α-linolenic, arachidic, eicosatrienoic and docosapentaenoic acids, among other milk fats. The time of milk sampling also had a significant effect (P < 0.05) on caproic, lauric, myristic, palmitic, palmitoleic, margaric, stearic, linoleic, arachidonic, docosapentaenoic and conjugated linoleic acids of milk fat. In addition, Nguni goats' milk fat had a healthier fatty acid than those of Boer and non-descript goats, characterized by a lower content in saturated fatty acid (68.65, 73.77 and 71.73 (P < 0.05), respectively). Goat genotypes and milk sampling time had an influence on the fatty acid composition of goat milk. These findings support the fact that goat milk is an important source of healthpromoting substances and support the sustainable use of animal genetic resources to improve goat milk fat quality, and hence deserve further investigation with local indigenous goat breeds.

The aim of the study was to assess small-scale farmers' attitude and willingness to consume goat milk and its products. A structured questionnaire was used to collect data from 151 household farmers by using a 15% random sampling technique. Data were analysed using descriptive frequencies and chi-square tests to check for any association between the variables and farmers' willingness to consume goat milk and its products. The results showed that a large share (41.78%) of the respondents do not consume goat milk. Taste (20.83%), cultural bias (8.33%), strong smell and natural dislike (64.58%) were some reasons why farmers do not consume goat milk. Some proportions (38.10%) of farmers were not aware of any nutritional benefits of goat milk. However, when these benefits were explained to them, a high percentage (93.10%) of these farmers indicated their willingness to consume goat milk and/or its products based on its nutritional benefits. Age, gender and educational status had a significant influence (P ≤ 0.05) on farmers' willingness to consume goat milk and its products. The nutritional importance of goat milk and its products should be strongly promoted to improve the human diet in the study area.

Abstract:The polyphenolic constituents and antioxidant activity of aqueous and acetone extracts of Vachellia karroo leaves were determined in order to evaluate its efficacy in scavenging radicals such as DPPH, ferric reducing power and nitric oxide as an antioxidant model. The flavonols and flavonoid and phenolic content of the leaf extracts were also accessed using benchmark phytochemical reaction methods. Results of the phytochemical analyses revealed the presence of flavonoids and flavonol and phenolic compounds in the leaf extracts. The total phenolic content values in the aqueous and acetone leaf extracts were 7.40 and 11.09 mg tannic acid equivalent/g of extract powder, respectively. The total flavonol and flavonoid content values of the aqueous leaf extracts were 9.90 and 53.23 mg quercetin equivalent/g of extract, respectively, while those of the acetone leaf extracts were 1.18 and 5.18 mg quercetin equivalent/g of extract, respectively. At 0.2 mg/mL, the values for the scavenging activities of the acetone and aqueous extracts of the V. karroo leaves were significantly higher (p < 0.05) than that of the ascorbic acid but comparable to BHT against ferric oxide radicals. The findings from the study reveal that the antioxidative potentials of V. karroo leaf extract and could serve as free radical inhibitors, possibly acting as principal antioxidants.