A. Hugo

Nutritional characterization of Moringa ( Moringa oleifera Lam.) leaves

calcium (3.65%), phoshorus (0.3%), magnesium (0.5%), potassium (1.5%), sodium (0.164%), sulphur (0.63%), zinc (13.03 mg/kg), copper (8.25%), manganese (86.8 mg/kg), iron (490 mg/kg) and selenium (363 mg/kg). 17 fatty acids were observed with α-Linolenic acid (44.57%) having the highest value followed by heneicosanoic (14.41%), g-linolenic (0.20%) palmiteic (0.17%) and capric acid (0.07%). Vitamin E had the highest concentration of 77 mg/100 g than beta-carotene, which had 18.5 mg/100 g in the dried leaves. The fiber content was neutral detergent fibre (NDF) (11.4%), acid detergent fibre (ADF) (8.49%), acid detergent lignin (ADL) (1.8%) and (acid detergent cellulose (ADC) (4.01%). The condensed tannins had a value of 3.2%, while total polyphenols were 2.02%. The values of amino acids, fatty acids, minerals and vitamin profiles reflect a desirable nutritional balance.

Sensory evaluation and its relationship to physical meat quality attributes of beef from Nguni and Bonsmara steers raised on natural pasture

The current study compared sensory characteristics and their relationships with physical meat characteristics of beef from Nguni and Bonsmara steers. Nguni beef was more (P < 0.05) tender than Bonsmara beef after ageing for 2 and 21 days, and had higher (P < 0.05) intramuscular fat (IMF; 1.12%) than Bonsmara beef (1.07%). Nguni beef had higher (P < 0.05) sensory scores than Bonsmara beef after ageing for 2 days. There were no (P > 0.05) relationships between IMF and sensory characteristics. Aroma intensity, impression on juiciness and tenderness-related scores were affected (P < 0.05) by pH. There were significant (P < 0.05) correlations between most physical meat characteristics and sensory characteristics. Nguni beef had better sensory scores than Bonsmara beef for beef aged for 2 days. While most physical meat characteristics were correlated to sensory scores, all sensory scores were not significantly correlated to IMF.

Atherogenicity index and health-related fatty acids in different stages of lactation from Friesian, Jersey and Friesian × Jersey cross cow milk under a pasture-based dairy system

The objective of the study was to investigate the effect of stage of lactation on the fatty acid profiles of milk from Friesian, Jersey and Friesian×Jersey cows. Linoleic acid in pastures was highest in the second phase which coincided with mid-lactation days (p<0.05). Highest milk moisture content and lowest fat free dry matter content was seen in early lactation (p<0.05). Higher fat content was observed in late lactation than early lactation. Highest butyric, caproic, linoleic, omega-6 and polyunsaturated fatty acids were observed for milk from Friesian cows. Highest conjugated fatty acids, α-linolenic acid, linoleic acid, saturated fatty acids, polyunsaturated fatty acids, omega-6, and omega-3 were observed in early lactation. Atherogenicity index and desaturase activity indices were highest in late lactation. In conclusion, stage of lactation and genotype affected milk health-related fatty acid profiles.

Effect of dietary supplementation with Acacia karroo leaves on fatty acid profiles and consumer sensory attributes of Xhosa lop-eared goats under artificial haemonchosis

The effect of Acacia karroo supplementation on fatty acid profiles and sensory attributes of Xhosa lop-eared goats meat was evaluated in 18 4-month-old goats exposed to a single dose of 6000 L3 Haemonchus contortus larvae. The goats were allotted into two groups: non-supplemented (NSP) and supplemented (AK). The AK goats received 200 g of fresh A. karroo leaves. At the end of the experiment, all the goats were slaughtered to determine the fatty acid profiles and sensory perceptions. Faecal larval counts decreased significantly in the AK group as the infection progressed, while it increased in the NSP group. At necropsy, the NSP group had significantly higher worm counts than the AK group. The AK group contained significantly higher (P < 0.05) amounts of intramuscular fat and had almost twice (P < 0.05) the total polyunsaturated fatty acids and polyunsaturated fatty acid/monounsaturated fatty acid ratio. Furthermore, the AK goats also had higher amounts (P < 0.05) of n-3. Mean sensory scores for juiciness and tenderness were superior in the AK goats (P < 0.05). In conclusion, A. karroo supplementation positively influenced the fatty acid composition and sensory attributes of chevon from goats infected with H. contortus.

Antioxidant activities of Moringa oleifera L. and Bidens pilosa L. leaf extracts and their effects on oxidative stability of ground raw beef during refrigeration storage

ABSTRACT The study examined the leaf extracts of Moringa oleifera and Bidens pilosa for presence of bioactive phytochemicals and their antioxidant activities on pH and lipid oxidation of fresh ground beef during 6 days cold storage. The results revealed that B. pilosa leaf extract contained higher amount of bioactive compounds and antioxidant contents (p < 0.05) than M. oleifera leaf extract. The extract of B. pilosa leaf exhibited higher antiradical activity against 2,2-Diphenyl-2-picrylhydrazyl and 2,2íazino- bis-3-ethylbenzothiazoline-6-sulfonic acid radicals than M. oleifera leaf extract and standard butylated hydroxytoluene (BHT) (p < 0.05). Addition of M. oleifera and B. pilosa leaf extracts (0.5 and 1 g/kg) to fresh ground beef were found to lower the pH and thiobarbituric acid-reactive substances values compared with control and BHT treatments (0.2 g/kg) during the storage period (p > 0.05). The antioxidant activities of the extracts indicate that M. oleifera and B. pilosa leaf can be used as nutraceuticals or preservative agents in food industry.

Comparison of the Milk Composition of Free-Ranging Eland, Kudu, Gemsbok and Scimitar Oryx, with Observations on Lechwe, Okapi and Southern Pudu

The proximate composition of milk from freefree-ranging-ranging kudu, eland, and oryx is reported with detailed analysis of fatty acid composition and protein identification by electrophoresis. The milk of the eland, kudu and gemsbok contained, respectively, 88.0 ± 13.3,67.5 ± 5.6 and 61.7 ± 12.3 g/kg protein, 67.9 ± 22.7,61.0 ± 18.0 and 71.9 ± 27.1 g/kg fat, and 50.0 ± 10.5,41.0 ± 2.5 and 41.9 ± 2.3 g/kg lactose, and are comparable with ovine milk. The gemsbok milk contained 4.4 ± 1.5 g/kg oligosaccharide, which is four times higher than that found in other ruminants. The milk of the eland and kudu contained significantly lower levels of saturated fatty acids than that of the gemsbok, the levels being respectively, 62.55 ± 3.61,69.70 ± 1.62 and 79.46 ± 0.84%, due to the saturated acids of 8–14 carbon chain lengths. When adding the milk composition of sable antelope from the literature, statistical analysis (PCA) showed a difference between the milk composition of the subfamilies Hippotraginae and Bovinae (tribe Tragelaphini), suggesting phylogenetic effects. Observations on the composition of milk from scimitar oryx, lechwe, okapi and southern pudu are also reported.

Intermediate added salt levels as sodium reduction strategy: Effects on chemical, microbial, textural and sensory quality of polony

The purpose of this study was to evaluate the use of intermediate added salt levels (1.33% w/w and 1.84% w/w) as a strategy for reducing the total sodium content of polony, an emulsified, heat-treated meat product, which is reliant on the various functions of salt normally included at a 2.5% (w/w) level. Chemical, microbial, and textural stability over 180days as well as sensory quality were evaluated. At 1.84% (w/w) added salt content, the product was indistinguishable from the positive control except for a slightly wetter cutting surface. A level of 1.33% (w/w) added salt showed similar results, except for a slight variation in initial moisture content and a much wetter cutting surface. The hardest texture was achieved at 1.33% (w/w) added salt up to 90days of shelf-life. Consumers had a slight preference for a lower salt content. From this research it can be recommended that salt reduction as sole approach in sodium reduction should be evaluated for meat products in limiting the possibly costly and negatively perceived use of sodium replacers.

Differences in Health-related Fatty Acids, Intramuscular Fat and the Physico-chemical Quality in Mutton as Affected by Season, Place of Purchase and Meat Portion

The objective of the study was to determine the quality and fatty acid profiles of mutton cuts purchased from rural and urban localities in South Africa. Five hundred and ten samples were collected in four seasons from both rural and urban shops and butcheries. Samples were immediately transported to the laboratory in cooler boxes with ice where the following physico-chemical characteristics of mutton were determined; meat pH, color (L*, a*, and b*), cooking losses and Warner Braztler shear force and replicates stored at −20°C pending fatty acid analysis. Meat L* values were lowest (24.7±0.49) in winter and highest (32.2±0.49) in spring. The loin and sirloin cuts recorded the highest intramuscular fat whilst rib and leg cuts recorded the lowest intramuscular fat. In conclusion intramuscular fat, fatty acid profiles and physico-chemical quality of mutton were significantly affected by season and meat portion and not necessarily by the locality and class of shop.

Overall liking and sensory profiling of boiled Amaranthus leaves using the Check-all-that-apply question

ABSTRACT The study investigated consumers’ overall liking and sensory profiling of 13 boiled Amaranthus genotypes by using the Check-all-that-apply question. Fifty consumers ranked their preference on a nine-point hedonic scale to determine overall liking of boiled samples. Additionally, 100 consumers completed a CATA question, which contained 19 descriptive terms related to Amaranthus leaves. Significant differences were found in the frequency in which consumers used 11 out of the 19 terms. Correspondence analysis, explaining 68.1% variance, illustrated differences in sensory characteristics between genotypes. Hierarchical cluster analysis identified three consumer segments, indicating the heterogeneous acceptance of samples. External mapping of the samples’ configuration identified regions of maximum liking. Sensory characteristics of Amaranthus leaves varied between genotypes and species, with no relationship between specific species and their sensory properties. The information obtained can be recommended to farmers to be incorporated into breeding programmes.

Descriptive sensory analysis and consumer acceptability of lucerne (Medicago sativa L.)

Purpose – A lack of available literature exists about sensory data on lucerne (which is mainly used for animal feed) as an underutilised protein source for human consumption in South Africa (SA). Developing tasteless lucerne products is meaningless. Therefore, the purpose of this paper is to determine the descriptive sensory profile and consumers’ acceptability of lucerne. Design/methodology/approach – Three lucerne cultivars and one spinach beet (Beta vulgaris var. cicla L.) cultivar were used: first, to determine sensory descriptive attributes by generic descriptive analysis; and second, to determine consumers’ acceptance of lucerne, which were evaluated for degree of liking for aroma, taste, mouthfeel and overall acceptability with a nine-point hedonic scale. Principal component analysis of attributes for all the lucerne cultivars was applied to identify any factors differentiating between these cultivars. Findings – “SA Standard” showed the lowest value, of the lucerne samples, for fibrous appearance, chewy and fibrous mouthfeel, bitter taste and bitter and metallic aftertaste. “SA Standard” was the most acceptable lucerne cultivar, indicating its application in future studies to profile new emerging cultivars. Originality/value – No sensory analysis studies have been performed on South African lucerne cultivars to determine their sensory acceptability. These cultivars could have potential for food nutritionists, food scientists and food product developers and the commercial market.