Muscle nanostructure and physicochemical characteristics of South African A and AB mutton classes
- Authors: Mdikili, Zizipho
- Date: 2019
- Subjects: Meat -- Quality -- South Africa
- Language: English
- Type: Thesis , Masters , (MSc) (Animal Science)
- Identifier: http://hdl.handle.net/10353/12005 , vital:39126
- Description: Significant variations exist in quality of red meat due to the effect of various intrinsic and extrinsic factors. Research has been conducted in early 1990s to prove that carcasses from A and AB classes differ in meat quality due to age variation. This led to a conclusion that the two should be separated in the South African Red meat Classification System (SARCS). However, an interesting debate arose from a carcass classification workshop that A and AB meat classes have the same quality and thus must be integrated into one class in the carcass classification system. In addition, as much as it can be debated that these classes have the same quality, it is also possible that slight differences exist between the two since they are from different age groups. The current study was therefore developed and two trials were conducted to evaluate the impact of age differences on physicochemical attributes and muscle nanostructure of A and AB classes in sheep. In the first trial a total of ninety (n=90) Dorper sheep of the same sex but different age groups slaughtered at a high throughput abattoir in the Eastern Cape province were used to evaluate meat ultimate pH (pH24), colour (L* , a* , b* , H* , C* ), thawing loss (TL%), cooking loss (CL%) and tenderness (Warner Bratzler Shear Force - WBSF) of A and AB classes, whereas, on the second trial forty (n=40) Dorper sheep were used to evaluate muscle nanostructure and its relationship with tenderness. Meat samples were harvested from the Muscularis longissimuss thoracis et lumborum (LTL) for v meat quality and nanostructure measurements. The results showed significant variations (P<0.05) between the two classes for lean a* , H* and CL%. Significant differences (P<0.01) were observed in pH24, TL% and WBSF between A and AB classes. However, there were no significant differences (P>0.05) observed in meat L*, b* and C * . Ultimate pH was negatively correlated with thawing loss and some colorimetric attributes of lamb such as lightness, yellowness and hue angle. Moreover, tenderness was positively correlated with cooking and thawing losses. Significant differences were not (P>0.05) observed in sarcomere length, myofibrilar diameter and shear force between A and AB classes. Both sarcomere length and myofibrilar diameter were not correlated (P>0.05) with meat tenderness. These results suggest that A and AB classes are the same in nanostructure and that muscle nanostructure of these two classes is not related to meat tenderness. It was concluded that meat from sheep carcasses falling under the A and AB classes in the South African classification system vary greatly in physicochemical quality. Moreover, sheep carcasses from A and AB classes have the same sarcomere lengths and hence, they do not differ in meat tenderness (WBSF). However, when these classes were observed under a microscope, slight differences were noted in sarcomere lengths and myofibrilar diameters, which led to a conclusion that the two should remain as separated classes because their combination would result in the expansion of the non-uniformity of red meat tenderness. Therefore, A and AB classes should not be combined in the South African classification system. Further research is, however, recommended to evaluate the influence of other factors that were not examined in the current study.
- Full Text:
- Authors: Mdikili, Zizipho
- Date: 2019
- Subjects: Meat -- Quality -- South Africa
- Language: English
- Type: Thesis , Masters , (MSc) (Animal Science)
- Identifier: http://hdl.handle.net/10353/12005 , vital:39126
- Description: Significant variations exist in quality of red meat due to the effect of various intrinsic and extrinsic factors. Research has been conducted in early 1990s to prove that carcasses from A and AB classes differ in meat quality due to age variation. This led to a conclusion that the two should be separated in the South African Red meat Classification System (SARCS). However, an interesting debate arose from a carcass classification workshop that A and AB meat classes have the same quality and thus must be integrated into one class in the carcass classification system. In addition, as much as it can be debated that these classes have the same quality, it is also possible that slight differences exist between the two since they are from different age groups. The current study was therefore developed and two trials were conducted to evaluate the impact of age differences on physicochemical attributes and muscle nanostructure of A and AB classes in sheep. In the first trial a total of ninety (n=90) Dorper sheep of the same sex but different age groups slaughtered at a high throughput abattoir in the Eastern Cape province were used to evaluate meat ultimate pH (pH24), colour (L* , a* , b* , H* , C* ), thawing loss (TL%), cooking loss (CL%) and tenderness (Warner Bratzler Shear Force - WBSF) of A and AB classes, whereas, on the second trial forty (n=40) Dorper sheep were used to evaluate muscle nanostructure and its relationship with tenderness. Meat samples were harvested from the Muscularis longissimuss thoracis et lumborum (LTL) for v meat quality and nanostructure measurements. The results showed significant variations (P<0.05) between the two classes for lean a* , H* and CL%. Significant differences (P<0.01) were observed in pH24, TL% and WBSF between A and AB classes. However, there were no significant differences (P>0.05) observed in meat L*, b* and C * . Ultimate pH was negatively correlated with thawing loss and some colorimetric attributes of lamb such as lightness, yellowness and hue angle. Moreover, tenderness was positively correlated with cooking and thawing losses. Significant differences were not (P>0.05) observed in sarcomere length, myofibrilar diameter and shear force between A and AB classes. Both sarcomere length and myofibrilar diameter were not correlated (P>0.05) with meat tenderness. These results suggest that A and AB classes are the same in nanostructure and that muscle nanostructure of these two classes is not related to meat tenderness. It was concluded that meat from sheep carcasses falling under the A and AB classes in the South African classification system vary greatly in physicochemical quality. Moreover, sheep carcasses from A and AB classes have the same sarcomere lengths and hence, they do not differ in meat tenderness (WBSF). However, when these classes were observed under a microscope, slight differences were noted in sarcomere lengths and myofibrilar diameters, which led to a conclusion that the two should remain as separated classes because their combination would result in the expansion of the non-uniformity of red meat tenderness. Therefore, A and AB classes should not be combined in the South African classification system. Further research is, however, recommended to evaluate the influence of other factors that were not examined in the current study.
- Full Text:
Pharmacological Evaluation and Medicinal Potential of Vachellia Karroo (Hayne) Banfi & Galasso Pods traditionally used to treat Sexually Transmitted Diseases in the Eastern Cape, South Africa.
- Authors: Maposa, Sandisiwe
- Date: 2019
- Subjects: Medicinal plants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14583 , vital:40017
- Description: Vachellia karroo is widely used in folk medicine in the Eastern Cape Province South Africa, however, the pods are usually discarded as waste. The current study was conducted to evaluate the phytochemical content and the antioxidant activity of V. karroo pods. The pods were extracted using acetone, distilled water, hexane and methanol. The total phenol, flavonoid, proanthocyanidin, alkaloid and saponin contents of the various extracts were determined spectrometrically and antioxidant activity was evaluated using inhibition of 2,2-diphenyl-1- picrylhydrazyl (DPPH), 2,2´-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), nitric oxide (NO) radicals, while total antioxidant capacity (TAC) was estimated by the phosphomolybdenum assay. V. karro pods had significant amounts of total phenols, flavonoids and proanthocynadin, although, proanthocynadin was not detected in the aqueous and hexane extracts. Methanol and acetone extracts showed higher phenolic, proanthocynadin and flavonoids contents (52.47 ± 6.82 and 29.31 ± 1.49), (334.8±85.1 and 231.22 ±1.80),(288±4.26 & 208.2±17.7) compared to the aqueous and hexane extracts. The alkaloid and saponin contents were 26.67 and 12.85 % respectively. The IC50 values of the methanol extract for DPPH, ABTS and total antioxidant capacity (TAC) were 0.345, 0.017 and 0.116 mg/mL, respectively. Methanol extract of V. karroo pod showed higher polyphenolic content of all the extracts analysed with corresponding strong free radical scavenging potential. These underutilized pods could serve as a new source of antioxidant compounds which could help in combating various ailments. The great antioxidant activity displayed by V. karroo pods extract supports the therapeutic use of this plant in traditional medicine and are attributed to the phytochemical content.The current information suggests that extracts from Vachellia karroo pods might be a ix cheap potential source of natural antioxidants that could be of great importance for the treatment of free radical related diseases. Furthermore, it makes a case for the utilization of the pods instead of discarding them as waste materials. The evaluation of antimicrobial potential of Vachellia karroo extracts was carried out using agar dilution assay against 8 bacterial strains-4 gram-positive [ Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (OK), Bacillus subtilis KZN, Bacillus cereus, and Streptococcus pyogenes] and 4 gram-negative strains[ Vibrio cholera, Klebsiella pneumonia (ATCC 4352), Pseudomonas aeruginosa (ATCC 19582), Salmonella typhi (OK) ]. Six fungal isolates[ Trichophyton mucoides ATCC 201382, Candida albicans (ATCC 10231), Candida glabatra, Penicillium chrysogenum, Aspergillus fumigatus, Penicillum aurantiogriseum] were usedor antifungal assessment. The methanol extract exhibited broad-spectrum activity, with Gram-positive strains being more sensitive than Gram-negative strains. The extracts also showed great inhibition against Candida albicans the fungal isolate responsible for causing candidiasis in women. Since the pods showed promising antimicrobial activity, they could serve as a cheap source for the treatment and management of these sexually transmitted infections. The brine shrimp toxicity test revealed successful hatching of the cysts was in the order: Aqueous extract> methanol extract> hexane extract> acetone extract. The hatching of nauplii was in a concentration dependent fashion, with hatching success decreasing with increase in concentration of extracts. Lethality of extracts determined based on Meyerʼs index of toxicity, showed that the acetone and hexane extracts of V. karroo were moderately toxic. The results of this study indicated that aqueous and methanolic extracts of Vachellia karroo pods were not toxic, therefore supporting its traditional therapeutic usage. This implies that rather than discard x the pods as is waste as it being currently done, Vachellia karroo pods could be salvaged and processed along with the leaves, thus reducing environmental pollution. Proximate parameters (moisture, ash, crude fibre, crude fat, proteins, and carbohydrate) were evaluated using ALASA methods, and elemental analysis by ICP-OES technique. Nutritional analysis showed that V. karroo pods had low content of crude fat and high content of crude fibre, ash, crude protein, and carbohydrate sufficient to meet the recommended dietary allowances. The pods were rich in major minerals Ca, K, P and Mg, with sufficient amount of trace elements Na, Fe, Zn, and Cu. The outcome of this study suggests that Vachellia karroo pods have good nutritional potentials to support or complement the recommended dietary allowance and could be a cheap source of essential nutrients that could help in ameliorating most nutritional challenges as well as contribute remarkably to the amount of nutrient intake in human and animal diets.
- Full Text:
- Authors: Maposa, Sandisiwe
- Date: 2019
- Subjects: Medicinal plants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14583 , vital:40017
- Description: Vachellia karroo is widely used in folk medicine in the Eastern Cape Province South Africa, however, the pods are usually discarded as waste. The current study was conducted to evaluate the phytochemical content and the antioxidant activity of V. karroo pods. The pods were extracted using acetone, distilled water, hexane and methanol. The total phenol, flavonoid, proanthocyanidin, alkaloid and saponin contents of the various extracts were determined spectrometrically and antioxidant activity was evaluated using inhibition of 2,2-diphenyl-1- picrylhydrazyl (DPPH), 2,2´-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), nitric oxide (NO) radicals, while total antioxidant capacity (TAC) was estimated by the phosphomolybdenum assay. V. karro pods had significant amounts of total phenols, flavonoids and proanthocynadin, although, proanthocynadin was not detected in the aqueous and hexane extracts. Methanol and acetone extracts showed higher phenolic, proanthocynadin and flavonoids contents (52.47 ± 6.82 and 29.31 ± 1.49), (334.8±85.1 and 231.22 ±1.80),(288±4.26 & 208.2±17.7) compared to the aqueous and hexane extracts. The alkaloid and saponin contents were 26.67 and 12.85 % respectively. The IC50 values of the methanol extract for DPPH, ABTS and total antioxidant capacity (TAC) were 0.345, 0.017 and 0.116 mg/mL, respectively. Methanol extract of V. karroo pod showed higher polyphenolic content of all the extracts analysed with corresponding strong free radical scavenging potential. These underutilized pods could serve as a new source of antioxidant compounds which could help in combating various ailments. The great antioxidant activity displayed by V. karroo pods extract supports the therapeutic use of this plant in traditional medicine and are attributed to the phytochemical content.The current information suggests that extracts from Vachellia karroo pods might be a ix cheap potential source of natural antioxidants that could be of great importance for the treatment of free radical related diseases. Furthermore, it makes a case for the utilization of the pods instead of discarding them as waste materials. The evaluation of antimicrobial potential of Vachellia karroo extracts was carried out using agar dilution assay against 8 bacterial strains-4 gram-positive [ Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (OK), Bacillus subtilis KZN, Bacillus cereus, and Streptococcus pyogenes] and 4 gram-negative strains[ Vibrio cholera, Klebsiella pneumonia (ATCC 4352), Pseudomonas aeruginosa (ATCC 19582), Salmonella typhi (OK) ]. Six fungal isolates[ Trichophyton mucoides ATCC 201382, Candida albicans (ATCC 10231), Candida glabatra, Penicillium chrysogenum, Aspergillus fumigatus, Penicillum aurantiogriseum] were usedor antifungal assessment. The methanol extract exhibited broad-spectrum activity, with Gram-positive strains being more sensitive than Gram-negative strains. The extracts also showed great inhibition against Candida albicans the fungal isolate responsible for causing candidiasis in women. Since the pods showed promising antimicrobial activity, they could serve as a cheap source for the treatment and management of these sexually transmitted infections. The brine shrimp toxicity test revealed successful hatching of the cysts was in the order: Aqueous extract> methanol extract> hexane extract> acetone extract. The hatching of nauplii was in a concentration dependent fashion, with hatching success decreasing with increase in concentration of extracts. Lethality of extracts determined based on Meyerʼs index of toxicity, showed that the acetone and hexane extracts of V. karroo were moderately toxic. The results of this study indicated that aqueous and methanolic extracts of Vachellia karroo pods were not toxic, therefore supporting its traditional therapeutic usage. This implies that rather than discard x the pods as is waste as it being currently done, Vachellia karroo pods could be salvaged and processed along with the leaves, thus reducing environmental pollution. Proximate parameters (moisture, ash, crude fibre, crude fat, proteins, and carbohydrate) were evaluated using ALASA methods, and elemental analysis by ICP-OES technique. Nutritional analysis showed that V. karroo pods had low content of crude fat and high content of crude fibre, ash, crude protein, and carbohydrate sufficient to meet the recommended dietary allowances. The pods were rich in major minerals Ca, K, P and Mg, with sufficient amount of trace elements Na, Fe, Zn, and Cu. The outcome of this study suggests that Vachellia karroo pods have good nutritional potentials to support or complement the recommended dietary allowance and could be a cheap source of essential nutrients that could help in ameliorating most nutritional challenges as well as contribute remarkably to the amount of nutrient intake in human and animal diets.
- Full Text:
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