Effect of post-slaughter handling on physico-chemical and microbiological quality of red meat along the distribution chain in the Eastern Cape Province, South Africa
- Authors: Rani, Zikhona Theodora
- Date: 2015
- Subjects: Meat -- Microbiology Meat -- Transportation -- South Africa -- Eastern Cape Meat -- Quality -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/2490 , vital:27875
- Description: The broad objective of the study was to investigate the effect of post-slaughter handling in the distribution chain on red meat quality and safety. A survey was conducted among 300 consumers and 100 meat handlers in five different municipalities (Buffalo City, Nkonkobe, Ngqushwa, Lukhanje and Amahlathi) in the Eastern Cape Province of South Africa to investigate their perceptions on meat quality and safety, together with challenges faced by meat handlers during the distribution of meat from the abattoir to retailers. The microbiological profile and physico-chemical quality of red meat at different stages of the abattoir to retail outlets in the distribution chain were also determined. Swabs (n=216) and meat samples (n=450) were collected from beef, pork and mutton carcasses during the loading process of carcasses into trucks at the abattoir, when offloading carcasses at the supply points and during marketing. Physico-chemical qualities such as colour (L* - lightness, b* - redness and a* - yellowness) and meat pH measurements were taken at each point. To determine the microbiological profiles of the carcasses, four microbiological parameters were considered: Total bacteria count (general bacteria), coliform count (related to hygiene and indicator for pathogens), Escherichia coli (Gram-negative pathogen) and Staphylococcus aureus (Gram-positive pathogen). Two types of packaging (vacuum and overwrapping) were used to determine their effect on shelf-life and microbiological quality of red meat under the normal marketing conditions over a storage duration of 15 days. The results from the study showed low awareness of consumers about the pathogenic diseases which arise from meat. A strong significant association (p ˂ 0.05) between educational status and awareness on meat safety was observed. Most of the consumers perceived that quality goes beyond safety such that 35.6 percent of the respondents indicated that they did not have a problem with consuming spoiled meat, whilst the remaining 64.4 percent indicated that they would r eject spoiled meat. Although retailers indicated that they take meat safety into consideration in their shops, 92 percent of the retailers revealed that they do not perform microbial assessment of meat in their shops. A series of loading and off-loading, temperature fluctuations, environmental temperatures and ques during offloading were reported as the major challenges during transportation of carcasses from the abattoir to the supply points. The microbial counts were significantly (p<0.05) higher in samples from the commercial abattoir than in those from the communal abattoir. Escherichia coli was the predominant microbial contaminant in the samples from both abattoirs. When following the chain, total bacterial count (TBC), coliform count (CC) and the levels of E. coli contamination increased progressively between the loading and the off-loading points (5.1 to 7.9 log10 CFU/cm2; 5.0 to 5.6 log10 CFU/cm2 and 2.7 to 3.7 log10 CFU/cm2, respectively). The storage period, meat type, distance during transportation and temperature were found to have a significant impact on the microbial levels during the distribution of carcasses. Distribution stage had a significant effect (p<0.05) on some of the physico- chemical meat quality attributes and differences in the lightness (L*) and redness (a*) values between the loading, off-loading and display points were observed. Consumers perceived retailer class as one of the factors influencing meat quality, but according to the instrumental measurements retailer class did not have a significant effect on physico-chemical meat quality. However, distance and storage duration significantly (p<0.05) affected (L*) and (a*) values in the meat during distribution chain. Vacuum and overwrapping packaging significantly affected (p<0.05) the shelf life of meat. Therefore, it was concluded that post-slaughter handling during the distribution chain affects the physico- chemical, microbiological and shelf-life of meat.
- Full Text:
- Date Issued: 2015
- Authors: Rani, Zikhona Theodora
- Date: 2015
- Subjects: Meat -- Microbiology Meat -- Transportation -- South Africa -- Eastern Cape Meat -- Quality -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/2490 , vital:27875
- Description: The broad objective of the study was to investigate the effect of post-slaughter handling in the distribution chain on red meat quality and safety. A survey was conducted among 300 consumers and 100 meat handlers in five different municipalities (Buffalo City, Nkonkobe, Ngqushwa, Lukhanje and Amahlathi) in the Eastern Cape Province of South Africa to investigate their perceptions on meat quality and safety, together with challenges faced by meat handlers during the distribution of meat from the abattoir to retailers. The microbiological profile and physico-chemical quality of red meat at different stages of the abattoir to retail outlets in the distribution chain were also determined. Swabs (n=216) and meat samples (n=450) were collected from beef, pork and mutton carcasses during the loading process of carcasses into trucks at the abattoir, when offloading carcasses at the supply points and during marketing. Physico-chemical qualities such as colour (L* - lightness, b* - redness and a* - yellowness) and meat pH measurements were taken at each point. To determine the microbiological profiles of the carcasses, four microbiological parameters were considered: Total bacteria count (general bacteria), coliform count (related to hygiene and indicator for pathogens), Escherichia coli (Gram-negative pathogen) and Staphylococcus aureus (Gram-positive pathogen). Two types of packaging (vacuum and overwrapping) were used to determine their effect on shelf-life and microbiological quality of red meat under the normal marketing conditions over a storage duration of 15 days. The results from the study showed low awareness of consumers about the pathogenic diseases which arise from meat. A strong significant association (p ˂ 0.05) between educational status and awareness on meat safety was observed. Most of the consumers perceived that quality goes beyond safety such that 35.6 percent of the respondents indicated that they did not have a problem with consuming spoiled meat, whilst the remaining 64.4 percent indicated that they would r eject spoiled meat. Although retailers indicated that they take meat safety into consideration in their shops, 92 percent of the retailers revealed that they do not perform microbial assessment of meat in their shops. A series of loading and off-loading, temperature fluctuations, environmental temperatures and ques during offloading were reported as the major challenges during transportation of carcasses from the abattoir to the supply points. The microbial counts were significantly (p<0.05) higher in samples from the commercial abattoir than in those from the communal abattoir. Escherichia coli was the predominant microbial contaminant in the samples from both abattoirs. When following the chain, total bacterial count (TBC), coliform count (CC) and the levels of E. coli contamination increased progressively between the loading and the off-loading points (5.1 to 7.9 log10 CFU/cm2; 5.0 to 5.6 log10 CFU/cm2 and 2.7 to 3.7 log10 CFU/cm2, respectively). The storage period, meat type, distance during transportation and temperature were found to have a significant impact on the microbial levels during the distribution of carcasses. Distribution stage had a significant effect (p<0.05) on some of the physico- chemical meat quality attributes and differences in the lightness (L*) and redness (a*) values between the loading, off-loading and display points were observed. Consumers perceived retailer class as one of the factors influencing meat quality, but according to the instrumental measurements retailer class did not have a significant effect on physico-chemical meat quality. However, distance and storage duration significantly (p<0.05) affected (L*) and (a*) values in the meat during distribution chain. Vacuum and overwrapping packaging significantly affected (p<0.05) the shelf life of meat. Therefore, it was concluded that post-slaughter handling during the distribution chain affects the physico- chemical, microbiological and shelf-life of meat.
- Full Text:
- Date Issued: 2015
Effects of natural antioxidants and thermal treatment on quality of meat from Bonsmara and non-descripts cattle
- Authors: Falowo, Andrew Bamidele
- Date: 2015
- Subjects: Meat -- Preservation Antioxidants Meat -- Microbiology
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/2589 , vital:27906
- Description: The broad objective of this study was to determine the effects of natural antioxidants and thermal treatment on quality of meat from Bonsmara and non-descript cattle. A survey was conducted among 222 consumers in Alice (Fort Hare University community), Eastern Cape Province to determine the level of their awareness on application of antioxidants as preservatives in meat and meat products during storage. Representative samples of Muscularis longissimuss thoracis et lumborum and liver were collected from each carcass of Bonsmara (n=40) and non-descript (n=40) cattle reared on natural pasture to determine the effect of natural antioxidants and thermal treatment on their quality. The results from the survey revealed that 51.35 percent of the respondents had not heard about the use of antioxidant as preservatives in meat products. However, among the remaining respondents (48.65 percent) that were aware of antioxidant and its use as preservative, about 19 percent knew of natural antioxidants, 35 percent synthetic antioxidants while 46 percent had knowledge of both. The results further revealed that the majority of the respondents (82 percent) that had knowledge of natural antioxidants were concerned about the use of synthetic antioxidants in meat and meat products due to their health consequences. The in vitro antioxidant and antibacterial analyses of Bidens pilosa and Moringa oleifera leaf extracts revealed that they contain rich bioactive compounds. Furthermore, the addition of leaf extracts from Moringa oleifera (ML, 0.05 and 0.1 percent w/w) and Biden pilosa (BP, 0.05 and 0.1 percent w/w) to ground raw beef as a natural antioxidant were found to improve the physicochemical, oxidative stability and microbiological qualities of meat compared to the control (meat without extract) and BHT treatment (0.02 percent w/w) during 6 days storage at 40 C. Cattle breed did not have much effect on colour parameters. However, the overall pH of ground beef treated with extracts showed lower values than control and BHT treated beef. Also, ground beef samples containing extracts exhibited (P < 0.05) better colour stability, especially higher redness (a* values), than the control. The formation of TBARS in beef samples treated with extracts was significantly (P < 0.05) lower than the control and BHT treatment. The antibacterial assay of the extracts revealed an appreciable broad spectrum activity against the tested bacteria and microbial counts in ground beef samples compared to control and BHT group. Ground beef treated with plant extracts exhibited lower microbial and lactic acid bacterial counts (P < 0.05) at day 0 and 3 than control samples. Moreover, it was observed that application of sous vides thermal method did not significantly affect the fatty acids and mineral loss in beef and liver across the treatments. However, the total concentration of MUFA was lower in raw liver (20.11±2.38 - 21.08±1.23 percent) than in beef (40.22±1.90 - 42.53±1.29 percent), while total PUFA content were higher in liver (30.73±2.60 - 31.11±1.19 percent) than in beef samples (10.13±3.36 - 11.02±2.74 percent) (p < 0.05). The results also revealed that liver samples from Bonsmara and non-descript cattle had a higher percentage of intramuscular fat content of 4.67 ± 0.53 percent and 4.44 ± 0.53 percent respectively, and fat free dry matter of 27.51 ± 1.05 percent and 25.73 ± 1.05 percent, respectively, than the beef samples (p < 0.05). The concentrations of Mg (52.80±0.22 - 53.70±0.02mg/100g) and Zn (8.90±0.15 - 19.60±0.15mg/100g) were higher in beef than liver samples. The level of Ca (17.00±0.17 - 17.50 ± 0.17mg/100g) in liver was higher than that of beef samples. It was concluded that most consumers preferred the use of natural antioxidants in meat products than synthetic antioxidants due to their health risk. The effectiveness of M. oleifera and B. pilosa leaf extracts on meat quality also revealed that these plants are promising candidates as natural preservatives and their application should be considered in the meat industry. Lastly, findings from this study showed that application of the sous vide technique could protect meat products from nutritional loss during thermal treatment.
- Full Text:
- Date Issued: 2015
- Authors: Falowo, Andrew Bamidele
- Date: 2015
- Subjects: Meat -- Preservation Antioxidants Meat -- Microbiology
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/2589 , vital:27906
- Description: The broad objective of this study was to determine the effects of natural antioxidants and thermal treatment on quality of meat from Bonsmara and non-descript cattle. A survey was conducted among 222 consumers in Alice (Fort Hare University community), Eastern Cape Province to determine the level of their awareness on application of antioxidants as preservatives in meat and meat products during storage. Representative samples of Muscularis longissimuss thoracis et lumborum and liver were collected from each carcass of Bonsmara (n=40) and non-descript (n=40) cattle reared on natural pasture to determine the effect of natural antioxidants and thermal treatment on their quality. The results from the survey revealed that 51.35 percent of the respondents had not heard about the use of antioxidant as preservatives in meat products. However, among the remaining respondents (48.65 percent) that were aware of antioxidant and its use as preservative, about 19 percent knew of natural antioxidants, 35 percent synthetic antioxidants while 46 percent had knowledge of both. The results further revealed that the majority of the respondents (82 percent) that had knowledge of natural antioxidants were concerned about the use of synthetic antioxidants in meat and meat products due to their health consequences. The in vitro antioxidant and antibacterial analyses of Bidens pilosa and Moringa oleifera leaf extracts revealed that they contain rich bioactive compounds. Furthermore, the addition of leaf extracts from Moringa oleifera (ML, 0.05 and 0.1 percent w/w) and Biden pilosa (BP, 0.05 and 0.1 percent w/w) to ground raw beef as a natural antioxidant were found to improve the physicochemical, oxidative stability and microbiological qualities of meat compared to the control (meat without extract) and BHT treatment (0.02 percent w/w) during 6 days storage at 40 C. Cattle breed did not have much effect on colour parameters. However, the overall pH of ground beef treated with extracts showed lower values than control and BHT treated beef. Also, ground beef samples containing extracts exhibited (P < 0.05) better colour stability, especially higher redness (a* values), than the control. The formation of TBARS in beef samples treated with extracts was significantly (P < 0.05) lower than the control and BHT treatment. The antibacterial assay of the extracts revealed an appreciable broad spectrum activity against the tested bacteria and microbial counts in ground beef samples compared to control and BHT group. Ground beef treated with plant extracts exhibited lower microbial and lactic acid bacterial counts (P < 0.05) at day 0 and 3 than control samples. Moreover, it was observed that application of sous vides thermal method did not significantly affect the fatty acids and mineral loss in beef and liver across the treatments. However, the total concentration of MUFA was lower in raw liver (20.11±2.38 - 21.08±1.23 percent) than in beef (40.22±1.90 - 42.53±1.29 percent), while total PUFA content were higher in liver (30.73±2.60 - 31.11±1.19 percent) than in beef samples (10.13±3.36 - 11.02±2.74 percent) (p < 0.05). The results also revealed that liver samples from Bonsmara and non-descript cattle had a higher percentage of intramuscular fat content of 4.67 ± 0.53 percent and 4.44 ± 0.53 percent respectively, and fat free dry matter of 27.51 ± 1.05 percent and 25.73 ± 1.05 percent, respectively, than the beef samples (p < 0.05). The concentrations of Mg (52.80±0.22 - 53.70±0.02mg/100g) and Zn (8.90±0.15 - 19.60±0.15mg/100g) were higher in beef than liver samples. The level of Ca (17.00±0.17 - 17.50 ± 0.17mg/100g) in liver was higher than that of beef samples. It was concluded that most consumers preferred the use of natural antioxidants in meat products than synthetic antioxidants due to their health risk. The effectiveness of M. oleifera and B. pilosa leaf extracts on meat quality also revealed that these plants are promising candidates as natural preservatives and their application should be considered in the meat industry. Lastly, findings from this study showed that application of the sous vide technique could protect meat products from nutritional loss during thermal treatment.
- Full Text:
- Date Issued: 2015
Nutritional value and cultivation requirements of Cleome Gynandra: a wild vegetable growing in the Eastern Cape Province, South Africa
- Sowunmi, Linda Ifeanyichukwu
- Authors: Sowunmi, Linda Ifeanyichukwu
- Date: 2015
- Subjects: Ethnobotany -- South Africa -- Eastern Cape Vegetables -- South Africa -- Eastern Cape Nutrition -- South Africa -- Evaluation
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/2600 , vital:27907
- Description: South Africa has wide ranges of plants among which are leafy vegetables growing in the wild. These wild vegetables have been reported to have high nutritive and medicinal potentials. Yet, there is still high prevalence of malnutrition and micronutrients deficiencies among the low income bracket of the population. Effective utilization of wild vegetables has been proposed as part of the solutions to address the problem of dietary deficiencies among the populace. Their importance is mainly as relish to accompany and complement starch based diets. They are also known to serve as supplements for food which have the potential to improve the health status of its consumers in many rural communities. Cleome gynandra L. (Capparaceae) is one of the underutilized species mentioned during asurvey conducted in Nkonkobe municipality of the Eastern Cape Province, South Africa. The plant is an erect annual herb with alternate, palmately compound leaves and its petals are white, pink or lilac. It grows as a weed in this part of the Province and is usually gathered from the wild for food and medicine. It is commonly found on wastes land, road sides and on grass lands. Therefore, this research work was designed to contribute to the possible domestication of this wild vegetable in order to explore the nutritive and therapeutic potentials which would broaden the food base in the Eastern Cape Province. The ultra-micromorphological features of plants have become an essential tool in proper identification and authentication of several plant species. In the light of this, the micromorphology of Cleome gynandra was examined to reveal the micro-morphological characters of the plantand to determine if micro and macro mineral elements are present using energy dispersive x-rays. The present study revealed the epidermal cells of the leaves to be asymmetric in shape with undulating cell walls having four subsidiary cells around the stomata. The leaves have anomocyctic stomata which are more distributed in the abaxial surface than the adaxial surface. The mean length and width of the guard cells in the abaxial surface are 0.09 ± 0.01 mm and 0.08 ± 0.01 mm respectively while that of adaxial surface are 0.1± 0.01 mm and 0.07 ± 0.01 mm respectively. The energy dispersive x-rays (EDXS) micro-analysis of the leaf revealed the presence of phosphorus, manganese, iron, calcium, sodium, magnesium, potassium and zinc as the major constituents of the crystal deposits present in the stomata pores and the mesophyll. C. gynandra was collected from the wild and analysed for its mineral and proximatecomposition using standard analytical methods. The plant showed high levels of sodium, iron, zinc, calcium and potassium while many other macro and micro minerals were moderately present. Amongst the proximate factors investigated, moisture content was found to be 82.1% while crude fibre and protein contents were 39.9 percent and 31.03 percent respectively. Vitamin C was also high (345.3 mg/100g). The anti-nutrients compositions revealed low concentrations of oxalate (7.4 ± 0.4) and phytate (0.6 ± 0.0) mg/100g. The study revealed high nutritive value of the species growing naturally from the wild. Interest in the phenolic compounds has greatly increased recently because these compounds have been implicated in suppressing the risk of degenerative diseases in humans. The pharmacological properties of plants may be related to their antioxidant capacities and hence there was need to investigate the antioxidant potential using aqueous, ethanolic and acetone extracts of different parts of C. gynandra. The quantities of phenols, flavonoids and flavonols were significantly higher (p < 0.05) in both aqueous and ethanol extracts of the leaf while the concentration of proanthocyanidins was higher in the aqueous stem extract compared to other plant parts. The aqueous extract of the different parts exhibited better ABTS, reducing power and NO radical scavenging abilities than ethanol extract.
- Full Text:
- Date Issued: 2015
- Authors: Sowunmi, Linda Ifeanyichukwu
- Date: 2015
- Subjects: Ethnobotany -- South Africa -- Eastern Cape Vegetables -- South Africa -- Eastern Cape Nutrition -- South Africa -- Evaluation
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/2600 , vital:27907
- Description: South Africa has wide ranges of plants among which are leafy vegetables growing in the wild. These wild vegetables have been reported to have high nutritive and medicinal potentials. Yet, there is still high prevalence of malnutrition and micronutrients deficiencies among the low income bracket of the population. Effective utilization of wild vegetables has been proposed as part of the solutions to address the problem of dietary deficiencies among the populace. Their importance is mainly as relish to accompany and complement starch based diets. They are also known to serve as supplements for food which have the potential to improve the health status of its consumers in many rural communities. Cleome gynandra L. (Capparaceae) is one of the underutilized species mentioned during asurvey conducted in Nkonkobe municipality of the Eastern Cape Province, South Africa. The plant is an erect annual herb with alternate, palmately compound leaves and its petals are white, pink or lilac. It grows as a weed in this part of the Province and is usually gathered from the wild for food and medicine. It is commonly found on wastes land, road sides and on grass lands. Therefore, this research work was designed to contribute to the possible domestication of this wild vegetable in order to explore the nutritive and therapeutic potentials which would broaden the food base in the Eastern Cape Province. The ultra-micromorphological features of plants have become an essential tool in proper identification and authentication of several plant species. In the light of this, the micromorphology of Cleome gynandra was examined to reveal the micro-morphological characters of the plantand to determine if micro and macro mineral elements are present using energy dispersive x-rays. The present study revealed the epidermal cells of the leaves to be asymmetric in shape with undulating cell walls having four subsidiary cells around the stomata. The leaves have anomocyctic stomata which are more distributed in the abaxial surface than the adaxial surface. The mean length and width of the guard cells in the abaxial surface are 0.09 ± 0.01 mm and 0.08 ± 0.01 mm respectively while that of adaxial surface are 0.1± 0.01 mm and 0.07 ± 0.01 mm respectively. The energy dispersive x-rays (EDXS) micro-analysis of the leaf revealed the presence of phosphorus, manganese, iron, calcium, sodium, magnesium, potassium and zinc as the major constituents of the crystal deposits present in the stomata pores and the mesophyll. C. gynandra was collected from the wild and analysed for its mineral and proximatecomposition using standard analytical methods. The plant showed high levels of sodium, iron, zinc, calcium and potassium while many other macro and micro minerals were moderately present. Amongst the proximate factors investigated, moisture content was found to be 82.1% while crude fibre and protein contents were 39.9 percent and 31.03 percent respectively. Vitamin C was also high (345.3 mg/100g). The anti-nutrients compositions revealed low concentrations of oxalate (7.4 ± 0.4) and phytate (0.6 ± 0.0) mg/100g. The study revealed high nutritive value of the species growing naturally from the wild. Interest in the phenolic compounds has greatly increased recently because these compounds have been implicated in suppressing the risk of degenerative diseases in humans. The pharmacological properties of plants may be related to their antioxidant capacities and hence there was need to investigate the antioxidant potential using aqueous, ethanolic and acetone extracts of different parts of C. gynandra. The quantities of phenols, flavonoids and flavonols were significantly higher (p < 0.05) in both aqueous and ethanol extracts of the leaf while the concentration of proanthocyanidins was higher in the aqueous stem extract compared to other plant parts. The aqueous extract of the different parts exhibited better ABTS, reducing power and NO radical scavenging abilities than ethanol extract.
- Full Text:
- Date Issued: 2015
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