In vitro evaluation of antimicrobial and antioxidant activities of olea europaea subsp. africana and euryops brevipapposus used by Cala community folkloric medicine for the management of infections associated with chronic non-communicable diseases
- Authors: Adegborioye, Abiodun
- Date: 2016
- Subjects: Antioxidants , Medicinal plants , Traditional medicine -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4869 , vital:28624
- Description: Chronic non-communicable diseses are a global public health challenge that continuously threatens the development and health of humans. Risk factors such as unbalanced diet-the high consumption of processed food or food from animal origin are responsible for NCDs. NCDs result in weakened immune system, making the host susceptible to opportunistic infections. Thus, the NCDs burden is most times chronic and multiple with the illness and suffering of the affected person numerous. The lack of cure for NCDs, the high cost of drugs, their high side-effects, and the emergence of multiple drug resistance has given rise to the investigation of other sources for therapeutic cure such as medicinal plants. The ethanol, n-hexane and ethyl acetate extracts of Olea europaea were analysed for their antioxidant and antimicrobial activities. The essential oil was also analysed for their chemical constituents. The n-hexane extracts of O. europaea exhibited no inhibition against all of the microorganisms tested, while the ethyl acetate and ethanol extracts exhibited inhibition, with minimum inhibitory concentration values between 0.625 mg/ml to 1.25 mg/ml. The ethanol leaf and ethyl acetate stem extracts exhibited significant activity in the inhibition of 2, 2-azinobis-(3-ethylbenzothiazolin - 6-sulfonic acid diammonium salt (ABTS) free radical, the n-hexane leaf extract had the overall significant lipid peroxidation inhibition activity, while in the inhibition of 2, 2- diphenyl-1-picrylhydrazyl radical (DPPH), the ethanol and ethyl acetate leaf extracts had strong activity. Nonanal, phytol, α-Pinene, α-Phellandrene, spatulenol and farnesol were some of chemical components identified after the GC-MS analysis of O. europaea oil. In the final part of the dissertation, Euryops brevipapposus essential oil was assessed for the antioxidant activities using free radical scavenging assays. In addition to this, the antimicrobial activities were assessed and the chemical composition was analysed using GC-MS. The essential oil demonstrated significant antioxidant activity against 2, 2-diphenyl-2-picryl-hydrazyl free radical (DPPH), 2, 2′-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and lipid peroxides with IC50 value of 0.0000000671 mg/ml, 1.05 mg/ml, and 1.170 mg/ml respectively. The essential oil also showed significant activity against all microorganisms tested with minimum inhibitory concentration (MIC) values between 0.055 mg/ml to 0.5 mg/ml. α-pinene, α- Phellandrene, germacrene D, β-pinene, trans- β.-Ocimene, bicyclogermacrene and β -Phellandrene were some of the chemical compounds identified in E. brevipapposus oil. The study has shown that E. brevipapposus and O. europaea are abundant in phytochemical compounds which were thought to be the root cause for the activities demonstrated. Therefore, these therapeutic properties observed validate and elucidate the traditional usage of the both plants in the treatment /management of diseases.
- Full Text:
- Date Issued: 2016
- Authors: Adegborioye, Abiodun
- Date: 2016
- Subjects: Antioxidants , Medicinal plants , Traditional medicine -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4869 , vital:28624
- Description: Chronic non-communicable diseses are a global public health challenge that continuously threatens the development and health of humans. Risk factors such as unbalanced diet-the high consumption of processed food or food from animal origin are responsible for NCDs. NCDs result in weakened immune system, making the host susceptible to opportunistic infections. Thus, the NCDs burden is most times chronic and multiple with the illness and suffering of the affected person numerous. The lack of cure for NCDs, the high cost of drugs, their high side-effects, and the emergence of multiple drug resistance has given rise to the investigation of other sources for therapeutic cure such as medicinal plants. The ethanol, n-hexane and ethyl acetate extracts of Olea europaea were analysed for their antioxidant and antimicrobial activities. The essential oil was also analysed for their chemical constituents. The n-hexane extracts of O. europaea exhibited no inhibition against all of the microorganisms tested, while the ethyl acetate and ethanol extracts exhibited inhibition, with minimum inhibitory concentration values between 0.625 mg/ml to 1.25 mg/ml. The ethanol leaf and ethyl acetate stem extracts exhibited significant activity in the inhibition of 2, 2-azinobis-(3-ethylbenzothiazolin - 6-sulfonic acid diammonium salt (ABTS) free radical, the n-hexane leaf extract had the overall significant lipid peroxidation inhibition activity, while in the inhibition of 2, 2- diphenyl-1-picrylhydrazyl radical (DPPH), the ethanol and ethyl acetate leaf extracts had strong activity. Nonanal, phytol, α-Pinene, α-Phellandrene, spatulenol and farnesol were some of chemical components identified after the GC-MS analysis of O. europaea oil. In the final part of the dissertation, Euryops brevipapposus essential oil was assessed for the antioxidant activities using free radical scavenging assays. In addition to this, the antimicrobial activities were assessed and the chemical composition was analysed using GC-MS. The essential oil demonstrated significant antioxidant activity against 2, 2-diphenyl-2-picryl-hydrazyl free radical (DPPH), 2, 2′-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and lipid peroxides with IC50 value of 0.0000000671 mg/ml, 1.05 mg/ml, and 1.170 mg/ml respectively. The essential oil also showed significant activity against all microorganisms tested with minimum inhibitory concentration (MIC) values between 0.055 mg/ml to 0.5 mg/ml. α-pinene, α- Phellandrene, germacrene D, β-pinene, trans- β.-Ocimene, bicyclogermacrene and β -Phellandrene were some of the chemical compounds identified in E. brevipapposus oil. The study has shown that E. brevipapposus and O. europaea are abundant in phytochemical compounds which were thought to be the root cause for the activities demonstrated. Therefore, these therapeutic properties observed validate and elucidate the traditional usage of the both plants in the treatment /management of diseases.
- Full Text:
- Date Issued: 2016
Moringa oleifera leaf powder as a functional antioxidant additive in pork droewors
- Authors: Mukumbo, Felicitas Esnart
- Date: 2016
- Subjects: Antioxidants , Moringa oleifera , Pork -- Quality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15354 , vital:40400
- Description: The study investigated the effect of Moringa oleifera leaf powder (MLP) on physico-chemical characteristics, antioxidant activity, antioxidant compound content and lipid oxidation in pork droëwors. Firstly, the physico-chemical properties (proximate composition, salt content, water activity (aw), pH) of commercially produced droëwors from different types of meat (beef, game, ostrich) were determined. In the second experiment beef and pork droëwors with similar fat content were produced. Physico-chemical properties and lipid oxidation (thiobarbituric reactive substances (TBARS)) during processing and 26 days of storage at 25 °C and 50percent relative humidity (RH) were measured. In the third experiment, antioxidant compounds (Total Phenolic Compounds (TPC), α-tocopherol, β-carotene) in MLP were quantified. Thereafter, 4 treatments of pork droëwors were produced, with MLP included at 0, 0.5, 1 and 2 g/ 100 g. Physico-chemical properties and TBARS were measured at intervals during drying (0, 1.5, 5.75, 27.25, 72 h) and after 7 days of storage under ambient conditions. Antioxidant activity (ferric reducing antioxidant power (FRAP)), TBARS, α- and γ-tocopherol, and β-carotene contents were measured. In the fourth experiment, three batches of droëwors were produced (C: no antioxidant, M0.75: 0.75 g/ 100 g MLP, VE: 15 mg/ kg α-tocopherol oil) and stored at 25 °C and 50percent relative humidity for 112 days. Drying kinetics and α-tocopherol contents of pork droëwors after drying were measured and the physico-chemical properties and TBARS were followed during storage. Results showed no differences (P > 0.05) in the physico-chemical characteristics of beef, game meat and ostrich droëwors; containing on average 25.8 ± 1.25 g/100 g moisture, 42.0 ± 0.10 g/100 g protein, 32.0 ± 1.68 g/100 g fat, 6.2 ± 0.13 g/100 g ash and 4.2 ± 0.10 g/100 g salt; with aw and pH of 0.79 ± 0.015 and 5.3 ± 0.05, respectively. During processing and storage, TBARS were higher (P < 0.05) in pork droëwors (maximum 3.83 mg MDA/kg DM) than in beef (maximum 0.99 mg MDA/kg DM). Moringa oleifera leaf powder contained high levels of TPC (7.5 ± 0.2 mg gallic acid eq/g) and substantial levels of α-tocopherol (76.7 ± 1.9 mg/100 g) and β-carotene (23.2 ± 2.8 mg/100 g). The FRAP, α-tocopherol and β-carotene content of pork droëwors increased (P < 0.05) proportionally with increasing levels of MLP inclusion. Lipid oxidation occurred more rapidly (P < 0.05) when MLP was not added and was similar (P > 0.05) for all MLP treatments. There was no significant effect of the inclusion of 0.75 g/100 g MLP on the drying curves and physico-chemical characteristics of the droëwors. The α-tocopherol content was higher (P < 0.05) and TBARS during storage were lower (P > 0.05) with MLP addition. The results of the current study give an overview of the composition of commercial droëwors and showed higher susceptibility to lipid oxidation in pork droëwors. Moringa oleifera leaf powder exhibited antioxidant activity in pork droëwors, inhibited lipid oxidation and increased the content of α-tocopherol in the product. It can be concluded that MLP could be used as a functional antioxidant additive in pork droëwors.
- Full Text:
- Date Issued: 2016
- Authors: Mukumbo, Felicitas Esnart
- Date: 2016
- Subjects: Antioxidants , Moringa oleifera , Pork -- Quality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15354 , vital:40400
- Description: The study investigated the effect of Moringa oleifera leaf powder (MLP) on physico-chemical characteristics, antioxidant activity, antioxidant compound content and lipid oxidation in pork droëwors. Firstly, the physico-chemical properties (proximate composition, salt content, water activity (aw), pH) of commercially produced droëwors from different types of meat (beef, game, ostrich) were determined. In the second experiment beef and pork droëwors with similar fat content were produced. Physico-chemical properties and lipid oxidation (thiobarbituric reactive substances (TBARS)) during processing and 26 days of storage at 25 °C and 50percent relative humidity (RH) were measured. In the third experiment, antioxidant compounds (Total Phenolic Compounds (TPC), α-tocopherol, β-carotene) in MLP were quantified. Thereafter, 4 treatments of pork droëwors were produced, with MLP included at 0, 0.5, 1 and 2 g/ 100 g. Physico-chemical properties and TBARS were measured at intervals during drying (0, 1.5, 5.75, 27.25, 72 h) and after 7 days of storage under ambient conditions. Antioxidant activity (ferric reducing antioxidant power (FRAP)), TBARS, α- and γ-tocopherol, and β-carotene contents were measured. In the fourth experiment, three batches of droëwors were produced (C: no antioxidant, M0.75: 0.75 g/ 100 g MLP, VE: 15 mg/ kg α-tocopherol oil) and stored at 25 °C and 50percent relative humidity for 112 days. Drying kinetics and α-tocopherol contents of pork droëwors after drying were measured and the physico-chemical properties and TBARS were followed during storage. Results showed no differences (P > 0.05) in the physico-chemical characteristics of beef, game meat and ostrich droëwors; containing on average 25.8 ± 1.25 g/100 g moisture, 42.0 ± 0.10 g/100 g protein, 32.0 ± 1.68 g/100 g fat, 6.2 ± 0.13 g/100 g ash and 4.2 ± 0.10 g/100 g salt; with aw and pH of 0.79 ± 0.015 and 5.3 ± 0.05, respectively. During processing and storage, TBARS were higher (P < 0.05) in pork droëwors (maximum 3.83 mg MDA/kg DM) than in beef (maximum 0.99 mg MDA/kg DM). Moringa oleifera leaf powder contained high levels of TPC (7.5 ± 0.2 mg gallic acid eq/g) and substantial levels of α-tocopherol (76.7 ± 1.9 mg/100 g) and β-carotene (23.2 ± 2.8 mg/100 g). The FRAP, α-tocopherol and β-carotene content of pork droëwors increased (P < 0.05) proportionally with increasing levels of MLP inclusion. Lipid oxidation occurred more rapidly (P < 0.05) when MLP was not added and was similar (P > 0.05) for all MLP treatments. There was no significant effect of the inclusion of 0.75 g/100 g MLP on the drying curves and physico-chemical characteristics of the droëwors. The α-tocopherol content was higher (P < 0.05) and TBARS during storage were lower (P > 0.05) with MLP addition. The results of the current study give an overview of the composition of commercial droëwors and showed higher susceptibility to lipid oxidation in pork droëwors. Moringa oleifera leaf powder exhibited antioxidant activity in pork droëwors, inhibited lipid oxidation and increased the content of α-tocopherol in the product. It can be concluded that MLP could be used as a functional antioxidant additive in pork droëwors.
- Full Text:
- Date Issued: 2016
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