Degradation of Aflatoxin B1 (AFB1) by lysates of bacteria obtained from a gold mine aquifer
- Authors: Adebo, Oluwafemi Ayodeji
- Date: 2016
- Subjects: Aflatoxins - Toxicology , Mycotoxicoses , Mycotoxins , Plant metabolites , Plant biotechnology
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/84361 , uj:19210
- Description: Abstract: Aflatoxins (AFs) are secondary metabolites (toxins) primarily produced by Aspergillus flavus and Aspergillus parasiticus. Aflatoxin B1 (AFB1), a member of AFs, is the most toxic mycotoxin, responsible for numerous adverse health and economic losses. Despite several physical and chemical means aimed at reducing or inactivating AFs, they still persist along the food chain. This has necessitated the need for efficient ways of reducing or at best eliminating them from foods and feeds. Bacterial degradation of AFs presents an effective, cost efficient and feasible way in doing so. This study thus, investigated AFB1 degradation by protease inhibited and uninhibited bacterial lysates. Aflatoxin B1 (2.5 μg/mL) was incubated with each of seven different bacterial lysates for 3, 6, 12, 24 and 48 hrs. As monitored on high performance liquid chromatography (HPLC), significant (p˂0.05) AFB1 degradation by all the lysates was recorded. After 48 hrs of incubation, the highest percentage degradation obtained for the lysates was 60.9% while the lowest was 31.7% corresponding to lysates of Lysinibacillus fusiformis and Sporosarcina sp. respectively. Conversely, a drastic increase in AFB1 degradation was observed after bacterial cells were treated with protease inhibitors prior to lysis. Following 12 hrs of incubation, a 100% detoxification was detected for all the protease inhibited lysates. Cytotoxicity studies on human lymphocytes following the MTT assay also indicated that the toxicity of AFB1 degraded samples were considerably reduced when compared to the parent AFB1. Results obtained from this study suggest that AFB1 degradation by these bacterial lysates is potentially enzymatic and the consequent decrease in fluorescence intensity based on HPLC indicates the cleavage of the furan ring of the AFB1 molecule. The successful degradation of AFB1 by these lysates could be an important bio-control measure in safeguarding the quality of agricultural commodities that may have a huge potential for industrial applications. , M.Tech. (Food Technology)
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- Authors: Adebo, Oluwafemi Ayodeji
- Date: 2016
- Subjects: Aflatoxins - Toxicology , Mycotoxicoses , Mycotoxins , Plant metabolites , Plant biotechnology
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/84361 , uj:19210
- Description: Abstract: Aflatoxins (AFs) are secondary metabolites (toxins) primarily produced by Aspergillus flavus and Aspergillus parasiticus. Aflatoxin B1 (AFB1), a member of AFs, is the most toxic mycotoxin, responsible for numerous adverse health and economic losses. Despite several physical and chemical means aimed at reducing or inactivating AFs, they still persist along the food chain. This has necessitated the need for efficient ways of reducing or at best eliminating them from foods and feeds. Bacterial degradation of AFs presents an effective, cost efficient and feasible way in doing so. This study thus, investigated AFB1 degradation by protease inhibited and uninhibited bacterial lysates. Aflatoxin B1 (2.5 μg/mL) was incubated with each of seven different bacterial lysates for 3, 6, 12, 24 and 48 hrs. As monitored on high performance liquid chromatography (HPLC), significant (p˂0.05) AFB1 degradation by all the lysates was recorded. After 48 hrs of incubation, the highest percentage degradation obtained for the lysates was 60.9% while the lowest was 31.7% corresponding to lysates of Lysinibacillus fusiformis and Sporosarcina sp. respectively. Conversely, a drastic increase in AFB1 degradation was observed after bacterial cells were treated with protease inhibitors prior to lysis. Following 12 hrs of incubation, a 100% detoxification was detected for all the protease inhibited lysates. Cytotoxicity studies on human lymphocytes following the MTT assay also indicated that the toxicity of AFB1 degraded samples were considerably reduced when compared to the parent AFB1. Results obtained from this study suggest that AFB1 degradation by these bacterial lysates is potentially enzymatic and the consequent decrease in fluorescence intensity based on HPLC indicates the cleavage of the furan ring of the AFB1 molecule. The successful degradation of AFB1 by these lysates could be an important bio-control measure in safeguarding the quality of agricultural commodities that may have a huge potential for industrial applications. , M.Tech. (Food Technology)
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Metabolomics, physicochemical properties and mycotoxin reduction of whole grain ting (a Southern African fermented food) produced via natural and lactic acid bacteria (LAB) fermentation
- Authors: Adebo, Oluwafemi Ayodeji
- Date: 2018
- Subjects: Sorghum , Mycotoxicoses , Fermentation
- Language: English
- Type: Doctoral (Thesis)
- Identifier: http://hdl.handle.net/10210/285006 , uj:30805
- Description: D.Tech. (Food Technology) , Abstract: Drought and challenges related to climate change are some of the issues facing sub-Saharan Africa countries, with dire consequences on agriculture and food security. Due to this prevailing situation, drought and climate resistant crops like sorghum (Sorghum bicolor (L) Moench) can adequately contribute to food security. The versatility and importance of sorghum is well reflected in its use as a major food source for millions of people in sub-Saharan Africa. Recent interest in gluten free food products has equally positioned this crop as a potential substitute for wheat, with numerous studies attesting to this possibility. Although other food processing techniques for the transformation of these sorghum grain exists, fermentation is an important and dominant technique for processing sorghum into other food products particularly in the developing world. Porridge and gruels are commonly and usually consumed in developing countries. A form of this sorghum fermented food is ting, referred to as mabele, bogobe (when processed to hard porridge) or motogo (when processed to soft porridge). It is commonly consumed in South Africa, Botswana and other neighbouring Southern African countries. Although ting is conventionally processed using refined grains, the role of whole grain meals with regards to the provision of desirable health benefits is emphasized in recent literatures. Their composition yields better contents of bioactive, health promoting and beneficial compounds in subsequent products as compared to products from refined grains. The composition of fermented foods depends on such factors as fermentation time and temperature, meaning that changes and choice of these conditions would influence the quality of the final product. Such differences in fermentation conditions would thus affect ting quality, necessitating an optimization of these conditions. Accordingly, a response surface methodology (RSM) optimization technique was employed in this study to optimize fermentation conditions of ting from two whole grain sorghum types: high tannin sorghum (Avenger) and low tannin sorghum (Titan). The effect of fermentation time and temperature on whole grain-ting parameters such as pH, titratable acidity (TTA), total viable bacteria count (TBC), total lactic acid bacteria count (TLABC), total fungal and yeast count (TFYC), tannin content (TNC), total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activities (AA) was investigated. Scanning electron microscopy (SEM) was also used to investigate possible morphological changes in the samples during fermentation...
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- Authors: Adebo, Oluwafemi Ayodeji
- Date: 2018
- Subjects: Sorghum , Mycotoxicoses , Fermentation
- Language: English
- Type: Doctoral (Thesis)
- Identifier: http://hdl.handle.net/10210/285006 , uj:30805
- Description: D.Tech. (Food Technology) , Abstract: Drought and challenges related to climate change are some of the issues facing sub-Saharan Africa countries, with dire consequences on agriculture and food security. Due to this prevailing situation, drought and climate resistant crops like sorghum (Sorghum bicolor (L) Moench) can adequately contribute to food security. The versatility and importance of sorghum is well reflected in its use as a major food source for millions of people in sub-Saharan Africa. Recent interest in gluten free food products has equally positioned this crop as a potential substitute for wheat, with numerous studies attesting to this possibility. Although other food processing techniques for the transformation of these sorghum grain exists, fermentation is an important and dominant technique for processing sorghum into other food products particularly in the developing world. Porridge and gruels are commonly and usually consumed in developing countries. A form of this sorghum fermented food is ting, referred to as mabele, bogobe (when processed to hard porridge) or motogo (when processed to soft porridge). It is commonly consumed in South Africa, Botswana and other neighbouring Southern African countries. Although ting is conventionally processed using refined grains, the role of whole grain meals with regards to the provision of desirable health benefits is emphasized in recent literatures. Their composition yields better contents of bioactive, health promoting and beneficial compounds in subsequent products as compared to products from refined grains. The composition of fermented foods depends on such factors as fermentation time and temperature, meaning that changes and choice of these conditions would influence the quality of the final product. Such differences in fermentation conditions would thus affect ting quality, necessitating an optimization of these conditions. Accordingly, a response surface methodology (RSM) optimization technique was employed in this study to optimize fermentation conditions of ting from two whole grain sorghum types: high tannin sorghum (Avenger) and low tannin sorghum (Titan). The effect of fermentation time and temperature on whole grain-ting parameters such as pH, titratable acidity (TTA), total viable bacteria count (TBC), total lactic acid bacteria count (TLABC), total fungal and yeast count (TFYC), tannin content (TNC), total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activities (AA) was investigated. Scanning electron microscopy (SEM) was also used to investigate possible morphological changes in the samples during fermentation...
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Optimization of fermentation conditions for ting production using response surface methodology
- Adebo, Oluwafemi Ayodeji, Njobeh, Patrick Berka, Mulaba-Bafubiandi, Antoine Floribert, Adebiyi, Janet Adeyinka, Desobgo, Zangue Steve Carly, Kayitesi, Eugenie
- Authors: Adebo, Oluwafemi Ayodeji , Njobeh, Patrick Berka , Mulaba-Bafubiandi, Antoine Floribert , Adebiyi, Janet Adeyinka , Desobgo, Zangue Steve Carly , Kayitesi, Eugenie
- Date: 2017
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/258846 , uj:27222 , Citation: Adebo, O.A. et al. 2017. Optimization of fermentation conditions for ting production using response surface methodology. J Food Process Preserv. 2017;e13381. https://doi.org/10.1111/jfpp.13381.
- Description: Abstract: This study investigated the effect of fermentation conditions (time and temperature) of sorghum on the composition of ting, using the Doehlert design of response surface methodology (RSM). Fermentation temperature and time were optimized and pH, titratable acidity (TTA), total viable bacteria count (TBC), total lactic acid bacteria count (TLABC), total fungal and yeast count (TFYC), tannin content (TNC), total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activities (AA) were determined. Experimental and predicted values obtained were similar, with statistical indices indicating the validity of the models generated (R2 between 93.45 and 99.71%, AAD values close to 0, Bf and Af values close to 1). Numerical multi-response optimization of parameters suggested optimal fermentation conditions to be 34 8C for 24 hr. Physicochemical characterization of ting samples using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier Transform Infrared Spectroscopy (FTIR) showed slight changes in morphology, similarity in diffraction patterns and presence of different functional groups, respectively. Results of this study could provide information for the commercialization of quality ting. Practical applications Response surface methodology was used to study the influence of fermentation conditions on the quality of ting and optimal fermentation conditions were obtained at 34 8C for 24 hr. The findings in this study will be useful for ting processors to obtain a product with maximal beneficial composition and traits.
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- Authors: Adebo, Oluwafemi Ayodeji , Njobeh, Patrick Berka , Mulaba-Bafubiandi, Antoine Floribert , Adebiyi, Janet Adeyinka , Desobgo, Zangue Steve Carly , Kayitesi, Eugenie
- Date: 2017
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/258846 , uj:27222 , Citation: Adebo, O.A. et al. 2017. Optimization of fermentation conditions for ting production using response surface methodology. J Food Process Preserv. 2017;e13381. https://doi.org/10.1111/jfpp.13381.
- Description: Abstract: This study investigated the effect of fermentation conditions (time and temperature) of sorghum on the composition of ting, using the Doehlert design of response surface methodology (RSM). Fermentation temperature and time were optimized and pH, titratable acidity (TTA), total viable bacteria count (TBC), total lactic acid bacteria count (TLABC), total fungal and yeast count (TFYC), tannin content (TNC), total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activities (AA) were determined. Experimental and predicted values obtained were similar, with statistical indices indicating the validity of the models generated (R2 between 93.45 and 99.71%, AAD values close to 0, Bf and Af values close to 1). Numerical multi-response optimization of parameters suggested optimal fermentation conditions to be 34 8C for 24 hr. Physicochemical characterization of ting samples using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier Transform Infrared Spectroscopy (FTIR) showed slight changes in morphology, similarity in diffraction patterns and presence of different functional groups, respectively. Results of this study could provide information for the commercialization of quality ting. Practical applications Response surface methodology was used to study the influence of fermentation conditions on the quality of ting and optimal fermentation conditions were obtained at 34 8C for 24 hr. The findings in this study will be useful for ting processors to obtain a product with maximal beneficial composition and traits.
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Development of a twin screw extruder
- Sobowale, Sunday Samuel, Adebo, Oluwafemi Ayodeji, Adebiyi, Janet Adeyinka
- Authors: Sobowale, Sunday Samuel , Adebo, Oluwafemi Ayodeji , Adebiyi, Janet Adeyinka
- Date: 2017
- Subjects: Extrusion , Twin screw extruder , Design
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/262072 , uj:27666 , Citation: Sobowale, S.S., Adebo, O.A. & Adebiyi, J.A. 2017. Development of a twin screw extruder. Agricultural Engineering International: CIGR Journal, 19(4): 181–186.
- Description: Abstract: The aim of this study was to design, construct a multi-purpose twin screw extruder and evaluate its performance. All parts of the extruder were constructed using locally available materials and was made suitable for both batch and continuous production. The extruder essentially consists of the hopper, barrel, variable screw speed and temperature control, electrical motor and replaceable dies to give different sizes and shapes in the final products. It could also handle feed materials of different rheology. Performance evaluation of the extruder was done using cocoyam flour, varying feed moisture content (FMC) and screw speed (SS). Both the FMC and SS were observed to significantly affect all performance indicators (expansion ratio, residence time, throughput and functional efficiency) of the extrusion process. The availability and efficient access to this equipment would encourage the development of locally made extruded products. Through effective utilization, it is expected that the extruder would expand the production and processing of extruded foods.
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- Authors: Sobowale, Sunday Samuel , Adebo, Oluwafemi Ayodeji , Adebiyi, Janet Adeyinka
- Date: 2017
- Subjects: Extrusion , Twin screw extruder , Design
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/262072 , uj:27666 , Citation: Sobowale, S.S., Adebo, O.A. & Adebiyi, J.A. 2017. Development of a twin screw extruder. Agricultural Engineering International: CIGR Journal, 19(4): 181–186.
- Description: Abstract: The aim of this study was to design, construct a multi-purpose twin screw extruder and evaluate its performance. All parts of the extruder were constructed using locally available materials and was made suitable for both batch and continuous production. The extruder essentially consists of the hopper, barrel, variable screw speed and temperature control, electrical motor and replaceable dies to give different sizes and shapes in the final products. It could also handle feed materials of different rheology. Performance evaluation of the extruder was done using cocoyam flour, varying feed moisture content (FMC) and screw speed (SS). Both the FMC and SS were observed to significantly affect all performance indicators (expansion ratio, residence time, throughput and functional efficiency) of the extrusion process. The availability and efficient access to this equipment would encourage the development of locally made extruded products. Through effective utilization, it is expected that the extruder would expand the production and processing of extruded foods.
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Process optimization of extrusion variables and its effect on properties of extruded cocoyam (Xanthosoma sagittifolium) noodles
- Sobowale, Sunday Samuel, Animashaun, Oluwatoyin Habibat, Antoine Mulaba-Bafubiandi, Floribert, Abidoye, Temitope Saratallahi, Kewuyemi, Yusuf Olamide, Adebo, Oluwafemi Ayodeji
- Authors: Sobowale, Sunday Samuel , Animashaun, Oluwatoyin Habibat , Antoine Mulaba-Bafubiandi, Floribert , Abidoye, Temitope Saratallahi , Kewuyemi, Yusuf Olamide , Adebo, Oluwafemi Ayodeji
- Date: 2018
- Subjects: Cocoyam , Extrusion , Noodles
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/286596 , uj:31013 , Citation: Sobowale, S.S. et al. 2018. Process optimization of extrusion variables and its effect on properties of extruded cocoyam (Xanthosoma sagittifolium) noodles. Food Science & Nutrition. DOI: 10.1002/fsn3.786
- Description: Abstract: The current industrial demand for starchy foods has been dominated by other roots and tubers, while cocoyam, despite being rich in fiber, minerals, and vitamins has remained under exploited. In this study, the effect of feed moisture content (FMC), screw speed (SS) and barrel temperature (BT) on the quality characteristics of cocoyam noodles (proximate, thermo-physical, physicochemical, texture, color, extrudate properties, and sensory characteristics) were investigated using central composite design (CCD) of response surface methodology (RSM). Flour was produced from fresh tubers of cocoyam (Xanthosoma sagittifolium) and subsequently processed into noodles using a twin screw extruder. Results showed that the proximate compositions, thermo-physical, physicochemical properties, and color of the cocoyam noodles were significantly (p < 0.05) influenced by the extrusion process variables. The texture and extrudate properties of cocoyam noodles were equally significantly (p < 0.05) different. The experimental data obtained and predicted values of the response models were comparable, with statistical indices [absolute average deviation (AAD, 0–0.23), bias factor (Bf, 1–1.08), and accuracy factor (Af, 1–1.23)] indicating the validity of the derived models. The optimal extrusion processing conditions for quality cocoyam noodles were FMC, SS, and BT of 47.5%, 700 rpm and 50°C, respectively, as cocoyam noodles obtained at these conditions had comparable properties and were most preferred and accepted by the sensory panelists.
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- Authors: Sobowale, Sunday Samuel , Animashaun, Oluwatoyin Habibat , Antoine Mulaba-Bafubiandi, Floribert , Abidoye, Temitope Saratallahi , Kewuyemi, Yusuf Olamide , Adebo, Oluwafemi Ayodeji
- Date: 2018
- Subjects: Cocoyam , Extrusion , Noodles
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/286596 , uj:31013 , Citation: Sobowale, S.S. et al. 2018. Process optimization of extrusion variables and its effect on properties of extruded cocoyam (Xanthosoma sagittifolium) noodles. Food Science & Nutrition. DOI: 10.1002/fsn3.786
- Description: Abstract: The current industrial demand for starchy foods has been dominated by other roots and tubers, while cocoyam, despite being rich in fiber, minerals, and vitamins has remained under exploited. In this study, the effect of feed moisture content (FMC), screw speed (SS) and barrel temperature (BT) on the quality characteristics of cocoyam noodles (proximate, thermo-physical, physicochemical, texture, color, extrudate properties, and sensory characteristics) were investigated using central composite design (CCD) of response surface methodology (RSM). Flour was produced from fresh tubers of cocoyam (Xanthosoma sagittifolium) and subsequently processed into noodles using a twin screw extruder. Results showed that the proximate compositions, thermo-physical, physicochemical properties, and color of the cocoyam noodles were significantly (p < 0.05) influenced by the extrusion process variables. The texture and extrudate properties of cocoyam noodles were equally significantly (p < 0.05) different. The experimental data obtained and predicted values of the response models were comparable, with statistical indices [absolute average deviation (AAD, 0–0.23), bias factor (Bf, 1–1.08), and accuracy factor (Af, 1–1.23)] indicating the validity of the derived models. The optimal extrusion processing conditions for quality cocoyam noodles were FMC, SS, and BT of 47.5%, 700 rpm and 50°C, respectively, as cocoyam noodles obtained at these conditions had comparable properties and were most preferred and accepted by the sensory panelists.
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