Tadesse F.Yehuala | Bahir Dar University (original) (raw)
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Papers by Tadesse F.Yehuala
Traditional fermentation using natural microorganisms often results in uncontrolled and inconsist... more Traditional fermentation using natural microorganisms often results in uncontrolled and inconsistent product quality. Identifying dominant LAB and yeast species through morphological, physiological, and biochemical characterization, this study aimed to optimize the traditional fermentation process of injera dough fermentation. Ersho and dough were prepared in the laboratory, and LAB and yeast were identified and enumerated by smearing on a petri dish at 24-hour intervals from 0 to 96 hours of fermentation. The growth kinetics of both LAB and yeast in fermented teff dough significantly increased (p < 0.05) from 8.91 to 9.97 log CFU/gm and 5.98 to 7.62 log CFU/gm as fermentation time increased. Five dominant LAB species (Lactobacillus fermentum, Lactobacillus Brevis, Lactobacillus Plantarum, Bacillus subtilis, and Enterococcus casseliflavus) and three dominant yeast strains (Saccharomyces cerevisiae, Candida krusei, and Pichia kudriavzevii) were identified. Based on the physicochemical analysis and sensory acceptability result, application of a single starter culture in teff dough fermentation improved fermentation time and acid production.
Drying is the oldest method of food preservation. However, the drying method can adversely affect... more Drying is the oldest method of food preservation. However, the drying method can adversely affect product quality. The present work aims to measure the texture, color, vitamin C and β-carotene content of solar, oven and integrated solar-oven drying of apple and kent mango slices. Micro stable texture profile analyzer (TPA), spectrometer and UV-Vis spectrophotometer were used to determine the texture, color, vitamin C and β-carotene content, respectively. The result shows variety had a non-significant effect (p>0.05), while the drying method has a significant effect (p<0.05) on the texture and color values of dried mango slices. The mango slice structure was become harder in texture and darkens in color. Apple (72.38mg/100g, (91.05µg/100g) and kent mango (66.72mg/100g, 73.80µg/100g) showed a significant difference (p<0.05) on their vitamin C and β-carotene content. The loss of vitamin C (58.41mg/100g) and β-carotene (58.60µg/100g), was low in the integrated solar-oven dryer. The loss of vitamin C was high in kent mango than the apple mango, while the β-carotene lost was high in apple mango than the kent mango. This study indicates that the use of integrated solar-oven drying was the preferred drying method to keep vitamin C and β-carotene loss minimum.
This study was examined to optimize extrusion conditions (barrel temperature, feed moisture, and ... more This study was examined to optimize extrusion conditions (barrel temperature, feed moisture, and blending ratios of rice, lupin, and pumpkin flour) during processing high-quality extruded products using a twin-screw extruder. A three-factor with three-level response surface methodology with a Box-Behnken design, was applied to evaluate the effects of selected processing conditions: blending ratios of lupin (10-20 %), barrel temperature (115-155 • C) and feed moisture content (14-20 %) on the functional, nutritional and sensory characteristics of the produced snack food. The independent variables significantly affected the nutritional, functional, and physical properties of the extruded snack food. A higher proportion of lupin showed higher bulk density but lower expansion ratio and water solubility index of the extrudates while higher feed moisture content led to a reduction in expansion ratio and water-soluble index of the extruded snack food. Lupin substitution and pumpkin flour addition significantly increased the protein, crude fiber, ash, fat, β-carotene, iron, and zinc contents of the white rice-lupin-pumpkin extruded snack, whereas the total carbohydrate content was reduced. The sensory evaluation showed that it was possible to incorporate lupin flour up to a certain level without affecting consumer acceptance. A blending ratio of 15 %, feed moisture of 14 %, and barrel temperature of 155 • C produced the extrudate with a desirability value of 0.75.
Mangiferin is a bioactive substance present in high concentration in mangoes and also in some oth... more Mangiferin is a bioactive substance present in high concentration in mangoes and also in some other fruits. Owing to its potential as a chemopreventive and chemotherapeutic agent against several types of cancer, this unique, significant, and well-researched polyphenol has received a lot of attention recently. It possesses the ability to treat cancers, including rectal cancer, prostate cancer, ovarian cancer, leukemia, gastric cancer, liver cancer, chronic pancreatitis, and lung cancer. It can control/regulate multiple key signaling pathways, such as signal transducer and activator of transcription 3 (STAT3), second mitochondria-derived activator of caspases/direct inhibitor of apoptosis (IAP)binding protein with low propidium iodide (pl) (Smac/DIABLO) nuclear factor kappa B (NF-κB), phosphatidylinositol 3 kinase/protein 3 kinase (PI3K/Akt), transforming growth factor beta/suppressor of mothers against decapentaplegic (TGFβ/SMAD), c-jun N-terminal kinase/p38 mitogen-activated protein kinase (JNK/p38-MAPK), and phosphor-I kappa B kinase (p-IκB), which are crucial to the development of cancers. By triggering apoptotic signals and halting the advancement of the cell cycle, it can also while it remains amorphous in some nonpolar liquids like diethyl ether. Its solubility in water is 0.111 mg/mL. Some countries, including Cuba, China, and India, have long grown and actively employed mangiferin-rich plants in conventional medicine to cure a diversity of ailments, for example various infections, diabetes, cardiovascular disease, and cancer . Figure shows the chemical structure of mangiferin. The active ingredient in therapeutic herbs, mangiferin has low hydrophilicity and lipophilicity. It can be characterized as a chemical in class IV (Low Solubility-Low Permeability) of the Biopharmaceutics Classification System (BCS) because of its low water solubility and prevent some cancer cell types from proliferating and developing. It has been revealed that mangiferin targets a variety of adhesion molecules, cytokines, pro-inflammatory transcription factors, kinases, chemokines, growth factors, and cell-cycle proteins. By means of preventing the onset, advancement, and metastasis of cancer, these targets may mediate the chemopreventive and therapeutic effects of mangiferin. Mangiferin has confirmed potential benefits in lung, cervical, breast, brain, and prostate cancers as well as leukemia whether administered alone or in combination with recognized anticancer compounds. More clinical trials and research investigations are required to completely unleash the potential of mangiferin, which may lower the risk of cancer onset and act as a preventive and therapeutic alternative for a number of cancers.
Traditional fermentation using natural microorganisms often results in uncontrolled and inconsist... more Traditional fermentation using natural microorganisms often results in uncontrolled and inconsistent product quality. Identifying dominant LAB and yeast species through morphological, physiological, and biochemical characterization, this study aimed to optimize the traditional fermentation process of injera dough fermentation. Ersho and dough were prepared in the laboratory, and LAB and yeast were identified and enumerated by smearing on a petri dish at 24-hour intervals from 0 to 96 hours of fermentation. The growth kinetics of both LAB and yeast in fermented teff dough significantly increased (p < 0.05) from 8.91 to 9.97 log CFU/gm and 5.98 to 7.62 log CFU/gm as fermentation time increased. Five dominant LAB species (Lactobacillus fermentum, Lactobacillus Brevis, Lactobacillus Plantarum, Bacillus subtilis, and Enterococcus casseliflavus) and three dominant yeast strains (Saccharomyces cerevisiae, Candida krusei, and Pichia kudriavzevii) were identified. Based on the physicochemical analysis and sensory acceptability result, application of a single starter culture in teff dough fermentation improved fermentation time and acid production.
Drying is the oldest method of food preservation. However, the drying method can adversely affect... more Drying is the oldest method of food preservation. However, the drying method can adversely affect product quality. The present work aims to measure the texture, color, vitamin C and β-carotene content of solar, oven and integrated solar-oven drying of apple and kent mango slices. Micro stable texture profile analyzer (TPA), spectrometer and UV-Vis spectrophotometer were used to determine the texture, color, vitamin C and β-carotene content, respectively. The result shows variety had a non-significant effect (p>0.05), while the drying method has a significant effect (p<0.05) on the texture and color values of dried mango slices. The mango slice structure was become harder in texture and darkens in color. Apple (72.38mg/100g, (91.05µg/100g) and kent mango (66.72mg/100g, 73.80µg/100g) showed a significant difference (p<0.05) on their vitamin C and β-carotene content. The loss of vitamin C (58.41mg/100g) and β-carotene (58.60µg/100g), was low in the integrated solar-oven dryer. The loss of vitamin C was high in kent mango than the apple mango, while the β-carotene lost was high in apple mango than the kent mango. This study indicates that the use of integrated solar-oven drying was the preferred drying method to keep vitamin C and β-carotene loss minimum.
This study was examined to optimize extrusion conditions (barrel temperature, feed moisture, and ... more This study was examined to optimize extrusion conditions (barrel temperature, feed moisture, and blending ratios of rice, lupin, and pumpkin flour) during processing high-quality extruded products using a twin-screw extruder. A three-factor with three-level response surface methodology with a Box-Behnken design, was applied to evaluate the effects of selected processing conditions: blending ratios of lupin (10-20 %), barrel temperature (115-155 • C) and feed moisture content (14-20 %) on the functional, nutritional and sensory characteristics of the produced snack food. The independent variables significantly affected the nutritional, functional, and physical properties of the extruded snack food. A higher proportion of lupin showed higher bulk density but lower expansion ratio and water solubility index of the extrudates while higher feed moisture content led to a reduction in expansion ratio and water-soluble index of the extruded snack food. Lupin substitution and pumpkin flour addition significantly increased the protein, crude fiber, ash, fat, β-carotene, iron, and zinc contents of the white rice-lupin-pumpkin extruded snack, whereas the total carbohydrate content was reduced. The sensory evaluation showed that it was possible to incorporate lupin flour up to a certain level without affecting consumer acceptance. A blending ratio of 15 %, feed moisture of 14 %, and barrel temperature of 155 • C produced the extrudate with a desirability value of 0.75.
Mangiferin is a bioactive substance present in high concentration in mangoes and also in some oth... more Mangiferin is a bioactive substance present in high concentration in mangoes and also in some other fruits. Owing to its potential as a chemopreventive and chemotherapeutic agent against several types of cancer, this unique, significant, and well-researched polyphenol has received a lot of attention recently. It possesses the ability to treat cancers, including rectal cancer, prostate cancer, ovarian cancer, leukemia, gastric cancer, liver cancer, chronic pancreatitis, and lung cancer. It can control/regulate multiple key signaling pathways, such as signal transducer and activator of transcription 3 (STAT3), second mitochondria-derived activator of caspases/direct inhibitor of apoptosis (IAP)binding protein with low propidium iodide (pl) (Smac/DIABLO) nuclear factor kappa B (NF-κB), phosphatidylinositol 3 kinase/protein 3 kinase (PI3K/Akt), transforming growth factor beta/suppressor of mothers against decapentaplegic (TGFβ/SMAD), c-jun N-terminal kinase/p38 mitogen-activated protein kinase (JNK/p38-MAPK), and phosphor-I kappa B kinase (p-IκB), which are crucial to the development of cancers. By triggering apoptotic signals and halting the advancement of the cell cycle, it can also while it remains amorphous in some nonpolar liquids like diethyl ether. Its solubility in water is 0.111 mg/mL. Some countries, including Cuba, China, and India, have long grown and actively employed mangiferin-rich plants in conventional medicine to cure a diversity of ailments, for example various infections, diabetes, cardiovascular disease, and cancer . Figure shows the chemical structure of mangiferin. The active ingredient in therapeutic herbs, mangiferin has low hydrophilicity and lipophilicity. It can be characterized as a chemical in class IV (Low Solubility-Low Permeability) of the Biopharmaceutics Classification System (BCS) because of its low water solubility and prevent some cancer cell types from proliferating and developing. It has been revealed that mangiferin targets a variety of adhesion molecules, cytokines, pro-inflammatory transcription factors, kinases, chemokines, growth factors, and cell-cycle proteins. By means of preventing the onset, advancement, and metastasis of cancer, these targets may mediate the chemopreventive and therapeutic effects of mangiferin. Mangiferin has confirmed potential benefits in lung, cervical, breast, brain, and prostate cancers as well as leukemia whether administered alone or in combination with recognized anticancer compounds. More clinical trials and research investigations are required to completely unleash the potential of mangiferin, which may lower the risk of cancer onset and act as a preventive and therapeutic alternative for a number of cancers.