Ayobamitale Adebiyi | Ladoke Akintola University of Technology (original) (raw)

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Papers by Ayobamitale Adebiyi

Research paper thumbnail of Purification and characterization of antioxidative peptides derived from rice bran protein hydrolysates

AbstractsRice bran protein fraction (RBPF)—albumin, globulin, glutelin and prolamin were hydrolyz... more AbstractsRice bran protein fraction (RBPF)—albumin, globulin, glutelin and prolamin were hydrolyzed with proteases M, N, P, S and pepsin under their optimal conditions for 24 h. Hydrolysates of various hydrolysis periods were collected and subjected to peptide mapping and the antioxidative activity measured by the 2,2-Azino-bis-3-ethylbenzothiazoline-6-sulfonic Acid (ABTS) method. Protease M hydrolysates showed high degree of hydrolysis (DH), but low antioxidative activity. On the contrary, pepsin hydrolysates showed low DH with high activity. Albumin and globulin hydrolysates had higher DH values, but lower values for glutelin and prolamin. The globulin hydrolysate (Opep2) from 2 h-pepsin hydrolysis was separated by using three consecutive purification steps with RP-HPLC. Nineteen antioxidative peptides were isolated and their amino acid sequences were determined by a gas-phase protein sequencer and MALDI-TOF mass spectrometry. These peptides were composed of 6–30 amino acid residu...

Research paper thumbnail of Determination of the growth rate and volume of lipid produced by Lipomyces species isolated from shear butter leaf (Vitellaria paradoxa)

African Journal of Biotechnology, 2007

A Lipomyces strains was isolated from shear butter leaf (Vitellaria paradoxa) by placing the leaf... more A Lipomyces strains was isolated from shear butter leaf (Vitellaria paradoxa) by placing the leaf sample in 10 ml of sterile distilled water containing 0.002 g of potassium dihydrogen phosphate and incubated for 3 days at 28oC. A drop of this was subsequently streaked nitrogen free medium. For determination of growth rate and volume of lipid produced, 24 h culture of the Lipomyces species isolated was washed into each of the following medium: yeast extract both (YE), nitrogen free broth (NF), maize broth free of salts (MF), maize broth with salts (MB), sorghum broth with salts (SB) and sorghum broth free of salts (SF). These were incubated for 7 days at 28oC on a shaker, and the lipid produced was extracted by using diethyl ether. The Lipomyces species was found to be able to grow and produce lipid more efficiently in yeast extract broth than in other medium used. The organism produced 25 ml of lipid per 8 g of glucose in yeast extract broth.

Research paper thumbnail of Biological studies on albino rats fed with Sorghum bicolor starch hydrolyzed with a-amylase from Rhizopus sp

African Journal of Biotechnology, 2008

Partially purified amylase was extracted from the culture medium of Rhizopus sp. grown in potato ... more Partially purified amylase was extracted from the culture medium of Rhizopus sp. grown in potato dextrose broth for 48 h at room temperature by precipitation with 96.9% ethanol. The enzyme was used to hydrolyze sorghum starch. The hydrolyzed product was afterwards formulated into rat feed, which was fed to albino rats for a period of thirty days. The average daily body weight of the albino rats fed with hydrolyzed formulated feed on the 30th day of the experiment was 131 g while the values recorded for the groups fed with unhydrolyzed and commercial feed were 120 and 97.4 grams respectively. The hematological analysis revealed that the packed cell volume (PCV), Hemoglobin (Hb), red blood cells (RBC), mean cell hemoglobin concentration (MCHC) of the group fed with hydrolyzed formulated feed of 51.8%, 16.9 g/dl, 8.7 × 10 5 µl-1 and 32.7%, respectively, were higher than the experimental animals fed with commercial feed with values of 44.2%, 14.4 g/dl, 7.7 × 10 5 µl-1 and 32.3%, respectively. The histopathological results shows that there were no lesion present in both the liver and the kidney of the albino rats fed with commercial feeds while lesions were observed in both the liver of the albino rats fed with hydrolyzed formulated feed and unhydrolyzed formulated feed.

Research paper thumbnail of The Effect of pH and Chemical Preservatives on the Growth of Bacterial Isolates from Some Nigerian Packaged Fruit Juices

Pakistan Journal of Nutrition, 2009

Research paper thumbnail of Rice bran protein-based edible films

International Journal of Food Science & Technology, 2008

The development of degradable and edible films from protein sources has drawn significant attenti... more The development of degradable and edible films from protein sources has drawn significant attention for the utilisation of natural resources as well as for the alleviation of the environmental burden. Rice bran protein (RBP) was applied to protein film preparation in this study. The protein solutions were casted on plastic tissue culture dishes with glycerol as a plasticiser after heat treatment. Functional properties of the films were then measured. The puncture strength (PS) of RBP films increased up to pH 8.0 and then decreased. PS of protein films depends on the degree of protein purity, quality and composition. Higher concentration of glycerol weakened the films. The pH affected the water solubility of RBP films and the films showed least solubility at pH 3.0. RBP could be utilised in the preparation of degradable protein-based films. The RBPbased film had functional properties comparable to those of the soy protein-based ones.

Research paper thumbnail of Isolation and characterization of protein fractions from deoiled rice bran

European Food Research and Technology, 2008

Rice bran contains underutilised protein materials. Sequential extraction of rice bran protein (R... more Rice bran contains underutilised protein materials. Sequential extraction of rice bran protein (RBP) from defatted rice bran was conducted based on the diVerences in their solubility. Three extraction methods were investigated. Method 1 involved the isoelectric and acetone precipitation using water, 50 g kg ¡1 NaCl, 0.02 mol L ¡1 NaOH and 70% ethanol as extracting solvents for albumin (pH 4.1), globulin (pH 4.3), glutelin (pH 4.8) and prolamin, respectively. Method 2 adopted dialysis and sequential extraction was carried out with 20 g kg ¡1 NaCl, 70% ethanol, 0.1 mol L ¡1 acetic acid and 0.1 mol L ¡1 NaOH solution as extracting solvents. Method 3 combined dialysis, isoelectric and acetone precipitation for the extraction. Based on the yields and data obtained from sodium dodecyl sulphate polyacrylamide gel electrophoresis, size-exclusion chromatography and diVerential scanning calorimetry, method 3 was chosen for the isolation and characterization of RBPs. Rice bran protein fraction (RBPF)-albumin, globulin, glutelin and prolamin were obtained in good yields. Denaturation temperature and enthalpy values of denaturation of RBPF vary. Highest phytate content was found in albumin and lowest in prolamin. The highest antioxidative and hemagglutinating activities were observed in albumin.

Research paper thumbnail of Short Communication - The phytochemical analysis and antimicrobial screening of extracts of Olax subscorpioidea

AFRICAN JOURNAL OF BIOTECHNOLOGY

The antimicrobial activities of the aqueous and ethanoic extracts of the stem of Olax subscorpioi... more The antimicrobial activities of the aqueous and ethanoic extracts of the stem of Olax subscorpioidea were evaluated. The ethanoic extract showed considerable activity on both the fungi and bacteria with zones of inhibition ranging from 7.2 mm to 21.5 mm, with minimum inhibitory concentrations ranging from 5 to 45 mg/ml, while the aqueous extract was only active against three of the test organisms used. Phytochemical test reveals the presence of alkaloids, steroids, and flavonoids together with other active ingredients in the ethanoic extract with the exception of saponins which is present in the aqueous extract alone.

Research paper thumbnail of Purification and characterization of antioxidative peptides derived from rice bran protein hydrolysates

AbstractsRice bran protein fraction (RBPF)—albumin, globulin, glutelin and prolamin were hydrolyz... more AbstractsRice bran protein fraction (RBPF)—albumin, globulin, glutelin and prolamin were hydrolyzed with proteases M, N, P, S and pepsin under their optimal conditions for 24 h. Hydrolysates of various hydrolysis periods were collected and subjected to peptide mapping and the antioxidative activity measured by the 2,2-Azino-bis-3-ethylbenzothiazoline-6-sulfonic Acid (ABTS) method. Protease M hydrolysates showed high degree of hydrolysis (DH), but low antioxidative activity. On the contrary, pepsin hydrolysates showed low DH with high activity. Albumin and globulin hydrolysates had higher DH values, but lower values for glutelin and prolamin. The globulin hydrolysate (Opep2) from 2 h-pepsin hydrolysis was separated by using three consecutive purification steps with RP-HPLC. Nineteen antioxidative peptides were isolated and their amino acid sequences were determined by a gas-phase protein sequencer and MALDI-TOF mass spectrometry. These peptides were composed of 6–30 amino acid residu...

Research paper thumbnail of Determination of the growth rate and volume of lipid produced by Lipomyces species isolated from shear butter leaf (Vitellaria paradoxa)

African Journal of Biotechnology, 2007

A Lipomyces strains was isolated from shear butter leaf (Vitellaria paradoxa) by placing the leaf... more A Lipomyces strains was isolated from shear butter leaf (Vitellaria paradoxa) by placing the leaf sample in 10 ml of sterile distilled water containing 0.002 g of potassium dihydrogen phosphate and incubated for 3 days at 28oC. A drop of this was subsequently streaked nitrogen free medium. For determination of growth rate and volume of lipid produced, 24 h culture of the Lipomyces species isolated was washed into each of the following medium: yeast extract both (YE), nitrogen free broth (NF), maize broth free of salts (MF), maize broth with salts (MB), sorghum broth with salts (SB) and sorghum broth free of salts (SF). These were incubated for 7 days at 28oC on a shaker, and the lipid produced was extracted by using diethyl ether. The Lipomyces species was found to be able to grow and produce lipid more efficiently in yeast extract broth than in other medium used. The organism produced 25 ml of lipid per 8 g of glucose in yeast extract broth.

Research paper thumbnail of Biological studies on albino rats fed with Sorghum bicolor starch hydrolyzed with a-amylase from Rhizopus sp

African Journal of Biotechnology, 2008

Partially purified amylase was extracted from the culture medium of Rhizopus sp. grown in potato ... more Partially purified amylase was extracted from the culture medium of Rhizopus sp. grown in potato dextrose broth for 48 h at room temperature by precipitation with 96.9% ethanol. The enzyme was used to hydrolyze sorghum starch. The hydrolyzed product was afterwards formulated into rat feed, which was fed to albino rats for a period of thirty days. The average daily body weight of the albino rats fed with hydrolyzed formulated feed on the 30th day of the experiment was 131 g while the values recorded for the groups fed with unhydrolyzed and commercial feed were 120 and 97.4 grams respectively. The hematological analysis revealed that the packed cell volume (PCV), Hemoglobin (Hb), red blood cells (RBC), mean cell hemoglobin concentration (MCHC) of the group fed with hydrolyzed formulated feed of 51.8%, 16.9 g/dl, 8.7 × 10 5 µl-1 and 32.7%, respectively, were higher than the experimental animals fed with commercial feed with values of 44.2%, 14.4 g/dl, 7.7 × 10 5 µl-1 and 32.3%, respectively. The histopathological results shows that there were no lesion present in both the liver and the kidney of the albino rats fed with commercial feeds while lesions were observed in both the liver of the albino rats fed with hydrolyzed formulated feed and unhydrolyzed formulated feed.

Research paper thumbnail of The Effect of pH and Chemical Preservatives on the Growth of Bacterial Isolates from Some Nigerian Packaged Fruit Juices

Pakistan Journal of Nutrition, 2009

Research paper thumbnail of Rice bran protein-based edible films

International Journal of Food Science & Technology, 2008

The development of degradable and edible films from protein sources has drawn significant attenti... more The development of degradable and edible films from protein sources has drawn significant attention for the utilisation of natural resources as well as for the alleviation of the environmental burden. Rice bran protein (RBP) was applied to protein film preparation in this study. The protein solutions were casted on plastic tissue culture dishes with glycerol as a plasticiser after heat treatment. Functional properties of the films were then measured. The puncture strength (PS) of RBP films increased up to pH 8.0 and then decreased. PS of protein films depends on the degree of protein purity, quality and composition. Higher concentration of glycerol weakened the films. The pH affected the water solubility of RBP films and the films showed least solubility at pH 3.0. RBP could be utilised in the preparation of degradable protein-based films. The RBPbased film had functional properties comparable to those of the soy protein-based ones.

Research paper thumbnail of Isolation and characterization of protein fractions from deoiled rice bran

European Food Research and Technology, 2008

Rice bran contains underutilised protein materials. Sequential extraction of rice bran protein (R... more Rice bran contains underutilised protein materials. Sequential extraction of rice bran protein (RBP) from defatted rice bran was conducted based on the diVerences in their solubility. Three extraction methods were investigated. Method 1 involved the isoelectric and acetone precipitation using water, 50 g kg ¡1 NaCl, 0.02 mol L ¡1 NaOH and 70% ethanol as extracting solvents for albumin (pH 4.1), globulin (pH 4.3), glutelin (pH 4.8) and prolamin, respectively. Method 2 adopted dialysis and sequential extraction was carried out with 20 g kg ¡1 NaCl, 70% ethanol, 0.1 mol L ¡1 acetic acid and 0.1 mol L ¡1 NaOH solution as extracting solvents. Method 3 combined dialysis, isoelectric and acetone precipitation for the extraction. Based on the yields and data obtained from sodium dodecyl sulphate polyacrylamide gel electrophoresis, size-exclusion chromatography and diVerential scanning calorimetry, method 3 was chosen for the isolation and characterization of RBPs. Rice bran protein fraction (RBPF)-albumin, globulin, glutelin and prolamin were obtained in good yields. Denaturation temperature and enthalpy values of denaturation of RBPF vary. Highest phytate content was found in albumin and lowest in prolamin. The highest antioxidative and hemagglutinating activities were observed in albumin.

Research paper thumbnail of Short Communication - The phytochemical analysis and antimicrobial screening of extracts of Olax subscorpioidea

AFRICAN JOURNAL OF BIOTECHNOLOGY

The antimicrobial activities of the aqueous and ethanoic extracts of the stem of Olax subscorpioi... more The antimicrobial activities of the aqueous and ethanoic extracts of the stem of Olax subscorpioidea were evaluated. The ethanoic extract showed considerable activity on both the fungi and bacteria with zones of inhibition ranging from 7.2 mm to 21.5 mm, with minimum inhibitory concentrations ranging from 5 to 45 mg/ml, while the aqueous extract was only active against three of the test organisms used. Phytochemical test reveals the presence of alkaloids, steroids, and flavonoids together with other active ingredients in the ethanoic extract with the exception of saponins which is present in the aqueous extract alone.