Department of Food Science & Technology
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- ItemOpen AccessA Biochemist's Adventure into the Processing and Preservation of Foods(Obafemi Awolowo University Press, 2000-06-27) Ogunsua, A.O.Several workers in these institutions carried out investigations aimed at incorporating cassava starch into bread. With cassava starch this does not present a serious problem, but bread qualities deteriorate with the addition of about 10% cassava flour. Cassava flour differs from cassava starch in that it contains other constituents besides starch. We therefore, studied the factor affecting the use of cassava flour in bread. There are several different methods of bread making but three of these are mainly used throughout the world, Bulk Fermentation Process (BFP), Mechanical Dough Development (MOD) process and Activated Dough Development (ADD) process. Wheat flour contains an unusual protein called gluten. On hydration it becomes elastic during dough development and that is why it retains gas during fermentation and baking. In the bulk, fermentation process, it is carbon dioxide generated during fermentation that develops the dough. In MOD, an intense mixing energy is put into the dough - 5
- ItemOpen AccessThe Development, Construction and Evaluation of a Micro-spray Dryer(Obafemi Awolowo University, 1985) Anjorin, Mojisola Oluyemisi; J., WypychA co-current laboratory spray dryer was designed to meet multipurpose requirements for drying food materials and constructed from relatively cheap locally available materials. Tests, on the basis of 100% moisture were carried out to characterise the equipment and milk was dried to determine the particle size distribution. The dryer efficiency at optimum conditions, varied between 44.7%-59.7% and the average particle size was 10ym - 20um. The highest temperature of the air possible for drying was 413K while the lowest was 355K and the maximum air flow rate in the chamber was 31 litres/minute. The drying rate was 0.65g/min and, the maximum relative humidity of the outgoing air at the minimum temperature was 96%.
- ItemOpen AccessDiet, Nutrition and Chronic Diseases: What You Eat is What You Get(Obafemi Awolowo University Press, 2007-03-13) Adelekan, Delana A.It is generally believed that man has 3 basic needs.viz: food, shelter and, clothing. The most important of these is unarguably food as humans can J I) survive for only a few weeks without food whereas there are millions of .people in the world without clothing and shelter who nonetheless survive into old age. Health is influenced by a variety of factors - environmental, . social and mental. One key environmental factor which is important in the . promotion and maintenance of good health throughout the entire life course is diet. Diet plays a key role in the prevention of chronic diseases. It is a matter for regret however that despite the importance of diet in the promotion and maintenance of health most individuals in both developed and developing countries pay very little attention to their diet with very . serious consequences for their health. There is increasing scientific evidence supporting the view that alterations in diet have strong effects, both positive and negative, on health throughout life. Most importantly, nutritional insults inflicted on an individual early in life have been shown to determine whether or not an individual will develop such chronic diseases as cardiovascular disease, cancer and diabetes much later in life (Barker's Hypothesis- Fetal origin of adult diseases )(Barker, 1995). The risk factors for chronic diseases begin to accumulate right from foetal life and become pronounced in adulthood.
- ItemOpen AccessEffect of Maize Fermentation on Some Physico-Chemical Properties of 'Ógi'.(Obafemi Awolowo University, 1985) Beckley, Olufela; Adeyemi, I. A.The effect of fermentation or souring period on some physico-chemical properties of ogi, manufactured by the wet- and dry-milling processes from downy mildew resistant white maize variety (DMR white) were evaluated. Determinations were carried out for titratable acidity, starch, diastatic activity, damaged starch, reducing and non-reducing sugars, liquefaction number, Brabender amylograph pasting characteristics and Adam's consistometer value. The results showed that titratable acidity increased from 0.18% to 0.37% lactic acid, while starch content was reduced from 89.2 to 70.5% with period of fermentation, although souring did not produce any appreciable change in starch content. Similarly, there was no appreciable change in diastatic activity, damaged starch and reducing and non-reducing sugars, except for samples fermented or soured for six days. Amylograph peak viscosity was higher for wet-milled ogi than dry-milled ogi being in the range of 1030 to 1250 B.U. and 210 to 960 B.U. respectively. Peak viscosity was observed to increase with souring period of maize flour. Set-back value, index of gelatinization and Adam's consistometer value were observed to decrease with either fermentation or souring period. The use of souring water in preparing ogi porridge, appreciably increased its titratable acidity, but produced ogi of poorer pasting viscosity.
- ItemOpen AccessExtrusion Characteristics of Cereal and Legume Flours.(Obafemi Awolowo University, 1985) Akinjayeju, Oluwole; Onayemi, O.Some physical factors that determine the extrusion characteristics of cereal-legume blends were examined. These were particle size, substitution level and type of legumes. Corn (Zea mays L.), Cowpea (Vigna unguiculata) and Winged beans ( Psophocar tetragonolobus L.) of three particle sizes namely flour (<:425 microns), grits (>425 microns, <600 microns) and coarser grits (>600 microns,< 850 microns) were used. Blends containing 10% and 20% of each legume with the respective corn fraction were prepared and analysed for proximate composition, water absorption capacity, pasting (cooking) characteristics and viscosity. Addition of legumes increased the nutritional composition of corn-meal with more increases in corn-winged bean than corn-cowpea blends. Winged bean produced greater adverse effects on viscosity and pasting characteristics of corn-legume blends than did cowpea. Statistical analysis showed that the type of legume had the greatest effect on most of the characteristics examined while substitution level produced the least effect. The CWBF (80:20), CWBG 600 (80:20) and CBG 600 (80:20) blends would most probably give the best extruded products since these blends would be able to withstand extrusion conditions of high shear and pressure. The CWBF (80:20), CWBG 600 (80:20) and CBG 600 (80:20) blends would most probably give the best extruded products since these blends would be able to withstand extrusion conditions of high shear and pressure.
- ItemOpen AccessInfluence of Yeast Strains on the Quality of Sorghum Beer.(Obafemi Awolowo University, 1987) Ogunyemi, Toyin Oluyemisi; Abiose, S.Studies were carried out on the influence of two commercial yeasts and palm wine yeast isolate (Saccharomyces cerevisiae) on the quality of sorghum beer. One of the two commercial yeasts was obtained from Africana Brewery, Ibadan and the other was a Bavarian bottom fermenting yeast purchased from host Germany. The sorghum wart samples were fermented at selected temperatures of 9°C, 15°C and 15°C /9°C (alternating both 15°C and 9°C) for 6, 4, 5 days respectively. The sorghum beer samples were evaluated for pH, acidity, alcohol content, sugar and protein content. The specific gravity of the samples and the yeast count of each culture were also monitored daily. Organoleptic tests were also carried out on the finished products. The results indicated that the different temperatures employed, produced differences in the levels of alcohol content, unfermented carbohydrate, protein, acidity and overall flavour of the products. The two commercial yeasts were observed to utilize more sugars and to produce more alcohol than palm wine yeast. The Africana brewery yeast particularly utilized the highest amount of sugar at all the throe temperatures and produced the highest percent alcohol at 9°C and 15°C while at 15°C /9°C, the Bavarian yeast produced the highest amount of 6.8% alcohol. The result obtained from the protein analysis of the final beer; samples showed that beer of better stability can obtained at 15o C and 15°C /9°C. The pH values of the beer samples ranged between 3.95 and 4.20. At 15°C and 15/9o C the palm wine yeast produced the lowest pH values of 3.95 and 4.05 respectively. It also produced' the highest amount of titratable acidity at the three temperatures. The quality evaluation of flavour, taste and acceptability of the finished products indicated that the palm wine yeast cave products of highest quality. This shows that the use of palm wine isolate may produce beer of acceptable quality.
- ItemOpen AccessAn Investigation into the Keeping Quality of “Agidi”.(Obafemi Awolowo University, 1986) Oluwamukomi, Mathew Olusola; Adeyemi, I. A.The effect of storage time and temperature, souring period, surfactant and packaging materials on the keeping quality of Agidi was investigated. Changes in quality were evaluated by determining the moisture content, syneresis, iodine blue value, acidity and pH. The gel strength, microbial load and the sensory qualities were also determined. The results showed that moisture content of Agidi decreased while syneresis increased with storage time. With increase in storage period, the gel strength of Agidi also increased up to a maximum value and later decreased for samples stored at 28oC and 50°C. There was an increase in acidity value and a corresponding decrease in pH for agidi samples stored at 28°C. Agidi prepared from 4 day soured ogi had a higher syneresis value and a faster staling rate than that prepared from a 2 day soured ogi. The use of surfactant resulted in an increase in initial gel strength of Agidi wrapped in Leaves but with relatively no effect on canned Agidi. The total microbial load also increased with increase in storage temperature, the counts obtained being 750,000/g at 28°C and 2,484,000/g at 50°C after 9 days storage for Agidi wrapped in Leaves. Corresponding counts for canned samples were 2000/g and 6000/g respectively after 8 weeks of storage. Sensory observation showed that Agidi wrapped in Leaves, PVC and Aluminium foil had shelf life of 6, 9 and 16 days respectively while canned Agidi maintained its quality throughout the 8 weeks of storage period.
- ItemOpen AccessInvestigations into the Textural Characteristics of Agidi (A Fermented Corn Meal).(Obafemi Awolowo University, 1986) Osungbaro, Taiwo Olujide; Adeyemi, I. A.The effect of particle size, maize variety, fermentation periods and methods of milling on textural properties of 'agidi' was investigated. Textural properties were evaluated, using the Brabender Amylograph, Gel tester, and sensory evaluation. The data obtained showed that 'agidi' manufactured from wet-milled ogi of 4 425 pm particle sizes exhibited the highest gel strength while that from the dry-milled ogi of .0 600 pm particle size fractions recorded the highest gel strength. Of the five maize varieties investigated, FARZ-27 had the best gelling characteristics for 'agidi' manufacture, while FARZ-34, recorded the lowest gel strength and kewesoke recorded the lowest stability and setback values. 'Agidi' from wet-milled ogi fermented for 4 days recorded the highest gel strength, peak viscosity and index of gelatinisation values. While the dry-milled ogi soured for 2 days recorded the highest values for the above parameters. Gel tester results were highly correlated with sensory evaluation for 'agidi' samples of the same particle size manufactured either from different maize varieties or subjected to different days of fermentation.
- ItemOpen AccessNot by Bread Alone(Obafemi Awolowo University Press, 1971-11-30) Howat, G. R.The growth in the consumption of bread, in the past ten years is associated with its convenience both in urban and in rural conditions. Bread is in fact the prime example of the silent revolution in eating habits that is now in progress in Nigeria. You can buy bread-wrapped bread, too, which is a hygiene plus-over the whole of Nigeria. It is now a regular item of diet of the urban dweller whether in the North or in the sophisticated South. It is eaten by children, by lorry drivers, by nursing mothers, by labourers, by students, indeed the entire range of social classes. Its convenience, its keeping ability ("shelf life" to the food technologist) and its relative cheapness have enabled it to become big business. The figures speak for themselves. In 1965, the value of the imports of wheat and wheat flour and similar products amounted to just over £3.5 million. By 1970, they had increased to £7,979,000, more than one hundred percent. No precise figures are available to indicate how much of this import goes into the baking of bread by professional bakers. One has to bear in mind that there is now a sizeable industry in biscuit production and that domestic and professional catering absorb a significant quantity. If we assume that the bread baking industry accounts for about eighty percent of the total wheat imports this means that for 1970, £6.4 million was used to import flour for bread-making. By any standard that is a lot of foreign currency for one item of food. It is indeed the largest single food import and on the evidence of the past ten years it is likely to become larger still. In such a situation it is inevitable that the minds of food technologists and of statesmen should turn towards import substitution programmes.
- ItemOpen AccessNutritional Evaluation of a Fortified Maize Weaning Food.(Obafemi Awolowo University, 1987) Komolafe, Abiola; Adeyemi, I. A.Nutritional evaluation was carried out on pregrelatinized maize flour blended with undefatted soy bean flour at 20, 32, 40 and 50% levels. The samples were evaluated for proximate composition, pepsin digestibility and mineral analysis for phosphorus, calcium and iron contents. The data were compared with values for Ogi, Soy-Ogi and Cerelac. Rat feeding experiments were also carried out on pregelatinidec maize flour fortified with soybean flour (at 30% Level), and cerelac. Protein content and pepsin digestibility Values: for fortified gelatinized maize flour samples found to range from 12 to 19% and 82 to 86% respectively. The corresponding values for Ogi, Soy-Ogi and cerelac were 7.06, 11.70 and 16.09% and 70.52, 78.73 and 91.55% respectively. Phosphorus contents of the pregrelatinized maize flour, 30% fortified maize flour, Ogi, Soy-ogi and cerelac were 280, 265, 200, 285 and 285mg/100g respectively. The corresponding values for calcium were 0.5, 56.5, 4.2, 205.3 and 352.5mg/100g respectively, while the values were 1.8, 3.1, 1.5, 5.6 and 6.8mg/100g respectively for iron. From rat feeding experiments, Protein Efficiency Ratio (PER), Net Protein Utilization (NPU) and Biological Value (BV) were1.14, 55.05% and 0.62 respectively for fortified maize flour while cerelac had corresponding values of 1.99, 71.09% and 0.83 respectively. It was apparent from the results obtained that pregelatinized maize flour fortified at 30% level with undefatted soybean flour could be nutritionally adequate as a weaning food.
- ItemOpen AccessStudies on Some Aspects of Oil and Protein Content of Conophor Nut (Tetracarpidium Conophorum)(2015-09-30) Gbadamosi, Saka OlasunkanmiThe functional properties, solubility profile, in vitro digestibility and antioxidant properties of Tetracarpidium conophorum (conophor nut) were studied. The storage stability and thermal oxidative changes of its oil were also evaluated with a view to increasing the underutilized nut as food ingredient. A portion of fresh conophor nuts was processed to obtain defatted flour, concentrate and isolate by a combination of solvent extraction, isoelectric precipitation, and lyophilization. The flour, protein concentrate and isolate were then subjected to chemical analyses using standard methods. Crude and purified oils were also obtained from another portion of the nuts subjected to cooking, shelling, drying, milling and solvent extraction. Samples of crude and purified oils were stored at ambient and refrigeration temperatures and the acid value, peroxide value, p-anisidine value and fatty acids composition were monitored as indices of oxidation. Thermal oxidative changes of conophor oil used for frying plantain slices were evaluated by determining changes in viscosity, colour, conjugated dienes and trienes, peroxide and p-anisidine values. Samples of plantain chips obtained by frying in conophor oils were compared with those obtained when fried in soy oil by sensory evaluation. Data obtained were subjected to appropriate statistical analysis. The results showed that conophor flour, concentrate and isolate exhibited high oil (2.35 - 2.95g oil/g sample) and water (4.03 - 4.88 g water/g sample) absorption capacities but low emulsion (3.00 - 7.50 mL oil/g sample) capacities. The foam capacities for isolate, flour and concentrate were 5, 20 and 27%, respectively. The least gelling concentrations (flour, 8%; concentrate 10%, isolate, 12%) were also low. The most effective conophor protein solubilizer was O.1M NaOH while water and 0.1M potassium phosphate buffer were the least effective protein solubilizers. The protein fractionation revealed that glutelins and globulins accounted for the major proteins of conophor nut. Moist heat and dry heat increased digestibility of conophor nut but moist heat was found to be more effective than dry heat. The total phenolic content was significantly (p < 0.05, LSD) higher in 100% methanolic extract (1.49 g/100 g crude extract) than in 100% acetone extract (0.85 g/100 g crude extract). The methanolic extracts exhibited a high radical scavenging effect (59.85%) compared to value of 44.67% in acetone extracts. Both primary and secondary oxidation products were low at low temperature but were found to be high at elevated storage temperatures. Apart from refractive index which remained almost constant, other physical and chemical characteristics of the oils such as acid value, peroxide value, conjugated dienes and trienes, and p-anisidine value increased with increasing frying sessions. Taste panel analysis showed plantain chips obtained by frying in purified conophor oil were preferred (5.70) to those fried in crude conophor oil (3.10) on 7-point hedonic scale. The study has shown that conophor nut flour, concentrate and isolate are useful as ingredient in food formulation.