Authors: O.T. Bolaji | S.O. Awonorin, A.P. Olalusi, M.A. Idowu, F.O. Henshaw and P.A. Adepoju
Advanced journal of food science and technology.Volume: 3; Issue: 2; page: 89; 2011
Abstract
The study aimed at investigating the effect of storage temperatures on some quality properties of Ogi putting into consideration the peculiar situation of power supply in Nigeria. Ogi was processed using traditional method and stored at different temperatures (27±3, 5 ±2, -10±3 and -20±3ºC) for a period of 12 weeks. Proximate, pH, total titrable acidity, pasting characteristics and sensory evaluation were carried out. The total titratable acidity (Lactic acid based) began to decrease as from week 2 and throughout the period of storage in ogi samples stored at ambient temperature of 27±3ºC. A similar observation was noticed in the ogi stored at 5 ±2ºC, while ogi stored at -10±3 and -20±3ºC maintained the total titrable acidity when compared with the fresh ogi. The mean values of pH were significantly different (p<0.05) in all the storage conditions, while high pH values of 3.61±0.25 and 3.65±0.05 were recorded at week 12 of ogi stored at ambient temperature and 5±2ºC respectively. There was significant difference (p<0.05) in moisture content throughout the period of storage. There was significant difference in proximate composition (p<0.05) in all the storage conditions and throughout the storage period. The peak viscosity and final viscosity of ogi stored under the ambient temperature witnessed a noticeable reduction throughout the period of storage compared with the fresh sample of ogi. Storage at 5±2,-10±3 and -20±3ºC conditions maintained the hold strength (hot paste viscosity). The range of pasting temperature for ogi samples throughout the period of storage was between 76 and 80ºC. There was no significant difference (p<0.05) in multiple comparison results of sensory evaluation and the values for consistency were 2.7 and 2.75 at weeks 8 and 10 respectively for ogi stored at ambient temperature. The acceptability results for consistency and colour showed a significant difference (p<0.05). Ogi stored at low temperatures (-10±3 and -20±3ºC) were preferred.