Effect of stabilizers on the physico-chemical and sensory attributes of thermized yoghurt

Stabilized thermized yoghurt was produced by the addition of gelatin, carboxyl methyl cellulose (CMC) and corn starch, into yoghurt mix as stabilizers, each at 0, 0.5, 0.75 and 1.0% concentrations. Theyoghurt samples produced after pasteurization of the mix, cooling, inoculation of starter culture and incubation for about 16 h were thermized at 75oC for 60 s followed by immediate cooling. Results showthat titratable acidity value of the control samples (0% stabilizer) was 0.92 ± 0.03. CMC, when added to yoghurt mix at levels of 0.5% and above, depressed lactic acid production (compare 0.92 ± 0.03 of thecontrol with 0.90 ± 0.01 of samples containing 0.5 and 0.75% CMC). This observation is in contrast to effects of corn starch and gelatin which enhanced lactic acid production (at least up to 0.75%concentration). This was also mirrored (in reverse order) in the pH values; as samples with higher titratable acidity had, expectedly, lower pH values. Addition of stabilizers decreased percent protein andash contents due to dilution effect but increased total solids and specific gravity of the thermized yoghurt samples. Sensory results showed that addition of corn starch produced the most desirableflavour and taste which differed significantly (p < 0.05) from flavour and taste produced by gelatin but did not differ significantly (p 0.050) from that produced by CMC at 0.5 and 0.75% concentrations.Yoghurt containing CMC had the best mouth feel/consistency as well as appearance which did not differ significantly (p 0.05) from the mouth feel and appearance of yoghurt containing corn starch butdiffered significantly from yoghurt containing gelatin. Yoghurt containing CMC at 0.75% concentration was the most generally accepted

Drying Kinetics of Ginger

The drying kinetics of ginger (Zingiber officiate Roscoe) slices of thickness 2.5 mm and diameter of 25 mm was studied at 40, 45, 50 and 55oC and air flow of 1m/s. Results show that drying proceeded faster at higher than at lower temperatures. Drying took place only in the falling rate period mainly by diffusion. The activation energy of drying based on Arhenius relationship between temperatures and apparent diffusivity was found to be 27.847KJ/mol and the regression coefficient (R2) was 0.937. KEY WORDS: Ginger, Drying, and moisture Diffusivity. Nigerian Food Journal Vol.22 2004: 105-11

Performance evaluation of a powered charcoal stove using different biomass

A powered stove was designed to effectively utilized biomass, quickly start and maintain fire and reduce cooking time. The stove consists of a blower with hand winder and a fuel carrier. Performance evaluation carried out show that boiling time decreased with increased volumetric air flow rate for all the biomass used. Comparing the three biomasses, it took longer timeto bring water to boiling point using charcoal followed by wood and corn cobs in that order. The percentage heat utilized and fuel efficiency increased with increase in the volumetric air flow rate. There was no significant difference (p=0.05) in the heat utilization and fuel efficiency of wood, corn cobs and charcoal. Results also show that the specific fuel consumption decreased with air flow rate when yam, rice and beans were cooked. On the other hand, time spent for cooking the items increased significantly (p&lt;0.05). Also in comparison, the specific charcoal consumption for cooking yam, rice and beans was less followed by wood and corncobs. On the other hand the time spent for cooking the food items was longer using charcoal followed by wood and corncobs. The results show that when powered the stove performed much better than under natural air flow condition and its efficiency increased with increase in volumetric air flow rate. Corncobs were more suitable replacer of wood fordomestic cooking followed by charcoal. The popularization of this stove will alleviate the problem of starting and maintaining fire and reduce over dependence on wood.Key words: Stove, biomass, wood fuel, corncobs, charcoal, airflow rat

Effect of food binders on the textual and sensory characteristics of ice cream

Ice cream was produced using local food binders namely: Afzelia africana, Deuterium microcapum and Taro tuber to find a suitable replacer for carboxylmethyl-celleuose (CMC). Results showed that, though viscosity, efflux time and foam stability increased with increase in A. africana, D. microcapum and T. tuber local food binder concentrations, they were significantly (p < 0.05) lower than CMC. The meltdown and overrun on the other hand decreased with increase in local food binder concentration. At 0.7% concentration, D. microcarpum had the same value with CMC. The pH of samples produced with the local binders did not differ statistically from CMC. Sensory evaluation results showed that sensory attributes generally improved with increased in concentration of A. africana, D. microcapum and T. tuber. On the basis of the textural and sensory characteristics of the local binders studied, D. microcarpum at0.7% concentration was found to be the best local food binder to replace CMC in ice cream