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Glycerol monostearate (GMS) and monoglyceride phosphate (MGP) were added to fufu flour at different levels (0.5%, 1.0% and 1.5%) in hydrated and powdered form. There were evaluated the effects of those additives on physicochemical and sensory properties of dried fufu. Addition of GMS and MGP had a significant effect on the swelling power, solubility, pasting properties and sensory quality of fufu flour. Results obtained were: Dispersibility (69%-70.33%), water absorption index (WAI, 47.7%-54.4%), least gelation concentration (LGC, 4.67%-6.67%) and water absorption capacity (WAC, 119.3%-136%) for the fufu flour treated with GMS and MGP. Solubility of the samples mixed with the powdered form of the modifier ranged between 23.2% and 31.7%, while that of the samples mixed with the hydrated form of GMS and MGP ranged between 5.3% and 12.7%. The pasting time varied between 8.25 min and 18.50 min, fufu flour mixed with 1.5% GMS powder had the lowest value while that mixed with 1.0% MGP powder and 0.5% hydrated MGP recording the highest value. Pasting temperature ranged from 67.00°C to 72.00°C, with flour mixed with 1.0% hydrated GMS and 0.5% GMS powder having the lowest and highest value, respectively. The highest value of peak viscosity (762.50 BU) was recorded by fufu flour containing 1.0% hydrated GMS. The lowest value of starch stability (255.50 BU) was recorded by fufu flour without modifier while the highest value (499.00 BU) was recorded by fufu flour containing 0.5% GMS powder. There were significant differences (p Ͻ 0.05) in the sensory qualities except for colour of fufu flour samples. The overall quality index (OQI) comprised between 5.24 and 6.01, fufu sample containing 0.5% hydrated GMS had the lowest OQI and that containing 1.0% hydrated MGP the highest OQI. Addition of 0.5% texture modifier to dried fufu may be economically feasible according to the estimated cost of production.

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Cassava (Manihot esculenta Cranzt) deteriorates rapidly. Hence it is processed into various products within 2 to 3 days after harvesting. For this work, tapioca was produced from three different varieties of cassava. They are Odongbo, Okoiyawo and TMS30572. The sorption isotherm for the tapioca grits from three different varieties of cassava at temperatures 25, 32 and 45°C were determined experimentally and modelled using five different models. Using analysis of variance at 0.01 level, it was shown that the experimental sorption isotherms of the tapioca from the various cassava varieties are not significantly different from each other. However, the Guggenheim (1966), Anderson (1946) & de Boer (1953 (GAB) model gave the best fit for sorption isotherm of tapioca from either the Odongbo or Okoiyawo varieties, while the exponential model was the best for that from TMS30572 variety.

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Water yam (Dioscorea alata) flour was processed using standard wet milling procedure prior to the extrusion process, which led to the determination of extrudate properties of the flours. A single‐screw extruder (DCE 330, NJ) was used in evaluating the extrudate properties, which included torque, mass flow rate, residence time, specific mechanical energy and expansion ratio of the flours from the water yam samples. The effect of extrusion and process variables: feed moisture content, screw speed and barrel temperature on the extruder torque, residence time, mass flow rate, specific mechanical energy and expansion ratio for the variety were determined and predictive models were also developed using response surface methodology. It was observed that changing the feed moisture content, barrel temperature and screw speed significantly (P < 0.05) affected expansion ratio, torque, mass flow rate, residence time and specific mechanical energy of all the extrudates. Increasing the feed moisture content (18–28% db) and screw speed (80–180 rpm) resulted in a substantial decrease in expansion ratio (46.6%), residence time (27.5%) and specific mechanical energy (83.6%); whereas, increasing the screw speed significantly increased the mass flow rate (64.5%) of extrudates. Regression analysis indicated that screw speed and feed moisture content were the major process variables showing significant (P < 0.05) linear, quadratic and interaction influences on mass flow rate, expansion ratio and specific mechanical energy. PRACTICAL APPLICATIONS This investigation was conducted with a broad intention of enhancing the value of water yam flours and its suitability for incorporation in the production of noodle‐like products. This was accomplished by varying the feed moisture content, screw speed and barrel temperature, and determining their effects on resulting extrudate properties.

The deep‐fat frying of yam slices was investigated with the aim of optimizing the processing conditions. During frying, frying temperature, initial dry matter and frying time have a significant effect on moisture loss and oil uptake. Response surface methodology central composite rotatable design was used to study the effects of the independent variables on quality attributes of yam chips. Breaking force, oil content, moisture content and color parameters were determined. Statistical analysis with response surface regression showed that breaking force, oil and moisture contents and color parameters (L*and a*) were significantly (P < 0.05) correlated with frying temperature, initial dry matter and frying time. The optimum conditions were a frying temperature of 175–180C, using tubers of initial dry matter of 0.179–0.214 kg/kg with a frying time of 4–5 min. It was suggested that the regression equation can be used to estimate the dependent variables for fried yam chips except b*(yellowness) parameter. PRACTICAL APPLICATIONS It is expected that the optimized processing conditions highlighted in this work will be useful in obtaining fried yam chips of acceptable quality attributes. This optimized condition would be a good prospect for commercialization in small‐scale industries.

Water absorption process during soaking of African breadfruit (ABF) seeds was studied at five typical soaking temperatures, ranging between 30 and 70 C. The progress of water absorption by the seeds followed an exponential increase with increase in temperature. The experimental data were fitted to three empirical equations. All the equations were able to explain over 90% of the experimental data. The predicted water absorption capacity (M e), which ranged between 68 and 92/100 g dry solid were not significantly affected by temperature changes (p > 0.05) while the time to achieve maximum water absorption capacity ranged between 9 and 140 h. The water absorption rate constant in Singh-Kulshrestha's model was more sensitive to temperature changes than from the others. By applying Arrhenius equation, it was shown that water absorption at 30-70 C was the predominant process responsible for the changes in mass of ABF seeds. The differences in the experimental and predicted data from the three models were compared to evaluate their goodness of fit. The chi-square and the