L.O. Sanni

Effect of Texture Modifiers on the Physicochemical and Sensory Properties of Dried Fufu

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 8.25min and 18.50min, 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 (762.50BU) was recorded by fufu flour containing 1.0% hydrated GMS. The lowest value of starch stability (255.50BU) was recorded by fufu flour without modifier while the highest value (499.00BU) was recorded by fufu flour containing 0.5% GMS powder. There were significant differences (p 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.

Moisture sorption isotherms of fufu and tapioca at different temperatures

Abstract Moisture sorption characteristics for two products of cassava, namely fufu and tapioca, at 25 °C, 32 °C and 45 °C were studied for water activity ranging from 0.1 to 0.96. At a given water activity, the results show that the moisture content decreases with increasing temperature for fufu and tapioca. Eight sorption models were used to analyze the data. The GAB model showed the best fit, whereas the BET model was the poorest over the whole range of water activity. Also, estimates of the net isosteric heats of sorption and their dependence on moisture content were presented for each product.

The Influence of Palm Oil and Chemical Modification on the Pasting and Sensory Properties of Fufu Flour

Abstract The effect of the addition of palm oil (0.1–2.5 m3/100 kg fufu) and chemicals [citric acid/sodium hydroxide (NaOH, food grade)] on the pasting and sensory properties of dried fufu flour were investigated. There was significant effect of addition of palm oil, citric acid, or NaOH to wet fufu on the pasting characteristic of dried fufu flour. The pasting characteristics of the samples only show a significant difference at the cooling stage where the viscosity after 20 min holding at 50°C are 480 BU for fufu sample with 0.1 M citric acid, fufu sample with distilled water. Fufu sample with 0.06 M NaOH and fufu sample with 0.1 M citric acid is more stable followed by fufu sample with 0.05 M citric acid. There were significant differences (P < 0.05) in the sensory qualities for taste, color, odor, texture, and overall acceptability of fufu with and without addition of palm oil. Sensory evaluation shows that fufu sample containing 0.1 and 0.5% palm oil to be the most acceptable in the overall general acceptability (P < 0.05). The sensory qualities of fufu samples modified with acid also vary with the panelists preferring both samples made from wet slurry and fufu samples with 0.05 M citric acid. There exist a negative correlation between sensory texture and peak viscosity or starch stability, while a positive correlation exists between sensory texture and setback value for the fufu samples P = 0.05 or 0.1.

Optimization of Blanching Conditions Prior to Deep Fat Frying of Yam Slices

The effect of low-temperature blanching and frying time at a frying temperature of 170°C on moisture and oil contents, breaking force and colour of yam chips was investigated using response surface methodology to establish the optimum blanching conditions and frying time. A central composite rotatable design was used to study the effects of variation in levels of blanching temperature (60–80°C), blanching time (1–5 min) and frying time (2–6 min) on quality attributes of yam chips. The effect of blanching temperature and frying time was more significant than the time of blanching on the quality attributes. The response variables were fitted to predictive models applying multiple linear regressions. Statistical analysis with response surface regression showed that moisture content, oil content, breaking force and L* (lightness) parameter were significantly (P < 0.05) correlated with blanching temperature and time and frying time. However, the regression equation showed a poor fit for a* and b* respectively. The optimum conditions were a blanching temperature of 70–75°C, blanching time of 4–5 min while frying for about 5 min.

Effect of variety and moisture content on some engineering properties of paddy rice

The effect of variety and moisture content on some engineering properties of five improved paddy rice varieties was investigated within moisture content range of 10% and 30% dry basis (d.b.). Increase in moisture content was found to increase the linear dimensions, mass of 100 seeds, surface area, apparent volume, true volume, arithmetic mean diameter, effective geometric diameter, sphericity, angle of repose, porosity and static coefficient of friction while bulk density and true density decreased with increase in moisture content. Static coefficient of friction was found to increase as moisture content increased from 0.34–0.46, 0.35–0.59, 0.36–0.46 and 0.34–0.45, respectively on plywood, galvanized steel, mild steel and glass structural surfaces. The highest static coefficient was found on galvanized steel. Angle of repose was found to increase as moisture content increases. The study concludes that variety and changes in moisture content significantly (P < 0.05) affected most of the engineering properties determined.

Effect of Hydrocolloids and Egg Content on Sensory Quality of Coated Fried Yam Chips

This study investigated the effect of hydrocolloid (xanthan gum, gum tragacanth, and carboxymethyl cellulose) at 0.5–1.5% concentration and egg content (egg white or whole egg) as coating ingredients on the sensory quality of fried yam chips (FYC). The coated chips were evaluated for appearance, texture, taste, flavor, and overall acceptability using a nine-point hedonic scale. Descriptive sensory evaluation of the samples using generic method was also conducted. The studied independent variables had significant (p < 0.05) effects mainly on the appearance and texture of the FYC. Generally, the acceptability scores decreased significantly with increased hydrocolloid concentration (p < 0.05). Appearance had highest significant correlation (p < 0.01, r = 0.764) with overall acceptability. Eight of over fifty descriptors generated by the trained panelists were agreed upon as non-redundant, discriminatory attributes of the coated FYC. Similarity map of the descriptors were defined by two principal components accounting for 53.06% and 40.18% of total variance of rotation sums of squared loadings.

Effects of solid content and temperature on viscosity of tapioca meal

The effect of solid content (2.5–10%, w/v) and temperature (30–70°C) on the viscosity of tapioca meal from three cassava varieties was investigated in this study. Viscosity measurements were conducted using a digital rotational Brookfield viscometer. The viscosity of tapioca meal increased with increasing solid content and decreasing viscometer speeds. An empirical power-law equation fitted the viscosity data of the tapioca meals with correlation coefficients between 0.94 and 0.99. Our results indicated that tapioca meal can be characterized as a pseudo-plastic fluid and a mean value of 0.32 ± 0.18 was proposed as the power law index of tapioca meal from the three cassava varieties used in this study. Neither solid content, temperature nor shear rate altered the rheological characteristics of tapioca meal.

Pasting, Color, and Granular Properties of Starches From Local and Improved Cassava Varieties in High Rainfall Region of Nigeria

This study investigated the pasting, color, and granule properties of starches produced from 39 different cassava varieties (36 varieties resistant to cassava mosaic disease and three checks, TMS 30572, 4(2) 1425, and 82/00058) in two planting seasons at the experimental farm of the International Institute of Tropical Agriculture, Onne, Rivers State, Nigeria. Varieties screened showed significant seasonal differences (p < 0.05) in all the properties over two harvesting seasons. The peak viscosity during heating ranged from 241.13 RVU to 485.21 RVU in year 1 and from 232.46RVU to 407.63RVU in year 2. Pasting time of the different starches ranged from 3.20–3.70 min in year 1 and from 3.6–4.2 min in year 2. Pasting temperature of the different starches ranged from 63.93–65.35 °C and from 73.15–77.15 °C in the years 1 and 2, respectively. Starch color intensity ranged from 85.05–94.49% in year 1 and from 90.27–92.96% in year 2. The structure of starches from cassava varieties was round in shape with granule size ranging from 12.50–22.50 μm in two years with varieties 97/0211 and 98/0510 as the smallest and variety 96/1632 as the largest. This study, therefore, showed that there were significant genotypic and seasonal variations in the pasting, color, and morphological properties of native starches from cassava.

Effect of Drying and Roasting on the Quality Attributes of Fufu Powder

Abstract The effect of drying and roasting on the physicochemical and sensory qualities of fufu powder were investigated. The four samples of fufu: cooked dried fufu, cooked roasted fufu, dried fufu slurry and roasted fufu slurry, respectively, were subjected to physicochemical and sensory analysis. The water binding index, water solubility index, and water absorption index, varies between 3.44 and 0.17 (g/g sample), 0.07 and 0.01 (g/g), and 4.73 and 0.83 (g/g) respectively, while the starch damage and amylose content varies between 50.8% and 0.4%, 10% and 13% respectively, with roasted fufu slurries recording the highest values. The proximate composition of dried and roasted fufu samples showed the values of fat (0.6%–0.4%), protein content (0.2%–0.1%), ash content (37.8%–1.0%), moisture content (8.2%–10.2%), crude fibre (1.25%–8.5%) and carbohydrate content (43.0%–84.65%) respectively. Generally, there were no appreciable differences in the proximate composition of dried fufu samples. The pasting temperature of fufu samples varies from 78 to 95°C with roasted fufu slurries recording the highest values. The peak viscosity of dried fufu samples ranges between (80 and 900BU) and viscosity at 50°C ranges between (260 and 460BU). There are no significant differences (P > 0.01) for the sensory qualities in term of color, taste, and overall acceptability except for odor and texture at (P < 0.01).

MODELLING SORPTION ISOTHERMS OF LAFUN AND SOYFLOUR USING A SPREADSHEET

ABSTRACT Spreadsheets are versatile tools that can be used for preparation, plotting and analysis of data. One of such spreadsheets that is readily available on personal computers is Microsoft Excel. A Microsoft Excel template for computing the GAB constants was developed and tested with experimentally determined sorption data for lafun and soyflour each at temperatures of 25, 32 and 45°C. Lafun is a cassava product while soyflour is obtained from soybean. The experimental equilibrium moisture content for lafun and soyflour were determined for water activity ranging from 0.1 to 0.96 at each temperature. The results obtained showed that the GAB model is a good fit for the various experimental data. It was also shown that Excel gave the similar result as two other statistical software namely SPSS and STATISTICA.