Investigation of disease incidence and nutritional storability of cassava roots under different storage techniques

A study was conducted to investigate the disease incidence and the nutritional storability of cassava roots under different storage condition, Fifty pieces each of two varieties of cassava tubers TMS 30572 and TMS 4(2) 1425 were preserved using four storage methods namely ; Trench (re-burying the cassava roots in trenches and keeping them moist by watering them daily, applying a thick coating of mud, piling the tubers in heaps and a traditionally practiced method, by randomly spreading the tubers orderly . The samples were analysed for carbohydrate, calcium, phosphorus and vitamin C. The weight loss as well as number of diseased tubers were determined, the significant difference was conducted at ( p≤0.05 ). The mean results for the two varieties (TMS 30572 and TMS 4(2) 1425) showing the trend in the nutritional compositions and weight loss were also determined. The level of infestation of disease on the cassava tubers preserved by piling in heaps and mud application for both varieties are very low compared to the trench and the control method. The weight loss for both varieties, irrespective of the storage type is even along the storage period.Keywords: Cassava, Disease, Preserved, storability, Storage

Nutritional response of Okra to various packaging materials and chemical pickling agents

The research is focused at determining the nutritional response of Okra when pickling is carried out using different antimicrobial liquids (vinegar, olive oil, and groundnut oil) and packaging materials (glass jar, plastic and stainless steel), as well as make a comparism when spices (garlic, ginger, mixture of garlic and ginger) are added as well as control (no treatment). The okra variety used was purchased from IITA (variety 47-4), based on NIHORT classification. Groundnut oil was extracted using a hydraulic press, and the physico-chemical properties of the groundnut oil was determined in the laboratory. The other antimicrobial liquids were purchased from a grocery store. The relative humidity and temperature of the storage environment was determined three times daily (8:00 a.m, 12:00 p.m, and 5:00 a.m.) for a period of 7 days. The nutritional content of okra such as crude fibre, calcium, vitamin A and vitamin C were determined at the end of the experiment. The mean result of crude fibre, calcium, vitamin C and vitamin A from okra samples after pickling showed that vitamin C of okra stored in stainless steel was significantly higher (36.06 mg/100g) than those of glass (35.02 mg/100g) and plastics (36.03 mg/100g).The mean calcium content of okra stored in plastic (80.730%) was significantly higher than those stored in glass (80.320%) and stainless steel (80.010%) respectively. Crude fibre of stored okra (3.24%) using groundnut oil was higher compared to when vinegar and olive oil were used respectively.Keywords: Pickling, okra, vinegar, groundnut oil, calcium, protei

Modelling and optimization of the drying process and the quality parameters of dried osmo-pretreated onions (Allium cepa)

Modelling and optimization represent an important aspect of drying in food processing, providing a fast and convenient means for quality prediction. The research focuses on modelling and optimization of process parameters such as drying rate, water loss, solid gain, vitamin C, manganese, and iron of dried osmo-pretreated onion slices. Least square regression analysis in the Math-lab computer software was used to model and optimise the process parameters., Six (6) mathematical models were developed for each output from the regression analysis that was carried out. The criteria for adjudging these models were the values of their adjusted coefficient of multiple determinations, prediction error sum of squares (also called deleted residual), R2 for prediction, coefficient of variation CV, and the Dubin-Watson test for autocorrelation. The models were checked for adequacy using these criteria, and those found to be adequate were selected from among the other possible combinations. Hence, the best-optimized obtained results from the models are 27.50 g/h, 1.61 g/g, 0.15 g/g, 77.52 mg/100 g, 2.79 mg/1000 g, and 2.19 mg/1000 g for drying rate, water loss, solid gain, vitamin C, manganese, and iron, respectively

Development and Evaluation of the Operational Parameters of a Rotary Oven

Developing an efficient rotary oven that is capable of addressing the issue of long baking duration and uneven heating distribution during baking could aid in encouraging indigenous use of the oven by small and medium scale bakeries in developing countries. This study aimed to develop and evaluate the performance of a rotary oven. Taguchi experimental design was used to investigate the influence of oven temperature (160, 180, 200°C) and oven rack speed (0, 10, 20 rpm) on the physical properties (baking time, mass, surface area, specific volume and density) of bread produced from the rotary oven. The baking capacity and efficiency of the rotary oven were 16 kg h-1 and 94%, respectively. Investigation showed that baking time ranges from 20 to 82 min, bread mass (884 to 925.7 g), surface area (1050 to 1370 cm2 ), specific volume (2.36 to 3.70 cm3 g -1 ) and density (0.25 to 0.39 g cm-3 ), respectively. The optimum baking time (20 min) was achieved at 200°C oven temperature and 10 rpm oven rack speed. The oven could be adopted for both domestic and industrial production of bread and other bakery products. Keywords: Bread, oven temperature, oven rack speed, taguchi, rotary oven

Determination of Some Selected Thermal Properties of Pumpkin Seeds (Cucurbita pepo)

In this study, some selected thermal properties (specific heat, thermal conductivity and thermal diffusivity) in the moisture content range of 5.0-5.6% or green and 4.80 – 5.20% for white varieties of pumpkin seeds were determined. The specific heat was measured using mixture method while the thermal conductivity was measured by transient technique using the heat line source. The green pumpkin seed has average moisture content of 5.2% higher than moisture content of white pumpkin seed of average 4.8%. The average specific heat values of green pumpkin seed are 6.171kJ/kgK and white pumpkin seed 4.327kJ/kgK. The thermal conductivity values for white pumpkin seed ranged from 0.074 to 0.288 W/m°C while that for green pumpkin seed ranged from 0.079 to 0.433 W/m°C. The thermal diffusivity values for green pumpkin ranged from 0.0011 to 0.06 m2/s while that for white pumpkin seed ranged from 0.01 to 0.06 m2/s. It was concluded that the higher the moisture content (5.2%) the higher the value of specific heat of seed (6.171kJ/kgK). It can also be concluded that the thermal conductivity (0.079 to 0.433 W/m°C) value is higher with high moisture content (5.2%)

Optimization of a two stage process for biodiesel production from shea butter using response surface methodology

The challenges of biodiesel production from high free fatty acid (FFA) shea butter (SB) necessitated this study. The reduction of %FFA of SB by esterification and its subsequent utilization by transesterification for biodiesel production in a two stage process for optimization studies was investigated using response surface methodology based on a central composite design (CCD). Four operating conditions were investigated to reduce the %FFA of SB and increase the %yield of shea biodiesel (SBD). The operating conditions were temperature (40–60°C), agitation speed (200–1400 rpm), methanol (MeOH): oil mole ratio: 2:1–6:1 (w/w) for esterification and 4:1–8:1 (w/w) for transesterification and catalyst loading: 1–2% (H2SO4, (v/v) for esterification and KOH, (w/w) for transesterification. The significance of the parameters obtained in linear and non-linear form from the models were determined using analysis of variance (ANOVA). The optimal operating conditions that gave minimum FFA of 0.26% were 52.19°C, 200 rpm, 2:1 (w/w) and 1.5% (v/v), while those that gave maximum yield of 92.16% SBD were 40°C, 800 rpm, 7:1 (w/w) and 1% (w/w). The p-value of <0.0001 for each of the stages showed that the models were significant with R2 of 0.96 each. These results indicate the reproducibility of the models and showed that the RSM is suitable to optimize the esterification and transesterification of SB for SBD production. Therefore, RSM is a useful tool that can be employed in industrial scale production of SBD from high FFA SB

Effect of Two Blanching Methods on the Nutritional Values of Tomatoes and Pumpkin Leaves

Various blanching methods were applied to tomatoes and pumpkin leaves (Telfairia occidentalis) to investigate the effect of the&nbsp; different blanching method on some of its nutritional content. The effects of steam and water blanching as a pretreatment on raw tomatoes and pumpkin leaves (control) were investigated in this study using standard methods. For tomatoes, the %nitrogen, potassium, vitamin A, C and E) mg/100g for raw were;0.48, 68.82mg/100g, 0.88mg/100g, 38.82mg/100g, 0.78mg/100g respectively. 0.45, 69.68mg/100g, 0.58mg/100g, 32.43mg/100g and 0.55mg/100g for water blanched respectively and 0.42, 69.14mg/100g, 0.47mg/100g, 29.66mg/100g, 0.42mg/100g respectively for steam blanching. * For pumpkin leaves, the %nitrogen, potassium, vitamin A, C and E) mg/100g for raw were; 0.98, 46.82mg/100g, 4.63mg/100g, 60.41mg/100g, 0.89mg/100g respectively. 0.95, 46.73mg/100g, 2.38mg/100g,41.08mg/100g and 0.59mg/100g for water blanched respectively and 0.94, 46.10mg/100g, 1.20mg/100g, 32.16mg/100g, 0.52mg/100g respectively for steam blanching. The results indicate that water and steam blanching significantly reduce the nutritional content. The values of the nutrient were higher in water blanching compared to steam blanching. Keywords: Fruits, vegetable, steam, water, blanchin