Nazmi Izli

Geometric and Mechanical Properties of Mung Bean (Vigna Radiata L.) Grain: Effect of Moisture

In this research, selected geometric and mechanical properties of mung bean grain were evaluated as a function of moisture content. Five levels of moisture content ranging from 7.28 to 17.77% d.b. (dry basis) were used. The average length, width, thickness, arithmetic and geometric mean diameters, sphericity, thousand grain mass and angle of repose ranged from 5.145 to 6.199 mm, 3.760 to 4.474 mm, 3.537 to 4.223 mm, 4.147 to 4.965 mm, 4.090 to 4.893 mm, 0.795 to 0.789, 52.3 to 64.6 g, and 25.87 to 29.38° as the moisture content increased from 7.28 to 17.77% d.b., respectively. The bulk density was found to be decreased from 821.3 to 745.2 kg/m3, whereas the grain volume, true density, porosity, terminal velocity, and projected area were found to be increased from 27.88 to 47.33 mm3, 1230.0 to 1456.7 kg/m3, 30.43 to 46.57%, 4.86 to 5.29 m/s, and 17.48 to 19.26 mm2, respectively. There is a 43% increase in surface area from grain moisture content of 7.28 to 17.77% d.b. The static coefficient of friction on various surfaces increased linearly with the increase in moisture content. The rubber as a surface for sliding offered the maximum friction followed by galvanised iron, medium density fibreboard, stainless steel, aluminium and glass sheet. As moisture content increased from 7.28 to 17.77%, the rupture forces values ranged from 67.39 to 39.44 N; 63.86 to 42.18 N, and 53.96 to 41.79 N for thickness (Z axis), length (Y-axis) and width (X-axis), respectively.

Color and Microstructure Properties of Tomatoes Dried by Microwave, Convective, and Microwave-Convective Methods

In this study, color and microstructure changes of tomato samples were investigated after microwave (90, 160, 350, and 500W), convective (50 and 75°C), and microwave-convective (90W-50°C, 90W-75°C, 160W-50°C, and 160W-75°C) drying treatments using a laboratory microwave-convective oven. The combined microwave-convective drying decreased the drying time required when compared to drying with either convective or microwave drying alone. The color of the samples dried at 50°C was closest to the fresh samples compared to other drying conditions. All color values of fresh tomato were affected by drying. Scanning electron microscopy images showed that disruption of the tomato samples significantly elevated with increasing drying temperature or microwave power level.

Comparison of some physical and chemical characteristics of buckwheat (Fagopyrum esculentum Moench) grains

ABSTRACT Several physical and chemical characteristics of two buckwheat varieties (commercial buckwheat and the Güneş variety) were determined and compared in terms of linear dimensions, length, width, thickness, arithmetic and geometric mean diameters, sphericity, surface area, aspect ratio, volume, weight of thousand grains, bulk and densities, porosity, terminal velocity, angle of repose, coefficient of static friction, rupture strength, apparent colour of buckwheat varieties, ash, protein, antioxidant capacity, total phenolic content and minerals (P, K, Mg, Na, Ca, Fe, Zn, Cu, B Cr and Pb) content. Multilinear models for two buckwheat varieties were developed and presented to predict the grain volume. All properties of the varieties that provide useful data to engineers in equipment design and post-harvest technology for the buckwheat grains were statistically different. These differences could be due to the individual characteristics of the varieties, environmental and growth conditions.

Impact of different drying methods on the drying kinetics, color, total phenolic content and antioxidant capacity of pineapple

ABSTRACT In this study, the effects of convective (60, 70, 80 and 90°C), microwave (120 and 350 W) and freeze-drying methods on the drying kinetics, color, total phenolic (TP) content and antioxidant capacity of pineapples were examined. The statistic tests proved that the Midilli et al., Two Term, Wang and Singh and Page models were superior to the other models and yielded the closest predictions to the experimental values. The lowest change in the color parameter (∆E) value (4.83) was obtained by freeze-drying the pineapples. The dried samples demonstrated a decrease in the TP content compared to the fresh samples and a decrease in the antioxidant capacity. The best antioxidant capacity and TP content values were obtained via freeze drying and microwave drying at 350 W, respectively. According to the results obtained from this study, convective, freeze drying and microwave methods are suitable for drying pineapple.

Analysis on Photovoltaic Energy-Assisted Drying of Green Peas

A photovoltaic energy-assisted industrial dryer has been analyzed. The dryer has been tested in various weather and working conditions with 3 kg of green peas from 75.6% initial moisture content to 20% final moisture content (w.b.). The effect of various drying air temperatures at three levels (40, 50, and 60°C) and two distinct air velocities (3 m/s and 4 m/s) was examined. Drying performance was assessed with regard to criteria including drying kinetics, specific and total energy consumption, and color and rehydration ratio. The results have proved that total drying duration reduces as air velocity rate and drying air temperature raise. Relying upon the drying durations, the generation performances of photovoltaic panels were between 5.261 and 3.953 W. On the other part, energy consumptions of dryer were between 37.417 and 28.111 W. The best specific energy consumption was detected in 50°C at 3 m/s for 600 minutes with 7.616 kWh/kg. All drying conditions caused darkening as color parameters. Rehydration assays have showed that rehydrated green peas attained higher capacity with raised air temperature and air velocity.