Modeling drying kinetics of fever leaves (Ocimum viride) in a convective hot air dryer

The drying behavior of fever leaves was investigated in a convective hot air dryer with forced convection at a fixed air velocity of 1.5m/s and drying air temperatures of 35, 45, 55 and 65°C. The constant rate period was absent and the drying curve took place in the falling rate period. Experimental data was fitted to six thin-layer drying models – Page, Modified page II, Henderson and Pabis, Modified Henderson and Pabis, Two term and Newton. The performances of the models were investigated by comparing the coefficient of determination (R2), reduced chi-square (÷2) and root mean square error (RMSE) between observed and predicted moisture ratios. The page model showed a good agreement with the data obtained while the effect of drying air temperature on the constants and coefficient of the page model was investigated. The effective diffusivity increases as temperature increases and range between 5.551 x 10-12 – 3.379 x 10-11m2/s while the activation energy was estimated to be 80.78kJ/mol

Convective Thin-layer Drying Characteristics of Sesame Seed

Fundamental information on drying and re-wetting characteristics of agricultural seeds is required in the design and aeration systems as well as in the prediction of drying rate using various mathematical models. Thin-layer drying experiments were conducted using air-ventilated oven to simulate the artificial drying at various moisture contents of sesame seed (6.9 to 18.2 % w.b) at three drying temperatures of 40, 50 and 60 oC. Five drying models were evaluated for the thin-layer data. The Page equation fitted the data best, where selection of the best model was obtained by comparing the coefficient of determination (R2), the standard error of moisture content (SEM) and mean relative percent error (e) between the experimental and estimated values. The drying rate of sesame seed under drying conditions increased with increased temperature of drying( 40 to 60 oC) and initial moisture content of seed( 6.9, 11.5 and 18.2 % w.b). The parameters “K” of the Page model increased with increase in temperature, while, parameter ”n” decreased with temperature increase and increased with increase in moisture content of seed. The effective diffusivity was found to be 2.32 x 10-11 m2s-1

Physical Characteristics of Soursop Seeds as affected by Moisture Content

Soursop (annona muricata) is an edible fruit which is reported to be potent against cancer and it is commonly found in the mangrove forest area of Nigeria. It is mostly eaten fresh and a potential source of raw material for puree, jam, jelly power fruits bar and flake. This study evaluated some physical, mechanical and oil properties of soursop seeds. Fresh and physiologically matured fruits obtained from the Nigeria Horticultural Research Institute (NIHORT), Ibadan were peeled and processed manually to obtain clean seeds. Seed samples were conditioned to four different moisture content levels of 5.62, 13.51, 17.31 and 21.39% (w.b) using standard methods. Physical properties determined included seed size, sphericity, surface area, porosity, true and bulk densities, Results revealed that significant (p 0.05) affected by the moisture content. The established values of the properties determined would assist engineers and food processors in the design of equipment and machines for handling and post-harvest processing of soursop seeds

Thin layer drying process of some leafy vegetables under open sun

Open sun drying experiments in thin layers of crain-crain (CC), fever (FV) and bitter (BT) leaves grown in Abeokuta, Nigeria were conducted. The drying process took place in the falling rate period and no constant rate period was observed from the drying curves. Eight thin layer mathematical drying models were compared using the multiple determination coefficients (R2), reduced chi-square (χ2) and root mean square error (RMSE) between the observed and predicted moisture ratios. Accordingly, Midilli et al. model satisfactorily described the drying curves of the three leaves with R2 of 0.9980, χ2 of 2.0×10-4 and RMSE of 1.09×10-2 for CC leaves; R2 of 0.9999, χ2 of 2×10-6 and RMSE of 1.11×10-3 for FV leaves; and R2 of 0.9998, χ2 of 1.9×10-5 and RMSE of 3.3×10-3 for BT leaves. The effective diffusivity was found to be 52.91×10-10, 48.72×10-10 and 43.42×10-10 m2s for CC, BT and FV leaves, respectively

OPTIMIZATION OF A CONVECTIVE DRYING PROCESS FOR PRODUCING STARCH-ALBUMEN POWDER AS COATING MATERIAL IN FRIED FOODS

Dried starch was added to egg albumen at concentration of 10-30% to increase solid matter content prior to convective air drying at 40-60oC with hot air velocity of 4.5 m/s. The functional properties of starch-albumen powder (SAP) and properties of the coated fried yam chips were fitted to response surface regression model. Our findings suggest that for a multiple objective of minimizing oil uptake and moisture content and, maximizing acceptability of fried chip drying at temperature of 40oC and starch content of 11.3% should be used

Changes in growth, digestibility and gut anatomy by broilers fed diets containing ethanol-treated castor oil seed (Ricinus communis L.) meal

Un ensayo de alimentación de ocho semanas se realizó para investigar la composición química, la respuesta del crecimiento, la digestibilidad aparente de nutrimentos, las características y la morfología intestinal de pollos de engorde alimentados con dietas que contienen harina de semillas de ricino tratada con etanol (HSRTE). Doscientos pollos de engorde Anak 2000 de un día de edad se asignaron a cuatro dietas experimentales que contienen HSRTE a 0, 100, 150 y 200 g/kg, respectivamente. Cada tratamiento se repitió cinco veces con 10 aves por repetición. El peso vivo final, la ganancia de peso y el consumo de alimento se redujo (P < 0,01) con la inclusión cada vez mayor de la dieta de HSRTE. Los pollos de engorde alimentados con el control y aquellos alimentados con dietas que contenían 100 y 150 g/kg de HSRTE tuvieron una relación alimento:ganancia similar. Los pollos de engorde alimentados con dietas que contenían 200g/kg de HSRTE registraron la menor proteína cruda y digestibilidad de fibra cruda (Contrastes lineal y cuadrático, P < 0,05) y la relación alimento:ganancia más pobre (Contraste lineal, P < 0,05). Se notó un mejoramiento similar en la relación alimento:ganacia y digestibilidad aparente de fibra cruda, grasa y cenizas con aves alimentadas con la dieta control, dietas que contenían 100 y 150 g/kg de HSRTE, respectivamente. El peso relativo de la molleja se incrementó (P < 0,05) con el aumento de los niveles de inclusión en la dieta de HSRTE. Los pollos alimentados con 200 g/kg de HSRTE registraron el mayor peso relativo de la molleja, el páncreas y el duodeno (P < 0,05) y la mayor longitud relativa del yeyuno y el íleon (P < 0,05). La longitud de las vellosidades y la profundidad de las criptas del duodeno se redujeron (P < 0,05) con un incremento de la inclusión en las dietas de HSRTE. En conclusión, la harina de semillas de ricino tratada con etanol puede ser incluida hasta 150 g/kg en dietas para raciones para pollos de engorde, sin perjudicar el crecimiento y la digestibilidad de los nutrimentos.Eight weeks feeding trial was conducted to investigate the chemical composition, growth response, apparent nutrient digestibility, gut characteristics and morphology of broiler chickens fed four diets containing ethanol-treated castor oil seed meal (ECAM). Two hundred day-old Anak 2000 broiler chicks were then allotted to the four experimental diets containing ECAM at 0, 100, 150 and 200 g/kg, respectively. Each treatment was replicated five times with 10 birds per replicate. The final live weight, weight gain and feed intake reduced (P < 0.01) with increasing dietary inclusion of ECAM. Control fed broilers and those fed diets containing 100 g/kg and 150 g/kg ECAM had similar feed to gain ratio. Broilers fed diets containing 200 g/kg ECAM recorded the least (Linear and quadratic contrast, P < 0.05) crude protein and crude fibre digestibility, and the poorest (Linear contrast, P < 0.05) feed to gain ratio. Similar improved feed to gain ratio, apparent crude fibre, fat and ash digestibility were noticed with birds fed the control diet, diets containing 100 g/kg and 150 g/kg ECAM, respectively. Relative gizzard weight increased (P < 0.05) with increasing dietary inclusion levels of ECAM. Broilers fed with 200 g/kg ECAM recorded the heaviest (P < 0.05) relative gizzard, pancreas, duodenum weight and the longest (P < 0.05) relative jejunum and ileum length. Villi length and crypt depth of the duodenum reduced (P < 0.05) with increasing dietary inclusion of ECAM. In conclusion, ethanol-treated castor seed oil meal can be included up to 150 g/kg diet in broiler ration without impairing growth and nutrient digestibility