No abstract

Oduntan O.B., Koya O.A. (2015): Effect of speed, die sizes and moisture contents on durability of cassava pellet in pelletizer. Res. Agr. Eng., 61: 35-39.The effect of pre-processing conditions such as speed, die sizes and moisture content on durability of cassava flour was investigated. Densification of cassava flour was done by pelletizing the flour through die and it is necessary to determine optimum conditions for designing and constructing a suitable processing plant. The flour was mixed with water at different blend ratios to form cassava mash of different moisture contents. The pellet quality was evaluated in terms of the durability of the pellets against the moisture content of the mash (18, 20 and 22% w.b.), die size (4, 6 and 8 mm) and the screw speed (90, 100 and 120 rpm). Test results showed that maximum durability of 84.437% was recorded at 20% (w.b.) moisture content using 4 mm die and low durability of 61.26% with using 8 mm die at 18% (w.b.) moisture content. The durability result shows that it decreased with increase in die size. Statistical analysis revealed that the die size had significant (P ≤ 0.05) effect on the durability.

Oduntan O.B., Koya O.A., Faborode M.O., 2014. Design, fabrication and testing of a cassava pelletizer. Res. Agr. Eng., This paper reports on the design of fabrication and testing of a machine for cottage level production of pellets from cassava mash. The pelletizer consists of a barreled screw auger which compresses cassava mash against perforated end plate, through which the pellets are pelletized. The result derived from the calculated design parameters (shaft diameter, tensile stress, torque, screw length, volumetric capacity mass flow rate and power rating) were used for the fabrication. The testing of the pelletizer was determined in terms of throughput of the machine, against the moisture content of the mash (18, 20 and 22% w.b.), die size (4, 6 and 8 mm) and the auger speed (90, 100 and 120 rpm). Test results showed that the pellets with the best quality attributes were obtained from cassava mash at 18% moisture content (w.b.) through the 4 mm die at 90 rpm and a maximum throughput of 54 kg/h.

A single screw water-cooled jacketed extruder has been proposed to produce the fruit waste extrusion process of fish feed because of its superficial characteristics. This research mainly examined the effects of various extrusion conditions: feeding rate, screw speed, feed moisture, barrel temperature, cutting speed, and die open surface area. While maintaining the feed specifications (38% proteins and 5% lipids), four formulations with different pomace inclusions were obtained. The processing methodologies (with mash moisture and varied extruder parameters) were then based on three fundamental aspects (machine torque, apparent viscosity, and efficiency). They were studied using Response Surface Methodology (RSM). The influence of screw speed, moisture, and pomace inclusion was most significant. Optimum extrusion conditions were found at a feed rate of 1.47 kg.min-1, screw speed of 356.44 rpm, humidity of 16.04%, temperature of 60 °C, cutting speed of 1300 rpm, pomace inclusion rate of 10.59%, and an open surface die obtained 88.63%. The maximum desirable value of 0.61 resulted in 444.16 Nm-1 torque, 1008.98 Pa-s apparent speed, and 75.21% efficiency. The extruder evaluation demonstrated remarkable performance in producing pineapple pomace extrudates without impeding machine operating principles, redefining the robustness of extrusion process factors and their interactions in the process state.

Extrusion cooking, a high-temperature short-time processing technique holds promise for lowering enzyme inhibitor activities and improving nutrient bioavailability in grain legumes, thus improving their feeding value. The effect of extrusion cooking of two grain legumes; pigeon pea (Cajanus cajan) and bambara groundnut (Vigna subterranean) at varied temperatures on growth performance, endogenous enzyme activity and organ development of 35d-old meat-type chickens was investigated. Pigeon pea and bambara groundnut were milled and extruded at two temperatures (100 C and 140 C)from which six diets were formulated containing 30g/100g diet of non-extruded (control), 100 C or 140 C extrudates of bambara groundnut or pigeon pea. Two hundred and fifty-two, one day-old, meat-type chicks were allotted to the six diets in six replicates, seven birds each. Weight gain and feed intake (FI)were monitored weekly and feed conversion ratio (FCR) was estimated. Relative weight (g) of pancreas, proventriculus, gizzard and liver as well as duodenal, jejunal and ileal lengths and weights were measured. Activities of pancreatic amylase, proteases; chymotrypsin and trypsin, and brush border disaccharidases; sucrase and maltase were also assayed in the pancreas, ileal and jejunal digesta, and ileal and jejunal tissues respectively. Data was analyzed using ANOVA (p<0.05) and pre-planned contrasts, elucidating the effect of extrusion (raw vs extruded;100 C and 140 C) and temperatures (100 C vs 140 C) on each grain legume investigated. Weight gain of chickens on both bambara groundnut and pigeon pea diets were not affected by extrusion temperatures or extrusion throughout the study period except during 8-14d in the pigeon pea groups. However, FI significantly reduced and FCR improved with extrusion cooking and extrusion temperatures (P<0.05) for meat-type chickens on the pigeon pea diets. The FI also reduced and FCR improved with extrusion cooking and extrusion temperatures for meat-type chickens on the bambara groundnut diets between 8-21d and 29-35d of age (FI: 604.83±0.71g vs 530.58±6.47g and 532.20±15.36g respectively; FCR: 3.89±0.15 vs 3.25±0.17 and 3.27±0.21, respectively). Relative organ weights, weights and lengths of intestinal segments as well as pancreatic amylase and protease activities were not influenced by extrusion cooking or extrusion temperatures.       La cuisson par extrusion, une technique de traitement de courte durée à haute température, est prometteuse pour réduire les activités des inhibiteurs enzymatiques et améliorer la biodisponibilité des nutriments dans les légumineuses à grains, améliorant ainsi leur valeur nutritive. L'effet de la cuisson par extrusion de deux légumineuses à grains ; Cajanus cajan (pois cajan) et Vigna subterranean (arachide bambara) à des températures variées sur les performances de croissance, l'activité enzymatique endogène et le développement des organes de poulets de type viande âgés de 35 jours ont été étudiés. Le pois cajan et le pois cajan ont été broyés et extrudés à deux températures (100oC et 140oC) à partir desquels six régimes ont été formulés contenant 30g/100g de régime alimentaire non extrudé (témoin), 100oC ou 140oC d'extrudés de pois cajan ou de pois cajan. Deux cent cinquante-deux poussins de type viande d'un jour ont été répartis dans les six régimes en six répétitions, sept oiseaux chacun. Le gain de poids et la prise alimentaire (PA) ont été surveillés chaque semaine et le ratio de conversion alimentaire (RCA) a été estimé. Le poids relatif du pancréas, du proventricule, du gésier et du foie (g) ainsi que les longueurs et poids duodénaux, jéjunaux et iléaux ont été mesurés. Activités de l'amylase pancréatique, des protéases ; la chymotrypsine et la trypsine, et les disaccharidases de bordure en brosse; la sucrase et la maltase ont également été dosées dans le pancréas, le digesta iléal et jéjunal et les tissus iléaux et jéjunaux respectivement. Les données ont été analysées à l'aide d'ANOVA (p<0,05) et de contrastes pré-planifiés, pour élucider l'effet de l'extrusion (brut vs extrudé ; 100 oC et 140 oC) et des températures (100 oC contre 140oC) sur chaque légumineuse à grains étudiée. Le gain de poids des poulets recevant à la fois des régimes à base d'arachide et de pois cajan n'a pas été affecté par les températures d'extrusion ou l'extrusion tout au long de la période d'étude, sauf pendant 8 à 14 jours dans les groupes de pois cajan. Cependant, le PA a diminué de manière significative (P<0,05) et le RCA s'est amélioré avec la cuisson par extrusion et les températures d'extrusion pour les poulets de type viande sur les régimes de pois cajan. Le PA a également diminué et le RCA s'est amélioré avec la cuisson par extrusion et les températures d'extrusion pour les poulets de type viande sur les régimes à base d'arachide bambara entre 8-21 jours et 29-35 jours d'âge (PA : 604,83 ± 0,71 g vs 530,58 ± 6,47 g et 532,20 ± 15,36 g respectivement ; RCA : 3,89±0,15 vs 3,25±0,17 et 3,27±0,21 respectivement). Les poids relatifs des organes, les poids et les longueurs des segments intestinaux ainsi que les activités de l'amylase et de la protéase pancréatiques n'étaient pas influencés par la cuisson par extrusion ou les températures d'extrusion.