ABSTRACT

Periwinkle meat presents economic potentials mainly due to its excellent protein quality and availability all year round. Hitherto studies on periwinkle have not been focused on periwinkle handling and processing. There was a dearth of information on development of periwinkle meat extraction. This hinders the efficient mechanization of periwinkle processing. This study was conducted to design, fabricate and optimize a periwinkle meat extraction machine. Selected design related physical, mechanical and thermal properties of periwinkle shell and meat on two periwinkle varieties were determined, which were the input parameters for the design and fabrication of the periwinkle meat extraction machine. A central composite rotatable design of Response Surface Methodology (RSM) at 3 factors 5 levels and 4 factors and 5 levels was adopted for the performance evaluation experiments. Based on the preliminary tests and literature, cracking speed,  (100, 110, 120, 130, and 140 rpm); agitation speed,  (0.76, 0.95, 1.04, 1.11, and 1.23 m/s); feed rate,  (0.10, 0.20, 0.30, 0.40, and 0.50 kg/s) and heat conditioning time levels,  (0, 2, 4, 6, and 8 mins) at 100℃ were chosen. Machine performance criteria namely; cracking efficiency ( ), separating efficiency ( ), throughput ( ) and periwinkle meat loss ( ) were determined and optimized. Data analyses were done using multiple linear regressions at  Predicted optimum performance parameters were validated using experimental values. The engineering properties evaluated did not vary widely between the two periwinkle varieties. CE of 84.08 % at  of 134 rpm,  of 0.26 kg/s and  of 6 mins was obtained for T. fuscatus, while CE of 86.50 % at  of 133 rpm,  of 0.23 kg/s and  of 6.2 mins was obtained for P. aurita. SE of 78.60 % at  of 133.6 rpm,  of 1.12 m/s,  of 0.23 kg/s and  of 6.2 mins was obtained for T. fuscatus, whereas   SE of 77.30 % at  of 134 rpm,  of 1.14 m/s,   of 0.20 kg/s and  of 6.8 mins was obtained for P. aurita. TP of 28.10 kg/h at  of 133.6 rpm,  of 1.13 m/s,  of 0.23 kg/s and  of 6.2 mins was obtained for T. fuscatus, while TP of 19.10 kg/h at  of 134 rpm,  of 1.13 m/s,   of 0.20 kg/s and  of 6.8 mins was obtained for P. aurita. PML of 6.71 % at  of 133.6 rpm,  of 1.12 m/s,  of 0.23 kg/s and  of 6.2 mins was obtained for T. fuscatus, while PML of 14.97 % at  of 134 rpm,  of 1.13 m/s,   of 0.20 kg/s and  of 6.8 mins was obtained for P. aurita. It was established from comparison analysis of the two periwinkle varieties that T. fuscatus showed a better cracking efficiency profile with respect to the machine operating and crop factors, this is so because the mechanical properties of the shells of P. aurita required higher energy to crack than that of T. fuscatus. A protype periwinkle meat processing machine has been developed for efficient handling and processing of periwinkle. The results of this study are of immense benefit to periwinkle processors, researchers and the government by utilizing the information provided by detailed analysis of some the design related physical, mechanical and thermal properties of two periwinkle varieties. Also, Government and the Manufacturers should adopt the periwinkle meat processing machine prototype developed for further enhancement towards commercialization.