Development of computational models for the production of fermented African locust beans using petri net

Production of iru, a fermented condiment from African locust bean is characterized by low productivity and drudgery. The hierarchical timed coloured Petri nets (HTCPN) formalisms were used to design computational models on unit operations of the iru production process. The developed models for the traditional iru production process (TIPP) and mechanized iru production process (MIPP) were simulated using CPN tools varying production scenarios. In this paper, the simulation results revealed that the measured quantities of 16, 32, 48, 80 kg of raw locust bean (iyere) gave production times of 4644, 5094, 5559 and 6493 mins and 4540, 4728, 4910 and 5267 mins for TIPP and MIPP, respectively. The production ratios of iyere:iru (per kg) for the TIPP were observed to be 16:12.8; 32:25.6; 48:38.4 and 80: 64; and for MIPP were 16:12.64; 32:25.28; 48:37.92 and 80:63.2; respectively. The resource (water) usage ratio of TIPP to MIPP (in percentage) was 6.7:10 for the washing operation; 56.67:60 for the long-cooking operation and 23:23 for the short-cooking operation, respectively. The individual dehulling and sieving operations in the TIPP took 1.70 and 11.7, respectively. Meanwhile, combined operations of dehulling and sieving in the MIPP gave 7.00. Conclusively, the mechanized process was found to utilize lesser quantity of water and shorter production time. Hence, more iru was obtained from traditional process. The developed computational models could serve as reference models for future process automation, further studying and improving iru production