Kinetics, modelling and evaluation of Bombay duck (Harpodon nehereus) dried in solar-LPG hybrid dryer

Abstract

This work investigated the kinetics, modelling and quality of Bombay duck (Harpodon nehereus) dried in the solar-LPG hybrid dryer. The moisture content of the Bombay duck was lowered from 86.4 ± 0.52% to 16.4 ± 0.67% (w.b) within 11 h. The reduction in weight of Bombay duck samples during drying was measured at 1 h interval. LPG backup maintained the desirable drying conditions in the dryer. The drying process was observed to occur under the falling rate period. Effective moisture diffusivity during drying of Bombay duck was determined to be 3.7 × 10 -10 m2/s. Drying parameters were fitted into thin layer drying models. The Page model was a suitable fit for the data under study (R2 = 0.9986, RMSE = 0.01268 and χ2 = 0.000134). The maximum drying and collector efficiency recorded for Bombay duck drying in solar-LPG dryer was 40.67% and 33.7%, respectively. The rehydration ratio and shrinkage of dried Bombay duck were found to be 1.94 and 26.42% respectively. Microbial analysis of dried fish was within the safe limits. Benefit-cost ratio, payback period, NPW, annuity and IRR were also determined to check the economic feasibility of the study.