Modelling The Drying Characteristics Of Tiger Nut (Cyperus Esculentus)

Abstract

Modelling the drying characteristics of tiger nut During Thin layer drying was studied. Tiger nuts are being consumed either in a fresh, dried or semi-dried state. Microbial deterioration starts easily immediately after harvesting because of its high systemic moisture. Tiger nuts are seasonal agro-products and they are harvested in large quantities during their season of harvest but are scarce and very expensive in the market places during off-season due to post harvest handling. Drying is a process whereby the activities of most decay causing microbes are either deactivated or reduced to safe levels therefore, reducing post-harvest losses. Thus, utilizing a laboratory convection oven drier as a heating source with temperature varying from 60, 80, and 100°C applied variably in multiples of 20°C, this work predicted and analyzed the drying behavior of tiger nuts. The effective moisture diffusivity process and the emanating drying constants and coefficients were assessed utilizing the linearized Fick's second law equation method and non-linear regression statistical approach, respectively. The data from the tests were modeled using three well-known semi-empirical models, including Page, Lewis, and Henderson-Parbis. According to established results from actual experiments, moisture loss from the samples grew quite fast at the beginning of drying but slowed significantly at the end. The results demonstrate that the temperature-dependent effective diffusivity values ranged from 1.21x10-7m2/min to 7.2x10-8m-8/min. For all the temperature ranges employed in this study, the drying profile displayed a declining rate period rather than a clear constant rate period. In order to forecast the drying behavior of tiger nuts, it was discovered that the Henderson-Pabis model was the most accurate. 1.66kJ/mol is the relative activation energy.