Infrared drying characteristics of locust (L. migratoria): physical and techno-functional characterization of locust powder

Abstract This study examined some physical and techno-functional properties of locust ( Locusta migratoria ) powder produced by infrared drying at temperatures of 60, 70, and 80 °C. Water activity, pH, Carr’s index, Hausner ratio, water holding capacity (WHC), oil holding capacity (OHC), and color parameters of the powders were measured. In addition, infrared drying kinetics were analyzed. Increasing the drying temperature from 60 to 80 °C resulted in a 2.8-fold reduction in drying time, without causing significant changes in the measured properties. Except for WHC, the properties of infrared-dried powders were comparable to those of freeze-dried powder. WHC (2.1–2.3 g water/g) of infrared-dried powders was lower than that of the freeze-dried powder (3.3 g water/g). The locust powder exhibited poor flowability. Drying occurred in the falling rate period, with the Page model best describing the drying behavior. Effective moisture diffusivity ( D eff ) ranged from 1.17 × 10 –10 to 10.9 × 10 –7 m 2 /s, and the activation energy was calculated as 53.81 kJ/mol. The influence of drying temperature on the drying rate was most pronounced during the early stages of drying. Overall, infrared drying, with its shorter processing time, appears to be a promising alternative for the production of locust powder.