Comparative study on microwave and tray drying of beef: Effect of partial salt replacement on drying kinetics and structural characteristics

Abstract

Beef cuts were dried by tray drying (TD), microwave drying (MD), and TD+MD. Salting as pre-treatment was carried out with NaCl or NaCl+KCl salts to evaluate the effect of sodium reduction. The beef was divided into nine groups: three were subjected to TD, MD, and TD+MD; for the other six groups, dry salting was applied with 100% NaCl or 50% NaCl + 50% KCl, followed by MD, TD, or TD+MD. Processing times of TD, MD, and TD+MD were about 660, 250, and 300 min, and effective diffusivities (Deff) were 1.33 × 10-8, 3.88 × 10-8, and 3.57 × 10-8 m2/s, respectively. Compared with TD, the MD procedure resulted in significantly harder texture and lower rehydration ratio (p < 0.05). SEM images of dried beef indicated fractures and disruption after TD, while a compact structure was obtained with MD. Both salt types contributed a softer texture in rehydrated MD, but KCl did not change the hardness values of dried meat. MD could have great potential for drying meat by reducing drying time, and KCl could be applied as a substitute for NaCl without adversely affecting the structural quality.