Optimization of Carboxymethyl Cellulose and Calcium Chloride Dip-Coating on Mushroom Slices Prior to Hot Air Drying Using Response Surface Methodology

Abstract

This paper deals with the key issue of the coating technology applied to button mushroom (Agaricus bisporus) slices prior to convective drying. Response surface methodology (RSM) was used to predict the effects and to optimize the concentrations of carboxymethyl cellulose (CMC) (0–3% w/w) and CaCl2 (0–2% w/w) on the quality of dried mushroom slices. The final product was evaluated in terms of responses such as water absorption capacity (WAC), dry matter holding capacity (DHC), rehydration ability (RA), scavenging effect (SE) assay, shear stress (SS) and color (L0 – L and ΔE). The results showed that WAC, RA, SE and SS increased and L0-L and ΔE decreased with CMC concentration increase. Based on response surface and desirability functions, the optimum product qualities in terms of RA (0.50), SE (78.51%), L0-L (20.86), ΔE (27.73) and SS (307.01 N/cm2) responses were obtained at 3% CMC concentration. Practical Applications Fresh mushrooms are very perishable and usage of the best postharvest techniques to enhance the shelf life and to maintain their quality plays a crucial role for commercialization. Materials with high moisture content such as mushrooms do not have a stable structure necessary during conventional dehydration; therefore, a special process must be developed to provide a crispy dried product. Using carboxymethyl cellulose (CMC) as a coating agent provided dried mushroom slices with better quality attributes, including more rehydration ability, brighter color and higher nutritional value (more antioxidant properties).