Pré-tratamentos na secagem e reidratação de champignon em fatias

Abstract

The objective of this paper was assessments the effect of pre-treatment (pt) in osmo-convective dehydration: Chemical pretreatment at 20°C for 5min with 0.1% solution of citric acid, sodium bisulfite and calcium carbonate (pt-ABC) and bleaching at 80°C for 5min (pt-B), as well the combination pt-ABC followed by pt-B (sample:solution = 1:10 w/w). The pt-ABC provoked mass increase (13% on average), while pt-B caused loss (-34% on average). Osmotic dehydration at 20°C for 60 min with 10% NaCl reduced mass of slices not pretreated at 43%. This level of mass reduction was not achieved for the pt-ABC, but it was improved for 49% to slices subjected to pt-B. Pretreatments reduced drying time (70°C and air circulation 18m3 h-1) from 150min to 60min to achieve the desired aw. Water activity of dried product was equal to or less than the commercial product. Slices subjected to pt-ABC or from control group had good rehydration capacity. Slices subjected to combined pt and dried showed lighter color and were less wrinkled. pt-ABC allowed very similar results. The pt-ABC must be used to obtain slices of dry champignon with visual aspect and rehydration capacity suitable for the development of new products for direct consumption or require rehydration.