Effect of foaming agent concentration and drying temperature on biochemical properties of foam mat dried tomato powder

The purpose of the study was to optimize the effective drying conditions and different foaming agent concentrations on the biochemical properties of foam mat dried tomato powder. Foaming was achieved by using egg albumin as foaming agent and sodium salt of Carboxymethyl Cellulose (CMC) as foam stabilizer with different concentrations. Drying was achieved by using different drying temperatures. The changes in different physicochemical properties of foam mat dried powder viz. total soluble solid (TSS), pH, ascorbic acid, titratable acidity, β-Carotene, DPPH radical scavenging activity were observed. Foams were prepared from different concentrations of egg albumin (3-7% w/w) and sodium salt of Carboxymethyl Cellulose (1%, 0.5%). The drying temperatures were varied from 60°C to 70°C. The drying time changes with different drying temperatures. It was found that the drying time decreased with the increased foaming agent concentrations as well as with higher drying temperature. It takes almost 13 hrs for drying at 70°C. TSS and pH content was increased with the increase of foaming agent concentrations and foam stabilizer's concentrations but decreased with the increasing temperatures. Ascorbic acid decreased with the increase of foaming agent concentrations and temperatures but increased with CMC concentration. Titratable acidity content of foam mat dried tomato powder was decreased with the increasing foaming agent concentrations but increased with the higher temperatures and decreased CMC concentration. β-Carotene contents increased with the increase of foaming agent concentrations but decreased with the increase of temperatures and foam stabilizer concentration. DPPH free radical scavenging activity increased with the increase of foaming agent, foam stabilizer and temperatures. Based on the maximum retention of physicochemical properties, the optimum treatment of foaming agent was found to be 7% egg white + 1% CMC at 60°C.