Usability of soapwort and horse chestnut saponin extracts as foaming agents in foam mat drying of pomegranate juice

BACKGROUND This study evaluated the usability of saponin-rich extracts (soapwort and horse chestnut) as a foaming agent for foam mat drying of pomegranate juice. RESULTS According to the foaming and stabilization studies, the optimum conditions were determined as 0.4% of soapwort extract, 0.03% of carboxymethyl cellulose as a stabilizer, and 3 min of whipping time. The foams produced using these conditions were dried at different spreading thicknesses and drying temperatures. The results showed that the thicker spreading thicknesses provided a higher antioxidant activity. On the other hand, drying temperature had a significant effect on all measured parameters except moisture content and water activity. The higher drying temperature caused a greater colour change and a lower content of total phenolics, total monomeric anthocyanins, cyanidin-3-glucoside, and delphinidin-3-glucoside. On the other hand, a higher content of ascorbic acid and better antioxidant activity was determined in the samples dried at 70 degrees C. CONCLUSION According to the results obtained, spreading thickness of 2 mm and drying temperature of 70 degrees C were suggested for pomegranate juice powder production by foam mat drying. Overall, it was demonstrated that saponin-rich extracts are a good foaming agent alternative that provides foaming at very low concentrations and a product with high quality. (c) 2020 Society of Chemical Industry