Background: In the present study, the usability of saponin rich extracts (soapwort and horse chestnut) was evaluated 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 (CMC) as a stabilizer and 3 min of whipping time. The foam produced using these conditions were dried at the different spreading thickness 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 the higher colour change and lower content of total phenolics, total monomeric anthocyanins, cyanidin-3-glucoside and delphinidin-3-glucoside. On the other hand, higher content of ascorbic acid and better antioxidant activity was determined in the samples dried at 70°C.

Conclusion: According to the obtained results, spreading thickness of 2 mm and drying temperature of 70°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. This article is protected by copyright. All rights reserved.

Keywords: Foam mat drying; foaming properties; pomegranate powder; saponin; stabilization.