Foam-mat drying of potato powder: effect of foaming agents and preservatives agents on the physical attributes

Abstract

Foam-mat drying is known for drying aqueous or semi-aqueous food products. This study aimed to investigate the influence of foaming agents and preservatives on the physical attributes of foam-mat dried potato powder. The foaming agents used were whey protein isolate/WPI (5% w/w) and glycerol monostearate/GMS (5% w/w), while the preservatives agents were ascorbic acid (25, 50, 100 ppm) and sodium metabisulfite (25, 50, 100 ppm). The foaming agents and preservative agents were added to the potato slurry and were whipped using a food mixer for 10 min (velocity= 100 rpm). The foamed potato was then removed to a stainless steel tray and oven-dried at 60 °rc for 6 h. The results showed that the yield of 55-60%, moisture content of 3.5-8%, L*value/lightness of 85-92, a* value/redness of-2.7 to-0.5, and b* value/yellowness of 20-32. Foam-mat drying is a feasible method for producing potato powder and gives products retaining colour properties of the original potato slurry.