Abstract: In this paper, the degree of molecular linearization of the maltdrier was measured: the degree of molecular linearization is bigger than that of the original flour ; the range of the differences of molecular size is bigger than that of the original flour; the potato maltdrier produced by heat stable α- amylase showed even granule with obvious cavity in relatively sponge like brokenstone structure. The granularity reduced notably, and it achieved the mimic sense of fat. The hydrolysate had the kindred crystal apex as the original flour. The results indicated that the maltdrier after hydrolysis and torrefaction still retained the crystal frame. The crystal degree of the hydrolysate was 14.6356%. The upper and lower limits were 10% and 40% respectively when the maltdrier was used in practice.

Key words: maltdrier of potato flour, heat stable α-amylase, fat mimics