Heat-Moisture-Treated Starch; Its Production, Properties, and Uses.

Abstract

Heat-Moisture-Treatment (HMT) was originated by V.L. Sair in 1944. It is a very interesting method to modify the structures and functions of starches. HMT is carried out by heating starch at 100-125°C under 100% relative humidity. Recently, much attention has been paid to HMT as a suitable method for modifying starch instead of chemical methods, from the viewpoint of health for uses for foods. However, it was not possible to produce commercially, because of difficulty in ob-taining a uniform product by partial gelatinization. We have solved this problem by introducing a new device suitable for both laboratory and industrial uses. The device consists of a combination of vacuum evacuation of a vessel containing starch and subsequent heating of the starch by introduc-ing live steam. This device provides a good uniform product in shorter time than conventional methods. We called it "reduced-pressurized heat-moisture treatment." Using this treatment (USP 5362329 (1994)), HMT has been recognized as one of the useful means of modifying starch, espe-cially for food uses. Heat-Moisture-Treated Starch (HMTS) swells but retains granular shape with-out dissolving by heating above 100°C in the presence of water. HMT increases the stability for acid and mechanical agitation in pasting. HMT increases hydrophiricity and decreases hydrophobic-ity of starch granules. On the contrary, HMT decreases hydrophiricity and increases hydrophobicity of starch paste. HMTS appears to be a suitable material for the production of retort foods, dress-ings, noodles, baked foods, batter products, confections, dairy products, creams, fat minetics and resistant starches.