Preparation of acetylated distarch adipates by extrusion

Abstract Acetylated, cross-linked and pre-gelatinized cassava starches were produced in a single-screw extruder with different moisture contents (180, 220 and 260 g/kg), reagent–adipic acetic mixed anhydride-concentration (4, 11 and 18 g/kg) and screw speeds (100, 130 and 160 rpm). The acetylation, cross-linking and pre-gelatinization steps increased the cold viscosity, water absorption index and gel hardness, and reduced the gel cohesiveness, paste clarity and retrogradation of the starches produced. Products manufactured under less severe operational conditions (260 g/kg moisture and 100 rpm screw speed), and at higher reagent concentration (18 g/kg), had the major group of functional characteristics preferred for puddings, instantaneous desserts and foods subjected to low-temperature storage. Using 260 g/kg moisture, 11 g/kg reagent concentration and a screw speed of 160 rpm, the starch products gave high clarity, no syneresis and could be used in fruit pie fillings, soups and canned foods.