A Response Surface Analysis of Commercial Corn Starch Annealing

Native starch is composed of granules that are organized, durable, and morphologically identifiable microscopic structures of amylose and amylopectin molecules (Virtanen and Autio 1993; Snyder 1984). Sahai and Jackson (1994) reported that native starch granules from a single starch source were not homogeneous in character and had different functional properties. Because of their heterogeneity, it should not be expected that starch granules behave uniformly when heated in water (Sahai and Jackson 1996). The extent of heat treatment, starch hydration. and the inherent physical and chemical properties of native starch determine the structure and functionality of starch in a food system. During heating of native starch in water, some changes occur such as loss of birefringence, loss of crystallinity, granule swelling, leaking of amylose and amylopectin molecules from disrupted granules, and gelatinization (Eliasson and Gundmusson 1996). Starch functionality in food is governed by the inherent chemical and physical properties of its structures. One of the starch forms that exists in certain food systems is annealed starch. For example, corn steeped for tortilla processing is considered to have annealed starch (Gomez et al 1992; Sahai et al 1999). Krueger et al (1987a) postulated that annealing occurs during commercial wet-milling of corn starch, sometime after steeping but before starch drying. Annealing is a physical treatment that modifies the chemical and physical properties of starch without destroying granular structure