Standards Development

Scope

This International standard specifies requirements for chemical, microbiological and test methods of starch acetates.

Purpose

Starch consists mainly of amylose and amylopectin. Amylose is a linear molecule of -Dglucopyranosyl units linked by (1-4)-linkages. Amylopectin is a highly-branched polymer of -D glucopyranosyl units linked by (1-4)--linkages and by (1-6)- linkages that constitute the branch points. In general, each glucose unit possesses a maximum of three hydroxyls that can undergo chemical substitution. A fourth substitution is also possible if at the carbon four there is no involvement with the glycosidic bond. Native starches can be chemically modified for improved functionality. The most common sources of native starch used in these modifications are various roots, tubers, cereals and legumes. Modified starches are used in applications requiring special properties that are not attainable by their respective native starches.

Acetylated forms of food starches (including those extracted from hybrid crops such as high-amylose maize) are widely accepted additives that are used in the food supply globally. Starch acetate (INS No. 1420), produced by esterification of food starch with acetic anhydride or vinyl acetate, with the acetyl groups not exceeding more than 2.5% in the acetylated starch product is included in the Codex General Standard for Food Additives (CODEX, 2013).

Starch acetates is an example of a modified starch which increases the viscosity of starch pastes, paste clarity and freeze thaw stability. These properties are desirable to food manufacturers as they improve the products in which they are utilized for example: in sauces, fillings (e.g. pie) and dressings. Additionally, in some instances smaller quantities of modified starch is required to enhance the functional properties of the starch product, to achieve similar or better finished products attained potentially for economic benefits than native starch.

For example, the food and pharmaceutical manufacturers would benefit from this standard. This standard would provide a methodology of preparing acetylated starches as well as testing the extent of the modification to ensure that it is in the required limits and guidelines.