Enzyme-resistant starch and method for its production

Starch comprising an alpha-amylase resistant component, produced by:

• (a) providing an aqueous feed composition that comprises (i) starch that contains at least about 50% by weight amylose, (ii) water, and (iii) alcohol, wherein the concentration of starch in the feed composition is between about 5% and about 50% by weight, and wherein the pH of the feed composition is between about 3.5 and about 6.5;
• (b) heating the feed composition in a first heating step to a temperature between about 130-170° C. for about 0.1-3.0 hours;
• (c) cooling the feed composition to a temperature between about 4-70° C. for about 0.1-6.0 hours;
• (d) heating the feed composition in a second heating step to a temperature between about 1 10-150C for about 0.1-10.0 hours;
• (e) separating the starch from the majority of the water and alcohol;
• and
• (f) drying the starch.

A food product, comprising starch that comprises an alpha-amylase resistant component, the starch produced by:

• (a) providing an aqueous feed composition that comprises (i) starch that contains at least about 50% by weight amylose, (ii) water, and (iii) alcohol, wherein the concentration of starch in the feed composition is between about 5% and about 50% by weight, and wherein the pH of the feed composition is between about 3.5 and about 6.5;
• (b) heating the feed composition in a first heating step to a temperature between about 130-170° C. for about 0.1-3.0 hours;
• (c) cooling the feed composition to a temperature between about 4-70° C. for about 0.1-6.0 hours;
• (d) heating the feed composition in a second heating step to a temperature between about 110-150° C. for about 0.1-10.0 hours;
• (e) separating the starch from the majority of the water and alcohol;
• and
• (f) drying the starch.

Starch comprising an alpha-amylase resistant component, characterized by:

• having substantially lost its native crystalline structure;
• a differential scanning calorimetry melting point of about 150° C. at an enthalpy of about 5-20 Joules/gram;
• a water holding capacity less than about 3 grams of water per gram of dry starch;
• wherein about 82-90% by weight of the starch has a molecular weight less than about 350,000, and about 20-35% by weight of the starch has a molecular weight less than about 10,000.

A method of making an alpha-amylase resistant starch, comprising:

• heating high amylose starch in aqueous alcohol to a temperature above its gelatinization temperature, thereby destroying its native molecular structure;
• maintaining the mixture at or above the gelatinization temperature until the molecular weight of the starch has been reduced to a desirable range;
• and
• cooling the starch.

A method of making an alpha-amylase resistant starch, comprising:

• treating high amylose starch with aqueous acid to reduce its molecular weight to a desirable range;
• neutralizing the starch-water mixture with a base;
• concentrating or drying the starch;
• mixing the starch with alcohol and heating to an extent sufficient to gelatinize the starch, thereby destroying its native molecular structure;
• and
• cooling the starch.