Starch spherulites having controlled enzymatic digestion

Patent metadata

Field	Value
Publication number	US-10443080-B2
Application number	US-201514714457-A
Country	US
Kind code	B2
Filing date	May 18, 2015
Priority date	Nov 20, 2012
Publication date	Oct 15, 2019
Grant date	Oct 15, 2019

Abstract

Starch spherulites are produced by debranching of amylopectin-containing starch into short linear α-1,4-linked glucans (e.g., short-chain amylose, SCA). The debranched linear glucans are directly converted into spherulites by heating the debranched starch mixture followed by cooling and crystallization to form well-developed spherulites. The spherulites exhibit controlled enzyme digestibility.

First claim

We claim:

1. A method of producing spherulites comprising linear α-1,4-linked glucans, said method comprising:
(i) forming an aqueous slurry comprising from 15% to about 50% by weight of a waxy starch material having an amylopectin content of greater than 50% by weight;
(ii) cooking said starch material by heating said aqueous slurry to a temperature of 110° C. to about 150° C. for 5 minutes to about 2 hours, thereby destroying the crystalline structure of said starch material and forming a cooked starch slurry;
(iii) cooling said cooked starch slurry to a temperature of 35° C. to 75° C., thereby forming a cooled starch slurry;
(iv) treating said cooled starch slurry with one or more enzymes capable of hydrolyzing alpha-1,6 linkages within amylopectin thereby causing debranching of said starch material and resulting in the creation of a debranched starch mixture having greater than 50% α-1,4-linked glucans by weight based upon the total starch weight;
(v) heating said debranched starch mixture to a temperature above the melting point of the starch contained therein and within the range of 160° C. to 210° C., thereby melting the starch contained in the debranched starch mixture and forming a melted starch mixture; and
(vi) either:
(a) cooling said melted starch mixture to a temperature of greater than 25° C. to 75° C. thereby crystallizing said spherulites, said spherulites having predominantly A-type crystallinity and an average particle size of 1 to 5 μm; or
(b) cooling said melted starch mixture to a temperature of from 0° C. to 25° C. thereby crystallizing the starch into said spherulites, said spherulites having predominantly B-type crystallinity and an average particle size of 5 to 10 μm.

2. The method according to claim 1 , wherein said enzyme treatment step results in said starch mixture having greater than 90% α-1,4-linked glucans by weight based upon the total starch weight.

3. The method according to claim 1 , wherein said one or more enzymes comprise isoamylase or pullulanase.

4. The method according to claim 1 , wherein said spherulites have melting point of between about 80° C. to about 160° C.

5. The method according to claim 1 , wherein said spherulites are resistant to enzyme digestion, exhibiting less than 30% digestion when exposed to an α-amylase-containing solution for 3 hours at 37° C.

6. The method according to claim 1 , wherein said waxy starch material has an amylopectin content of greater than 90% by weight.

7. The method according to claim 1 , wherein said debranched starch mixture comprises short-chain amylose (SCA).

8. The method according to claim 1 , wherein said spherulites comprise amylose molecules having an average molecular weight of less than 200,000.

9. The method according to claim 1 , wherein said spherulites comprise amylose molecules have a degree of polymerization of between about 10 to about 100.

10. The method of claim 1 , wherein said aqueous slurry comprises from about 25% to about 40% by weight of said waxy starch material.

Assignees

• Univ Kansas State

Inventors

• Shi Yong-Cheng
• Cai Liming

Classifications

• C12P19/14

  produced by the action of a carbohydrase {(EC 3.2.x)}, e.g. by alpha-amylase {, e.g. by cellulase, hemicellulase} · CPC title

• A23L29/35

  Degradation products of starch, e.g. hydrolysates, dextrins; Enzymatically modified starches · CPC title

• C12P19/16 Primary

  produced by the action of an alpha-1, 6-glucosidase, e.g. amylose, debranched amylopectin (non-biological hydrolysis of starch C08B30/00) · CPC title

• C12P19/04

  Polysaccharides, i.e. compounds containing more than five saccharide radicals attached to each other by glycosidic bonds · CPC title

• C08B30/18

  Dextrin {, e.g. yellow canari, white dextrin, amylodextrin or maltodextrin; Methods of depolymerisation, e.g. by irradiation or mechanically} · CPC title