Compositions and methods for producing starch with novel functionality

Patent metadata

Field	Value
Publication number	US-9988641-B2
Application number	US-201615135106-A
Country	US
Kind code	B2
Filing date	Apr 21, 2016
Priority date	Apr 5, 2016
Publication date	Jun 5, 2018
Grant date	Jun 5, 2018

Abstract

This invention disclosure relates to novel maize starch. The starch can be made from the newly developed waxy sugary-2 double-mutant maize that has low activity of Granule Bound Starch Synthase I (GBSSI), which results in low amylose level. The starch from newly developed waxy sugary-2 double-mutant is freeze-thaw stable and has high viscosity. In comparison with the starch of the existing waxy sugary-2 double-mutant maize, the new waxy sugary-2 double-mutant maize starch showed, inter alia, improved pasting profile, starch granule integrity, larger starch granule size, and higher viscosity.

First claim

What is claimed is:

1. A starch comprising:
an amylose content of from about 2 wt % to about 20 wt % as measured using an amylose/amylopectin assay kit; and
an aqueous starch pasting temperature that is at least about 5% greater than the starch pasting temperature of a control starch as measured using RVA analysis,
wherein, the starch is derived from a waxy-sugary 2 corn plant comprising at least one wxS allele in the endosperm.

2. The starch of claim 1 , wherein the amylose content is from about 8 wt % to about 15 wt %.

3. The starch of claim 1 , wherein the aqueous pasting temperature is from about 5% to about 14% greater than that of the control starch.

4. The starch of claim 1 , further comprising an enthalpy change of crystallinity of at least about 30% greater than an enthalpy change of crystallinity of the control starch as measured using RVA analysis.

5. The starch of claim 4 , wherein the enthalpy change of crystallinity is from about 70% to about 200% greater than an enthalpy change of crystallinity of the control starch as measured using a differential scanning calorimeter (DSC).

6. The starch of claim 1 , further comprising a distribution of starch granule sizes, wherein the distribution of starch granule sizes comprises at least about 40% fewer granules less than 5 microns compared to a proportion of granules less than 5 microns of the control starch as observed using a scanning electron microscope.

7. The starch of claim 1 , wherein the starch is a granule which exhibits increased integrity compared to the control starch as observed using a scanning electron microscope.

8. The starch of claim 1 , wherein the starch is capable of withstanding at least three freeze-thaw cycles.

9. The starch of claim 1 , wherein the starch is capable of withstanding at least three to at least five freeze-thaw cycles.

10. The starch of claim 1 , wherein the waxy-sugary 2 corn plant is generated by cross pollination of a first corn plant having the genotype of wxwxsu2su2, and a second corn plant having the genotype of wxSwxSsu2su2, or the genotype of wxSwxsu2su2.

11. The starch of claim 1 , wherein the endosperm of the waxy-sugary 2 corn plant has one dose, two doses, or three doses of the wxS allele, and the endosperm has the genotype of wxSwxwxsu2su2su2, wxSwxSwxsu2su2su2, or wxSwxSwxSsu2su2su2.

12. A method for improving at least one characteristics in a pasting profile of a starch comprising introducing at least one wxS allele into the endosperm of a waxy corn plant, wherein the resultant starch derived from the waxy corn plant comprising at least one wxS allele in the endosperm comprises an aqueous starch pasting temperature which is at least about 5% greater than a starch pasting temperature of a control starch as measured using RVA analysis, thereby improving at least one characteristic of the pasting profile of the starch compared a control starch.

13. A double-mutant corn plant, wherein the corn plant is homozygous recessive for the starch synthase IIa (su2) gene, and either homozygous or heterozygous for a mutated Granule-bound starch synthase I (GBSSI) gene, wherein the mutated GBSSI gene has less GBSSI activity than the wild type GBSSI gene (Wx), but has higher GBSSI activity than the recessive, loss-of-function GBSSI gene (wx).

14. The double-mutant corn plant of claim 13 , wherein the mutated GBSSI gene is the wx-Stonor (wxS) allele.

15. The double-mutant corn plant of claim 14 , wherein the plant is generated by cross pollination of a first corn plant having the genotype of wxwxsu2su2, and a second corn plant having the genotype of wxSwxSsu2su2, or the genotype of wxSwxsu2su2.

Assignees

• Corn Products Dev Inc

Inventors

• Jiang Hongxin
• Ostrander Brad
• Lane Chris

Classifications

• C12N9/1051

  Hexosyltransferases (2.4.1) · CPC title

• C08B30/044 Primary

  from corn or maize · CPC title

• C12N15/8241

  Phenotypically and genetically modified plants via recombinant DNA technology · CPC title

• C12Y204/01021

  Starch synthase (2.4.1.21) · CPC title

• C12Y204/01242

  NDP-glucose--starch glucosyltransferase (2.4.1.242) · CPC title