Structural Basis for the Slow Digestion Property of Native Cereal Starches

Abstract

Native cereal starches are ideal slowly digestible starches (SDS), and the structural basis for their slow digestion property was investigated. The shape, size, surface pores and channels, and degree of crystallinity of starch granules were not related to the proportion of SDS, while semicrystalline structure was critical to the slow digestion property as evidenced by loss of SDS after cooking. The high proportion of SDS in cereal starches, as compared to potato starch, was related to their A-type crystalline structure with a lower degree of perfection as indicated by a higher amount of shortest A chains with a degree of polymerization (DP) of 5-10. The A-type amorphous lamellae, an important component of crystalline regions of native cereal starches, also affect the amount of SDS as shown by a reduction of SDS in lintnerized maize starches. These observations demonstrate that the supramolecular A-type crystalline structure, including the distribution and perfection of crystalline regions (both crystalline and amorphous lamellae), determines the slow digestion property of native cereal starches.

The influence of amylose-LPC complex formation on the susceptibility of wheat starch to amylase

“…Hydrolysis starts with the enlargement of these surface channels during heating allowing the enzyme to penetrate the core. The hydrolysis starts from the interior parts of the granules -a so-called inside-out digestion (Dona et al, 2010;Zhang, Ao, et al, 2006;Zhang, Venkatachalam, et al, 2006). Hence, starch in its crystalline structure is resistant to enzyme hydrolysis.…”

“…The GI describes the level of the postprandial glucose rise in blood as compared to ingestion of a standard dose of glucose (Zhang, Ao, & Hamaker, 2006;Zhang, Venkatachalam, & Hamaker, 2006). High peaks in blood glucose are considered a risk factor in diabetes type II.…”

“…For instance, endogenous lipids and phospholipids in cereal starches have the ability of complexation with amylose (Kwasniewska-Karolak, Nebesny, & Rosicka-Kaczmarek, 2008) thus rendering the amylose less susceptible to amylolytic enzymes (Nebesny, Rosicka, & Tkaczyk, 2002;Zhang, Ao, et al, 2006;Zhang, Venkatachalam, et al, 2006). In vivo and in vitro digestibility studies on the effect of these components have shown that they can considerably slow down the enzymatic digestibility (Singh et al, 2010).…”

Wheat Belly—An Analysis of Selected Statements and Basic Theses from the Book

“…The starch digestibility of different plant species is also dependent on the structure of the starch granule and its regions of semicrystallinity (21). Starch chemists describe the crystalline patterns of starches as having A, B, and C structures (22).…”

Comparative proteome analysis of A- and B-type starch granule-associated proteins in bread wheat (Triticum aestivum L.) and Aegilops crassa

“…In addition, due to the structure difference, the A-type starch granules have a higher susceptibility to hydrolysis than that of the B-type starch granules [48][49][50]. The A-type starch granule is more easily digestible than the B-type starch granule since it contains more short double helices than the B-type starch granule [48,51,52].…”