Enzyme Resistant Dextrins from High Amylose Corn Mutant Starches

Abstract

This work was undertaken to investigate the effects of amylose content and chemical modification on enzyme resistant dextrin content of high amylose corn mutant dextrins. Dextrins made from high amylose corn mutant starches, including dull sugary 2 (du su2), amylomaize V, amylose extender dull (ae du), amylomaize VII, and chemically modified amylomaize V and VII, were characterized for moisture, solubility, reducing sugars, and enzyme resistant dextrin contents after dextrinization. Moisture content decreased, whereas soluble and reducing sugar contents rose rapidly in the first 60 min of conversion. Reducing sugar content began to decrease after 60 min of reaction, which corresponded to the onset of a rapid increase in enzyme resistant dextrin content. The enzyme resistant component in dextrin was not detected until fragments of low molecular-weight saccharides were produced by hydrolysis. These fragments recombined into randomly branched molecules that were resistant to enzymatic digestion. One proposed mechanism contributing to the lower enzyme resistant dextrin content of chemically modified high amylose corn dextrins is that the introduction of modifying groups to starch presented a steric hindrance for transglucosidation and repolymerization reactions during dextrinization, consequently resulting in lower enzyme resistant dextrin content.

Pressurization of some starches compared to heating: Calorimetric, thermo-optical and X-ray examination

“…Jane et al (1999) gelatinized 25% aqueous mixtures of normal maize (29.4% AML), Amylomaize V (52.0% AML), and Amylomaize VII (68.0% AML). Wang, Kozlowski, and Delgado (2001) reported that there was no correlation between apparent amylose content and peak gelatinization temperature for four high amylose corn (mutant) starches at 30% concentration, Amylomaize V (53% AML) and Amylomaize VII (70% AML) among them.…”

The effect of extrusion cooking on resistant starch formation in waxy and regular barley flours

“…Food processing which involve heat and moisture, in most cases destroys RS1 and RS2 but may form RS3. Some RS2 e.g in high amylose maize starch (HAMS) has been reported to be heat stable and can retain its resistance under commonly used food processing conditions (Thompson, 2000;Wang, Kozlowski, & Delgado, 2001). It has been reported Brown, 1996;Muir et al, 1995;Raben et al, 1994) that resistant starch has both physiological and health benefits in humans.…”

Resistant Dextrins as Prebiotic

“…In accessible throughout the whole products (resistant dextrin Nutriose, Fibersol) bigger percentage presence of (12)-, (13)-, (16)-and -glycoside bonds than in native starch which is the source of getting them [62,115].…”

“…Formation of bonds other than typical for starch, i.e. (14) and (16) causes that end product doesn't undergo hydrolysis through the human digestive enzymes [115].…”