Blending of soluble corn fiber with pullulan, sorbitol, or fructose attenuates glycemic and insulinemic responses in the dog and affects hydrolytic digestion in vitro

Abstract

The objective of these experiments was to measure in vitro hydrolytic digestion and glycemic and insulinemic responses of select carbohydrate blends, all containing the novel carbohydrate soluble corn fiber (SCF). Two SCF that varied in their method of production were used to formulate the carbohydrate blends. One set of blends contained a SCF that was spray dried (SCFsd) and then blended with different amounts of either pullulan, sorbitol, or fructose. The other set of blends contained a SCF produced using longer evaporation time (SCF) and then blended with different ratios of pullulan, sorbitol, and fructose. Free sugar concentrations found in the individual SCFsd and SCF substrates were low but varied. Spray-dried soluble corn fiber had a reduced free sugar concentration compared with SCF (2.8 vs. 14.2%). Glucose was the main free sugar found in both SCFsd and SCF but at different concentrations (2.7 vs. 12.7%, respectively). The majority of the SCFsd blends were completely hydrolyzed to their monosaccharide components. Glucose accounted for most of the hydrolyzed monosaccharides for SCFsd and all the SCFsd blends. Hydrolyzed monosaccharide concentrations for the SCF:pullulan:sorbitol:fructose blends followed similar trends to the SCFsd blends where greater percentages of fructose and sorbitol resulted in decreased (P < 0.05) hydrolyzed monosaccharide concentrations. The SCFsd blends had intermediate to high amounts of monosaccharides released as a result of in vitro hydrolytic digestion. The SCFsd:pullulan blends were more digestible in vitro (approximately 91%; P < 0.05) than SCFsd:fructose or SCFsd:sorbitol. Total released monosaccharides were high in SCFsd blends containing either 50% fructose or sorbitol, but the combination resulted in reduced concentrations of glucose released (P < 0.05). The SCF:pullulan:sorbitol:fructose blends also had intermediate to high released monosaccharides as a result of in vitro hydrolytic digestion. All SCF blends resulted in decreased glycemic and insulinemic responses compared with the maltodextrin control (P < 0.05) using a canine model. The addition of pullulan reduced the glycemic response compared with maltodextrin at all concentrations, but only 50:50 SCFsd:pullulan resulted in a reduction of the glycemic response compared with SCFsd alone (P < 0.05). The addition of fructose and sorbitol in the blends had the greatest impact on glycemic and insulinemic responses, even at concentrations as low as 5% of the blends. Overall, SCF and their blends may prove beneficial as components of low glycemic foodstuffs.

Alternative Dietary Fiber Sources in Companion Animal Nutrition

“…In agreement with the glycemic response, all soluble corn fibers had lower (1.3–3.0 kcal/g) true metabolizable energy in contrast to maltodextrin (4.1 kcal/g; p < 0.05) [34]. A similar study examined the effects of blends of soluble corn fibers with pullulan and sorbitol, both slowly digestible carbohydrate sources, and fructose, a non-insulinemic sugar [35]. In this study, soluble corn fiber had an in vitro hydrolytic digestion of approximately 50%.…”

“…Soluble corn fiber and its blends had lower glycemic and insulinemic responses than maltodextrin. The lowest glycemic response was observed for blends containing 30%–50% fructose or sorbitol, resulting in an average relative glycemic response of 4.8% in contrast to maltodextrin (100%) [35]. Similar to soluble corn fiber, corn-based soluble fiber dextrin, produced by submitting corn starch to a thermal, chemical and enzymatic treatment, has been shown to lower glycemic and insulinemic responses by as much as 27% and 20%, respectively, in adult dogs and to have lower true metabolizable energy (37%) using the cecectomized rooster model when compared to maltodextrin [36].…”

In vitro hydrolytic digestion, glycemic response in dogs, and true metabolizable energy content of soluble corn fibers

“…These blood glucose patterns were consistent with sugar composition data. Although G1-SCF-hydrog had a greater free sugar concentration than G1-CS-HCl, G1-SCF-HCl, and G1-SCF-SD, the increased concentrations of sorbitol and fructose are likely explanations for the lack of a glycemic response (de Godoy et al, 2013). Free sugar and released monosaccharide data show that G1-CS-HCl, G1-SCF-HCl, and G1-SCF-SD have glucose available for digestion, as reflected in the intermediate blood glucose responses.…”