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

Abstract

The objective of this research was to measure in vitro hydrolytic digestion, glycemic and insulinemic responses in dogs, and true ME (TMEn) content of select soluble corn fibers (SCF) in roosters. The first generation (G1) SCF included hydrochloric acid-treated corn syrup (G1-CS-HCl), an SCF with an increased total dietary fiber (TDF) content (G1-SCF-HCl), an SCF that was spray-dried (G1-SCF-SD), and a hydrogenated SCF (G1-SCF-hydrog). The second generation (G2) SCF included those prepared using phosphoric acid catalyzation in both a liquid [G2-SCF-phos (Lq)] and powder [G2-SCF-phos (Pw)] form, and SCF that were prepared using hydrochloric acid catalyzation in both a liquid [G2-SCF-HCl (Lq)] and powder [G2-SCF-HCl (Pw)] form. Also, in the G2 set of samples were SCF prepared using the same method, but in 3 separate batches, all of which contained 70% TDF and 15% sugars. Two were in liquid form [G2-SCF-phos+HCl (Lq1)] and [G2-SCF-phos+HCl (Lq2)], and one in powder form ([G2-SCF-phos+HCl (Pw)]. A lower sugar form (80% TDF and 5% sugar) of SCF was also evaluated (G2-SCF-low sugar). Glucose was the major free sugar and bound monosaccharide in all SCF except for G1-SCF-hydrog that had greater concentrations of sorbitol. All SCF had intermediate to low amounts of monosaccharides released as a result of in vitro hydrolytic digestion, with glucose being the primary sugar component released. The G1-SCF were more digestible in vitro (approximately 50%) compared to G2-SCF (approximately 32%). All SCF had attenuated glycemic responses in adult dogs compared to a maltodextrin control (P < 0.05). The G2-SCF, on average, had lower glycemic responses and TMEn values in roosters than G1-SCF. All SCF had low free sugar concentrations with varying degrees of resistance to digestion, reduced caloric content, and attenuated glycemic and insulinemic responses in adult dogs. These ingredients are potential candidates for inclusion in reduced calorie and low glycemic canine diets.

Alternative Dietary Fiber Sources in Companion Animal Nutrition

“…Soluble corn fibers, when orally provided to adult dogs, resulted in lower glycemic and insulinemic responses when compared with maltodextrin ( p < 0.05), a highly digestible and rapidly absorbable carbohydrate used as a positive control. 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 vitro hydrolytic digestion, glycemic and insulinemic responses and true metabolizable energy using canine and avian models have been measured on a series of soluble corn fibers originating from different processing methods: hydrochloric acid and (or) phosphoric acid catalyzation, hydrogenation and spray-drying [34]. Among the soluble corn fibers, glucose was the primary free and bound monosaccharide after in vitro hydrolytic digestion, except for the hydrogenated fiber source, which had a greater concentration of sorbitol.…”

Amino acid digestibility and nitrogen-corrected true metabolizable energy of mildly cooked human-grade vegan dog foods using the precision-fed cecectomized and conventional rooster assays

“…However, in recent years, the cecectomized rooster assay has become a more popular alternative because it can be used to evaluate individual ingredients, experimentation requires a shorter length of time, and it comes with fewer animal welfare concerns and expense than ileal-cannulated dogs ( Deng and Swanson, 2015 ). Conventional roosters have been used in past studies to estimate the TME n of individual ingredients and complete and balanced pet foods ( Knapp et al, 2010 ; de Godoy et al, 2014 ; Oba et al, 2020 ).…”

Evaluation of soluble corn fiber on chemical composition and nitrogen-corrected true metabolizable energy and its effects on in vitro fermentation and in vivo responses in dogs

“…Our TMEn value of 2.6 kcal/g is accurate because the SCF used in this study was treated with hydrochloric acid and was consistent with the TMEn value obtained previously using the same processing method (2.4 kcal/g; de Godoy et al, 2014). The variation in TMEn values of different SCF substrates has been attributed to differences in processing methods and molecular structures of the carbohydrates (de Godoy et al, 2014).…”