Effect of Heat-Moisture Treatments on Digestibility and Physicochemical Property of Whole Quinoa Flour

Abstract

The starch digestion processing of whole grain foods is associated with its health benefits in improving insulin resistance. This study modified the digestibility of whole quinoa flour (WQ) via heat-moisture treatment (HMT), HMT combined with pullulanase (HMT+P), HMT combined with microwave (HMT+M), and HMT combined with citric acids (HMT+A), respectively. Results showed that all the treatments significantly increased (p < 0.05) the total dietary fiber (TDF) content, amylose content, and resistant starch (RS) content, however, significantly decreased (p < 0.05) the amylopectin content and rapidly digestible starch (RDS) content of WQ. HMT+P brought the highest TDF content (15.3%), amylose content (31.24%), and RS content (15.71%), and the lowest amylopecyin content (30.02%) and RDS content (23.65%). HMT+M brought the highest slowly digestible starch (SDS) content (25.09%). The estimated glycemic index (eGI) was respectively reduced from 74.36 to 70.59, 65.87, 69.79, and 69.12 by HMT, HMT+P, HMT+M, and HMT+A. Moreover, a significant and consistent reduction in the heat enthalpy (ΔH) of WQ was observed (p < 0.05), after four treatments. All these effects were caused by changes in the starch structure, as evidenced by the observed conjunction of protein and starch by a confocal laser scanning microscope (CLSM), the decrease in relative crystallinity, and transformation of starch crystal.

Effect of Heat–Moisture Treatment on the Physicochemical Properties, Structure, Morphology, and Starch Digestibility of Highland Barley (Hordeum vulgare L. var. nudum Hook. f) Flour

“…When the system moisture content was 15%, Δ H did not change significantly with the increasing heating temperature; however, this reduction in Δ H was pronounced when the system moisture content was 35%. The decrease in gelatinization enthalpy indicated that HMT promoted water molecules to enter the crystalline region from the amorphous region and destroyed the hydrogen bond in the starch, leading to the disintegration of the double helix in the crystalline region and the disruption of the amorphous region [ 29 ]. This effect could be exacerbated by an increase in heating temperature.…”

Valorization of Starch to Biobased Materials: A Review

“…The works of Corsato Alvarenga et al and Zarski et al, among many other researchers, also provided insight into the physical starch modification approach [ 94 , 95 ]. Heat-moisture treatment (HMT), HMT combined with pullulanase (HMT + P), HMT combined with microwave (HMT + M), and HMT combined with citric acids (HMT + A) were used to improve the digestion of whole quinoa flour (WQ) [ 64 , 96 ]. Results showed that all the effects were induced by changes in starch structure, as indicated by the confocal laser scanning microscopy (CLSM) observation of protein and starch together, the decrease in relative crystallinity, and the transformation of starch crystals.…”

Diversity of quinoa genetic resources for sustainable production: A survey on nutritive characteristics as influenced by environmental conditions

“…(Aluwi et al, 2017) evaluated maximal starch content in genotype "CO 407D" [64% in dry weight (dw)] and the lowest for "UDEC-1" (55%), both cultivated in the USA. Quinoa starch is rich in polysaccharide amylopectin, which represents 54-85% of dw (Dong et al, 2021;Kheto et al, 2022). Amylose content is, on the other hand, relatively low.…”

“…Overall protein digestibility can be improved by various processing methods (Rizzello et al, 2016;Lorusso et al, 2017;Dong et al, 2021;He et al, 2022), as well as sprouting (Jimenez et al, 2019). On the other hand, digestibility is reduced by the presence of starch, fiber (Opazo-Navarrete et al, 2019), and various antinutritional compounds (Gilani et al, 2012).…”