Effects of α‐maltotriohydrolase hydrolysis prior to debranching on the structure and digestibility of normal maize starch

Abstract

Gelatinized normal maize starch was hydrolyzed by glucan 1,4 α‐maltotriohydrolase (AMTS) to various degrees, and then debranched by pullulanase and retrograded at 4°C for 48 h to enhance the formation of type III resistant starch (RS3). AMTS hydrolyzes starch through combined exo‐ and endo‐action, and favors the production of maltotriose. After AMTS hydrolysis, the relative crystallinity and RS contents had all increased, and the highest relative crystallinity (59.2%) and RS content (40.8%) were obtained after 2 h of hydrolysis. The short‐length chains (degree of polymerization (DP) 13–30) and long‐length chains (DP > 130) were nearly simultaneously hydrolyzed by AMTS; thus, medium‐length chains with a DP of 30–130 accumulated after moderate hydrolysis. The results suggest that RS3 formation is affected by branch chain lengths, especially medium‐length chains (DP 30–130), and it can be improved when AMTS hydrolysis precedes debranching.

Structural factors governing starch digestion and glycemic responses and how they can be modified by enzymatic approaches: A review and a guide

“…In conclusion, crystallinity of debranched starch is a dominant feature responsible for the increased SDS and RS contents. We found a positive linear relationship (R 2 = .634, p < .001) between the relative crystallinity and the RS contents (analyzed as in Englyst et al, 1992) of 161 modified starches by debranching enzymes (Figure 4) (Bunyasetthakun et al, 2020;Cai & Shi, 2010Chang et al, 2020;Chen et al, 2017;Duyen & Van Hung, 2021;Hu et al, 2020;Huang et al, 2015;Liang et al, 2021;Liu et al, 2019Liu et al, , 2020Luckett & Wang, 2012;Miao et al, 2009;Ning et al, 2020;Shi et al, 2021;Villas-Boas et al, 2020;Villas-Boas & Franco, 2016;Wu et al, 2017;Zeng et al, 2014Zeng et al, , 2015Zeng et al, , 2016Zeng et al, , 2019Zhang et al, 2012;Zhou et al, 2020). In many cases, postmodification treatments such as storage at low temperature, hydrothermal treatments, and complexation with hydrophobic compounds were employed to promote crystallinity.…”

Effect of heat‐moisture treatment on the structural and physicochemical characteristics of sand rice (Agriophyllum squarrosum) starch

“…The powder method of XRD was applied to starch samples using a Bruker D8‐advance X‐ray diffractometer (Bruker AXS Inc.) (Wu et al., 2017 ). XRD pattern was scanned in a range from 3° to 35° (2 θ ) at 40 kV and 4 mA, with a step size of 3° per min.…”

Resistant starch formation in rice: Genetic regulation and beyond

“…A study showed that amylopectin retrogradation was affected by both external chain length and inter-block chain length ( Vamadevan and Bertoft, 2018 ). Similarly, an increase in amylopectin with medium-length chains enhances retrogradation in maize, thereby increasing the RS content ( Wu et al., 2017 ). These results suggest that medium- and long-chain amylopectin contributes to the formation of RS.…”