Enzymatic synthesis, structure of isomalto/malto-polysaccharides from linear dextrins prepared by retrogradation

Naixiang Xue; Yanli Wang; Xiaoxiao Li; Yuxiang Bai

doi:10.1016/j.carbpol.2022.119350

Enzymatic synthesis, structure of isomalto/malto-polysaccharides from linear dextrins prepared by retrogradation

Carbohydr Polym. 2022 Jul 15:288:119350. doi: 10.1016/j.carbpol.2022.119350. Epub 2022 Mar 15.

Authors

Naixiang Xue¹, Yanli Wang¹, Xiaoxiao Li¹, Yuxiang Bai²

Affiliations

¹ State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China; Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, Jiangsu 214122, China.
² State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China; Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, Jiangsu 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, Jiangsu 214122, China. Electronic address: ybai@jiangnan.edu.cn.

PMID: 35450622
DOI: 10.1016/j.carbpol.2022.119350

Abstract

Isomalto/malto-polysaccharides (IMMPs) with degree of polymerization (DP) 10-100 have novel potential applications, including enhanced solubility and anti-inflammatory. However, there are minimal synthetic methods for preparing IMMPs with a relatively higher DP, which is due to the lack of suitable molecular weight linear dextrins (I-LDs). The existing I-LDs preparation methods have disadvantages, such as low yield and uncontrollable molecular weight. Therefore, this study proposes a method for preparing soluble linear dextrins (S-LDs, M_w = 2.1 kDa) by low-temperature retrogradation from debranched waxy corn starch (M_w = 3.0 kDa). S-LDs reacted with 4,6-α-glucanotransferase GtfB-ΔN from Limosilactobacillus reuteri 121 to yield IMMPs with 12.3 kDa M_w and 83.8% α1 → 6 linkages content. Process monitoring revealed the synthesis mechanism and a detailed reaction process. Finally, IMMPs were identified by enzyme fingerprinting as α1 → 6 chains with α1 → 4 fragments inlaid at the reducing, non-reducing end, and middle part. This study provides a new synthesis method and more structural information for IMMPs.

Keywords: 4,6-α-Glucanotransferase; Isomalto/malto-polysaccharides; Linear dextrins; Retrogradation.

MeSH terms

Amylopectin
Dextrins*
Polysaccharides*
Starch / chemistry

Substances

Dextrins
Polysaccharides
Starch
Amylopectin