Structure and in vitro digestibility of amylose–lipid complexes formed by an extrusion-debranching-complexing strategy

• Published in: Food chemistry 2024-03, Vol.437, p.137950-137950, Article 137950
• Main Authors: Liu, Qing, Guan, Huanan, Guo, Yuanxin, Wang, Dongxu, Yang, Yueyue, Ji, Hangyan, Jiao, Aiquan, Jin, Zhengyu
• Format: Article
• Language: English
• Subjects: Amylose; corn; corn starch; Debranched starch-lipid complex; digestibility; dissociation; dodecanoic acid; electron microscopy; enthalpy; Extrusion; food chemistry; industry; pullulanase; Resistant starch; temperature; Thermal stability
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2023.137950

[Display omitted] •Amylose-lipid complexes are prepared by an extrusion-debranching-complexing method.•Both long and short amylose formed ordered form II complexes with lauric acid.•The enthalpy change of amylose–lipid complexes could reach 9.42 J/g.•The resistant starch content of the amylose–lipid complexes was greater than 30%.•The proposed strategy for preparing resistant starch is feasible and efficient. The formation of amylose–lipid complexes, known as resistant starch type Ⅴ (RS5), is limited by the low content of amylose in natural starch, increasing the amylose content is an effective approach to improve the yield of RS5. In this paper, an extrusion-debranching-complexing strategy with two extrusions was proposed to increase the formation of amylose–lipid complexes. A combination of corn starch (CS), pullulanase (60 U/g, w/w), and lauric acid (LA) with different contents of 4 %, 6 % and 8 % (w/w) generated enzymatically debranched extruded corn starch-lauric acid (EECS-LA) complexes after the second extrusion. The EECS-LA complexes were ordered form II complexes, with a significantly improved short-range molecular order. The melting temperature was in the range of 105–145℃. The enthalpy change increased with the increase of LA content and the value was 9.42 J/g for EECS-8 %LA complexes; these complexes could reform after dissociation. Scanning electron microscopy examination of the EECS-LA complexes revealed an irregular lamellar structure. The RS content of EECS-LA complexes increased significantly, achieving a value of 38.34 % for EECS-8 %LA complexes. This extrusion-debranching-complexing strategy is effective for preparing RS5 and could be useful in industry for the continuous production of RS5.