Hierarchical structure and slowly digestible features of rice starch following microwave cooking with storage. (15th October 2019)

• Record Type: Journal Article
• Authors: Li, Nannan; Cai, Zexi; Guo, Yan; Xu, Tong; Qiao, Dongling; Zhang, Binjia; Zhao, Siming; Huang, Qilin; Niu, Meng; Jia, Caihua; Lin, Lizhong; Lin, Qinlu
• Is Part Of: Food chemistry. Volume 295(2019)
• Page Start: 475
• Page End: 483
• Publication Date: 2019-10-15
• Subjects: Starch -- Microwave cooking -- Digestion feature -- Hierarchical structure; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2019.05.151
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: Microwave cooking-storage induced more orders than did conventional cooking-storage. Microwave cooking-storage induced more amorphous-crystalline structures. Microwave cooking-storage increased the content of slowly digestible starch. Microwave cooking-storage lowered the digestion rate of starch. The evolutions in starch digestion features were enhanced by the increased amylose. Abstract: By inspecting starch hierarchical structural evolutions, this work explores how microwave cooking with storage tailors the slowly digestible features of indica (IRS) and waxy (WRS) rice starches. Particularly, relative to conventional cooking-storage, the microwave treatment especially at high powers (8 and 10 W/g) increased the molecular orders (crystallites) and periodic amorphous-crystalline structures. Such changes facilitated the formation of domains with intermediately-densely packed starch chains, being modestly accessible to the diffusion, absorption and catalysis of enzymes and dominantly showing slowly digestible features. Consistently, the microwave processed starches showed a higher SDS (slowly digestible starch) level and a lower digestion rate. This microwave-enhanced SDS generation became more prominent for IRS, and the treated IRS at 10 W/g showed the highest SDS content ( ca . 54%). This is related to the enhanced reassembly of glucan chains into ordered/semicrystalline structures and the formation of slowly digestible domains as induced by the increase of amylose molecules.