Experimental characterization and dual-temperature molecular dynamics simulation on the intervention of tea saponin
Fan Wang1, Jianfu Shen1, Baiyi Lu1
1College of Biosystems Engineering and Food Science, Key Laboratory for Quality Evaluation and Health Benefit of Agro-Products of Ministry of Agriculture and Rural Affairs, Key Laboratory for Quality and Safety Risk Assessment of Agro-Products Storage and Preservation of Ministry of Agriculture and Rural Affairs, Zhejiang University, Hangzhou 310058, China.
Abstract:
In this work, the typical properties of starchy products were innovatively described as six types of chain dynamic behaviors. Dual-temperature molecular dynamic simulations, alongside multi-experimental methods, were employed to tandemly explore the intervention effect and mechanism of tea saponin (TS, 0 %-40 % w/w) on these behaviors. The findings reveal that the hydrophilic and hydrophobic ends of TS provide numerous sites for hydrogen bonding and steric hindrance, respectively, which hinder the formation of hydrogen bonds between starch chains. This interaction mode facilitated the chain unwinding (pasting temperature: 79.8 → 76.4 °C) and movement (viscosity: 267.67 → 38.92 Pa.s), and also retarded chain short/long-term reassociation (elastic modulus: 0.41 → 0.14 Pa/min; hardening rate: 2.72 → 0.07 gf/d) and rearrangement (hardness: 15.50 → 10.00 gf). Notably, a critical TS content was observed between 10 % and 20 % w/w, beyond which textural collapse (hardness: 15.50 → 10.00 gf) occurred. This research offers a new strategy and relevant theoretical backing for the property regulation of starch products.
