Chitin nanocrystals as natural gel modifier for yielding stronger acid-induced soy protein isolate gel

• Published in: Carbohydrate polymers 2024-01, Vol.323, p.121446-121446, Article 121446
• Main Authors: Zhang, Qin, Sun, Ping, Xu, Zejian, Qu, Wenwen, Zhang, Yan, Sui, Xiaonan
• Format: Article
• Language: English
• Subjects: Acid-induced soy protein isolate gel; chitin; Chitin nanocrystals; crosslinking; gelation; gels; hydrogen; hydrophobicity; nanocrystals; particle size; Rheological properties; soy protein isolate; temperature; Thermal behavior; thermal stability
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2023.121446

This study aimed to enhance the rheological properties and thermal stability of acid-induced soy protein isolate (SPI) gels by incorporating chitin nanocrystals (ChNCs) and proposing a gelation mechanism. SPI gels exhibited pseudo-plastic behavior. Increasing ChNCs concentration from 0.00 % to 1.00 % improved G' values, recovery rate, and initial degradation temperature: from 75.6 Pa to 1024.3 Pa, 80.27 % to 85.47 %, and 261.5 °C to 275.8 °C, respectively. FTIR analysis confirmed electrostatic and hydrogen bonding interactions between SPI and ChNCs. Adding 1.00 % ChNCs reduced α-helix content from 19.7 % to 12.1 % while increasing β-sheet content from 46.5 % to 52.6 %. This led to protein unfolding, exposure of Trp residues, and orderly aggregation, forming a dense cross-linked gel network. Gel particle size increased from 185.5 nm (no ChNCs) to 504.4 nm (1.00 % ChNCs), with reduced surface charges. Hydrophobic and electrostatic interactions were key forces stabilizing SPI-ChNCs gels. These findings offer a practical approach to enhancing traditional acid-induced protein gel-based functional foods using naturally sourced chitin nanocrystals. [Display omitted]