Cold plasma pretreatment enhances the structure and controlled release of neutral soybean protein isolate amyloid fibril emulsion gels loaded with resveratrol

This study adopted a cold plasma (CP) pre-treatment strategy to enhance the gelation characteristics of SPI (soybean protein isolate) fibrils. In this work, the effects of different CP treatment times (0–25 min) on the structure, interfacial properties, and rheological characteristics of neutral SPI fibrils and fibril emulsion gels were evaluated. The results indicated that CP treatment helped to promote the generation and maturation of SPI fibrils. Specifically, CP treatment for 5 min (SPIF-5) resulted in an increase in the average length of the fibrils by approximately 39.08 %, and the formation of a short-flexible fibril structure with higher hydrophobic and electrostatic interactions. Cryo-SEM images showed that SPIF-5 fibril emulsion gel had strong interfacial interactions and dense network structures, resulting in an increase in hardness and storage modulus by 67.03 % and 69.43 %, respectively. In contrast, CP treatment for 25 min induced the formation of amorphous fibril aggregates from SPI, leading to a decrease in the preparation efficiency of fibrils and the interfacial activity of emulsion gels. Moreover, using CP-modified SPI fibril emulsion gels as a delivery carrier not only effectively alleviated the degradation of resveratrol caused by heat/UV exposure, but also achieved a controlled release of resveratrol during the oral and intestine digestion stage. This study provides valuable insights for improving the gel performance of SPI fibrils and their application in delivery systems for hydrophobic components.