Development of soy protein isolate-based orally disintegrating film: Improvement of disintegration speed, mechanical properties, and thermal stability by β-Cyclodextrin

Abstract

The effect of β-Cyclodextrin (β-CD) at different concentrations (0–20% w/w) on the function and properties of soy protein isolate (SPI)-based orally disintegrating films (ODF) was studied. The results of moisture content and contact angle indicate that the inclusion of β-CD enhances the moisture content and surface hydrophilicity of ODF. The thickness ODF samples is between 0.031 and 0.041 mm. Due to the addition of β-CD, ODF disintegration rates increased by 47.86%–64.62%. Scanning electron microscope, and mechanical analysis show that ODF with a β-CD concentration of 10% w/w has the best performance, presenting the smoothest surface, maximum tensile strength (TS) and elongation at break (EB). FTIR spectrum results show that there are physical entanglements and hydrogen bonding interactions between SPI and β-CD, and appropriate concentrations of β-CD (5% w/w and 10% w/w) can transform random coils into β-sheets. Once the concentration exceeding 10% w/w, β-CD will crystallize and precipitate on the ODF surface, which weakens the mechanical properties of the ODF and the strength of the SPI network structure. Thermogravimetric test results show that β-CD improves ODF thermal stability. This research offers a significant theoretical foundation for the advancement of ODF that are protein-based and not hydrolyzed.