In vitro fecal fermentation of acylated porous Canna edulis starch and corresponding stabilized Pickering emulsions.

ABSTRACT

In this study, acylated porous Canna edulis starch with varying degrees of substitution (DS) were prepared and employed for stabilizing Pickering emulsions. Subsequently, the fermentation characteristics of them were investigated. Enzymatically produced porous starch (PS) was esterified with acetic, propionic, butyric, or valeric anhydrides, yielding acetylated (PSA-0.116), propionylated (PSP-0.163), butyrylated (PSB-0.304), and valerylated PS (PSV-0.462) with different DS. Scanning electron microscopy revealed the presence of pores and surface micro-particles in the modified PS, confirming successful esterification through characteristic peaks in 1H NMR and a CO peak at 1736 cm-1 in the FT-IR spectrum. With increasing DS, starch exhibited reduced crystallinity (PSV, 26.61 %), elevated resistant starch content (PSV, 91.63 %), and a higher contact angle (PSV, 87.13°). Acylated PS particles effectively stabilized Pickering emulsions. Pickering emulsions stabilized by acylated PS with higher DS exhibited higher emulsification index and smaller droplet sizes. In vitro fermentation of acylated PS and corresponding stabilized Pickering emulsions fostered short-chain fatty acid production, boosted the relative abundance of beneficial bacteria (Bifidobacterium, Prevotella, etc.) while inhibited the growth of harmful bacteria (Escherichia-Shigella, Comamonas, etc.), maintaining the intestinal microbiota balance. These findings support the potential applications of acylated PS and corresponding stabilized Pickering emulsions in functional foods and drug delivery.