<p>To assess the influence of guest compound hydrophobicity on encapsulation using citric acid-modified starch nanoparticles (mSNPs), saturated fatty acids with varying chain lengths (C:4–18) were subjected to nanoprecipitation using mSNPs at concentrations of 1, 3, and 5%. The interactions between fatty acids and mSNPs were characterized through transmission electron microscopy and Fourier-transform infrared spectroscopy, revealing the formation of spherical aggregates facilitated by hydrogen bonding and hydrophobic interactions. Higher mSNP content and fatty acids with longer chains resulted in larger composite sizes. Additionally, with an increase in the fatty acid chain length, the amount of bound fatty acids in the composites decreased, while the absolute zeta potential and hydrophobicity of the composites increased. In simulated intestinal fluid, the release of fatty acids from the composites exhibited a gradual pattern, with a delayed release rate observed for fatty acids with longer chain lengths.</p>