Effects of rice protein on the formation and structural properties of starch-lipid complexes in instant rice noodles incorporated with different fatty acids

Abstract

Herein, the influence of rice protein (10%, w/w) on the formation of indica rice starch-lipid complexes in pure indica rice starch (IRS) system, and the influence of rice starch-lipid complexes formed in instant rice noodles (IRN) after the incorporation of fatty acids (FAs) on in vitro starch digestion were systemly evaluated. The viscoelastic properties of IRS samples increased after the incorporation of protein and lipids. The V-type diffraction intensity in IRS-lipid samples compounded with protein was greater than that of IRS-lipid samples supplemented without protein. In comparison to natural IRN samples, IRN fortified with FAs (especially for LOA) displayed significantly higher relative crystallinity (35.76%) and resistant starch content (14.42%). As shown by SEM, the microstructure of IRN incorporated with SA and LOA presented more denser and regular lamellar structures than those supplemented with shorter-chain FAs; confirmed by the significantly increased short-range order structure and better thermal stability. Collectively, this research may provide a deep understanding on how these three macronutrients (starch, protein, and lipids) interactions taken place during food processing, which might be helpful to develop novel stable foods with desirable digestive and functional properties in an innovative pathway.