Synthesis and Characterization of Fatty Acid Oat β-Glucan Ester and Its Structure-Curcumin Loading Capacity Relationship

An amphiphilic fatty acid oat beta-glucan ester (FAOGE) was first synthesized, and its structure-curcumin loading capacity (CLC) relationship was investigated. The DS of product increased with the addition of acyl imidazole, decreased with Mw of beta-glucan, and did not relate to the acyl chain length. Characterizations by FT-IR and H-1 NMR evidenced the presence of ester groups in FAOGE and confirmed its successful synthesis. The aqueous self-aggregation behavior of FAOGE was revealed by transmission electron microcopy and dynamic light scattering. With the aid of response surface methodology, a quadratic polynomial equation was obtained to quantitatively describe the structure-CLC relationship of FAOGE by using M-w of beta-glucan, acyl chain length, and DS as variables. The CLC increased with Mw of beta-glucan and acyl chain length but maximized at a medium DS. The maximum CLC value was obtained as 4.05 mu g/mg. Hence, FAOGE is a potential candidate in solubilizing and delivering hydrophobic food ingredients.