Effect of chain length on the structure and physicochemical properties of active compound/linear dextrin composites.

Abstract Three linear dextrins (LDs) with different chain length were obtained through fractionating short-chain LD by gradient precipitation with 65%, 70% and 75% alcohol, signed as 65LD, 70LD, and 75LD, respectively. The LDs were employed to encapsulate arachidonic acid (ARA) and geranic acid (GA). Fourier infrared spectrometry, differential scanning calorimetry and thermogravimetric analysis confirmed the formation of ARA/LD and GA/LD composites. The ARA/65LD and GA/75LD composites showed higher crystallinity, indicating the formation of more ordered and compact structures in ARA/65LD and GA/75LD composites. The micromorphology of ARA/65LD composite was a clear ellipsoidal like structure, whereas GA/75LD composite presented a spherical shape. The release behavior, thermal, photochemical and antioxidant abilities of ARA and GA were improved after forming composites. Overall, the longer chain LD displayed better encapsulation efficiency with the longer chain ARA, while the shorter chain LD had higher encapsulation capability with GA.