Emulsifying properties of naturally acetylated xylans and their application in lutein delivery emulsion

Xylans play an important role in dispersing and lubricating cellulose fibrils in lignocellulosic plant cell walls. However, the effect of acetylation on the dispersing and emulsifying properties of xylan is still unclear. In this study, we show that the natural degree of acetylation is vital to ensure xylan an excellent water solubility and emulsifying ability. Alkali extracted xylans were artificially acetylated to degree of substitution (DS_Ac) between 0.12 and 2.00, while the DMSO extracted originally acetylated xylan (OAX) shows a DS_Ac of 0.18. Artificially acetylated xylans (AX) with DS_Ac value similar to OAX shows water solubility and emulsifying ability similar to those of OAX and the best among all the AX samples with different DS_Ac. They demonstrate excellent emulsifying properties with an emulsifying activity of ~1.3 and an emulsion cream index of ~5 %. AX with the natural DS_Ac value also demonstrates strong barrier effects in preparing lutein delivery emulsions.