Assessing the stabilizing effect of xanthan gum on vitamin D-enriched pecan oil in oil-in-water emulsions

摘要

Oil-in-water emulsions of vitamin D incorporated in pecan oil were developed, using xanthan gum (XG) as a stabilizer. Fourteen formulations, composed of 2% surfactants, 5% pecan oil/vitamin D3 and 93% water were prepared in the presence of the hydrophilic Tween 20 degrees and lipophilic Span 80 degrees surfactants at different compositions. The hydrophilic/lipophilic balance (HLB = 10.70) of the oil phase, which led to the slowest rate of creaming and the lowest amount of creaming after 90 days, was chosen as the best composition of the nonionic surfactants. Using XG as stabilizing agent a 0.25, 0.5 and 1.0% concentrations, preliminary tests were carried out to evaluate the rheological properties and droplet size distribution of the emulsions. Their stability were also investigated after being submitted to environment stresses (centrifugation cycles, and storage at varying temperatures for 30 days). The emulsions prepared with XG at 0.5% concentration maintained their stability after five centrifugation cycles a 3000 rpm for 30 min, and after storage a 4, 25 and 40 degrees C, as revealed by rheological and droplet size measurements.