Influence of carrier oil on the physical stability and in vitro digestion of vitamin K lipid nanocarriers

The present study aimed to investigate the physical stability and in vitro digestion of vitamin K loaded lipid nanocarriers with different carrier oils. The incorporated vitamin K in nanocarriers was determined by the HPLC. The diameters of nanocarriers were 102.3-119.6 nm, and PDI and zeta-potential were lower than 0.3 and -40 mV, respectively, which means a stable dispersion system. The physical stability after heat, freeze (-18 degrees C) thaw, and salt treatments were maintained, but the size and PDI of nanocarriers with soybean oil significantly increased after freeze (-70 degrees C) thaw treatment. The destabilization of the dispersion by creaming was observed by turbidimetric measurements, which revealed that the nanocarrier prepared with coconut oil showed higher stability than others. The vitamin K retention after UV irradiation was higher in nanocarriers than in ethanolic solution. Moreover, nanocarriers with coconut oil were digested faster than others, due to their lower unsaturation degree and shorter chain length.