Preparation and evaluation of sunflower oil by enzymatic aqueous extraction

The objective of this study was to produce sunflower oil using pectinase, flavor protease, and alkaline protease. The optimal parameters for the enzymatic hydrolysis process were determined through sensory evaluation, resulting in a temperature of 120°C, a duration of 30 minutes, a polysaccharide to protein ratio of 2:1 for the enzymatic hydrolysate, and an enzymatic hydrolysate to oil ratio of 1:3. Under these specific conditions, the sunflower oil (K4) achieved the highest sensory score of 13.9, exhibiting a pronounced oily flavor alongside moderate baked and nutty flavors. Compared to the controls of first-grade sunflower oil (K1), sunflower kernel oil (K2) and sunflower oil prepared by roasting (K3), the acid value (AV) in K4 exhibited a statistically significant decrease compared to K2 and K3, conversely, the peroxide value (PV) and BaP content in K4 demonstrated a statistically significant increase compared to K1 and K2. Additionally, the tocopherols in K4 exhibited a lower concentration compared to K1, while the sterols were effectively retained and showed no significant difference to these control groups. The fatty acid composition of the four different sunflower oil samples were analyzed, revealing that the contents of oleic acid (C18:1) and monounsaturated fatty acid (MUFA) in K4 were significantly higher than K2, and there was no significant difference compared to K1. This investigation of the present study could provide a certain theoretical basis for the production of sunflower oil by enzymes.