Comparative evaluation of different enzyme pretreatment on the oxidative stability and volatile compounds of sunflower oil

Abstract

In order to determine the influence of enzyme pretreatment to modify the aromas of sunflower seed oil (SSO). In this study, different enzyme combinations prepared SSO as raw material, using reducing sugar, amino acids, oxidation stability, and basic aroma characteristics to compare the whole. The results show that reducing sugar increased approximately 1.5-fold after enzymatic hydrolysis. Arginine, lysine, and histidine decreased most after roasting. The combination of cellulase and protease showed the greatest increase in heterocyclic substances (from 1681.81 to 13865.84 μg/kg), resulting in a strong caramel and nutty flavor. Interestingly, it was identified by aroma extract dilution analysis (AEDA) combined with relative odor activity value (ROAV) that 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP) was a common key aroma compound in enzyme-treated SSO, and phenylacetaldehyde, furfuryl alcohol and acetic acid were considered to be important contributors to the aroma after cellulase, hemicellulose and pectinase treatment, respectively. All of these were newly identified as odorants in enzyme-treated sunflower oil. The enzyme-treated oil also had advantages in terms of oxidative stability, including the reduction of acid value and peroxide value. This work provides a feasible method to enhance the aroma flavor and extend the shelf-life of sunflower oil in future production.