Dynamic changes in the sensory properties, composition and antioxidant activity of sesame residues and oil during the preparation of sesame oil by aqueous extraction

The preparation of sesame oil by aqueous extraction is a traditional process with a long history. In this study, samples were obtained from key stages of the sesame oil process, such as baking, stone grinding, and hot water oil extraction, and the changes in sensory properties, composition, and antioxidant properties of the samples were studied to control product quality. The results showed that the flavor and color in sesame oil were mainly formed by Maillard reactions, and the two key stages for these reactions were roasting and hot water oil extraction. Adding hot water reduced the total amino acid, alkaline amino acid, and essential amino acid contents in the sample, corresponding to a significant increase in the total amount of brown matter, richness of taste, types of volatile nitrogen oxides, center dot OH scavenging ability, and Fe2+ chelating ability. In addition, the bitterness value and DPPH center dot scavenging ability of sesame residues were significantly positively correlated with the absorbance value of the sesame residue aqueous solution at 420 nm. The roasting process enhances the oxidative stability of oil during storage, while the water extraction process does not alter this stability.