Comparative Analysis of the Physicochemical Properties, Changes in Volatile Substances and Antioxidant Capacity of Black Jujube Vinegar Egg Liquid

The differences in composition and function between black jujube vinegar egg liquid and white vinegar egg liquid were analyzed to develop the black jujube vinegar egg liquid with both nutritional and functional properties. The changes of polyphenols, phosphorus, amino acids and volatile components during the soaking process were tracked. The antioxidant capacity of the vinegar egg liquid and the different volatile components of the black jujube vinegar egg liquid and white vinegar egg liquid were investigated. The results indicated that the most suitable soaking method for black jujube vinegar egg liquid was secondary soaking. The concentration of polyphenols in black jujube vinegar egg liquid reached the peak at 40 h, which was 2.38 times as high as that before soaking. The concentration of phosphorus showed an overall increasing trend. Compared with soaked for 24 h, the total amount of amino acids in black jujube vinegar egg liquid soaked for 64 h were increased by 42.62%. The volatile components of the two types of vinegar egg liquid differed greatly during the soaking process, and the types of volatile components detected in black jujube vinegar egg liquid were about twice as many as that of white vinegar egg liquid. There were more ketones and aromatic hydrocarbon substances such as geranyl acetone in black jujube vinegar egg liquid, and its aroma was fuller. The radical scavenging rate of 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH), 2,2-azido-bis(3-ethyl-benzothiazole-6-sulfonic acid) diammonium salt (ABTS) radical scavenging rate, and the total reducing power (FRAP) results showed that the IC₅₀ values of black jujube vinegar egg liquid were lower than those of white vinegar egg liquid, which were 0.19, 0.31 and 0.66 mg/mL respectively, indicating that it had better antioxidant capacity. The results demonstrated that black jujube vinegar egg liquid was better than ordinary vinegar egg liquid in terms of nutrient composition and antioxidant capacity, which fully proved the superiority and feasibility of black jujube vinegar egg liquid.