Investigation of the multiple biological effects of some vinegar and chemical compounds under in vitro conditions

In this study, some chemical and biological properties of hawthorn, rose, grape, cranberry, apple, and aronia vinegars were investigated; the findings were compared with four pure chemical compounds (2-hydroxycinnamic acid, methionine, amitriptyline HCl, and Fmoc-D-Val-OH). The pH values of the vinegar samples ranged from 3,18 to 3,51, which is consistent with the literature. Titration acidity varied between 0,92% and 2,76%, remaining below the minimum value specified in the TS 1880 EN 13188 standard. °Brix values were determined to be in the range of 1,5% to 4,5%. Total phenolic content ranged from 0,1347 to 1,3658 mg GAE/mL; the highest values were found in hawthorn, rose, and aronia vinegars. In PPO inhibition analyses, IC₅₀ values were found to be in the range of 0,0133–0,031 mg GAE/mL, and the strongest inhibitory effect was observed in apple cider vinegar. Among pure compounds, only 2-hydroxycinnamic acid was identified as a significant PPO inhibitor. In antimicrobial analyses, it was observed that the effects of vinegar samples varied depending on the type of microorganism. Grape vinegar was effective against Candida dubliniensis and Salmonella Enteritidis, while the highest efficacy against Pseudomonas aeruginosa was found in cranberry, hawthorn, aronia, and rose vinegars. Among pure chemicals, only amitriptyline HCl showed significant antimicrobial activity. DNA protection analyses revealed that apple cider vinegar and 2-hydroxycinnamic acid, exhibited a strong protective effect under oxidative stress. In conclusion, natural vinegar samples particularly those with high phenolic content may represent strong alternatives to pure chemical compounds in terms of PPO inhibition and DNA protection, while their antimicrobial efficacy appears to be highly dependent on the type of microorganism.