Effects of ultrasonic treatment on the maturation of Zhenjiang vinegar.

High-quality vinegars are traditionally produced by aging them in barrels or bottles. However, these processes are very time-consuming. To accelerate of Zhenjiang vinegar maturation, the ultrasound was used to treat the steeped vinegar. Results showed that, the optimum ultrasonic power, time and ethanol addition for aging vinegar were determined to be 50W/100mL, 75min and 0.75% (V/V), respectively. Under the optimum experimental conditions, the total amino acid of fresh vinegar decreased from 1082.259mg/100mL to 871.045mg/100mL. Several volatile components increased significantly, such as the total esters, aldehydes and heterocyclic. Total non-volatile organic acids increased from 202.59mg/10mL to 233.87mg/10mL. The changes of above-mentioned components develop towards the direction of mature vinegar. Coupling the HS-SPME/GC-MS analysis data with Principal Components Analysis, ultrasonic treatment vinegar was determined to be equivalent to 2-3years of natural aged Zhenjiang vinegar. This study has showed that ultrasound is promising not only in shortening the aging time and lowering costs for the vinegar-making industry, but also in producing fine vinegar.