Lycopene isplantA natural substance contained withinpigmentIt mainly exists in the mature fruit of tomato plants in the Solanaceae family. Acid value is a metric for the number of free carboxylic acid groups in a compound (such as fatty acids) or mixture. Under the conditions of fat production, acid value can be used as an indicator of hydrolysis degree, and under its storage conditions, it can be used as an indicator of rancidity. Due to the interference of lycopene's own color, it is difficult to determine the endpoint during manual titration. In this study, the potentiometric titration method was used to detect the acid value of lycopene, which has the advantages of simple operation and accurate results.