The study compared the amount of piperine in different types of pepper. They used HPLC and UV methods to measure piperine in black pepper, pepper root, bell pepper, and white pepper. Results showed that black pepper has more piperine than pepper root, and white pepper has more than black pepper. Pepper from Xi'an has more piperine than from Hainan. Using brine to process pepper resulted in the highest piperine content, while vinegar led to the lowest. This research provides valuable information for ensuring the quality of pepper.