Standardizing traditional TCM processing for modern needs

For centuries, traditional Chinese medicine processors had no thermometers or automated equipment to tell them when a herb was ready to be dispensed.

Instead, they observed its color, smelled its aroma and judged the heat through years of practice. These skills, passed down from masters to apprentices, became part of paozhi — the traditional methods used to process raw herbs before they are prescribed.

The methods worked but no one could fully explain the methodology.

That question has occupied professor Yang Ming and his colleagues at Jiangxi University of Chinese Medicine for nearly four decades.

Their efforts recently earned the team the second prize in the 2025 State Scientific and Technological Progress Award.

Supported by a series of national-level research programs, the researchers have spent years studying traditional herbal processing techniques — not only to preserve them, but also to understand how they work and make them suitable for modern pharmaceutical production.

"Paozhi is unique to traditional Chinese medicine," Yang said. "Raw herbs often need to be processed before they are prescribed. Depending on the herb, processing can reduce toxicity, enhance efficacy or change its medicinal properties."

Many of these techniques have been practiced for hundreds of years, but they were preserved largely through experience rather than scientific evidence. "People knew the methods worked," Yang said. "But they couldn't explain why they worked."

One of the team's biggest challenges involved xianzhuli, or fresh bamboo sap, a traditional medicine commonly used to relieve phlegm and treat certain respiratory and neurological conditions.

Ancient medical texts describe two traditional methods for making it. One heats fresh bamboo directly over an open fire. The other seals bamboo inside clay containers before heating it. Both depend heavily on the processor's experience.

When researchers first tried to reproduce the ancient techniques, the results were inconsistent.

The team carried out repeated experiments, adjusting the temperature and heating process again and again. At times the bamboo burned before enough sap could be extracted. And other times, it produced little more than water. Even when the liquid looked right, its quality varied from batch to batch.

After multiple attempts, the team discovered that temperature control was a key component.

The researchers found that the compounds needed for the medicine formed efficiently only within a relatively narrow temperature range — between 160 C and 230 C. At lower temperatures, the bamboo released mainly water. At higher temperatures, it began to carbonize, producing unwanted impurities. The discovery changed the way fresh bamboo sap can be optimally produced.

Instead of relying on a craftsman's judgment, the team developed a temperature-controlled, oxygen-limited distillation system that keeps the process within the optimal range from beginning to end while preventing excessive oxidation.

According to the project team, the technology increased processing capacity by 3.6 times while reducing smoke emissions by 92.3 percent. It has also been used to build China's first fully automated and intelligent GMP production line for traditionally dry-distilled fresh bamboo sap.

Fresh bamboo sap is only one example. The researchers also examined dozens of other traditional processing techniques, including qingdai, a medicinal indigo product. By identifying the biological and chemical processes behind traditional fermentation and purification, they developed new technologies that improved product quality and consistency.

Over nearly four decades, the team has developed 11 key technologies, eight sets of specialized equipment and four automated demonstration production lines. Their work has enabled the standardized, large-scale production of 97 types of processed Chinese medicinal materials. Over the past three years, the technologies have been applied by more than 1,900 pharmaceutical companies and drug-testing institutions across China.

For Yang, modernization is not about replacing traditional knowledge. "Ancient techniques were developed through generations of practice," he said. "Our job is to understand them scientifically, so they can be preserved, reproduced and passed on."

The team is now working on digital databases, intelligent quality-monitoring systems and more affordable equipment for manufacturers. It is also taking part in developing international standards for TCM processing, with the hope that more traditional techniques can be understood and applied beyond China.