U.S. Patent Granted for Advanced Processing of Huizhou Fermented Mandarin Fish

August 19 – A novel production method for high-quality, ready-to-eat fermented mandarin fish with room-temperature storage capability has been granted a patent by the United States Patent and Trademark Office (USPTO). This marks the first international Patent Cooperation Treaty (PCT) patent awarded in the field of advanced processing technology for Huizhou-style fermented mandarin fish.

The patent was jointly developed by Huangshan University, the Huangshan Fisheries and Fishing Vessel Supervision Station (Huangshan Aquaculture Station), and Huangshan Huimu Industrial Co., Ltd. Dr. Wu Yongxiang of Huangshan University is listed as the primary inventor.

As a representative traditional delicacy of the Huizhou region, fermented mandarin fish is widely appreciated for its distinctive flavor. However, advancements in processing technology and standardized production have long been constraints to its expansion into broader markets.

In 2017, Dr. Wu Yongxiang established a dedicated research and innovation team at Huangshan University focusing on fermented mandarin fish. The team has since been recognized as an Anhui Province Special Technology Commissioner Group, a Anhui Rural Revitalization Collaborative Technology Service Center, and a Huangshan Technological Innovation Center for Huizhou-style Prepared Dishes and Functional Bio-products.

The patented method combines a plant-derived antibacterial solution with mild heat treatment to achieve high microbial inactivation rates and significantly extend shelf life. This enables the product to be stored for up to 9 months at room temperature while improving overall quality.

Dr. Wu explained that the process involves steps such as thawing, washing and dicing, antibacterial and deodorizing treatment, freshness-locking immersion, low-temperature air-drying, oil-frying for shaping, and sterilization. Experimental results show a 9.32% increase in moisture content and a 17.84% improvement in water-holding capacity. Under accelerated storage conditions at 30°C, thiobarbituric acid content was reduced by 43.39% by the fifth month, indicating greatly enhanced safety and stability during storage. The patent had already been granted in China in January of this year.

This patent authorization represents a major breakthrough in core technology for high-end green food processing of Huizhou fermented mandarin fish, said Yang Yongsheng, Senior Advisor of the Huangshan Huizhou Fermented Mandarin Fish Industry Association. It provides solid technical support for standardizing, branding, and internationalizing this traditional specialty, paving the way for its entry into global markets.