Research progress on fermentation technology and equipment for dry-cured ham

Dry-cured ham is one of the most popular meat products, produced from pork legs through trimming, salting, air-drying, and fermentation. As the longest and most crucial stage, fermentation determines the final quality and safety of the ham. While western and Chinese hams share similar origins, China's fermentation technology and equipment have trailed behind western standards, resulting in inconsistencies in quality and production efficiency. This review introduces the research progress on fermentation technology and equipment for dry-cured ham. The ham fermentation process mainly included moisture migration and salt penetration, accompanied by the enzymatic and microbial decomposition of proteins and lipids. Environmental parameters, such as specifically temperature, humidity, and airflow velocity are the primary factors governing the drying rate, salt diffusion, and biochemical activity. Suboptimal conditions, particularly inappropriate humidity and airflow, can lead to surface crusting, thereby compromising quality. Currently, the production of Chinese ham relies heavily on manual experience, and existing equipment often suffers from uneven temperature and humidity distribution, necessitating further optimization. To address these challenges, recent research has focused on enhancing equipment through advanced airflow configuration and integrated control systems. Innovations such as optimized air supply outlets and adhering jet systems have significantly improved the uniformity of the internal micro-climate. Furthermore, while heat pump dehumidification and waste heat recovery systems have been implemented, the inherent coupling of temperature and humidity complicates precise regulation. Consequently, independent control systems utilizing liquid desiccant or solid rotor dehumidification are being adopted to decouple these variables, enhancing both regulation accuracy and energy efficiency. Advanced control strategies, including proportional integral derivative control (PID), model predictive control (MPC), neural networks, and fuzzy logic control (FLC), are further refining these processes. Currently, the Chinese market lacks large-scale, intelligent fermentation equipment, with many producers relying on imported or rudimentary customized systems. This paper identifies three strategic directions for future optimization: the standardization of fermentation protocols, the modular design of fermentation warehouses, and the enhancement of equipment energy efficiency. By conducting in-depth research into fermentation mechanisms, airflow dynamics, temperature-humidity control and energy-saving technologies, future efforts should focus on developing standardized processes and modular, energy-efficient equipment tailored for Chinese dry-cured ham. Such advancements will address the diversified needs of different ham varieties and production scales. Ultimately, the integration of these technologies aims to achieve significant loss reduction, quality improvement, and operational efficiency, providing a robust technical foundation for the modernization and intelligent transformation of the dry-cured ham industry.