Postmortem aging is a critical approach to improving the eating quality of meat, such as tenderness, juiciness, and flavor. There are three common aging methods, namely wet aging, dry aging, and their combination, each of which has its own characteristics. The final goal of these aging methods is to improve the edibility and palatability of meat. However, too long aging will lead to adverse effects such as severe mass loss and lipid and protein oxidation. Therefore, elucidating the postmortem aging mechanism of meat, monitoring and optimizing the aging process, and improving the eating quality of meat and simultaneously minimizing the quality defects caused by excessive aging are of great significance to the development of the meat industry. Although few studies have so far been reported on the monitoring and optimization of the meat aging process and meat quality prediction, precise control of the postmortem aging process will be an important development direction for the meat industry in the future. In this paper, the effects and mechanisms of different postmortem aging strategies on meat tenderness, flavor, color and oxidation stability are reviewed. Monitoring of the dry aging process based on mold coverage and electrical resistance on meat surfaces, and monitoring of the wet aging process based on meat exudate are discussed and future prospects are proposed in order to lay a theoretical foundation for the establishment of muscle-specific aging strategies.

Dry-aging is the aerobic aging process where meat carcasses or primal cuts are hanged and aged for a period of time (28 to 55 days, or even longer) under specific environmental conditions of temperature (0–4 ℃), relative humidity (61%–85%), and air flow (0.5–2.0 m/s). Dry-aging in a breathable bag, dry-aging combined with ultraviolet irradiation treatment, and stepwise dry/wet-aging have been successively developed. Due to dehydration during dry-aging, the surface of meat shrinks to produce a hard ‘crust’, resulting in significant mass loss and trim loss. However, compared with wet-aging, dry-aging can significantly enhance meat flavor characteristics, imparting a strong ‘dry-aged flavor’ and unique roasted beef-like, roasted nutty and buttery aromas to aged meat. Dry-aging can be used effectively to improve the eating quality and economic value of low-marbled beef. In this paper, the key parameters of dry-aging are reviewed, the potential mechanism by which dry-aging improves meat quality, especially flavor, is discussed. Future prospects for the application and development of dry-aging are discussed as well. This review will provide theoretical support for the development of the meat industry and for exploring the market for high-quality meat.