Monitoring and Maintaining the Freshness of Royal Jelly: A Review of Analytical Approaches and Preservation...

Royal jelly, a high-value natural product rich in bioactive compounds, is highly susceptible to quality deterioration during storage and processing. However, current quality standards rely predominantly on basic physicochemical parameters and measuring the content of 10-hydroxy-2-decenoic acid (10-HDA), which fail to capture the comprehensive and dynamic nature of its freshness. This significant knowledge gap hinders the accurate assessment, prediction, and control of royal jelly quality throughout its supply chain. To address this limitation, this review systematically elucidates the molecular mechanisms underlying the deterioration of royal jelly freshness, including key pathways such as protein denaturation, Maillard reactions, enzymatic inactivation, and lipid oxidation, and analyzes the combined effects of intrinsic and extrinsic factors on its quality stability. It highlights the potential applications of novel biochemical markers-including major royal jelly proteins (MRJPs), Maillard reaction products, enzymatic activity indicators, and energy metabolites-while comparing the advantages and limitations of traditional chromatographic techniques with modern rapid sensing and spectroscopic analysis methods. Regarding preservation, a critical yet inadequately summarized area, this review systematically evaluates the applicability and limitations of various approaches, including low-temperature storage, drying treatments, non-thermal sterilization, microencapsulation, and modified atmosphere packaging. Future directions for integrated quality control are outlined, providing a theoretical basis for holistic quality management of royal jelly.