Freshness determination of royal jelly by analyzing decomposition products of adenosine triphosphate

Abstract

Royal jelly (RJ), widely used in food products, is highly perishable. To ensure its quality, it is necessary to identify an indicator of RJ freshness. In this study, we measured the concentrations of adenosine triphosphate (ATP), adenosine diphosphate (ADP), adenosine monophosphate (AMP), inosine monophosphate (IMP), inosine (HxR), hypoxanthine (Hx), adenosine (Ao), and adenine (Ai) in RJ stored at different temperatures and for different storage periods. An F-value, defined as ratio between the sum of Ao, Ai, HxR, and Hx and the sum of ATP, ADP, AMP, IMP, HxR, Hx, Ao, and Ai, was evaluated as an indicator of RJ freshness. When the F-value of an RJ sample was evaluated, the equivalent biochemical age could be determined based on linear equations. An F-value of 20%, with an equivalent biochemical age of 60.69 days when stored at 4 °C or 6.82 days when stored at 30 °C, was the calculated RJ freshness threshold value in this study. This novel indicator could contribute to the establishment of standardized criteria for the identification of RJ freshness and provide more rigorous standards for harvesting, packaging, and storage procedures of RJ.