Royal jelly is one of the most important products of honeybees. Given its role in development of bee brood
into fertile individuals of the royal caste it is also used in health products for human consumption. Royal jelly spoils and
loses its health-promoting properties depending on storage duration and conditions. To ensure product quality before
selling, it is therefore necessary to assess royal jelly freshness. Many indexes of freshness have been suggested, but they all
lack reliability or require complex and time-consuming analyses. Here we describe a method to detect royal jelly freshness
based on a chromogenic reaction between royal jelly and HCl. We demonstrate that analyses based on color parameters
allow for the discrimination of royal jelly samples based on the duration of their storage. Color parameters of royal jelly
stored at −18 and 4 ◦C for 28 d remained comparable to that of fresh samples, which supports the reliability of the
method. The method of freshness determination described is practical, cheap, and fast and can thus be used in real-time
when trading royal jelly