Determination of protein and lipid oxidation products and some enzyme activities as freshness criteria of royal jelly

Royal jelly is a bee product with a rich chemical composition that has been evaluated as a functional and nutraceutical product in the pharmaceutical, food and cosmetic industries in recent years. Royal jelly, which is reported to be sensitive to heat, light and oxygen, can lose its nutritional and functional properties under inappropriate storage conditions. In this study, changes in the physicochemical, oxidation, enzymatic and antioxidant properties of royal jelly stored at different temperatures and time. It was determined that physicochemical stability was provided, oxidation was largely limited, and enzyme activities were significantly preserved in royal jelly samples stored at low temperature values (-20°C and +4°C). However, storage at room temperature caused changes in some physicochemical parameters, a rapid increase in the concentration of oxidation products and significant decreases in enzyme activities. Significant changes were detected in oxidation products depending on storage conditions, and it was determined that advanced oxidation protein products (AOPP) could be a suitable indicator for evaluating royal jelly freshness. The findings contribute to the development of reliable criteria for optimizing storage conditions and assessing the freshness of royal jelly.