Determination of main components by capillary electrophoresis and antioxidant activities in anatolian royal jellies: discrimination by principal component analysis

Royal jelly (RJ), a secretion of worker honey bees, is a nutritionally valuable bee product known for its bioactive properties. Different regions offer distinct floral sources that bees feed on, resulting in a unique composition of the RJ they produce. Moreover, certain components of RJ are highly valued for the significant health benefits they offer humans. In this study, 15 RJ samples collected from 13 provinces across Anatolia were analyzed for their chemical composition and antioxidant properties. The glucose and fructose contents were determined by capillary electrophoresis with indirect UV detection, ranging from 2.05 to 7.69 g/100 g and 3.15 to 7.09 g/100 g RJ, respectively. The content of (E)-10-hydroxy-2-decenoic acid (10-HDA), a unique fatty acid marker of RJ, was quantified by CE-UV and found to vary between 1.17 and 3.17 g/100 g RJ. Gluconic acid, the predominant organic acid with antimicrobial properties, was determined using CE with capacitively coupled contactless conductivity detection (CE-C4D), and its concentration ranged from 0.50 to 4.59 g/100 g RJ. Antioxidant activity was evaluated through total phenolic content (TPC) and ferric reducing antioxidant power assays. TPC values ranged from 9.99 to 118.83 µg GAE/mL RJ. Principal component analysis effectively distinguished the RJ samples based on their chemical and antioxidant profiles, indicating a strong influence of geographical origin. The CE-based analytical methods employed provide reliable tools for quality control and standardization of RJ products, thereby supporting their potential for functional food and nutraceutical applications.