Fatty acids are distinctive components of royal jelly (RJ), serving as a crucial indicator for assessing the quality of RJ. This study aimed to establish a rapid and simultaneous quantification method for various fatty acids in RJ utilizing gas chromatography. An optimized two-step extraction process, incorporating ethanol and diethyl ether followed by derivatization with N,O-bis-(trimethylsilyl) trifluoroacetamide, was developed to enhance sensitivity and precision in detecting fatty acids. Validation of the methodology revealed excellent linearity (R² > 0.999), precision (relative standard deviation (RSD) < 1%), repeatability (RSD < 1%), and recoveries (94.4%–104%). Furthermore, the limits of detection and quantification were found to be low. The results indicated that the method offered reliable and consistent quantification of major fatty acids, thereby improving quality control for RJ and facilitating its applications in food, pharmaceutical, and biochemical research.

The objective of this study was to investigate the structural and antioxidative properties of royal jelly protein (RJP) at different degrees of hydrolysis (DH) by partial enzymatic hydrolysis. RJP was hydrolyzed by alcalase for 0 min, 15 min, 1 h, 5 h and 8 h to obtain hydrolysates at DH of 5.34%, 11.65%, 15.19%, 21.38% and 23.91%, respectively. With the increased DH, the RJP hydrolysates showed elevated antioxidative activities. The molecular weight of RJP hydrolysates was significantly decreased but their primary backbone kept unchanged. Analysis of circular dichroism spectra revealed that the enzymolysis reduced the content of α-helix but increased the contents of β-sheet, β-turn and random coil. Meanwhile, the surface hydrophobicity and fluorescence intensity of RJP hydrolysates were decreased and a red shift occurred. As the enzymolysis continued, the surface morphology of RJP was gradually changed from a sheet-like structure into microparticles. Changes in antioxidative activities and structures generally followed a DH-dependent manner, however these changes became insignificant for samples at DH beyond 20%. Taking into consideration of both effectiveness and productivity, the optimum enzymatic duration was determined at 5 h.