Targeted determination and distribution of six rare ginsenosides in boiled eggs from laying hens fed ginseng extraction residue

Ginseng extraction residue is an agricultural and herbal-processing by-product that retains ginsenoside-related compounds and may serve as a feed ingredient. The occurrence and distribution of rare ginsenosides in eggs after dietary supplementation with this residue remain poorly characterized. This study established a UPLC-MS/MS method for determining six rare ginsenosides in boiled egg yolk and albumen under different dietary inclusion levels. A UPLC-MS/MS method was developed for the simultaneous determination of six rare ginsenosides, including Rg2, Rg3, Rh1, Rh2, F1, and compound K (CK). The method showed linearity over 1–100 ng/mL, precision RSDs of 1.27–2.68%, and spike recoveries of 80.72–87.07%. No target rare ginsenosides were detected in boiled eggs from the control group. In the 20% group, Rg2 concentrations were 4.697 ± 0.895 µg/g in yolk and 2.287 ± 0.297 µg/g in albumen. The corresponding Rg3 concentrations were 6.061 ± 0.482 µg/g and 2.982 ± 0.625 µg/g, respectively. Rg2 and Rg3 were the predominant target ginsenosides, with higher mean concentrations in yolk than in albumen. Albumen Rh1 and Rg2 and yolk Rg3 were higher in the 20% group than in the 10% group ( p < 0.05). Rg2 and Rg3 were detected in the supplemented-group eggs despite being undetected in the tested residue and basal diet. Dietary supplementation with ginseng extraction residue was associated with the detection of rare ginsenosides in boiled eggs from Black Silkie hens. The findings provide an analytical basis for evaluating this residue as a feed resource for ginsenoside-containing egg products. The origin of the detected compounds requires precursor tracking and paired analysis of raw and boiled eggs to distinguish biological from heat-related transformation.