Pomolic acid as a stable botanical marker for authenticating loquat (Eriobotrya japonica) monofloral honey.

Monofloral honey from Eriobotrya japonica (Thunb.) Lindl. (MH-Erj) is highly valued for its distinctive flavor and potential health-promoting properties. However, its high economic value makes it particularly susceptible to adulteration, highlighting the need for a scientific and reliable method for authenticity verification. In this study, non-targeted metabolomic profiling was conducted using Orbitrap LC-MS on samples collected throughout the loquat plant-to-honey transformation process, including leaves, flowers, floral nectar, bee crop contents, and mature honey. Among twelve plant-derived compounds consistently detected in all samples, four (amygdalin, licarin A, pomolic acid, and ursolic acid) were selected as potential botanical markers. These candidate markers were subsequently quantified using targeted UHPLC-QqQ-MS/MS analysis, and their specificity was evaluated by comparing MH-Erj with non-loquat honey samples. Pomolic acid was identified as a promising botanical marker for MH-Erj, with concentrations ranging from 63.86 to 207.13 μg/kg. Stability studies demonstrated that pomolic acid exhibited excellent stability during 180-day storage at 4 °C (degradation <2%) and acceptable stability at 25 °C (degradation 2.48-7.66%), supporting its potential applicability as a relatively stable authenticity marker during storage. These findings establish pomolic acid as a reliable plant-derived authenticity marker, providing a scientific basis for developing traceable authenticity evaluation systems to ensure MH-Erj quality control, prevent fraud, and promote the standardization and sustainable development of the apiculture.