Insight into the effects of different storage methods on ginkgotoxin and ginkgotoxin-5’-glucoside in the embryo and endosperm of Ginkgo biloba seeds

The primary poisonous components in Ginkgo biloba seeds are ginkgotoxin (4’-O-methylpyridoxine, MPN) and its 5’-glucoside (MPN-5’-glucoside, MPNG). When Ginkgo biloba kernels are consumed in excess at one time, the total amount of MPN and MPNG (TMPN) can reach toxic levels. We investigated the effects of four storage methods (room temperature storage, sand storage, 4 °C storage, -20 °C storage) on MPN and MPNG levels and their distribution in embryos and endosperms of different Ginkgo biloba cultivars. Results showed that room temperature and sand storage promoted embryonic post-maturation of Ginkgo biloba seeds, whereas 4 °C and − 20 °C storage inhibited embryo development. During all storage treatments, the total TMPN mass in the whole kernel and its proportional distribution between embryo and endosperm remained stable, while the content concentrations (µg/g) of MPN, MPNG, and TMPN in the two tissues exhibited dynamic fluctuations driven by the interconversion of MPN and MPNG. Notably, over 93% of TMPN was concentrated in the endosperm across all storage conditions, with only 1.49 ± 0.00 ~ 5.04 ± 0.05%, 0.52 ± 0.02 ~ 6.13 ± 0.08%, 0.2 ± 0.00 ~ 2.01 ± 0.12% and 0.19 ± 0.00 ~ 2.36 ± 0.04% of TMPN detected in the embryo under room temperature storage, sand storage, 4 °C storage, and − 20 °C storage, respectively. This study refutes the long-standing misconception that the embryo is the most toxic part of Ginkgo biloba seeds and that mechanical embryo removal achieves effective detoxification, providing a scientific basis for the precise detoxification of Ginkgo biloba seeds.