Development of pressurized hot water extraction for five flavonoid glycosides from defatted Camellia oleifera seeds (byproducts)

•Five flavonoid glycosides were extracted from defatted C. oleifera seeds by using PHWE.•The experimental conditions of PHWE were optimized by using orthogonal array design.•Five flavonoid glycosides were quantified by HPLC/(−)ESI–MS-MS.•PHWE method showed higher extraction efficiency and shorter extraction time for the extraction of flavonoid glycosides when compared to traditional extraction methods.•PHWE is a simple, efficient, and excellent alternative method for the extraction of highly polar potent antioxidants (flavonoid glycosides) in defatted C. oleifera seeds.