Detection of Alternaria alternata infection in winter jujubes based on optical properties and their correlation with internal quality parameters during storage

•The quality traits and optical properties of infected jujube flesh were measured.•The μa at 680 and 690 nm presented chlorophyll, weight loss, ascorbic acid changes.•The μs′ at 700–920 nm were related to chlorophyll and a* of infected jujubes.•Optical properties can classify diseased jujubes after 3 d at 20 °C during storage.