Impact of two different dehydration methods on saffron quality, concerning the prevalence of Saffron latent virus (SaLV) in Iran

•Various drying processes differentially affect saffron’s secondary metabolites.•Freeze-drying and dark-drying effect on metabolites vary as per SaLV infection.•Picrocrocin and safranal content differ in dark-dried samples from freeze-dried ones.•Kaempferol-3-O-sophoroside-7-O-glucoside content can differ by SaLV infection.•Dark-drying process improve lower content of crocins in SaLV-infected plants. The dehydration process is a prerequisite to preserve saffron for a long time. According to this process, saffron shows differences in the main compounds responsible for its quality (colour, taste, aroma, and flavonol content). At present, the freeze-drying method obtains dried products with the highest quality. Viruses can modify the physiology and metabolism of plants, being able to affect the activities of several enzymes. For this reason, the main compounds of saffron have been analyzed under two different dehydrating processes, freeze-drying and dark-drying, considering their infection status with the Saffron latent virus (SaLV). Results showed that the picrocrocin and safranal content enables to differ dark-dried samples from freeze-dried ones. Besides, the kaempferol-3-O-sophoroside-7-O-glucoside content allows differentiating between SaLV-infected (SaLV+) and uninfected (SaLV−) saffron samples. Moreover, our data suggest that the freeze-drying would decrease crocins content, and dark-drying can nullify the adverse effect of SaLV on crocins content.