From saffron residues to natural safranal: Valorization of waste through a β-glucosidase

Saffron (Crocus sativus L.) spice, traditionally used as food additive for its coloring and flavor-ing properties, has shown great potential to promote health. Among the main constituents of saffron spice, safranal has been shown to alleviate and prevent gastric disorders, cardiovas-cular diseases and to exert anticonvulsant, anxiolytic, antidepressive and neuroprotective activities. In this work, we recovered picrocrocin from saffron residues and efficiently bio-transformed it using a halo-thermophilic beta-glucosidase from Alicyclobacillus acidophilus (Aac), which gave the corresponding aglycone 4-hydroxysafranal with complete conversion (>99%) and rapid reaction times (15 min). After a thermic treatment, safranal was obtained in excellent yields. To make the process even more efficient and sustainable a one-pot, 2 -step chemo-enzymatic transformation was set up, yielding a marketable natural safranal as final product. (c) 2021 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Automated summary

Saffron, traditionally used as a food additive, has great potential for promoting health due to the presence of safranal as one of its main constituents. Efficient bioconversion of picrocrocin extracted from saffron residues using a halo-thermophilic beta-glucosidase can yield natural safranal. A one-pot, 2-step chemo-enzymatic transformation process has been established for more efficient and sustainable production.