Microwave irradiation to pretreat rosemary (Rosmarinus officinalis L.) for maintaining antioxidant content during storage and to extract essential oil simultaneously

► Microwave pretreatment enable high retention of CA and RA in rosemary during storage. ► Pretreated rosemary stored in the shade and −20 °C have better retention of CA and RA. ► Pretreatment and essential oil extraction processes were simultaneously carried out. ► Essential oils are quickly obtained through pretreatment process.