NATURAL INDICO FROM ISATIS TINCTORIA L. FOR THE VALORISATION OF SICILIAN CROPS
Isatis tinctoria L. or woad (Brassicaceae) is an upright herbaceous biennal species up to 120 cm in height. It is in Mediterranean counlries, a common plant cultivated through out centuries to produce the blue dye indigo. With increasing concem for sustainability and a demand from consumers for naturally sourced products, there is a revival of interest in naturai indigo as an agricultural crop produci. Indigo is formed after the extraction of indigo precursors in the leaves of these plants: mainly isatans in woad These compounds are extracted by steeping leaves in warm water. With woad, the addition of alkali to the steep water releases free indoxyl, which forms indigo after a vigorous aera…