Cashew apple (Anacardium occidentale L.) extract from by-product of juice processing: a focus on carotenoids.

Cashew apple fibrous residue is a by-product of the cashew juice industry. After pressing using a helical type continuous press followed by crossflow microfiltration, an aqueous extract was obtained from these cashew apple fibres. It was characterised by an intense yellow colour due to carotenoid pigments. Carotenoids were identified and quantified in the cashew apple before extraction, in its aqueous extract and in the concentrate obtained by microfiltration. Cashew apple aqueous extract and its concentrate presented a carotenoid profile with 11 carotenoids, most of them were tentatively identified by HPLC-DAD-MS and are xanthophylls present under an esterified form. Auroxanthin and β-cryptoxanthin represented around 50% of total carotenoids. Concentration of the extract by microfiltration led to epoxy-furanoxy rearrangement of violaxanthin and antheraxanthin. The process allowed an increase of 10 times total carotenoid content compared with initial cashew apple. Total carotenoid content of the final concentrated extract reached 54 mg/kg.