Concentration of Pigments and Health-Promoting Bioactive Compounds from Annatto Seeds by Ultrafiltration

Abstract

The interest in extracting and purifying bioactive compounds from natural sources is growing due to the large health benefits of these substances. Annatto seeds are mainly used to produce dye pigments and represent a promising source of phenolic and antioxidant compounds. Here we propose the recovery of pigments and bioactive compounds from annatto seeds by sequential aqueous extraction and ultrafiltration processes. The aqueous extract presented bixin and total phenolic concentrations of 5.80 ± 0.32% and 2.02 ± 0.01 mgGAE g−1, respectively. According to the ABTS and FRAP methods, the antioxidant activities of the aqueous extract were 96.07 ± 0.35 and 111.30 ± 0.17 µMTE g−1, respectively. The ultrafiltration process through a polymeric 10 kDa membrane was able to retain almost all bixin and 62% of the phenolic molecules. A pronounced flux decay was observed during ultrafiltration due to cake formation on the membrane surface, and the steady state flux was 24.02 ± 0.16 kg h−1 m−2. Thus, the ultrafiltration process is a suitable alternative to concentrate bioactive compounds from the aqueous extract of annatto seeds. Graphical Abstract: [Figure not available: see fulltext.]