Organic solvent-free extraction of carotenoids from carrot bio-waste and its physico-chemical properties

The bio-wastes (like peels, seeds, etc.) from food industry are rich source of bio-active components, but are poorly managed. In present study, carotenoids were extracted from carrot pomace using ultrasonication and high shear dispersion techniques and flaxseed oil as green solvent (green biorefinery approach). Various combinations of time and temperature were used and final selection was made on the basis of maximum recovery of carotenoids. High shear disperser yielded maximum carotenoids (recovery 94.8 ± 0.08%). The total carotenoid content, antioxidant activity as ABTS, DDPH and FRAP and β-carotene of carotenoid rich extract from carrot pomace (CREP) were 82.66 ± 0.06 μg/g, 1596.04 ± 69.45 μg Trolox eq./ml, 380.21 ± 39.62 μg Trolox eq./ml, 941.20 ± 19.91 μM Trolox eq./ml, 78.37 μg/g, respectively were significantly higher (p < 0.05) when compared with the extracting medium. The L*, a* and b* values of CRE were 18.65 ± 0.037, 19.42 ± 0.21, 27.947 ± 0.65 and were significantly higher than extracting medium. The CRE could be used as a natural source of β-carotene and natural colorant for food applications.