Carotenoid composition of locally found seaweeds of Dakshina Kannada district in India

The alarming consequences of the current day lifestyle practices demand the need for natural metabolites. The recent shift of people's interest in natural therapy over synthetic medicine is gaining popularity. Carotenoids are one such group of pigments produced by photosynthetic organisms that have excellent antioxidant properties. Consumption of carotenoids is recommended for specific health benefits on the eye and the central nervous system. However, the increasing need for commercial availability of carotenoids has made it challenging for the researchers to identify better sources. The extraction of carotenoids for the production of nutraceutical-formulations requires the use of efficient sources concerning availability, production cost, extractability, and resourcefulness. Seaweeds are marine macroalgae that contain abundant photosynthetic pigments. Considering their availability and low cost of processing, seaweeds are a resourceful source of natural carotenoids like xanthophylls and provitamin-A carotenes. This study mainly focused on analyzing the carotenoid profile of locally found seaweeds of Dakshina Kannada district in India to understand their potential of using as an alternative source for commercial extraction of carotenoids. A total of 14 seaweeds including Chlorophyta, Rhodophyta, and Phaeophyceae were collected from the coastal belt of Mangaluru from selected representative stations. Xanthophyll carotenoids and provitamin-A carotenes were estimated and the former was found to be major pigments among the collected seaweeds. Results revealed the total carotenoid content in the order; Chlorophyta > Rhodophyta > Phaeophyceae. However, among the seaweeds studied only four showed the presence of β-carotene and α-carotene was detected only in Bryopsis sp. (40.72 μg/g). Among the xanthophyll carotenoids, lutein and zeaxanthin were detected in all the seaweed samples. Cladophora sp. showed the highest accumulation of lutein (248.67 μg/g) and zeaxanthin (50.20 μg/g). The findings of this study might consolidate the way to utilize natural bio-resources for commercial production of nutraceutical-formulations containing carotenoids.