Harnessing the bioactive potential of Indian seaweeds through multivariate analysis

Seaweed is an important natural resource with wide-ranging applications in the food and health industries due to its bioactive properties. In this study, 30 types of seaweed collected from the Indian coast were analyzed for their antioxidant potential, focusing on total phenolic content (TPC), flavonoid content (FC), and their ability to scavenge free radicals, such as DPPH and hydrogen peroxide. The results revealed considerable variation in these properties among the species. Padina tetrastromatica exhibited the highest TPC at 52.39 ± 0.51 mg GAE g⁻1, while Champia sp. showed the lowest at 8.08 ± 1.85 mg GAE g⁻1. For flavonoid content, Spatoglossum asperum had the highest value at 49.68 ± 1.4 mg QE g⁻1, and Padina gymnospora the lowest at 14.84 ± 1.25 mg QE g⁻1. In ferrous ion chelating ability, Turbinaria sp. exhibited the highest at 48.94 ± 2.31%, while Sciania fasciularis recorded the lowest at 14.77 ± 0.35%. Caulerpa vervelansis demonstrated the highest DPPH radical scavenging activity at 74.86 ± 0.45%, and Sciania hatei showed the lowest at 24.98 ± 2.33%. The highest hydrogen peroxide radical scavenging activity was found in Ulva reticulata at 34.55 ± 0.56%, while Sciania hatei exhibited the lowest at 10.16 ± 1.81%. The study also examined the mineral composition of these seaweeds, revealing a wide range of mineral content. Potassium content varied from 7.37% in Turbinaria sp. to 1.22% in Hypnea musciformis, sodium content ranged from 4.75% in Gelidiella acerosa to 2.85% in Sargassum linearifolium, and calcium content ranged from 8.41% in Boodlea composita to 1.06% in Rhodymenia dissecta. Magnesium levels were highest in Gelidium micropertum at 1.866% and lowest in Portieria hornemannii at 0.764%. Iron content peaked at 1.42% in Gelidiella acerosa and was lowest at 0.07% in Grateloupia indica. Cobalt content ranged from 0.06‰ in Acrosiphonia orientalis to 0.01‰ in Sciania fasciularis, while zinc content ranged from 1.796‰ in Gelidium micropertum to 1.087‰ in Boodlea composita. Manganese content varied from 0.053‰ in Padina tetrastromatica and Sciania fasciularis to 0.005‰ in species like Spatoglossum asperum. Principal Component Analysis (PCA) revealed strong positive correlations between TPC, FC, and antioxidant activities, emphasizing the bioactive potential of these seaweed species. These findings highlight the significant nutritional and antioxidant properties of seaweed, confirming its value as a promising resource for industrial applications in various fields.