Nutraceutical properties of the marine macroalga Gayralia oxysperma

We analyzed Gayralia oxysperma (Monostromataceae, Ulvales) from coastal waters in India for nutrients and biochemicals including nutritionally important fatty acids and active radical scavenging properties. This seaweed had moderately high lipid and other biochemical components, which were comparable to levels in other nutritionally rich seaweeds. The species is an important source of Ca (2.74 mg g(-1)) and other essential elements with sufficiently low (below permissible limits) contaminant trace metals. There were four major fatty acids: palmitic acid (PA, C16; 34.6%), linoleic acid (LA, C18:2n-6; 15.8%), gamma-linolenic acid (GLA, C18:3n-6; 15%) and stearic acid (SA, C18; 9.6%). Totally saturated fatty acids predominated (TSFA, 57%), followed by polyunsaturated acids (PUFA, 39%); the monounsaturated fraction (MUFA) was smallest (3.8%). Antioxidant potential assessed through phenolic content, di(phenyl)-(2,4,6-trinitrophenyl) iminoazanium (DPPH), hydrogen peroxide (H2O2), reducing potential and metal chelating ability indicated a dose-dependent relationship of increasing activity with increased concentration. Thus, G. oxysperma has essential properties of nutritional, antioxidant and medicinal value for its use in dietary and pharmaceutical applications.