The implications of diet on health sustainability have assumed a major importance. Microcystis are able to enhance the nutritional content of conventional food and feed preparation and hence to positively affect humans and animal health due to their original chemical compositions, protein contents, antioxidant properties, vitamins and other biologically active compounds. Butylated hydroxytoluene 'BHT' is one of the synthetic antioxidant agents commonly used for food additives. Cyanobactria like Oscillatoria sp. and Microcystis aerungionosa, those are commonly available in the coastal zone of Puri District of Odisha State were capable of producing this compound. Extracts from these two species exhibited various degrees of antioxidant properties when they were tested with free radical scavenging assay. The highest antioxidant activity was observed in the extracts of Microcystic aerungionosa, which displayed a similar activity to synthetic BHT. Gas chromatography and mass spectroscopy analysis concluded that the compounds are very similar to the synthetic BHT. This synthetic antioxidant was produced in the cells irradiated with higher light intensity. More BHT was produced in the cells irradiated with a higher light intensity and its production was irradiance dependent. The quantity of cellular BHT displayed a positive correlation with antioxidant activity of the tested species. The present study confirms the production of natural antioxidant like BHT from these two species of Puri District of Odisha State which constitute a potential source for producing natural antioxidant.