AbstractAmong the photosynthetic powerhouses of aquatic ecosystems, microalgae are now the most promising source of sustainable and bioactive compounds with massive potential in the functional food category. Unicellular cell plants differing the synthesis of various substances, including proteins, lipids, carbohydrates and pigmented substances, which are important to their living and contribute to the workout of human health. Carotenoids and polyunsaturated fatty acids (PUFAs) present in a wealth of compounds have been the most attractive compounds due to their antioxidative and anti-inflammatory properties, which may be beneficial in alleviating oxidative stress and chronic inflammation. Spirulina and chlorella are two of the most consumable microalgae. They have been developed commercially as nutraceuticals because they offer a useful nutrient profile that includes essential amino acids, vitamins, and minerals needed to maintain human health. Because of its diverse bioactivity, microalgae can be used to create functional foods that target particular health issues like metabolic disorders and cardiovascular diseases. Because microalgae can be grown on non-arable land with little freshwater requirements, they do not compete with traditional agriculture, which further justifies their integration into the food industry. Furthermore, the heterotrophic cultivation of microalgae techniques that depend on sources of organic carbon for growth offers a chance to raise the yield of bioactive compounds and possibly lower production costs. This strategy aligns with the biorefinery concept, which maximizes resource utilization and economic viability by using microalgae as a biotechnological platform to produce high-value nutraceuticals and biofuels simultaneously. Only a few microalgal compounds have been successfully commercialized, and most studies on them are still preclinical. However, continued research and technological developments in the processing and cultivation of microalgae are opening the door to a broader range of uses in functional foods.
