Comprehensive Characterization of the Nutritional Composition, Mineral Profile, Phytochemical Characteristics, and Antioxidant Capacity of Aquaponically Grown Red Amaranth (Amaranthus cruentus L.)

Aquaponics is an integrated and resource-efficient production system that combines aquaculture and hydroponics in a closed-loop environment with reduced water consumption and nutrient losses. The present study evaluated the nutritional composition, mineral profile, microbiological quality, and antioxidant-related phytochemical characteristics of red amaranth (Amaranthus cruentus L.) cultivated in a recirculating aquaponic system under controlled environmental conditions. Leaf biomass was analyzed for proximate composition, macro- and micronutrient content, total phenolic and flavonoid compounds, betalains, chlorophyll pigments, and antioxidant activity using standard analytical and spectrophotometric methods. The results demonstrated high crude protein content and substantial accumulation of essential minerals, particularly calcium, potassium, and magnesium. The analyzed biomass also exhibited elevated levels of phenolic compounds, flavonoids, betalains, and chlorophyll pigments associated with considerable antioxidant potential. The pigment profile suggested good physiological adaptation of plants to aquaponic cultivation conditions. In addition, microbiological analysis confirmed acceptable hygienic quality and safety of the harvested plant material. Overall, the findings indicate that red amaranth can be successfully cultivated in aquaponic systems while maintaining high nutritional value and functional food potential. The study highlights aquaponic cultivation as a sustainable approach to producing nutrient-dense leafy vegetables within environmentally responsible agricultural systems.