Nutritional and functional profiles of aquaponic leaf lettuce across seasons

Aquaponics is a sustainable food production system that combines aquaculture and hydroponics. However, limited studies have focused on the nutritional and functional properties of aquaponic produce. Thus, this study aimed to explore the nutritional and functional components of 4 leaf lettuce lines with different colors cultivated in a commercial aquaponic farm in 4 seasons from summer 2022 to spring 2023. The leaf lettuce lines grown in aquaponics had high levels of micronutrients such as vitamin C, vitamin K, and folic acid, with the levels of vitamin K and folic acid meeting Japan's health claim criteria. The lettuce lines, especially red leaf lettuce, were also rich in bioactive compounds such as nitrate ions, which are linked to blood pressure regulation, and antioxidants such as anthocyanins and chlorogenic acid. These findings suggest that leaf lettuce grown in aquaponics has potential use as a high-value functional food.