From Waste To Wealth: Pistachio Green Hulls as a Novel Source of Antioxidants and Dietary Supplements

Purpose: Pistacia vera L., known for its rich phenolic content and antioxidant potential, often has its hulls discarded. This study aimed to explore the antioxidant potential of pistachio green hulls, using advanced analytical methods to assess their suitability for dietary supplements. Methods: Green hull samples were collected, dried, and extracted with water, methanol, and hexane to isolate bioactive compounds. Biochemical composition, including amino acids, organic acids, carnitines, vitamins, minerals, and fatty acids, was analyzed using LC-MS/MS, HPLC, ICP-MS, and GC-FID. Phenolic content and antioxidant activity were assessed with the Folin-Ciocalteu method and FRAP assay. Results: The results highlight key nutritional differences between green hulls and pistachio kernels. Pistachios had higher levels of essential amino acids, while green hulls were richer in non-essential amino acids and organic acids, boosting their antioxidant capacity. Both had similar vitamin and carnitine profiles, though certain carnitines were more concentrated in hulls. Green hulls had more aluminum and iron, while pistachios were richer in copper, zinc, and heart-healthy oleic and linoleic acids. Green hulls strong antioxidant activity suggests their potential in dietary supplements. Their methanol extract showed significant cholinesterase inhibition, while the hexane extract was most effective against tyrosinase and amylase. Conclusion: These findings suggest that green hulls may support metabolic health and immune function due to their nutrient-rich profile and high phenolic content. Further research on bioavailability and therapeutic potential could solidify their role in nutrition and medicine, while also promoting sustainability by converting pistachio green hulls from waste into a valuable bioactive resource.