Inedible sites of Earl’s melon (<i>Cucumis melo</i> L.) have antihypertensive properties

This study aimed to clarify the characteristics of gamma-aminobutyric acid (GABA), citrulline (Cit), nicotianamine (Nit), angiotensin I-converting enzyme (ACE) inhibition, antioxidant capacity, and antioxidant contents in the inedible sites of Earl’s melon that are discarded during food processing: placental tissue, fruit skin, and seeds. These sites are antihypertensive, contain GABA, Cit, Nit, and antioxidants, and have ACE inhibitory activity, and antioxidant capacity; however, these sites have different characteristics. In particular, placental tissue had the highest GABA, Cit, antioxidant levels, and antioxidant capacity. These properties suggest that it is a useful raw material for new health foods; this provides a solution to utilize unused resources. These compounds are potential anti-hypertensive materials.