**From By-Product to the Food Chain: Melon (***Cucumis melo* **L.) Seeds as Potential Source for Oils**

**Adrián Rabadán 1, M. Antónia Nunes 2, Silvia M. F. Bessada 2, José E. Pardo 1, M. Beatriz P. P. Oliveira 2 and Manuel Álvarez-Ortí 1,\***


Received: 19 August 2020; Accepted: 17 September 2020; Published: 23 September 2020

**Abstract:** Fruit-processing industries annually discard large volumes of fruit by-products. Thousands of tons of melon seeds could be recovered through the year from melon production. These seeds are an excellent source of vegetable oil with significant health-promoting properties due to their unsaturated fatty acid profile and high content of specific bioactive compounds. However, little information exists about the influence of melon cultivars and oil-extraction methods on oil characteristics. In this study, oils from nine di fferent melon cultivars were evaluated. Additionally, two oil-extraction methods (screw and hydraulic press) were studied. Results showed that melon seeds may be used as a novel source of healthy oils. Higher-quality oils were obtained with the hydraulic press; however, low yields reduced industrial interest in this method. Oils extracted from the di fferent cultivars showed high variability in the content of linoleic (51–69%) and oleic (15–34%) acids. Regarding vitamin E, γ-tocopherol was the main isoform found in melon-seed oils (99.81–456.73 mg/kg), followed by αand δ-tocopherols. Significant concentrations of tocotrienols ( α, β, and γ) were also found. Although all cultivars showed positive attributes, principal-component analysis (PCA) showed that Honey Dew and Blanco de Ribatejo could be specifically considered as a potential source of polyunsaturated oils with high concentrations of vitamin E.

**Keywords:** melon-seed oil; fruit waste; tocopherols; tocotrienols; unsaturated fatty acids; screw press
