From by-product to unconventional vegetable: Preliminary evaluation of fresh fava hulls highlights richness in L-DOPa and low content of anti-nutritional factor

Faba bean hulls are a by-product, generated from the processing of beans and usually disposed of as waste, utilized in some recipes of Italian traditional cuisine. In this research, a quality evaluation of faba hulls in six genotypes (four local varieties—‘Cegliese’, ‘Iambola’, ‘San Francesco’ and ‘FV50—and two commercial ones—‘Aguadulce supersimonia’ and ‘Extra-early purple’) of faba bean (Vicia faba L. var. major Harz) for fresh consumption grown with two plant densities (4.16 and 2.08 plants m−2) was carried out. For all the measured parameters, the statistical analysis reveals that the interaction between plant density and genotype was not significant. On the other hand, independently of the genotype, the higher the plant’s density the higher was the pods’ yield per unit area, while the average percentage of hulls was of 75% with little differences between genotypes. All genotypes showed a low content of vicine (12.4 mg 100 g−1 FW), a well know favism-inducing factor, and a very high phenols content (between 443 and 646 mg 100 g−1 FW) and levo-dihydroxy phenylalanine (L-dopa—on average 170 mg 100 g−1 FW), used for the treatment of patients affected by Parkinson’s disease. In conclusion, this study highlights the good potential of faba hulls as unconventional vegetable, suggesting its use as a new functional food in the daily diet and also for patients with Parkinson’s disease.