Biochemical Characterization of Traditional Varieties of Sweet Pepper (Capsicum annuum L.) of the Campania Region, Southern Italy

Abstract

Bioactive compounds of different Campania native sweet pepper varieties were evaluated. Polyphenols ranged between 1.37 mmol g−1 and 3.42 mmol g−1, β-carotene was abundant in the red variety “Cazzone” (7.05 μg g−1). Yellow and red varieties showed a content of ascorbic acid not inferior to 0.82 mg g−1, while in some green varieties the presence of ascorbic acid was almost inconsistent. Interrelationships between the parameters analyzed and the varieties showed that ascorbic acid could represent the factor mostly influencing the antioxidant activity. Polyphenol profile was different among the varieties, with a general prevalence of acidic phenols in yellow varieties and of flavonoids in red varieties. Principal Component Analysis, applied to ascorbic acid, total polyphenols and β-carotene, revealed that two of the green varieties (“Friariello napoletano” and “Friariello Sigaretta”) were well clustered and that the yellow variety “Corno di capra” showed similarity with the green varieties, in particular with “Friariello Nocerese”. This was confirmed by the interrelationships applied to polyphenol composition, which let us to light on a clustering of several red and yellow varieties, and that mainly the yellow ”Corno di capra” was closer to the green varieties of “Friariello”.