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”.

Antioxidant Profile of Pepper (Capsicum annuum L.) Fruits Containing Diverse Levels of Capsaicinoids

“…Thus, about 60-80 g intake of fruits per day can provide 100 and 25% of recommended daily amounts of vitamin C and A, respectively [5,9]. Besides, this horticultural product contains important levels of other health-promoting substances with antioxidant capacity, and they include carotenoids, flavonoids and other polyphenols, among others [1,[10][11][12].…”

“…From a redox viewpoint, it has been found that reactive oxygen species (ROS) metabolism is also affected during fruit ripening, leading to major changes in total soluble reducing equivalents and the antioxidant capacity in fruits [41]. The profile of the major non-enzymatic antioxidants, including ascorbate, glutathione, carotenoids and polyphenols, has been followed during ripening in pepper fruits [4,11,12,[42][43][44][45][46], but less is known on how enzymatic antioxidants evolve with this physiological process. These enzyme systems basically include superoxide dismutase (SOD), catalase (CAT) and the ascorbate-glutathione cycle as the primary defense barriers against ROS, and some NADP-dehydrogenases as a secondary system to help the antioxidative enzymatic block.…”

“…This diversity is also mirrored by the number of common names to designate pepper fruits which, in most cases, are used very locally. From culinary and gastronomic points of view, pepper fruits are mainly classified as sweet and hot depending on the absence or presence of capsaicin, respectively [ 4 , 5 , 12 , 13 ]. Within the sweet pepper (also amply known as bell pepper) varieties, three main types are distinguished according to their shape and size: California, Lamuyo and Dulce italiano.…”

Antioxidant Profile of Pepper (<em>Capsicum annuum</em> L.) Fruits Containing Diverse Levels of Capsaicinoids

“…Thus, about 60-80 g intake of fruits per day can provide 100 and 25% of recommended daily amounts of vitamin C an A, respectively [5,9]. Besides, this horticultural product contains important levels of other health-promoting substances with antioxidant capacity, and they include carotenoids, flavonoids and other polyphenols, among others [1,[10][11][12].…”

“…From a redox view, it has been found that the reactive oxygen species (ROS) metabolism is also affected during fruit ripening, leading to major changes in total soluble reducing equivalents in fruits and the antioxidant capacity [42]. The profile of the major non-enzymatic antioxidants, including ascorbate, glutathione, carotenoids and polyphenols, have been followed during ripening in pepper fruits [4,11,12,[43][44][45], but less is known on how enzymatic antioxidants evolve with this physiological process. These enzyme systems basically include superoxide dismutase (SOD), catalase (CAT), the ascorbate-glutathione cycle as the primary defense barrier against ROS, and some NADPdehydrogenases as secondary system to help the antioxidative enzymatic block.…”