title: A comparative study of the capsaicinoid and phenolic contents and in vitro antioxidant activities of the peppers of the genus Capsicum: an application of chemometrics.
abstract: This paper presents a comparison of the contents of capsaicin, dihydrocapsaicin and total phenolics as well as of the antioxidant activities of six types of peppers of the genus Capsicum. The varieties were analyzed in terms of their in vitro antioxidant activity using ferric reducing antioxidant powder (FRAP), 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis 3-ethylbenzothiazoline 6-sulfonate (ABTS(●+)) assays. The contents of phenolics and capsainoids as well as the antioxidant activities were higher in seeds than in pulps. The correlations (ρ < 0.01) between the phenolic composition and the capsaicinoids levels were high (r = 0.98). Similarly high were also the correlations between the antioxidant activities and the contents of total phenolics and capsaicinoids. Data were analyzed using principal component analysis (PCA), hierarchical cluster analysis (HCA) and multiple linear regression (MLR). PCA explained 97.77 % of the total variance of the data, and their separation into three groups in a scatter plot was divised. Using HCA, three clusters were suggested. Cluster one, formed by pulps (bell pepper, orange habanero, cayenne, dedo de moça and red habanero), showed the lowest levels of the compounds quantified. Most seed samples were grouped in cluster two (bell pepper, cayenne, dedo de moça and malagueta) together with malagueta pulp. Cluster three was formed by orange and red habanero seeds, which showed the highest levels of all compounds analyzed. The MRL revealed that the values of capsaicinoids and total phenols are more adequate to predict the antioxidant activity measured by the FRAP assay.
authors.affiliation: Program in Food Science for Graduated Students and Department of Biochemistry, State University of Maringá, Av. Colombo 5790, 87020-900 Maringá, PR Brazil.
authors.forename: Gisele Teixeira Souza
authors.initials: GT
authors.lastname: Sora
authors.affiliation: Program in Food Technology for Graduated Students, Federal Technological University of Paraná (UTFPR), Via Rosalina Maria dos Santos 1233, CEP 87301-899 Campo Mourão, PR Brazil.
authors.forename: Charles Windson Isidoro
authors.initials: CW
authors.lastname: Haminiuk
authors.affiliation: Program in Food Science for Graduated Students and Department of Biochemistry, State University of Maringá, Av. Colombo 5790, 87020-900 Maringá, PR Brazil.
authors.forename: Marcos Vieira
authors.initials: MV
authors.lastname: da Silva
authors.affiliation: Program of Food Engineering for Graduated Students, Federal University of Paraná (UFPR), Centro Politécnico, CEP 81531-990 Curitiba, PR Brazil.
authors.forename: Acácio Antonio Ferreira
authors.initials: AA
authors.lastname: Zielinski
authors.affiliation: Program in Food Science for Graduated Students and Department of Biochemistry, State University of Maringá, Av. Colombo 5790, 87020-900 Maringá, PR Brazil.
authors.forename: Geferson Almeida
authors.initials: GA
authors.lastname: Gonçalves
authors.affiliation: Program in Food Science for Graduated Students and Department of Biochemistry, State University of Maringá, Av. Colombo 5790, 87020-900 Maringá, PR Brazil.
authors.forename: Adelar
authors.initials: A
authors.lastname: Bracht
authors.affiliation: Program in Food Science for Graduated Students and Department of Biochemistry, State University of Maringá, Av. Colombo 5790, 87020-900 Maringá, PR Brazil.
authors.forename: Rosane Marina
authors.initials: RM
authors.lastname: Peralta
keywords: Antioxidant activity; Capsaicinoids; Capsicum; Multivariate analysis; Phenolics