Qualidade, potencial funcional e perfil bioquímico de porções de infrutescências do abacaxizeiro ' Pérola', ' Vitória' e 'Imperial'

Abstract

Brazil is the third largest producer of fruit, generating an increase in the production of agroindustrial waste. In view of this, the objective of this work was to perform a biochemical characterization of pulp, stem, shell, and crown portions of three varieties of pineapple infructescences. Pineapples were purchased at the commercial maturity, characterized by slightly orange meshes at the base of the fruit, in four replicates of 20 fruits / variety (Pérola, Vitória and Imperial). The fruits came from different pineapple producing municipalities located in Mata Paraibana, Paraiba State, Brazil, and transported to the Laboratorio de Biologia e Tecnologia Pos-Colheita do Centro de Ciências Agrárias da Universidade Federal da Paraíba. Physical and physicochemical evaluations, quantification of phenolic compounds, soluble protein content, antioxidant activity evaluation, enzymatic activities (SOD, CAT, POD, and APX), proteolytic and specific activity of bromelain and SDS-PAGE electrophoresis were performed. The data were submitted to ANOVA and the means were compared by the Tukey test at 5% probability. A principal component analysis (PCA) was also performed. For the physical characteristics, the attributes of fresh mass, length and firmness differed among the varieties, and those related to the diameter and yield did not differ from 'Vitória' and 'Imperial', these also stood out in relation to 'Pérola' the higher soluble solids content. The highest titratable acidity (AT) contents for both pulp and stalk were found in 'Vitória'. The pH differed among the varieties, and the 'Imperial' had higher pH. The highest levels of ascorbic acid were registered in the ‘Pérola’. For the contents of total extractable polyphenols (PET), the crown portion stood out in relation to the other portions, independently of the evaluated varieties, followed by the shell, pulp, and stalk. The 'Vitória' presented lower antioxidant capacity by the DPPH. method. On the other hand, for the enzymatic activity, for SOD, CAT, POD, and APX, this variety was distinguished by the greater enzymatic activities independently of the portion evaluated. Regarding the proteolytic activity, in the pulp and stalk portions, 'Pérola' pineapple presented a higher average, while in the shell and crown portions, 'Imperial' stood out in relation to 'Pérola' and 'Vitória' cultivars, respectively. The specific activity ranged from 10 53 U.mg-1, for the stem portion in 'Vitória' pineapple, to 453 U.mg-1 for the 'Pérola' pulp portion. The variability of bromelain activity in the different portions studied was explained in 99% by two principal components: CP-1 = 74% and CP-2 = 25%. In the analysis of gel electrophoresis, the main components of proteins expressed in extracts of the pulp, stem, shell, and crown portions of the three pineapple varieties studied presented molecular weight of approximately 24 kDa for 'Pérola' and 'Vitória' and 26 kDa for ' Imperial'. The crown and shell portions are configured as the best source of bromelain as the pulp and stem portions for the 'Vitória' and 'Imperial' varieties. In this context, the importance of the use of the industrial residues of the pineapple processing to obtain bromelina and other compounds beneficial to human health is emphasized.