ABSTRACT
The aim of this study was to evaluate bioactive compounds in five apple cultivars and to analyze correlation of their quality characteristics with concentration of bioactive compounds. Phenolic compounds measurements were made in a spectrophotometer compared to a standard curve of gallic acid and expressed as gallic acid equivalent (GAE) per 100g of dry weight. Sugar and organics acids in five cultivars were quantified using high-performance liquid chromatograph (HPLC). Antioxidant activities were evaluated using three complementary tests 2,2-diphenyl-1-picrylhidrazyl (DPPH) scavenging activity, ferric reducing antioxidant power (FRAP), and 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS). 'GoldRush' had the highest total phenolic compared to the other four cultivars. Additionally, 'GoldRush' had slightly higher, DPPH activity followed by 'Crimson Crisp' and 'Wine Crisp'. 'GoldRush' and 'Crimson Crisp' cultivars also have higher antioxidant capacity based on the ABTS and FRAP methods. The antioxidant capacity was significantly correlated with total polyphenols present in the different cultivars, while organic acids and fruit color showed slightly significant correlation to total phenols.
O objetivo do estudo foi de analisar compostos bioativos e correlacioná-los com características de qualidade em cinco cultivares de maçãs. Os compostos fenólicos foram mensurados com espectrofotômetro, comparando-se a curva padrão de ácido gálico e expressos em acido gálico equivalente por 100g de matéria seca. Os açúcares e ácidos orgânicos foram quantificados por meio de HPLC. A capacidade antioxidante foi mesurada por meio de três métodos: 2,2-diphenyl-1-picrylhidrazyl (DPPH), poder antioxidante de redução do íon ferro (FRAP) e 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS). A cultivar GoldRush foi a que apresentou maiores valores de polifenóis totais, quando comparada com as demais cultivares, e também maior capacidade antioxidante pelo método DPPH, seguida pela cultivar 'Crimson Crisp' and 'Wine Crisp'. 'GoldRush' and 'Crimson Crisp' foram os que apresentaram os maiores valores da capacidade antioxidante por meio dos métodos ABTS e FRAP. A capacidade antioxidante apresentou correlação significativa com polifenóis totais, já os ácidos orgânicos e cor da epiderme apresentaram correlação com os polifenóis totais.