Atividade da fenilalanina amônia-liase (PAL) e compostos bioativos em Nopalea cochenilifera e Opuntia tuna.

Abstract

Phenylalanine ammonia lyase is an enzyme of secondary metabolism that influences the quality characteristics of the palm. In this context, the objective was to determine the enzymatic activity of phenylalanine ammonia lyase and bioactive compounds in palm cladodes at different stages of development. The design used was completely randomized, with the species 'Miúda' - Nopalea cochenilifera (L.) Salm Dyck and 'Orelha de Elefante Mexicana' - Opuntia tuna L., in 5 stages of development of the cladodes. Size 4 was 0.0 - 4.0 cm; the 8 was 4.1 - 8.0 cm; the 12 was 8.1 - 12.0 cm; the 16 was 12.1 - 16.0 cm and the size 20 was 16.1 - 20.0 cm, in transversal development of the cladodes, with five repetitions. Analyzes of longitudinal and transversal diameters, fresh mass, thickness, pH, H + ions, soluble solids, titratable acidity, ratio, total sugars, reducing sugars, non-reducing sugars, vitamin C, flavonoids, anthocyanins, phenolic compounds and the phenylalanine enzyme ammonia-lyase. In the 'Miúda' palm, the characteristics were significant, with the exception of anthocyanins and the enzyme. The enzymatic activity occurred in a stable manner, not differing between the sizes analyzed, due to the species not being in conditions of stress in the environment, in addition, the species presents a slower growth, consequently a less intense metabolic activity. Regarding the palm „Mexican Elephant Ear‟, all characteristics were significant. In general, enzyme activity grew from sizes 4 to 12, where there was a peak in enzyme activity, followed by a decrease in enzyme activity in sizes 16 and 20. The high enzyme activity occurred due to the stress conditions of the environment and to the accelerated growth of the species which consequently produces a more intense metabolic activity, thus obtaining a greater enzymatic activity. It was also possible to notice an increase in the values of bioactive compounds, analyzed for both species, with a positive correlation between the activity of the enzyme and the phenolic compounds for the species 'Mexican Elephant Ear'.