CARACTERIZAÇÃO QUÍMICA E AVALIAÇÃO DA ATIVIDADE ANTIOXIDANTE DA POLPA E ÓLEO ESSENCIAL DA PERA DO CERRADO (Eugenia klotzschiana Berg.)

Abstract

Brazilian pear (Eugenia klotzschiana), also called pear-of-field, small gourd-the-field or pear tree of-field belonging to the family of Myrtaceae, is a native plant of the cerrado. The cerrado despite of being the second largest Brazilian biome, has nutritionally rich flora with is little explored sustainably. The search for the consumption of foods rich in bioactive compounds and the use of natural products in order to replace the chemical additives in foods, has been an option for consumers seeking healthy habits combined with food safety. Therefore, this study was divided into two chapters. The objective of Chapter 1 was to evaluate the chemical composition and sequestering capacity of free radicals of the essential oil extracted from the flowers and leaves of Brazilian pear leaves (Eugenia klotzschiana Berg). The Brazilian pear leaves were subjected to two drying processes (natural room temperature and in an oven with forced air circulation). Both leaves and flowers were subjected to hydrodistillation in Clevenger apparatus for essential oil extraction. The components of essential oils were identified by gas chromatography coupled to mass spectrometry (GC/MS). The tests used to evaluate the antioxidant activity of essential oils were based on sequestration of free radical DPPH and ABTS. It was observed that the essential oils showed average income and consist mainly by sesquiterpenes as spathulenol, α-caryophyllene, D-germacrene and γ- elemene. Essential oils analyzed showed moderate antioxidant activity and may be used in the food industry. The objective of Chapter 2 was to characterize the chemical and physical-chemical composition of the fruit pulp, quantify their bioactive compounds and antioxidant activity by two extraction methods (aqueous and methanol-acetone). Fruits were collected between the months of November and December and the physical, chemical and physico-chemical evaluations were performed. The antioxidant activity was also determined by DPPH test, ABTS and FRAP. It found fruit with great yield and nutritional value, highlightting the amount of carbohydrates, dietary fiber and iron. The pulp of the Brazilian pear presents important bioactive compounds for human consumption, with high content of phenolic compounds and flavonoids, which contributed to its moderate to high antioxidant activity.