Characterization and Antioxidant Potential of Brazilian Fruits from the Myrtaceae Family Marina C. Pereira, † Rosana S. Steffens, † Andre ́ Jablonski, ‡ Plinho F. Hertz, † Alessandro de O. Rios, † Ma ́ rcia Vizzotto, § and Simone H. Flôres* ,† † Instituto de Ciê ncia e Tecnologia de Alimentos, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonç alves, 9500, Pre ́ dio 43.212, Campus do Vale, Porto Alegre, RS, CEP 91501-970, Brazil ‡ Departamento de Engenharia de Minas, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonç alves, 9500, Pre ́ dio 74, Campus do Vale, Porto Alegre, RS, CEP 91501-970, Brazil § Embrapa Clima Temperado, Rodovia BR 392, km 78, P.O. 403, Pelotas, RS, CEP 96010-971, Brazil ABSTRACT: The objective of this study is to evaluating the Brazilian biodiversity through physicochemical characterization and determination of antioxidant potential of three species from the Myrtaceae family, namely yellow guava (Psidium cattleyanum Sabine), guabiroba (Campomanesia xanthocarpa O. Berg), and uvaia (Eugenia pyriformis Cambess). Guabiroba had the greater quantity of phenolic compounds (9033 mg chlorogenic acid/100 g) and vitamin C (30.58 mg/g) and showed the best TSS/TTA (total soluble solid/total titratable acid) ratio (45.12). For the ABTS (2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic) method, the guabiroba (507.49 μM Trolox/g) presented the highest antioxidant potential; however, in the DPPH (2,2-diphenyl-1- picrylhydrazyl) method, uvaia (170.26 g/g DPPH) and guabiroba (161.29 g/g DPPH) were not statistically different. The uvaia outranked the other fruits with respect to its high carotenoid (909.33 μg/g) and vitamin A (37.83 μg/g) contents, and the yellow guava, although showing a lower bioactive compound content and antioxidant activity, nevertheless presented much higher values than many traditionally consumed fruits. KEYWORDS: Brazilian fruit, Myrtaceae, chemical composition, antioxidant activity, carotenoids ■ INTRODUCTION Brazil is recognized for the immense biological diversity of its flora and is considered to be one of the main centers of genetic diversity for fruit species in the world. Nevertheless, the greater part of this richness remains underused and its potential unknown. However, according to the Brazilian Institute of Fruits (IBRAF), 1 Brazil is one of the three largest fruit pro- ducers in the world, only losing to China and India, producing more than 43 million tons in 2008, which represents 5% of the world production. Although a greater variety of native Brazilian fruit species are found in the Amazon and the savanna, the southern region also shows great richness in wild fruits, among which the botanical family of Myrtaceae stands out for presenting the greatest number of species with food potential, which could be commercialized in natura for use in the manufacture of ice creams, juices, yogurts, liqueurs, desserts, cereal bars, sweetmeats, and jams. Of these fruits, the yellow guava (Psidium cattleyanum Sabine), guabiroba (Campomanesia xanthocarpa O. Berg), and uvaia (Eugenia pyriformis Cambess) are examples usually used in folk medicine and grown in home gardens that have great potential for economic explora- tion, since they show high productivity with low deployment and maintenance costs. In a market hungry for novelty and consumers more con- scious of the benefits of eating healthy food, such fruits provide greater variety to the diet, providing nutritious foods rich in functional compounds that could act as natural antioxidants, protecting the organism from chronic diseases and from pre- mature aging. According to Ratnam et al., 2 the human antioxidant defense system is incomplete without the dietetic antioxidants, confirming the importance of ingesting these compounds. Thus the consumption of antioxidants presents various benefits, providing an improvement in the quality of life of the population. In a review by Steinmetz and Potter 3 involving the data from 206 epidemiological studies, it was shown that an elevated consumption of fruits and vegetables was related to a reduced incidence of certain types of cancer and beneficial effects on cardiovascular diseases, diabetes, obesity, and cataract. The protective effect exerted by these foods has been attributed to the presence of antioxidant compounds, with emphasis on the vitamins and some special metabolites, such as phenolic com- pounds and carotenoids. Vitamin C can act by scavenging the oxygen radicals present in the medium by way of chemical reac- tions, consequently making them unavailable to act as a propagator of auto-oxidation. In addition, it has a high vitamin E regenerating capacity. 4 Phenolic compounds act by neutralizing and sequestering free radicals and also chelatimg transition metals. The inter- mediate compounds formed by the action of the phenolic anti- oxidants are relatively stable due to charge distribution throughout the aromatic ring system. The antioxidant capacity of these compounds is attributed to the reducing power of the aromatic hydroxyl group, which reduces the reactive free radicals. 5 Received: September 9, 2011 Revised: March 6, 2012 Accepted: March 7, 2012 Published: March 7, 2012 Article pubs.acs.org/JAFC © 2012 American Chemical Society 3061 dx.doi.org/10.1021/jf205263f | J. Agric. Food Chem. 2012, 60, 3061-3067