No abstract

IntroduçãoNa região Centro-Oeste, onde predomina o cerrado, ocorrem muitas espécies de frutas nativas consideradas fontes de proteínas, fibras, energia, vitaminas, cálcio, fósforo e ácidos graxos (SILVA et al., 1994;SANO;ALMEIDA, 1998; MARIN, 2006). Muitas frutas são comercializadas e consumidas in natura ou processadas em preparo caseiro, com grande aceitação popular (ALMEIDA, 1998). O aproveitamento tecnológico de espécies frutíferas nativas pode constituir uma preciosa fonte de alimentos e riqueza para o país.A bocaiúva é um fruto que pertence à família Palmae, sendo a espécie Acrocomia aculeata (Jacq.) Lodd. abundante e nativa no Estado do Mato Grosso do Sul. A polpa e a amên-doa na forma in natura são consumidas pela população local ou nas preparações da culinária regional, tais como sorvetes, bolos, paçoca doce e cocada, podendo enriquecer a dieta como fonte complementar de nutrientes essenciais (ALMEIDA, 1998;SANO;ALMEIDA, 1998).Frutas e vegetais são exemplos de importantes fontes de nutrientes essenciais, entre eles, encontram-se os minerais, que desempenham uma função vital no desenvolvimento e boa saúde do corpo humano. Os minerais são essenciais à manutenção de várias funções de importância fisiológica como na contratibilidade muscular, na função dos nervos, na coagulação sanguínea, nos processos digestivos e no equilíbrio ácido-básico (FRANCO, 2004;HARDISSON et al., 2001).Hortaliças e frutas também são consideradas fontes de carotenóides, os quais atuam não apenas como corantes naturais, mas como compostos bioativos com atuação benéfica à AbstractWith the aim at stimulating the consumption of natural food from the Brazilian Cerrado (vast tropical savanna ecoregion of Brazil), the contens of moisture, lipid, protein, carbohydrate, ash, fiber, minerals, and main carotenoids were determinated in the bocaiuva Acrocomia aculeata (Jacq.) Lodd. pulp. The edible portion of the fruit (pulp and kernel) corresponded to 50% of the whole fruit. The pulp presented 52.99% of moisture, 8.14% of total lipids, 1.5% of protein, 22.08% of carbohydrates, 1.51% of ash, and 13.76% of fiber. The energetic value was estimated to be 167.67 kcal.100 g -1 of wet pulp, which is higher than the other fruits from this region. Among the minerals examined, potassium was the element in higher concentrations (766.37 ± 18.36 mg.100 g ). The bocaiuva pulp may be classified as a rich source of copper for children, as a source of zinc and potassium for children, and as a source of copper and potassium for adults according to the dietary recommendation intake of those minerals. The bocaiuva pulp can be considered as rich in b-carotene (49.0 ± 2.0 mg.g -1 of integral pulp), the predominant carotenoid identified in the pulp, which can contribute to the enrichment of the regional diet, in supplementary diet programs, as a natural source of that nutrient as well as of vitamin A, copper, potassium and zinc minerals.

The bioactive compounds content and the antioxidant activity (AA) of twelve fruits native to the Cerrado were compared with the Red Delicious apple by means of the antiradical efficiency (using the 2,2-diphenyl-1-picrylhydrazil assay/DPPH), ferric reducing antioxidant power (FRAP) and the β-carotene/linoleic system. The antiradical efficiency (AE) and the kinetic parameters (Efficient concentration/EC50 and time needed to reach the steady state to EC50 concentration/TEC50) of the DPPH curve were also evaluated for comparison with the Trolox equivalent (TE) values. A strong, significant and positive correlation was observed between the TE and AE values, whereas a weak and negative correlation was observed between TE and EC50, suggesting that the values of AE and TE are more useful for the determination of antiradical activity in fruits than the widely used EC50. The total phenolic content found in the fruits corresponded positively to their antioxidant activity. The high content of bioactive compounds (flavanols, anthocyanins or vitamin C) relative to the apple values found in araticum, cagaita, cajuzinho, jurubeba, lobeira, magaba and tucum corresponded to the high antioxidant activity of these fruits. Flavanols and anthocyanins may be the main bioactive components in these Cerrado fruits. The daily consumption of at least seven of the twelve Cerrado fruits studied, particularly, araticum, cagaita, lobeira and tucum, may confer protection against oxidative stress, and thus, they may prevent chronic diseases and premature aging. The findings of this study should stimulate demand, consumption and cultivation of Cerrado fruits and result in sustainable development of the region where this biome dominates.

The protective effect of plant-based foods in human health has been attributed to the presence of bioactive compounds in all parts of the plants. A previous study found a high level of minerals, tannins and phytic acid in the baru nut (Dipteryx alata Vog.), which is a native fruit of the Brazilian savanna. This study investigated the antioxidant activity (AA) of the aqueous and ethyl acetate extracts of the baru nut and the effect of the consumption of this nut on the oxidative status of rats supplemented orally with iron. The AA was evaluated in vitro using the ferric reducing antioxidant power (FRAP), β-carotene/linoleic acid system and freeradical scavenging (DPPH) assays. The total polyphenol concentration was determined spectrophotometrically using the Folin-Ciocalteu reagent. The in vivo study was conducted in male Wistar rats that were fed an AIN-93M diet with or without 10% baru nut or 1% phytic acid and supplemented daily with iron or saline by gavages for 17 days. The liver, heart and spleen were collected for the determination of the malondialdehyde (MDA), carbonyl protein and iron concentrations. The specific activities of catalase, glutathione reductase, glutathione peroxidase and glutathione S-transferase were also determined in these tissues. A T test was used to compare the results among the rats groups and between the different baru nut extracts (p b 0.05). The aqueous extract of the baru nut contained a higher level of phenolic compounds and a higher antioxidant activity, as measured by FRAP and the β-carotene/linoleic system, relative to the EtOAc extract. The iron supplementation reduced the body weight gain, increased the levels of iron and MDA in the liver and the spleen and increased the carbonyl levels in all three tissues. Consumption of the baru nut reduced the carbonyl levels in the liver, heart and spleen of the iron-supplemented rats (p = 0.002, 0.012 and 0.036, respectively) relative to the heart carbonyl level of rats that were fed the control diet (p = 0.000); it also marginally reduced the ironinduced lipid oxidation in the liver (p = 0.117) and the spleen (p = 0.074). Phytic acid reduced the carbonyl level in the spleen (p = 0.020) and marginally reduced the carbonyl level in the liver (p = 0.098) of ironsupplemented rats. These results demonstrated that the consumption of the baru nut protects tissues against iron-induced oxidative stress, and the phytic acid from the baru nut may be partially responsible for this protective effect; however, other compounds such as phenols may also be involved.

Iron is an essential element. However, in its free form, iron participates in redox-reactions, leading to the production of free radicals that increase oxidative stress and the risk of damaging processes. Living organisms have an efficient mechanism that regulates iron absorption according to their iron content to protect against oxidative damage. The effects of restricted and enriched-iron diets on oxidative stress and aging biomarkers were investigated. Adult Wistar rats were fed diets containing 10, 35 or 350 mg/kg iron (adult restricted-iron, adult control-iron and adult enriched-iron groups, respectively) for 78 days. Rats aged two months were included as a young control group. Young control group showed higher hemoglobin and hematocrit values, lower levels of iron and lower levels of MDA or carbonyl in the major studied tissues than the adult control group. Restricted-iron diet reduced iron concentrations in skeletal muscle and oxidative damage in the majority of tissues and also increased weight loss. Enriched-iron diet increased hematocrit values, serum iron, gamma-glutamyl transferase, iron concentrations and oxidative stress in the majority of tissues. As expected, young rats showed higher mRNA levels of heart and hepatic L-Ferritin (Ftl) and kidneys SMP30 as well as lower mRNA levels of hepatic Hamp and interleukin-1 beta (Il1b) and also lower levels of liver protein ferritin. Restricted-iron adult rats showed an increase in heart Ftl mRNA and the enriched-iron adult rats showed an increase in liver nuclear factor erythroid derived 2 like 2 (Nfe2l2) and Il1b mRNAs and in gut divalent metal transporter-1 mRNA (Slc11a2) relative to the control adult group. These results suggest that iron supplementation in adult rats may accelerate aging process by increasing oxidative stress while iron restriction may retards it. However, iron restriction may also impair other physiological processes that are not associated with aging.