The bioactive compounds and antioxidant capacities of polyphenolic extracts of 18 fresh and dry native non-traditional fruits from Brazil were determined using ABTS, DDPH, FRAP and b-carotene bleaching methods. The study provides an adaptation of these methods, along with an evaluation of the compounds related to antioxidant potential. The results show promising perspectives for the exploitation of non-traditional tropical fruit species with considerable levels of nutrients and antioxidant capacity. Although evaluation methods and results reported have not yet been sufficiently standardised, making comparisons difficult, our data add valuable information to current knowledge of the nutritional properties of tropical fruits, such as the considerable antioxidant capacity found for acerola-Malpighia emarginata and camu-camu-Myrciaria dubia (ABTS, DPPH and FRAP) and for puçá-preto-Mouriri pusa (all methods).

Many tropical fruits are rich in anthocyanins, though limited information is available about the characterization and quantification of these anthocyanins. The identification and quantification of anthocyanin pigments in four tropical fruits were determined by HPLC-MS/MS. Fruits studied included acerola (Malphigia emarginata), jussara (Euterpe edulis), jambolão (Syzygium cumini), and guajiru (Chrysobalanus icaco). All four fruits were found to contain anthocyanin pigments. Anthocyanidin backbones included cyanidin, delphinidin, peonidin, pelargonidin, petunidin, and malvidin. Guajiru contained several acylated forms, while acerola, jussara, and jambolão contained only nonacylated glycosides. These results demonstrate that these tropical fruits are rich in anthocyanins and that the anthocyanins are widely ranging in anthocyanidin backbone, glycosylation, and acylation.

The antiradical capacity (radical-scavenging capacity, RSC) of seven tropical fruit from the Brazilian northeast (açaí, acerola, cashew apple, mangaba, murici, umbu and uvaia) were studied using the 2,2diphenyl-1-picrylhydrazyl radical (DPPH Å) assay. To determine their RSC, the second-order rate constants (k 2) for the oxidation of these extracts by DPPH Å were calculated. The values of k 2 were compared to natural and synthetic antioxidants. The k 2 values (l/mol g s), in methanol at 25°C, were 38.

This article reports a study of the concentrations of dietary fiber (DF) and antioxidant capacity in fruits (pulp and oil) of a new açaí (Euterpe oleraceae) cultivar-'BRS-Pará', with a view to determine the possibility of using it as a source of antioxidants in functional foods or dietary supplements. Results show that 'BRS-Pará' açaí fruits has a high content of DF (71% dry matter) and oil (20.82%) as well as a high antioxidant capacity in both defatted matter and oil. 'BRS-Pará' Açaí fruits can be considered as an excellent source of antioxidant dietary fiber. Antioxidant capacity of açaí 'BRS-Pará' oil by DPPH assay was higher (EC 50 = 646.3 g/g DPPH) than extra virgin olive oil (EC 50 = 2057.27 g/g DPPH). These features provide açaí 'BRS-Pará' fruits with considerable potential for nutritional and health applications.

The antiradical capacity (radical scavenger capacity, RSC) of bacuri, cajá, camu-camu, carnauba, gurguri, jabuticaba, jambolão, juçara, murta, black puçá and puçá were studied using the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) assay. To determine their RSC, the second-order rate constants (k 2 ) for the oxidation of these extracts by DPPH• were calculated. The values of k 2 were compared to natural and synthetic antioxidants. The k 2 values (L/mol g s), in methanol at 25°C, were 69.52, 26.03, 22.20, 18.04, 17.23, 16.56, 15.60, 10.03, 7.72 and 4.15 for camu-camu, murta, gurguri, carnauba, jabuticaba, black puçá, jambolão, cajá, juçara and bacuri.

This study aimed to determine the antioxidant capacity of cashew apple pulp and raw concentrated extract. The antioxidant potential of aqueous (EAq) and alcoholic (EAlc) extracts and of free phenolic acids (FPA) and esterified (soluble -SPA and insoluble -IPA) fractions of the by-products of the cashew apple clone CCP-76 were evaluated in a β-carotene-linoleate system by the free radical [2,2-diphenyl-1-picrylhydrazyl (DPPH•)] scavenging assay and the Rancimat test. In addition, the total phenolic content and phenolic acid profile were determined using Folin-Ciocateau reagent and gas chromatography, respectively. The EAq and the FPA fraction of the by-products showed the highest phenolic content. The phenolic acid fractions generally displayed stronger antioxidant activity than the extracts tested with the β-carotene-linoleate and DPPH systems. However, in the Rancimat test, the extracts showed higher antioxidant activity than the fractions and BHT. Nine phenolic acids (gallic, ferulic, caffeic, protocatechuic, quinic, cinnamic, gentisic, p-coumaric and salicylic acids), which give the fractions their antioxidant potential, were identified and quantified (both free and esterified forms). These results characterized the in vitro antioxidant capacity of the pulp and raw concentrated extract of the cashew apple clone CCP-76.

Summary Several tropical fruits have been described as natural sources of dietary fibre (DF) and phenolic compounds, associated with different health effects. The aim of this work was to ascertain the DF, phenolic compounds content (including non‐extractable polyphenols, mostly associated with DF) and antioxidant capacity in acerola fruits and cashew apples from selected clones. ‘BRS 236’ acerola fruits presented a high antioxidant capacity because of the combination of both extractable polyphenols and l‐ascorbic acid (providing together a Folin value of 170 kg−1 g d.m.). ‘CCP 76’ cashew apples contained 28 g kg−1 d.m. of extractable polyphenols and 13 g kg−1 d.m. of ascorbic acid as well as a high amount of non‐extractable condensed tannins (52 g kg−1 d.m.). DF content was of 260 g kg−1 d.m. in acerola fruit and of 209 g kg−1 d.m. in cashew apple. Acerola fruits and cashew apple should therefore be considered as new natural sources of DF and phenolic compounds.

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