Phenolic compounds and antioxidant activity of Brazil nut (Bertholletia excelsa)

Abstract

Antioxidant activityPhenolic compounds HPLC-DAD HPLC-MS A B S T R A C TBrazil nuts were shelled and separated as kernel and brown skin; whole nuts were also used. Soluble phenolics from each portion as well as the whole nut were extracted using 70% acetone under reflux conditions. Insoluble-bound phenolics were subsequently extracted into diethyl ether-ethyl acetate mixture (1:1, v/v) after alkaline hydrolysis. Both soluble and insoluble-bound phenolic extracts were separately examined for their total phenolics content; antioxidant activities were evaluated by trolox equivalent antioxidant capacity (TEAC), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and hydroxyl radical scavenging activities using electron paramagnetic resonance (EPR), reducing power, and oxygen radical scavenging capacity (ORAC). Soluble phenolics in brown skin was 1236.07 as compared to 406.83 in kernel and 519.11 mg/100 g in whole nut. Bound phenolics content of brown skin was also 86-and 19-folds higher than kernel and whole nut, respectively. Similarly extracts from the brown skin exhibited the highest antioxidant activity. Free-and bound phenolics were identified and quantified; these included nine phenolic acids and flavonoids and their derivatives (gallic acid, gallocatechin. protocatechuic acid, catechin, vanillic acid, taxifolin, myricetin, ellagic acid, and quercetin). However, some phenolics were present only in the bound form. Furthermore, the phenolics were dominant in the brown skin.

Phytochemical composition and antioxidant capacity in Mexican pecan nut

“…In addition to being rich in proteins, vitamin E, unsaturated fatty acids and fibers, nuts are an important source of numerous phytochemicals, including phenolic compounds with natural antioxidant capacity (Kornsteiner et al, 2009), which have attracted considerable attention in recent years due to their many health benefits, including anti-inflammatory and anti-cancer properties (Chen and Blumberg 2008). Therefore, great interest has arisen in characterizing and quantifying phenolic compounds of the edible part, classified among the foods with high antioxidant capacity (John and Shahidi, 2010), and byproducts such shells rich in phenolic compounds and in flavonoids (e.g. proanthocyanidins) (Pinheiro do Prado et al, 2014).…”

Anti-oxidant and anti-acetylcholinesterase activities of <i>Zygophyllum album</i>

“…Phenolic compounds (phenols, flavonoids and proanthocyanidins) received considerable attention because of their potential anti-oxidant activity (Suhartonoa et al, 2012;Pavithra and Vadivukkarasi, 2015;Khlif et al, 2015;John and Shahidi, 2010). These compounds are known for their ability of scavenging free radicals and active oxygen species such as single oxygen (Lahlou et al, 2014).…”

Antimicrobial and Antioxidant Activities of Selected Plants Used by Populations From Juruena Valley, Legal Amazon, Brazil

“…However, quercetin, the standard drug for this assay, presented intense antioxidant activity with IC50 = 3.12±0.05 µg/ml in all the in vitro antioxidant models tested. John and Shahidi reported antioxidant activity for the methanolic, ethanolic and acetone fractions of B. excelsa nuts in DPPH assay, however, with values of IC50 1000 times larger than those of HEBe [57]. The same authors showed that soluble and insoluble phenolic extracts of the kernel, nut, and shell, reduce ferric ion (0.21-59.20 µmol ascorbic acid eq/g), with activity equivalent to that obtained for HEBe (IC50 = 35.22 µmoles ascorbic acid eq/ml), indicating that the extracts of B. excelsa have antioxidant capacity in both models, being more active in the DPPH assay.…”