Micronization increases the bioaccessibility of polyphenols from granulometrically separated olive pomace fractions.

The effect of micronization of granulometrically fractionated olive pomace (OP) on the bioaccessibility of polyphenols and the antioxidant capacity was investigated during sequential in vitro static digestion. Crude OP was fractionated in a 2-mm sieve (F1: > 2 mm; F2: < 2 mm) and then micronized (300 r min-1, 5 h) generating F1AG (17.8 µm) and F2AG (15.6 µm). Micronization increased the release of hydroxytyrosol, oleuropein, caffeic acid, and decarboxymethyl oleuropein aglycone (3,4-DHPEA-EDA) in the salivary and gastric phase, beyond luteolin in the gastric phase. Micronization also increased the intestinal bioaccessibility of hydroxytyrosol, 3,4-DHPEA-EDA, oleuropein, luteolin, and apigenin; it was more effective for F2AG than F1AG. Micronized samples increased antioxidant capacity in the gastric phase. F2AG exhibited the highest antioxidant capacity in the insoluble intestinal fraction. Thus, micronization can be further exploited to improve the nutraceutical properties of OP by increasing the bioaccessibility and antioxidant capacity of phenolic compounds.

Characterization of olive oil flavored with Brazilian pink pepper (Schinus terebinthifolius Raddi) in different maceration processes.

The present study aimed to evaluate two different processes of olive oil aromatization with Schinus terebinthifolius Raddi, conventional maceration (CM) and ultrasound-assisted maceration (UM), and their influence on quality parameters, total phenolic compounds (TPC), fatty acid profile (FA), volatile organic compounds (VOCs), antioxidant capacity, and oxidative stability. Flavoring reduced peroxide values, although it increased free fatty acids and extinction coefficients. The flavorization process did not change the FA profile, which showed oleic acid as a major compound. The VOCs varied and the migration of oxygenated monoterpenes were more effective in UM-flavored olive oil compared to its CM counterpart. All flavored olive oils presented higher oxidative stability than the control samples and UM-flavored olive oil was highlighted for its higher antioxidant activity. These findings proved that aromatization with pink pepper assisted by ultrasound may be an alternative to improve olive oil quality and create a new competitive flavored product.

Ultrasound assisted maceration for improving the aromatization of extra-virgin olive oil with rosemary and basil.

Aromatization of extra-virgin olive oil (EVOO) with aromatic plants is commonly used to enrich the oil with aromatic and antioxidant compounds. Ultrasound can be an alternative to accelerate this process. The objective of this work was to determine if ultrasound is able to accelerate EVOO aromatization with rosemary and basil and how it affects the migration of volatile and other compounds, the oxidative stability and the antioxidant capacity of the aromatized products. Ultrasound parameters (amplitude, time, and temperature of extraction) were optimized for each herb with central composite designs. Free fatty acid, peroxide value, K232, K270, ΔK, fatty acid profile, total phenolics, antioxidant capacity, polar compounds, oxidative stability and volatile compounds profile were evaluated in all samples. Physical effects of ultrasound on the herbs were observed by scanning electron microscopy. In the optimization, variables related to the oxidative processes were minimized and compounds migration and oxidative stability were maximized. Results were 70.09% amplitude, 36.6 min and 35 °C for rosemary and 95.98% amplitude, 9.9 min and 30 °C for basil. These conditions were compared to 7 and 15 days of conventional maceration (CM). Aromatization of EVOO with rosemary, both by ultrasound assisted maceration (UAM) or CM, improved total phenolics, terpenes, esters, ketones, stability and induction times, as well as decreased the values for the quality parameters. The use of UAM accelerated the process to 37 min. However, aromatization with basil by CM increased the values for the quality parameters and reduced the total phenolics, the antioxidant capacity and the induction and stability times. UAM with basil reached better results than those observed for CM, in only 10 min. In conclusion, rosemary is more appropriate than basil for EVOO aromatization, and UAM was the best choice to accelerate the processes when compared to CM.

Application of Tamarind Waste Extracts to Improve the Antioxidant Properties of Tamarind Nectars.

Tamarind fruits are consumed worldwide and their seeds have an underexploited potential. We assessed the effect of the addition of a freeze-dried aqueous of extract tamarind seed (FAE) at three concentration levels (0.3, 1.15 and 2%) on the antioxidant capacity (DPPH, ABTS, FRAP and ORAC) and concentrations of total phenolic compounds in tamarind pulp. Conditions used to prepare the aqueous extracts were established using multivariate optimization. Moreover, nectars prepared from pulps combined with FAE were subjected to sensory tests. Tamarind fruits from three geographic regions in Brazil (Minas Gerais, São Paulo and Bahia) that were harvested in 2013 and 2014 were used in the study. Generally, the freeze-dried aqueous extracts increased the concentrations of antioxidants in the pulp. The results revealed a positive correlation between the FAE concentration in the pulp and the antioxidant capacity of all samples, particularly samples from Bahia and Minas Gerais, which presented an increase of up to 1,942% in the ABTS method when 2% FAE was incorporated into the pulp, from approximately 40.1 to 209.1 mMTrolox/gdw and 13.4 to 143.4 mMTrolox/gdw, respectively. Sensory tests indicated the satisfactory acceptance and non-distinction between nectar samples to which FAE was or was not added when the FAE concentration was less than 2.3gFAE/L, regardless of the geographic origin of the samples.

Extracts of Peels and Seeds of Five Varieties of Brazilian Jabuticaba Present High Capacity to Deactivate Reactive Species of Oxygen and Nitrogen.

Jabuticaba has a high concentration of phenolic compounds, which have a significant antioxidant capacity. Methodologies have been developed to evaluate the ability of plant extracts to fight free radicals such as H2O2, O2•-, HOCl, ONOO- and ROO•. Thus, the capacity of deactivation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in peel and seed extracts of five varieties of jabuticaba was evaluated. Sabará peel (SFP) deactivated HOCl with IC50 9.24 µg. mL-1; Paulista seed (PF) deactivated O2•- with IC50 16.15 µg. mL-1; Coroada seed (CFP) deactivated ONOO- with IC50 3.84 µg. mL-1; the peel of CFP deactivated ONOO- with IC50 5.88 µg. mL-1; the peel of SFP deactivated the ROO• at 918.16 µmol TE. g-1; and Sabará seed deactivated H2O2 with 49.11% inhibition at a concentration of 125 µg. mL-1 of extract. These results demonstrate the high antioxidant potential of this fruit, indicating that it could be extremely beneficial to human health.

Profile of phenolic compounds of Brazilian virgin olive oils by rapid resolution liquid chromatography coupled to electrospray ionisation time-of-flight mass spectrometry (RRLC-ESI-TOF-MS).

In recent years, agronomical researchers began to cultivate several olive varieties in different regions of Brazil to produce virgin olive oil (VOO). Because there has been no reported data regarding the phenolic profile of the first Brazilian VOO, the aim of this work was to determine phenolic contents of these samples using rapid-resolution liquid chromatography coupled to electrospray ionisation time-of-flight mass spectrometry. 25 VOO samples from Arbequina, Koroneiki, Arbosana, Grappolo, Manzanilla, Coratina, Frantoio and MGS Mariense varieties from three different Brazilian states and two crops were analysed. It was possible to quantify 19 phenolic compounds belonging to different classes. The results indicated that Brazilian VOOs have high total phenolic content because the values were comparable with those from high-quality VOOs produced in other countries. VOOs from Coratina, Arbosana and Grappolo presented the highest total phenolic content. These data will be useful in the development and improvement of Brazilian VOO.

Doehlert design-desirability function multi-criteria optimal separation of 17 phenolic compounds from extra-virgin olive oil by capillary zone electrophoresis.

In Brazil, the consumption of extra-virgin olive oil (EVOO) is increasing annually, but there are no experimental studies concerning the phenolic compound contents of commercial EVOO. The aim of this work was to optimise the separation of 17 phenolic compounds already detected in EVOO. A Doehlert matrix experimental design was used, evaluating the effects of pH and electrolyte concentration. Resolution, runtime and migration time relative standard deviation values were evaluated. Derringer's desirability function was used to simultaneously optimise all 37 responses. The 17 peaks were separated in 19min using a fused-silica capillary (50µm internal diameter, 72cm of effective length) with an extended light path and 101.3mmolL(-1) of boric acid electrolyte (pH 9.15, 30kV). The method was validated and applied to 15 EVOO samples found in Brazilian supermarkets.

Common sources and composition of phytosterols and their estimated intake by the population in the city of São Paulo, Brazil.

OBJECTIVE: Phytosterols have been used alone, or combined with lipid-altering drugs, to reduce cholesterol levels and the burden of cardiovascular disease. Considerable variation in the composition of phytosterols exists and its consumption, in a regular diet, by the Brazilian population is still unknown. Thus, the aim of the present study was to determine the phytosterols content of the most consumed plant foods and to estimate the phytosterols intake by this population. METHODS: Intake of plant foods of a representative population of the city of São Paulo (n = 1609), randomly selected on the basis of the Brazilian Institute for Geography and Statistics census data (2010), was obtained by a food frequency questionnaire (FFQ). Foods were chosen on the basis of the Consume Expenditure Survey (2002-2003) and from answers to the FFQ. Phytosterols composition of most consumed greens, legumes, cereals, and seeds, fruits, and vegetable oils was determined by gas chromatography (flame ionization detection). Daily phytosterols intake was estimated in terms of mg per 100 g (mg/100 g(-1)) of edible portion. Underreporters and overreporters were excluded. RESULTS: Mean (SE) daily phytosterols intake in the diet of the study population was 100.6 (1.2) mg, with ß-sitosterol as the largest sterol component (65.4%), followed by campesterol (23.2%), and stigmasterol (10%). No significant changes in daily phytosterols intake were observed after exclusion of underreporters and overreporters. Considerable variation was observed in phytosterols content among the most consumed plant foods. CONCLUSIONS: Analysis of phytosterols composition in most consumed plant foods has shown that phytosterols content varied among food groups. Dietary intake of phytosterols in a large population of the city of São Paulo is in the same range of some countries.

Use of multivariate statistical techniques to optimize the simultaneous separation of 13 phenolic compounds from extra-virgin olive oil by capillary electrophoresis.

Characterization of phenolic compounds in olive oil has not been achieved as yet, owing to the complexities of their chemical structures and analytical matrix. The aim of this work is to optimize and validate a method for simultaneous separation and quantification of 13 phenolic compounds from extra-virgin olive oil: tyrosol, hydroxytyrosol, oleuropein glycoside, ferrulic acid, p-coumaric acid, cinnamic acid, p-hydroxybenzoic acid, gallic acid, caffeic acid, luteolin, apigenin, vanillic acid and 3,4-dihydroxybenzoic acid. A statistical central composite design, response surface analysis and the simultaneous optimization method of Derringer and Suich were used to separate all the peaks. These multivariate procedures were efficient in determining the optimal separation condition, using five peak-pair resolutions and runtime as responses. The optimized method employed a fused-silica capillary of 50 µm i.d.× 60 cm effective length with extended light path, 50 mmol L(-1) boric acid electrolyte, 10.2 pH, 25°C, injection of 50 mbar for 25s with application of reverse voltage (-30 kV for 5s) before setting the running voltage (+30 kV) with detection at 210 nm and a run time of 12 min. Peak resolutions are found to be very sensitive to pH values outside the 10.15-10.25 range but acceptable electropherograms can be obtained for a wide range of boric acid concentrations within this pH interval.