Quinoa flavonoids and their bioaccessibility during in vitro gastrointestinal digestion

This research evaluated the effect of in vitro gastrointestinal digestion on the bioaccessibility of flavonoid compounds present in quinoa products (seeds, sprouts, and flakes) and changes in their antioxidant activity. Flavonoids that were present after treatment with gastric and intestinal enzymes were characterized using HPLC-ESI-MS³, and the antioxidant activity was measured using two different antioxidant assays. Seven out of eleven flavonoid compounds were found intact after in vitro digestion, and their concentration were significantly increased after in vitro gastrointestinal digestion. The increase in flavonoids led to an approximately 2-fold increase in the antioxidant activity. The main class of flavonoid compounds identified in quinoa were flavonols, mainly quercetin and kaempferol glycosides. The results suggest that flavonoid compounds from quinoa products, which are associated with health benefits, are bioaccessible after efficient extraction by the digestive enzymes, and are available for further absorption in the intestine.     

Bioaccessibility of Phenolic Compounds and Antioxidant Capacity of Chia (<Emphasis Type="Italic">Salvia hispanica</Emphasis> L.) Seeds

The aim of this work was to evaluate (i) the phenol and flavonoid recovery and bioaccessibility indexes and (ii) the antioxidant activity of both types of non-defatted and defatted chia seeds during the in vitro gastrointestinal digestion. The ground samples were subjected to in vitro simulated gastrointestinal digestion, and the resultant fractions were extracted and subjected to spectrophotometric assays. The results pointed to increasing concentrations of polyphenolic compounds during digestion, although only a low-medium percentage of phenols and a low percentage of flavonoids were available for absorption in the intestinal tract. In addition, the high level of fats seemed to have a negative effect on the bioaccessibility of flavonoids. Further studies should be undertaken to better understand the stabilization of the bioactive compounds of chia and to improve their bioaccessibility. Meanwhile, the present study represents a solid base for studying the bioavailability of bioactive compounds of chia seeds.     

Bioavailability of ferulic acid is determined by its bioaccessibility

Epidemiological studies have linked whole grain consumption to prevention of several chronic diseases. Whole grain is a source of important phytochemicals, such as ferulic acid (FA). FA is the most abundant phenolic and major contributor to the in vitro antioxidant capacity of wheat grain. Several studies have reported highly variable results on FA bioavailability (0.4–98%). The binding of FA to polysaccharides may limit its bioavailability. Therefore, our study aimed at monitoring release features of FA during gastrointestinal (GI) transit. This was termed bioaccessibility. The bioaccessibility of FA was studied from different wheat fractions and breads with the use of a dynamic in vitro system that simulates the upper GI transit and digestion. The results showed low bioaccessibility of FA from the wheat fractions and breads (<1%). However, the bioaccessibility was high when free FA was added to flour (∼60%). The bioaccessibility of FA appeared to be determined by the percentage of free FA. In wheat grain, most of FA is bound to arabinoxylans and other indigestible polysaccharides restricting its release in the small intestine. New processing developments should be considered to increase free FA in the cereal matrix in order to improve its bioavailability and systemic health effect.     

Microstructure and In Vitro Beta Carotene Bioaccessibility of Heat Processed Orange Fleshed Sweet Potato

Orange fleshed sweet potato (OFSP) has been identified as a good source of β-carotene but the β-carotene bioaccessibility is affected by processing. In this study, the effect of traditional heat processing methods on the microstructure and in vitro bioaccessibility of β-carotene from OFSP were investigated. Bioaccessibility was determined using simulated in vitro digestion model followed by membrane filtration to separate the micellar fraction containing bioaccessible β-carotene. Processing led to decrease in the amount of all-trans-β-carotene and increase in 13-cis-β-carotene. Processed OFSP had significantly higher (P?<?0.05) bioaccessible β-carotene compared to the raw forms. Bioaccessibility varied with processing treatments in the order; raw < baked < steamed/boiled < deep fried. Light microscopy showed that the microstructure of OFSP was disrupted by the processing methods employed. The cell walls of OFSP were sloughed by the traditional heat processing methods applied. The findings show that heat processing improves bioaccessibility of β-carotene in OFSP and this was probably due to disruption of the tissue microstructure.     

Double fortification of sorghum (Sorghum bicolor L. Moench) and finger millet (Eleucine coracana L. Gaertn) flours with iron and zinc

Finger millet and sorghum flours were used as vehicles for double fortification with ferrous fumarate, zinc stearate and EDTA. The iron and zinc salts were added at levels that provided 60 mg iron and 50 mg zinc per kg of flour. EDTA was added at levels equimolar to the added iron. The double-fortified finger millet and sorghum flours contained bioaccessible zinc contents of 0.83 and 1.63 mg/100 g, respectively, while the respective bioaccessible iron contents were 2.39 and 2.63 mg/100 g. The exogenous iron and zinc did not mutually interfere with their bioaccessibility. The shelf-life of the fortified flours was also satisfactory up to a period of 60 days, as indicated by the moisture and free fatty acid contents in the fortified flours. Double fortification of the millet flours did not negatively alter the sensory quality of the products prepared from them. The RDA for iron and zinc of Indian children, women and men can be sufficiently met with approximately 4 dumplings or 9 rotis. The use of such qualitatively and quantitatively rich flours can be promoted through welfare programs to reduce and subsequently eradicate iron and zinc deficiency.     

A combined procedure to evaluate the global antioxidant response of bread

Baking is the most representative manufacturing process applied to bread, involving thermal and moisture conditions that facilitate the Maillard reaction (MR) and, at the same time, the destruction-formation of natural-labile and thermally-induced antioxidant compounds respectively. In the present paper, the use of a new approach to measure the Global Antioxidant Response (GAR) of cereal derivatives is proposed: a combination of in vitro digestion – which enables measurement of the bioaccessible fraction – and the QUENCHER, which makes it possible to determine the antioxidant activity of the insoluble fraction, since it is a simple and direct procedure for determining the total antioxidant capacity of solid products. After digestion, the results obtained by the antioxidant assays are up to 20-fold higher than those reported using the standard extraction methods. The non-extractable residue displayed significant antioxidant activity that accounted for up to 17% of the total antioxidant activity. Moreover, the GAR obtained in some of the assays developed was 10–40% higher than the antioxidant activity registered by the QUENCHER procedure in wheat bread, and the difference was even higher in wheat bran bread. Therefore, the use of the GAR approach could avoid underestimation of the antioxidant activity of cereal derivatives.     

Black currant polyphenols: Their storage stability and microencapsulation

Interest in the consumption of fresh fruits is, to a large extent, due to its content of bioactive nutrients and their importance as dietary antioxidants. There is a growing demand for delivery of antioxidants through functional foods with the related challenge of protecting their bioactivity during food processing and subsequent passage through the gastrointestinal tract. This study focuses on the evaluation of concentration of bioactive compounds in black currant berries (Ribes nigrum L.) and retention of black currant polyphenol compounds and their antioxidant activity after microencapsulation by spray-drying. The polyphenol contents and antioxidant activities were assessed for 5 black currant cultivars grown in Canada in fresh and stored fruits at −20 °C for 9 months. The Ben Alder cultivar was the richest in anthocyanins and flavonols content with high antioxidant potential measured with ABTS and DPPH radicals (4.5 and 2.4 mM/100 g). Black currant polyphenols were stable during 9 month of storage at −20 °C. The results of this study indicated that in black currants storage did not affect negatively the antioxidant capacity. The good stability of bioactive compounds of black currants during freezer storage allows prolonging the storage time of these berries. Maltodextrins with different DE (dextrose equivalent): DE11, DE18, DE21 and inulin were selected as wall material. The stability of encapsulated polyphenols during 12 months storage at 8 °C and 25 °C was evaluated. Compared to maltodextrins DE18 and DE21, maltodextrin DE11 had not only higher drying yield but also offered better protection for phenolics during storage. Radical scavenging activity studies demonstrated significant antioxidant activity of microencapsulated powders before and after storage. The black currant polyphenol microcapsules described in this study represent a promising food additive for incorporation into functional foods due to antioxidant content.     

Carotenoid Content of Commonly Consumed Herbs and Assessment of Their Bioaccessibility Using an In Vitro Digestion Model

Herbs are a rich source of bioactive phytochemicals such as carotenoids, which are known to exert various positive biological effects. However, there is very limited information in the literature regarding the content and bioavailability of carotenoids from commonly consumed herbs. Therefore, the objectives of the present study were first, to determine the carotenoid content of eight herbs namely basil (Ocimum basilicum), coriander (Coriandrum sativum), dill (Anethum graveolens), mint (Metha L.), parsley (Petroselinum crispum), rosemary (Rosmarinus officinalis), sage (Salvia officinalis), and tarragon (Artemisia dracunculus L.); and second, to assess carotenoid bioaccessibility from these herbs using a simulated human in vitro digestion model. Carotenoid bioaccessibility is defined as the amount of carotenoids transferred to micelles after digestion when compared with the original amount present in the food. The content of individual carotenoids varied significantly among the herbs tested. Carotenoid bioaccessibility varied from 0 to 42.8%. Basil and coriander, and their respective micelles, contained the highest levels of β-carotene, β-cryptoxanthin, and lutein + zeaxanthin. Our findings show that herbs are rich sources of carotenoids and that these foods can significantly contribute to the intake of bioaccessible carotenoids.     

Analysis of bioaccessibility of campesterol,stigmasterol, and β-sitosterol in maize by in vitro digestion method

The content of campesterol, stigmasterol, and β-sitosterol in raw and cooked Big Flint Maize (BFM), Pop Corn Maize (PCM) and Red Maize (RM) were analyzed by using a chemical method and using in vitro digestion of cooked samples. RM contained 15.14, 8.36, and 72.19 mg/100 g campesterol, stigmasterol, and β-sitosterol, respectively, which were higher compared to in BFM and PCM. Samples cooking resulted in 6–48% increase in phytosterol content, while cooked RM had the highest phytosterol content. Using the in vitro digestion method, 44–61% reduction in phytosterol content was observed in contrast to the chemical method. The difference bioaccessible campesterol and β-sitosterol contents among varieties was insignificant, except for stigmasterol in RM. The bioaccessibility of campesterol was 44–56% higher than those of stigmasterol and β-sitosterol, and it was higher in BFM and PCM. In conclusion, phytosterol contents estimated in different maize samples using in vitro digestion can be another determinative for the ultimate content and reveals the necessity to consider with chemical method of determination.     

Optimization of extraction conditions of antioxidants from sunflower shells (Helianthus annuus L.) before and after enzymatic treatment

The effects of three independent variables: solvent polarity, temperature and extraction time on the antioxidant capacity, total phenolic content and phenolic acid composition in extracts obtained from sunflower shells before and after enzymatic treatment were studied. Response surface methodology based on three-level, three-variable Box-Behnken design was used for optimization of extraction parameters and evaluation of their effect on antioxidant capacity and total phenolic content in shell extracts.The average antioxidant capacities of extracts from sunflower shells without enzymatic treatment (368.1-1574.4 μmol TE/100 g) were higher than those for cellulolytic and pectolytic enzymes-treated shells (222.7-1419.0 and 270.7-1570.7 μmol TE/100 g, respectively). The content of total phenolic compounds ranged between 58.2-341.2 mg CGA/100 g, 26.7-277.3 mg CGA/100 g and 51.4-301.5 mg CGA/100 g for extracts obtained from shells without enzyme and treated with cellulolytic and pectolytic enzymes, respectively. Total phenolic content (TPC) in the studied shell extracts correlated significantly (p < 0.0001) positively with their antioxidant capacity determined by the ferric reducing antioxidant power (FRAP) method (r = 0.9275). Results of FRAP, TPC and phenolic acid composition in the studied shell extracts depend on the extraction conditions (solvent polarity, temperature, time), but they are independent on the addition of enzyme solutions. The antioxidant capacity and total phenolic content in the resulting extracts increased with a line in extraction temperature and solvent polarity.     

The Effect of Thermal and Ultrasonic Treatment on Amino Acid Composition, Radical Scavenging and Reducing Potential of Hydrolysates Obtained from Simulated Gastrointestinal Digestion of Cowpea Proteins

The effect of thermal and ultrasonic treatment of cowpea proteins (CP) on amino acid composition, radical scavenging and reducing potential of hydrolysates (CPH) obtained from in vitro simulated gastrointestinal digestion of CP was evaluated. Hydrolysis of native and treated CP with gastrointestinal pepsin and pancreatin yielded CPH that displayed antioxidant activities based on oxygen radical scavenging capacity (ORAC), ferric reducing antioxidant power (FRAP) and superoxide radical scavenging activity (SRSA). CPH derived from the treated CP yielded higher ORAC values than CPH from untreated proteins. However, lower significant FRAP and SRSA values were observed for these samples compared to untreated CPH (p?<?0.05). Amino acid analysis indicated that CP processing decreased total sulphur-containing amino acids in the hydrolysates, particularly cysteine. The amount of cysteine appeared to be positively related to FRAP and SRSA values of CPH samples, but not ORAC. The results indicated that thermal and ultrasonic processing of CP can reduce the radical scavenging and reducing potential of the enzymatic hydrolysates possibly due to the decreased amounts of cysteine. Since the hydrolysates were generated with gastrointestinal enzymes, it is possible that the resulting compounds are produced to exert some health functions during normal consumption of cowpea.     

In vitro Bioaccessibility of Lutein and Zeaxanthin of Yellow Fleshed Boiled Potatoes

Yellow fleshed potatoes contain significant amounts of lutein and zeaxanthin but the bioaccessibility of potato carotenoids has not yet been investigated. The purpose of this study was to estimate the in vitro bioaccessibility of carotenoids provided by potato. Lutein and zeaxanthin concentrations of boiled, freeze dried and milled samples of seven yellow fleshed potato accessions were determined by HPLC before and after different steps (gastric, duodenal and micellar phase) of in vitro digestion. The gastric and duodenal digestive stability of lutein and zeaxanthin in boiled tubers of the different accessions ranged from 70 to 95 % while the efficiency of micellarization ranged from 33 to 71 % for lutein and from 51 to 71 % for zeaxanthin. For all accessions, amounts of lutein and zeaxanthin after micellarization were significantly lower than the original amount found in the boiled samples. The accession 701862 showed the highest bioaccessible lutein concentration (280 μg/100 g, FW) and the accessions 703566 and 704218 showed the highest bioaccessible zeaxanthin concentration (above 600 μg/100 g, FW). Considering the mean potato intake in the Andes (500 g per day), the accession 701862 provides 14 % of the lutein intake suggested for health benefits and the accessions 703566 and 704218 provide 50 % more than the suggested zeaxanthin intake.     

Impact of Phlorotannin Extracts from Fucus vesiculosus on Human Gut Microbiota

Recent studies indicate that plant polyphenols could be pointed as potential prebiotic candidates since they may interact with the gut microbiota, stimulating its growth and the production of metabolites. However, little is known about the fate of brown seaweeds’ phlorotannins during their passage throughout the gastrointestinal tract. This work aimed to evaluate the stability and bioaccessibility of Fucus vesiculosus phlorotannins after being submitted to a simulated digestive process, as well as their possible modulatory effects on gut microbiota and short-chain fatty acids production following a fermentation procedure using fecal inoculates to mimic the conditions of the large intestine. The stability of phlorotannins throughout the gastrointestinal tract was reduced, with a bioaccessibility index between 2 and 14%. Moreover, slight alterations in the growth of certain commensal bacteria were noticed, with Enterococcus spp. being the most enhanced group. Likewise, F. vesiculosus phlorotannins displayed striking capacity to enhance the levels of propionate and butyrate, which are two important short-chain fatty acids known for their role in intestinal homeostasis. In summary, this work provides valuable information regarding the behavior of F. vesiculosus phlorotannins along the gastrointestinal tract, presenting clear evidence that these compounds can positively contribute to the maintenance of a healthy gastrointestinal condition.     

Total phenolics,flavonoids, antioxidant capacity in rice grain and their relations to grain color,size and weight

Total phenolics, flavonoid contents and antioxidant capacity from a wide collection of rice germplasm were measured, and their relations to grain color, grain size and 100-grain weight were investigated. Highly significant genotypic differences were observed in total phenolics, flavonoid contents and 2,2-azino-bis-(3-ehylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) radical cation antioxidant capacity. They displayed an increasing order in the white rice, red rice and black rice, yet several white rice had higher phenolics and flavonoids contents than the red rice. Significant positive pair-wise correlations were found among the phenolics, flavonoid contents and antioxidant capacity, and the coefficient between the phenolic contents and antioxidant capacity was extremely high (r = 0.96). Among all rice accessions, the grain color parameters had negative correlations with the phenolics, flavonoid contents and antioxidant capacity (p < 0.001). The negative correlation between a* and antioxidant capacity, and the positive correlation between H° and antioxidant capacity were consistent within the respective white rice and red rice groups. Flavonoid contents had positive correlation with grain length and length to width ratio, and had negative correlation with the 100-grain weight among all rice accessions. It was also found that 100-grain weight still had negative correlations with phenolics, flavonoid contents and antioxidant capacity within the white rice genotypes. These relationships may serve as indexes to indirectly select breeding lines high in the phenolics, flavonoids and antioxidant capacity. Principal component analysis including the information for phenolics, flavonoids, antioxidant capacity, grain color parameters, grain size and 100-grain weight extracted five principal components that explained 83.7% of the total variances. The results of this study may provide new opportunities for rice breeders and eventually commercial rice growers to promote the production of rice with enhanced nutritional quality.     

In Vivo Nutritional Assessment of the Microalga Nannochloropsis gaditana and Evaluation of the Antioxidant and Antiproliferative Capacity of Its Functional Extracts

Nannochloropsis gaditana is a microalga with interesting nutritional and functional value due to its high content of protein, polyunsaturated fatty acids, and bioactive compounds. However, the hardness of its cell wall prevents accessibility to these components. This work aimed to study the effect of a treatment to increase the fragility of the cell wall on the bioavailability of its nutrients and functional compounds. The antioxidant and antiproliferative capacity of functional extracts from treated and untreated N. gaditana was assessed, and the profile of bioactive compounds was characterized. Furthermore, to study the effect of treatment on its nutrient availability and functional capacity, an in vivo experiment was carried out using a rat experimental model and a 20% dietary inclusion level of microalgae. Functional extracts from treated N. gaditana exhibited higher antioxidant activity than the untreated control. Furthermore, the treated microalga induced hypoglycemic action, higher nitrogen digestibility, and increased hepatic antioxidant activity. In conclusion, N. gaditana has interesting hepatoprotective, antioxidant, and anti-inflammatory potential, thus proving itself an ideal functional food candidate, especially if the microalga is treated to increase the fragility of its cell wall before consumption.     

Unravelling the Anti-Inflammatory and Antioxidant Potential of the Marine Sponge Cliona celata from the Portuguese Coastline

Inflammation is a double-edged sword, as it can have both protective effects and harmful consequences, which, combined with oxidative stress (OS), can lead to the development of deathly chronic inflammatory conditions. Over the years, research has evidenced the potential of marine sponges as a source of effective anti-inflammatory therapeutic agents. Within this framework, the purpose of this study was to evaluate the antioxidant and the anti-inflammatory potential of the marine sponge Cliona celata. For this purpose, their organic extracts (C1–C5) and fractions were evaluated concerning their radical scavenging activity through 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), and anti-inflammatory activity through a (lipopolysaccharides (LPS)-induced inflammation on RAW 264.7 cells) model. Compounds present in the two most active fractions (F5 and F13) of C4 were tentatively identified by gas chromatography coupled to mass spectrometry (GC-MS). Even though samples displayed low antioxidant activity, they presented a high anti-inflammatory capacity in the studied cellular inflammatory model when compared to the anti-inflammatory standard, dexamethasone. GC-MS analysis led to the identification of n-hexadecanoic acid, cis-9-hexadecenal, and 13-octadecenal in fraction F5, while two major compounds, octadecanoic acid and cholesterol, were identified in fraction F13. The developed studies demonstrated the high anti-inflammatory activity of the marine sponge C. celata extracts and fractions, highlighting its potential for further therapeutic applications.     

Changes in bran structure by bioprocessing with enzymes and yeast modifies the in vitro digestibility and fermentability of bran protein and dietary fibre complex

Bran is a good source of dietary fibre, phytochemicals, and also protein, but highly insoluble and recalcitrant structure of bran hinders accessibility of these components for gastrointestinal digestion. In the present work, influence of bioprocessing on the microstructure and chemical properties of rye bran and wheat bread fortified with the rye bran were studied. In vitro protein digestibility, and release of short chain fatty acids (SCFA) and ferulic acid in a gut model were studied. Bioprocessing of rye bran was performed with subsequent treatments with cell-wall hydrolysing enzymes (40 °C, 4 h) and yeast fermentation (20 °C, 20 h). Bioprocessing of rye bran resulted in reduced total dietary fibre content, caused mainly by degradation of fructan and β-glucan, and increased soluble fibre content, caused mainly by solubilisation of arabinoxylans. Microscopic analysis revealed degradation of aleurone cell wall structure of the bioprocessed rye bran. Bioprocessing caused release of protein from aleurone cells, assessed as a larger content of soluble protein in bran and a higher hydrolysis rate in vitro. Bioprocessed bran had also faster SCFA formation and ferulic acid release in the colon fermentation in vitro as compared to native bran.     

Antioxidant Capacity of Flaxseed Products: The Effect of In vitro Digestion

This study evaluated the effect of in vitro digestion of flaxseed products on Folin-Ciocalteu reagent reducing substances (FCRRS), its antioxidant capacity and prevention of oxidative DNA damage in human monocyte cell line U937. Flaxseed protein isolate was obtained from defatted flaxseed meal and the protein hydrolysate with high antioxidant capacity was obtained from hydrolysis of the protein isolate with Alcalase in a two factor central composite rotatable design (pH 8.5 and enzyme: substrate 1:90, w/w). The FCRRS content and antioxidant capacity measured by FRAP and ORAC in aqueous and 70 % methanol extracts were the highest in protein hydrolysate, followed by protein isolate, while the defatted meal showed the lowest values. After in vitro gastrointestinal digestion, the FCRRS content of protein isolate and hydrolysate reached similar values, however the hydrolysate had the highest antioxidant capacity, measured by FRAP while the isolate had the highest ORAC values. The defatted meal showed the lowest capacity in all assays (p?<?0.05). The hydrolysate did not protect against DNA damage induced by H₂O₂ in U937 cells under the conditions of the present study. The results suggest that flaxseed protein isolate and hydrolysate are potential functional food ingredients with antioxidant capacity.     

Seaweed Polysaccharides (Laminarin and Fucoidan) as Functional Ingredients in Pork Meat: An Evaluation of Anti-Oxidative Potential,Thermal Stability and Bioaccessibility

The anti-oxidative potential of laminarin (L), fucoidan (F) and an L/F seaweed extract was measured using the DPPH free radical scavenging assay, in 25% pork (longissimus thoracis et lumborum (LTL)) homogenates (TBARS) (3 and 6 mg/mL) and in horse heart oxymyoglobin (OxyMb) (0.1 and 1 mg/mL). The DPPH activity of fresh and cooked minced LTL containing L (100 mg/g; L₁₀₀), F₁₀₀ and L/F_100,300, and bioaccessibility post in vitro digestion (L/F₃₀₀), was assessed. Theoretical cellular uptake of antioxidant compounds was measured in a transwell Caco-2 cell model. Laminarin displayed no activity and fucoidan reduced lipid oxidation but catalysed OxyMb oxidation. Fucoidan activity was lowered by cooking while the L/F extract displayed moderate thermal stability. A decrease in DPPH antioxidant activity of 44.15% and 36.63%, after 4 and 20 h respectively, indicated theoretical uptake of L/F antioxidant compounds. Results highlight the potential use of seaweed extracts as functional ingredients in pork.     

Antioxidant activity of phenolic compounds obtained by autohydrolysis of corn residues

This study aimed to evaluate the effect of autohydrolysis temperature of corn residues in the antioxidant activity of the phenolic compounds extracted from the liquid phase. The treatments were carried out at 160, 180, 190 and 200 °C for 30 min in a pressurized batch reactor. Two different methods for phenolic compounds extraction from the autohydrolysis liquors were investigated. For that purpose, solvent extraction with ethyl acetate and acidic precipitation were performed for phenolic compounds recovery. These methods have been compared in terms of extraction yield, physicochemical properties of obtained polyphenols (characterization by Fourier Transform Infrared Spectroscopy, Thermogravimetric Analysis and Gel Permeation Chromatography), total phenolic content, total antioxidant capacity and Trolox equivalent antioxidant capacity (TEAC) values, measured in DPPH (2,2-diphenyl-1-picrylhydrazyl) test system. The maximum phenolic contents ranged from 6.04 mg GAE/100 mg extract in acidic precipitated samples to 16.45 mg GAE/100 mg extract in ethyl acetate soluble fractions. The results indicated that the ethyl acetate fractions possessed the highest antioxidant activity, reaching after 30-60 min the same capacity reported for the reference synthetic antioxidants (Trolox).