Nutritional composition and antioxidant properties of Canarium odontophyllum Miq. (dabai) fruits

The present study sought to determine the nutritional composition and antioxidant properties of Canarium odontophyllum Miq. (dabai) fruits from different districts in Malaysia, namely Kanowit, Sarikei, Kapit and Song in Sarawak. Two varieties of the fruits were investigated. Lipid (21.16 ± 4.71 to 25.76 ± 3.03 g/100 g FW) was the major macronutrient in dabai fruits, while the predominant minerals were calcium, sodium and potassium. The fruit protein was rich in aspartic and glutamic acids which accounted for 45–49% of total amino acids. Purple dabai fruits from Kapit were found to contain the highest total phenolic levels, flavonoids and anthocyanin contents (p < 0.01) and to exhibit the most significant antioxidant activities (p < 0.01), using trolox equivalent antioxidant capacity (TEAC) and ferric reducing ability (FRAP) assays. Antioxidant activities were highly correlated with total phenolic and flavonoid contents of dabai fruits.     

Effects of cooking on in vitro sinigrin bioaccessibility,total phenols,antioxidant and antimutagenic activity of cauliflower (Brassica oleraceae L. var. Botrytis)

Cauliflower (Brassica oleraceae L. var. Botrytis) is a good source of bioactive compounds, such as glucosinolates, phenolic compounds and vitamins. In this study, the effects of some processes (i.e. boiling, steaming) on the sinigrin bioaccessibility as a major glucosinolate found in cruciferous vegetables after in vitro digestion, also in vitro antimutagenic activities, total phenols and total antioxidant capacities of cauliflower were determined. The sinigrin content was reduced by approximately 9.6% and 29.1% in steamed and boiled cauliflower (p > 0.05), respectively. After in vitro simulated digestion, sinigrin content was decreased by 26.4% in raw samples, increased by 29.5% and 114.7% in steamed and boiled samples, respectively. In all samples, mutagenic effect to Salmonella typhimurium TA 100 was not seen. When samples were steamed, phenol content was increased by 14.83%. After boiling total phenol content of cauliflower was decreased by 1.8%. Total antioxidant capacities (TAC) measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3 ethylbenzothiazoline-6-sulfonic acid) (ABTS) methods were increased by 47% and 39%, respectively (p < 0.05) in steamed samples and decreased by 8% and 7% with boiling, respectively (p > 0.05). TAC in raw sample of cauliflower, which was investigated in phosphomolybdenum assays, was determined as 18.7 mg ascorbic acid equivalents (AAE)/100 g. In all cases, the highest antioxidant activity was determined in the steamed samples, while the lowest antioxidant activity was in boiled samples.     

Phenolic compounds and antioxidant activity of Spanish commercial grape juices

Evaluation of the antioxidant activity of components of the diet is important in order to establish healthy consumption patterns. Data are reported here on the antioxidant activity (FRAP and ABTS), of 20 commercial grape juices and 10 typical Spanish wines and on their content of total phenolic compounds, anthocyanins, flavonoids and 10 individual phenolic compounds (flavanols, benzoic acids and cinnamic acids, measured by HPLC-UV). Red grape juices had a significantly higher (p < 0.05) concentration of total phenols (1177 vs. 744 mg gallic acid/L), flavonoids (98 vs. 63 mg catechin/L) and a higher antioxidant activity (9.16 vs. 2.83 meq Trolox/L) in comparison to white grape juices. In comparison to the white wines, white grape juices contained more total phenols (744 vs. 286 mg gallic acid/L) and flavonoids (63 vs. 29 mg catechin/L) and evidenced higher antioxidant activity (p < 0.05). In comparison to the red wines, a lower content of total phenols (286 vs. 2358 mg gallic acid/L) and flavonoids (228 vs. 29 mg catechin/L) and an absence of anthocyanins were observed in the white wines, which are therefore less antioxidant. Although a two-fold higher concentration of antioxidant compounds was found in red wines than in red grape juices, the latter may be a good option for all age groups because of the absence of alcohol and the potentially beneficial health effects of their phenolic composition and elevated antioxidant activity.     

Antioxidant activity,quality parameters and mineral content of Portuguese monofloral honeys

Physicochemical properties (pH, free, lactonic and total acidity, electrical conductivity and moisture), main mineral content (potassium, sodium, calcium, magnesium and iron) and antioxidant activity (total phenolics, 1,1diphenyl-2-picrylhydrazyl radical scavenging and ferric reduction antioxidant power) were determined for 39 Portuguese monofloral honeys (rosemary, orange, thyme, arbutus, locust podshrub and heather) with different geographical origins. Portuguese honeys showed good chemical and nutritional qualities fulfilling the criteria described in Directive 2001/110/CE. Potassium was the main mineral component representing 85% of total minerals. The mineral composition of sodium (4.63–200.60 mg/kg), calcium (0.43–72.30 mg/kg), magnesium (3.05–82.20 mg/kg) and iron (below 7.06 mg/kg) were higher for heather, eucalypt and arbutus honeys. Monofloral honeys of arbutus (Arbutus unedo), locust podshrub (Ceratonia siliqua L.) and heather (Erica umbellata) showed higher antioxidant activity with phenolic contents higher than 600 mg gallic acid equivalents (GAE)/kg, a DPPH scavenging activity higher than 50% and a ferric reduction antioxidant power above 600 μM Fe²⁺. Furthermore, the chemometric analysis revealed that total phenolic content was a crucial variable explaining the antioxidant activity of arbutus and locust podshrub honeys characteristic of the south of Portugal.     

Survey of antioxidant capacity and nutritional quality of selected edible and medicinal fruit plants in Hong Kong

Twenty-two samples (including fruits, pulp, peel, or seeds) from 13 edible and medicinal fruit plant species selected in Hong Kong were investigated for their antioxidant capacity, nutritional quality and phenolic profiles. Significant variation existed among the tested samples in all the antioxidant and nutritional parameters. Proanthocyanidins, flavonoids and phenolic acids were identified as major categories of phenolic compounds in these samples. Whole fruits of Hong Kong gordonia exhibited the strongest antioxidant capacity (213.4 mmol trolox/100 g DW) and had the second highest content of carotenoids. Seeds of Annona squamosa possessed the highest contents of total protein, fat and amino acids (17.6, 37.2 and 14.4%, respectively). Most peel and some seeds contained high levels of phenolics, carotenoids and vitamin C, which contributed to their strong antioxidant activity. Some of the fruits, peel or seeds from these Hong Kong plants can be a potential resource of functional components and nutraceuticals.     

Determination of free and bound phenolics using HPLC-DAD,antioxidant activity and in vitro digestibility of Eragrostis tef

White and brown Eragrostis tef were assessed for total flavonoid and phenolic content, HPLC profile of the most common phenolics and antioxidant activity including both free and bound phenolics. Antioxidant activity was evaluated in correlation with free and bound phenolics and in vitro digestibility was determined. Content of flavonoids (0.52–1.02 mg RE/g) and phenolics (0.90–1.42 mg GAE/g) as well as antioxidant activity (1.70–4.37 μmol TEAC/g using ABTS method) was higher in free phenolic fraction. Correlation showed that bound flavonoids were not significant contributors to antioxidant activity (R² = 0.4513 and 0.4893, respectively). The main free phenolics in brown teff were trans-p-coumaric, protocatechuic, ferulic and gallic acids, while the major free phenolics in white teff were rutin, protocatechuic and ferulic acids. The main bound phenolics in brown teff were ferulic and gallic acids, quercetin and catechin, in white teff ferulic acid, rutin, catechin and quercetin. Cooked teff showed very high level of in vitro organic matter digestibility (80.5–85.1%), whereas brown teff was significantly more digestible than white teff (P < 0.05).     

Characterization,bioactive compounds and antioxidant potential of three Brazilian fruits

With the objective of stimulating the cultivation and consumption of native Brazilian fruits, the physicochemical composition and antioxidant potential of three native species, namely the araticu-do-mato (Rollinia sylvatica A. St.-Hil.), pindo palm (Butia capitata (Mart.) Becc.) and mandacaru-de-três-quinas (Cereus hildmannianus K. Schum.) were determined in this study. The pindo palm fruit stood out because of its elevated carotenoid content (39.6 μg/g) and greater antioxidant capacity (26 μM trolox/g of fresh sample) by the ABTS (2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic) method, although by the DPPH (2,2-diphenyl-1-picrylhydrazyl) method, the pindo palm fruit (3847.5 g of fresh sample/g DPPH) and mandacaru-de-três-quinas fruit (3249.8 g of fresh sample/g DPPH) were considered to have the same antioxidant potential with no difference between them. The mandacaru-de-três-quinas fruit also showed the highest total phenolic compound content (1337.3 mg/100 g). Although the araticu-do-mato presented the highest vitamin C content (0.32 mg/g), it did not differ statistically from the mandacaru-de-três-quinas fruit (0.25 mg/g); on the other hand, it was considered to be equal to the pindo palm fruit (0.23 mg/g). The araticu-do-mato also showed the best result for the TSS/TTA (total soluble solids/total titratable acidity) ratio (41.92), thus it was adequate for in natura consumption and for processing as well.     

The effect of fruit size and fruit colour on chemical composition in ‘Kordia’ sweet cherry (Prunus avium L.)

The effect of fruit size (<26 mm, 26–28 mm, >28 mm) and fruit colour (Ctifl 4 and Ctifl 6) of ‘Kordia’ sweet cherry on composition of nutritive (sugars, organic acids) and bioactive (phenolics) compounds, on content of vitamin C, total phenolic content (TPC) and total antioxidant activity (TAA) was evaluated. The compositional data analysis was used for comparing relative contents of chemical compounds. The differences in average composition were examined on the basis of multivariate analysis of variance and further analysis of variance for each isometric log-ratio transformed variable. Five compounds have been identified for the first time: dicaffeoylquinic acid ([M−H]⁻ at m/z 515), procyanidin trimer ([M−H]⁻ at m/z 865), quercetin-3-(2G-glucosyl-rutinoside) ([M−H]⁻ at m/z 771), quercetin-3-galactoside ([M−H]⁻ at m/z 463) and kaempferol-3-glucoside ([M−H]⁻ at m/z 447). In the composition of sweet cherry ‘Kordia’ fruit bioactive compounds represented from 0.6% to 0.8%. The fruit colour modifies the chemical composition of phytochemicals more than fruit size; the two variables were correlated. More coloured fruit were larger, with better pomological traits and changed composition of nutritive compounds and phenolics.     

Comparison of fatty acids, vitamin E and physicochemical properties of Canarium odontophyllum Miq. (dabai), olive and palm oils

Canarium odontophyllum Miq. fruit (dabai) is an important food and oil resource for the native people in Sarawak, Malaysia. However, there is little information regarding their oil composition. In this paper, fatty acid compositions, vitamin E contents and physicochemical properties of dabai pulp and kernel oils were studied. These parameters were compared with commercial olive and palm oils. The content of total saturated fatty acid was found to be 44.4% in dabai pulp, kernel (60.8%), palm oil (47.9%) and olive (25.5%) oils. Palmitic, myristic, oleic and linoleic acids were detected in dabai pulp oil (36.1, 5.8, 41.5 and 11.8%) dabai kernel oil (46.4, 9.3, 35.1 and 2.8%), palm oil (33.8, 9.2, 39.7 and 10.9%) and olive oil (9.9, 12.9, 64.4 and 5.1%). Vitamin E was not detected in the dabai pulp oil, while palm oil had the highest vitamin E content, followed by dabai kernel oil and olive oil. In addition, the physicochemical characteristics of dabai oils show better quality than the studied commercial oils. The present study also showed that dabai pulp and kernel oils have good fatty acid composition and a high potential to be developed into healthy cooking oils.     

Radical scavenging,antioxidant and metal chelating activities of Annona cherimola Mill. (cherimoya) peel and pulp in relation to their total phenolic and total flavonoid contents

This study aimed to evaluate the total phenolic and flavonoid content, radical scavenging activity (by DPPH and ABTS tests) and antioxidant capacity (by β-carotene bleaching test) of Annona cherimola (cherimoya) fruits cultivated in Italy for human consumption. The metal chelating activity and ferric reducing power were also determined. A. cherimola peel and pulp were characterized by a total phenolic content of 14.6 and 12.6 mg chlorogenic acid equivalents/100 g fresh weight, respectively. A similar trend was observed with flavonoid content. Both extracts exhibited high antioxidant activity through different mechanisms of action. In particular, peel extract demonstrated the strongest free radical scavenging activity with an IC₅₀ value of 57.7 μg/mL. The same extract was more effective in preventing β-carotene oxidation (IC₅₀ value of 63.5 μg/mL after 60 min) and showed higher chelating ability (IC₅₀ value of 79.6 μg/mL) than pulp extract. This work demonstrated the high quality of cherimoya fruits cultivated in Italy, and recommends the peel of this fruit product that may be of interest from a functional point of view as a major source of natural antioxidants.     

The study of antioxidant capacity of varieties of nalewka,a traditional Polish fruit liqueur,using EPR,NMR and UV–vis spectroscopy

The antioxidant properties of various kinds of the traditional Polish alcoholic beverage nalewka were investigated using electron paramagnetic resonance (EPR), nuclear magnetic resonance (NMR) and ultraviolet–visible (UV–vis) spectroscopy. The antioxidant capacity was measured by EPR spectroscopy in μmol Trolox (TE) in a 100 mL nalewka sample. The total phenolic content was measured by Folin–Ciocalteu (FC) assays while aromatic proton content (H_ar) was determined by NMR spectroscopy; subsequently the correlation among these values was explored. All of the investigated nalewkas exhibited antioxidant properties. The values of Trolox equivalent antioxidant capacity (TEAC_DPPH) were in the range 45–1045 μmol TE/100 mL. It was found that the value of the TEAC_DPPH corresponded to the TP (r = 0.96) and H_ar (r = 0.95). Moreover, the TEAC_DPPH values depended on the kinds of fruits used for nalewkas’ preparation.     

Anthocyanin profile and antioxidant capacity of black carrots (Daucus carota L. ssp. sativus var. atrorubens Alef.) from Cuevas Bajas,Spain

The present work deals with the study of the anthocyanin profile of two different black carrots (Daucus carota L. ssp. sativus var. atrorubens Alef.) cultivars, associated with Antonina and Purple Haze varieties, from Cuevas Bajas (Málaga, Spain) and some of their antioxidant features. The main anthocyanins detected by LC–MS were found to correspond to five cyanidin-based anthocyanins: cyanidin 3-xylosylglucosylgalactoside, cyanidin 3-xylosylgalactoside and the sinapic, ferulic and coumaric acids derivative of cyanidin 3-xylosylglucosylgalactoside. The anthocyanins present in the black carrots were essentially acylated and their levels were found to correspond to 25% and 50% of the total phenolic content for the Purple Haze and Antonina varieties, respectively. Moreover, the reducing capacity of the two black carrots extracts (86.4 ± 8.0 and 182.0 ± 27 μM TE/100 g fw) and the radical scavenging ability (17.6 ± 9.0 and 240.0 ± 54.0 μM TE/100 g fw) expressed in Trolox equivalents units were determined. The antioxidant features of the black carrot extracts were shown to be significantly higher than those of orange carrots used herein for comparison. Overall, this work highlights the Cuevas Bajas black carrots as rich sources of anthocyanins with significant antioxidant capacities and good nutritional value.     

Identification and quantification of phenolic compounds responsible for the antioxidant activity of sweet potatoes with different flesh colours using high performance thin layer chromatography (HPTLC)

The objectives of the present study were to develop a simple high performance thin layer chromatography (HPTLC)-based protocol: (i) to allow high-throughput profiling of phenolic compounds of microwaved roots from 295 sweet potato varieties and breeding lines, (ii) to quantify the content of anthocyanins and caffeoylquinic acid (CQA) derivatives, and (iii) to determine their respective contributions to the antioxidant activity of sweet potato methanolic extracts using the DPPH test. Analysed accessions were separated into three groups: white-fleshed (n = 100), orange-fleshed (n = 64) and purple-fleshed (n = 131). Purple-fleshed accessions presented the highest mean CQA content. After DPPH treatment and transmittance scanning of the plate at 517 nm, the most active free radical scavengers were found to be the four CQAs (CGA, 3,4-, 4,5- and 3,5-diCQA) while the anthocyanins were found to be less active. The total antioxidant capacity of the sweet potato methanolic extracts was mostly linked to total CQAs content. This method can now be used for fast routine analysis and selection of sweet potato breeding clones.     

Changes of antioxidant activity and total phenolic compounds during storage of selected fruits

The antioxidant activity and total phenolic compounds in various fruits (common fruits—two varieties of mangoes (ripe and unripe), guava, papaya, mangosteen and banana; and two indigenous fruits—makiang and maluod) were investigated. Banana and papaya showed the lowest activity, and mangosteen, mango and guava exhibited high levels of antioxidant activity (oxygen radical absorbance capacity (ORAC), and ferric-reducing antioxidant power (FRAP)) as well as total phenolic compounds. The studied indigenous fruits (makiang and maluod) are high in both antioxidant activity (ORAC and FRAP) and total phenolic compounds. Three independent batches of selected fruits—guava (Psidium guajava), makiang (Cleistocalyx nervosum var paniala) and maluod (Elaeagnus iatifolia, Linn)—were used to determine the changes in antioxidant activity (AO) and total phenolic compounds (TP) during storage at −20 °C for 3 months and at 5 °C for 10 days. The ORAC-AO during storage at −20 °C for 2 wk decreased significantly in homogenised guava (23%) and in whole fruits of maluod (62%), whereas that of makiang was constant. A continuous decrease in TP was found in homogenised guava throughout the 3-months storage period (69% retention) whereas constant levels were found in other fruits. At 5 °C, a decrease in the ORAC-AO in the whole fruits of makiang (14%) and maloud (70%) was found after a 3-days storage, whereas a gradual increase in the activity (120–190%) was found in the whole fruit of guava throughout the storage period. Among the factors which can affect the levels of antioxidant activity and total phenolic compounds in fruits could be the species, size and texture of fruits, the prepared form of the samples and the conditions of storage (e.g. time, temperature). Preliminary studies on the effect of storage in individual types of fruits are suggested before making a sampling plan for systematic analyses of their antioxidant activity.     

Effect of solvents in extracting polyphenols and antioxidants of selected raw vegetables

Thirty-seven raw vegetables were extracted using four solvent systems: 70% acetone, 70% ethanol, 70% methanol, and distilled water. The extracts were tested for their total phenolic content, total flavonoid content and antioxidant activities (using diphenylpicryl-hydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays). The results revealed the effect of different extracting solvents in altering the quantitative analyses of all vegetables and 70% acetone was identified as the most efficient solvent for extracting polyphenolic antioxidants from the vegetables. The highest total phenolic content and total flavonoid content were obtained from 70% acetone extract of Portulaca oleracea (138.2 ± 2.1 mg GAE/g dw basis) and 70% methanol extract of Cosmos caudatus (27.7 ± 1.0 mg QE/g dw basis), respectively. The 70% acetone extract of Etlingera elatior with moderate amount of total phenolic content exhibited the highest antioxidant activity in both assays. The correlation analyses within 37 different extracts of each solvent extraction demonstrated weak to moderate relationships between all the studied parameters. The highest r value of 0.7139 (p < 0.001) was determined between total phenolic contents and FRAP values of the 70% methanol extracts. Meanwhile, a wide range of correlation coefficients was derived from correlation analyses within four different extracts of each vegetable, with the highest relationship between total phenolic contents and FRAP values for the extracts of Coriandrum sativum (r = 0.9998, p < 0.001).     

Vitamin D2 content and antioxidant properties of fruit body and mycelia of edible mushrooms by UV-B irradiation

Our objective was to study the effect of ultraviolet-B (UV-B) light irradiation on the vitamin D₂ content of several edible fruit bodies and mycelia and their antioxidant properties. Eleven species of fresh mushroom fruiting bodies, including species from each of the six genera, Agaricus, Agrocybe, Auricularia, Hypsizigus, Lentinula and Pholiota, and five species from Pleurotus genus, were irradiated with UV-B light for 2 h. For three species of mushroom fruiting bodies with excellent vitamin D₂ yield, their mycelia were obtained by liquid culture, and subjected to the same time as the UV-B irradiation. Vitamin D₂ content of irradiated fruit bodies significantly increased from 0–3.93 to 15.06–208.65 μg/g, of which the amount in golden oyster mushroom increased by a maximum of 204.7 μg/g. Vitamin D₂ content in irradiated mycelia of golden oyster, oyster and pink oyster mushrooms increased from 0.28–5.93 to 66.03–81.71 μg/g, respectively. The three irradiated mycelium polysaccharide contents decreased in a range from 1.3% to 24.6%. Overall, EC₅₀ values of non-irradiated and irradiated fruiting bodies and mycelia were 0.92–4.94, 0.20–6.90 and 0.02–0.84 mg/mL for reducing power, scavenging ability and chelating ability, respectively. Although UV-B irradiation influenced the content of ergothioneine, flavonoids and total phenols, these irradiated samples still contained a sufficient amount of these antioxidant components.     

The influence of nitrogen and potassium fertilisation on the content of polyphenolic compounds and antioxidant capacity of coloured potato

The effect of fertilisation rates of nitrogen: 0 (control treatment—no soil fertilisation), 40, 80 and 120 kg/ha and potassium: 0 (control treatment), 120, 150 and 180 kg/ha on the content of anthocyanins, phenolic acids and antioxidant capacity in purple–blue potato cv. ‘Blue Congo’ was examined. Anthocyanins and phenolic acids were identified and quantified by LC–MS and UPLC–PDA. Nitrogen was more effective in increasing the anthocyanin content—their quantity in tubers after nitrogen application was twice as much as that found after potassium application. Among phenolic acids, the dominant one was chlorogenic acid, the content of which significantly increased after nitrogen fertilisation at 120 kg/ha, in line with the increase in total concentration of phenolic acids and antioxidant capacity. The adjustment of nitrogen and potassium fertilisation levels during the growth of purple–blue potatoes seems to be an effective way to increase the expression of polyphenolic compounds in these cultivars. Therefore, fertilisation with N at 120 kg/ha and K at 120 and 150 kg/ha is recommended as a way to improve the content of biologically active compounds and antioxidant properties, and consequently, to enhance the nutritional value and the functionality of purple–blue potatoes.     

Polyphenols,methylxanthines, and antioxidant capacity of chocolates produced in Serbia

Different kinds of chocolates produced in Serbia were analyzed regarding total polyphenol, flavonoid and proanthocyanidin content using spectrophotometric methods. Flavan-3ols and methylxanthines in all samples were determined with RP-HPLC. DPPH, FRAP, ABTS and ORAC assays were applied for measuring antioxidant capacity. The average of all four antioxidant tests for each cocoa product was used for calculating antioxidant potency composite index (ACI). Obtained results for all four assays have shown that antioxidant capacity of analyzed chocolate/cocoa extracts followed cocoa, polyphenol, flavonoid, and proanthocyanidin contents. Although the addition of raspberries to dark chocolates had no significant influence on their total polyphenol, flavonoid and proanthocyanidin contents, statistical analysis showed that there was significant increase in the antioxidant capacity of dark chocolates with raspberry compared to plain dark chocolates (p = 0.007). Overall range for theobromine content varied from 5.5 to 22.3 mg/g depending on the product type, while the content of caffeine was 13–30 times lower in all analyzed cocoa products. In addition, correlation between antioxidant potency composite index and declared percentage of cocoa was high (R² = 0.798, p < 0.05) and indicated that declared cocoa content was a reliable indication for antioxidant capacity of chocolates produced in Serbia.     

Antioxidant compounds and antioxidant activity in acerola (Malpighia emarginata DC.) fruits and derivatives

Acerola (Malpighia emarginata DC.) is a wild plant from Central America. This fruit is well known as an excellent food source of vitamin C, and it also contains phytochemicals such as carotenoids and polyphenols. The present work evaluates the antioxidant capacity of hydrophilic extracts of acerola pulps and juices by 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ORAC and 1,1-diphenyl-2-picrylhydrazyl (DPPH) methods. Antioxidant activity values obtained for acerola juice were higher than those reported for other fruit juices particularly rich in polyphenols such as strawberry, grape and apple juices, among others. Vitamin C, total phenol index (TPI), total anthocyanins and polyphenolic compounds by high performance liquid chromatography (HPLC), as main factors responsible for antioxidant activity, were determined. Contents in total ascorbic acid ranged from 6.32 to 9.20 g kg⁻¹ of pulp and 9.44 to 17.97 g L⁻¹ of juice. Five different polyphenolic compounds were identified in the samples by means of HPLC and diode-array detection: chlorogenic acid, (−)-epigallocatechin gallate, (−)-epicatechin, procyanidin B1 and rutin, being the two last predominant. By means of solid phase extraction (SPE) three soluble polyphenolic fractions (phenolic acids, anthocyanins and flavonoids) were separated from the different sample extracts, and their respective antioxidant activities calculated. Among them, phenolic acids are the main contributors to the antioxidant activity.     

Dietary fiber,phytochemical composition and antioxidant activity of Mexican commercial varieties of cactus pear

Cactus pear is one of the most important fruit in Mexican culture; however the phytochemical characterization of the whole cactus pear (pulp, peel and seeds) has not been studied. Therefore, the goal of this research was to evaluate the dietary fiber, vitamin C, total phenolic (TP), flavonoid and betalain concentrations and antioxidant activity (AOX) in the pulp, juice, peel and seeds of four Mexican commercial varieties of cactus pear. Rojo Cenizo and Rojo San Martín pulps presented concentrations of total dietary fiber, vitamin C, TP, betalains, and AOX of 145–166 g, 3–7 g ascorbic acid, 3–6 g gallic acid equivalents (GAE), 500–3444 mg betanin equivalents and 1044–5954 mg indicaxanthin equivalents, and 46–67 mm Trolox equivalents (TE) per kg, respectively. Rojo San Martín peel presented TP content over two times greater than the pulp, whereas AOX levels of Rojo San Martín and Verde Villanueva peels were 4–9 higher than their respective pulp. Cactus pear peel was the most important source of phytochemical compounds and AOX of the fruit, because of that it has to be considered in future applications for the formulation of new health-promoting ingredients and/or foods.