Antioxidant Capacity Of Juice Research Articles

The Effects of Different Solvents on Phenolic, Flavonoid, Anthocyanin Contents and Free Radical Scavenging Activity on Pomegranate Juice and Seeds

Our phytochemical investigation defined the polyphenol, anthocyanin and flavonoid content from methanolic, ethanolic 50% and watery extracts from fresh pomegranate juice and seeds with a spectrophotometric method. The antioxidant capacity was defined with the ABTS and DPPH methods. We determined the polyphenols with the Folin-Ciocalteu method, the anthocyanins with the method in Hungarian Pharmacopoeia VIIIth edition at Myrtilli fructus monography and the flavonoids with a modified method of the Romanian Pharmacopeia Xth edition Cynarae folium monography. We expressed the concentration of polyphenols in gallic acids (GA). The values indicated the following: in fruit juice, 47.57 μg GA/ml, in methanol seed extract 7 μg GA/g, the ethanol 50% and in watery seed extracts 8 μg GA/g. The definition of flavonoids indicated the following values expressed in quercetin (QE): in fruit juice 706 μg QE/ml, in methanol seed extract 416 μg QE/g, in ethanol 50% seed extract 46 μg QE/g and in watery seed extract 57 μg QE/g. The anthocyans from juice 3.95 mg/100 ml and seed 6.47 mg/100 g expressed in cyanidin-3-0-glycoside. We determined the following values with the ABTS method: the antioxidant capacity of juice is 25.40 μg/ml, in methanol seed extract 2.87 μg/ml, in ethanol seed extract 2.52 μg/ml, in watery 9.15 μg/ml. With the DPPH method, we obtained the following values: from juice 54.2 μg/ml, from methanolic extract 14.7 μg/ml, from ethanolic extract 10.58 μg/ml and watery extract 18.22 μg/ml. The received data shows the importance of pomegranate, which can be a new phytotherapeutic potential resource.

Evaluation of the Antioxidant Capacity of Fruit Juices by Two Original Analytical Methods.

Two analytical methods previously developed by our groups were employed to estimate the antioxidant capacity of commercial fruit juices. The electrochemical method, which measures the scavenging activity of antioxidants towards OH radicals generated by both hydrogen peroxide photolysis and Fenton's reaction, is based on the recovery of the cyclic voltametric response of the redox probe Ru(NH3)63+ at a Glassy Carbon electrode modified with a thin film of an insulating polyphenol, in the presence of compounds with antioxidant properties. The values of the antioxidant capacity of the fruit juices are expressed as vitamin C equivalents/L. The chromatographic method is based on the generation of OH radicals via Fenton's reaction in order to test the inhibition of their formation in the presence of antioxidant compounds by monitoring salicylate aromatic hydroxylation derivatives as markers of •OH production, by means of HPLC coupled to coulometric detection. The results are expressed as the percentage of inhibition of •OH production in the presence of the tested juice compared to the control sample. When OH radicals are produced by Fenton's reaction, the antioxidant capacity of the juices, estimated by both methods, displays an analogous trend, confirming that they can be considered an alternative for measuring the ability of antioxidants to block OH radical formation.

Spatial Distribution and Antioxidant Activity of Extracts from Citrus Fruits.

Citrus fruits are recommended components of the human diet because of their enriched composition in bioactive compounds and health benefits. Among their notable components are phenols, with a special emphasis on flavonoids, limonoids, and carboxylic acids. In this research, we have carried out a spatial metabolomics analysis for the characterization of these bioactive families in three citrus fruits, namely, lemons, limes, and mandarins. Sampling was undertaken, for which the juices and three fruit tissues, namely, albedo, flavedo, and segments, were analyzed. This characterization allowed for the determination of 49 bioactive compounds in all the samples. The composition of the different extracts was correlated with the antioxidant capacity measured by the DPPH radical scavenging activity and β-carotene bleaching assays. Flavonoids, found in the albedo and flavedo at higher concentrations, were the main components responsible for DPPH radical scavenging activity. On the other hand, the combined action of flavonoids and limonoids contributed to explaining the antioxidant activity measured by the β-carotene bleaching assay. Generally, the antioxidant capacity of juices was lower than that estimated for extracts from citrus tissues.

Impact of the Anodic and Cathodic Electro-Activation Treatment on the Physico-Chemical and Antioxidant Capacity of Red Beetroot Juice

The aim of the present work was to study the feasibility of using electro-activation as a nonthermal treatment to produce stable beetroot juice. Specifically, red beetroot juice was electro-activated under two different reactor configurations by using three electric current intensities (100, 200, and 300 mA) during 120 min. Different parameters of the juice were measured such as the pH, redox potential, juice titratable acidity, Brix degree and total dry matter, color, betalain and polyphenolic contents, and antioxidant capacity of the electro-activated juice. By using the reactor Configuration A in which the targeted juice was electro-activated in the anodic compartment of the used reactor, acidic juice with pH 4 and 5 as well as a redox potential close to +300 mV was obtained. The Brix degree, color, dry matter, and phenolic content were not significantly influenced by this electro-activation. However, the treatment permitted increasing the antioxidant capacity of the juice as measured by the DPPH and ABTS assays. By using the reactor Configuration B in which the targeted beet juice was electro-activated in the cathodic compartment of the used compartment, a juice with an alkaline pH of approximately pH 9 and a reducing redox potential of -697 mV was obtained. With this reactor configuration, the Brix degree and total dry matter were not affected, but the color and total polyphenolic content changed. The betalains and polyphenolic compounds were degraded under the alkaline conditions of this electro-activation treatment, which had a negative consequence on the juice quality by decreasing its antioxidant capacity. In conclusion, this study demonstrated that anodic electro-activation of a beet juice can be technologically feasible since this treatment permitted producing stable juice as well as maintaining the main physico-chemical properties of the juice, enhancing its antioxidant capacity, and keeping the juice color at high level.

Comparative study of two cold plasma technologies on apple juice antioxidant capacity, phenolic contents, and enzymatic activity

Cold plasma technologies are being developed as an alternative to thermal processes aiming toward preservation while retaining or improving several quality parameters. This research evaluates the use of dielectric barrier discharge (DBD) plasma and glow discharge plasma on browning enzyme activity, antioxidant capacity, and total phenolic content of apple juice. This work evaluated the effects of the main DBD plasma operating conditions, such as excitation frequencies (50–900 Hz), and glow plasma discharge operating conditions, such as air plasma flow rates (10–30 ml/min) and processing time (10–30 min). Both plasma systems partially inactivated the enzymes polyphenol oxidase and peroxidase and consequently increased apple juice's total phenolic content and antioxidant activity. DBD plasma technology presented better efficacy in increasing apple juice's total phenolic content and antioxidant capacity. DBD plasma and glow discharge plasma have the same effectiveness in inactivating browning enzymes in apple juice. Novelty impact statement This work compares two cold plasma technologies for apple juice processing. The results showed that different plasma technologies lead to different outcomes and that the right choice of technology should be made for a given goal.

Effect of harvest time on the chemical composition and antioxidant capacity of Gannan navel orange (Citrus sinensis L. Osbeck ‘Newhall’) juice

The present study investigates the chemical composition and antioxidant capacity of juice from the Gannan navel orange, which is harvested at one- to two-week intervals during the ripening period. The total soluble solid (TSS), total polyphenol content (TPC), total flavonoid content (TFC), sucrose and hesperidin contents gradually increase with the ripening of the fruit, followed by slight declines at the late maturity stage. Contrary to these observations, the contents of titratable acid (TA), vitamin C (Vc), and limonin trend downward throughout the ripening period. However, the contents of fructose, glucose, and narirutin fluctuate throughout the harvest time. Three in vitro antioxidant assays consistently indicate that the harvest time exerts no significant influence (P>0.01) on the antioxidant capacity. Furthermore, principal component analysis (PCA) and Pearson's correlation test are performed to provide an overview of the complete dataset. This study provides valuable information for evaluating the fruit quality and determining when to harvest the fruit in order to meet the preferences of consumers. Meanwhile, our observations suggest that the fruits subjected to juice processing should be harvested at the late maturity stage to alleviate the “delayed bitterness” problem without compromising the antioxidant capacity and the flavonoid content in the juice.

Ex Vivo Antioxidant Capacities of Fruit and Vegetable Juices. Potential In Vivo Extrapolation.

Background: In support of claims that their products have antioxidant properties, the food industry and dietary supplement manufacturers rely solely on the in vitro determination of the ORAC (oxygen radical antioxidant capacity) value, despite its acknowledged lack of any in vivo relevance. It thus appears necessary to use tests exploiting biological materials (blood, white blood cells) capable of producing physiological free radicals, in order to evaluate more adequately the antioxidant capacities of foods such as fruit and vegetable juices. Materials: Two approaches to assessing the antioxidant capacities of 21 commercial fruit and vegetable juices were compared: the ORAC assay and the “PMA–whole blood assay,” which uses whole blood stimulated by phorbol myristate acetate to produce the superoxide anion. We described in another paper the total polyphenol contents (TPCs) and individual phenolic compound contents of all the juices were investigated. Results: Ranking of the juices from highest to lowest antioxidant capacity differed considerably according to the test used, so there was no correlation (r = 0.33, p = 0.13) between the two assays when considering all juices. Although the results of the ORAC assay correlated positively with TPC (r = 0.50, p = 0.02), a much stronger correlation (r = 0.70, p = 0.004) emerged between TPC and % superoxide anion inhibition. In the PMA–whole blood assay, peonidin-3-O-glucoside, epigallocatechin gallate, catechin, and quercetin present in juices were found to inhibit superoxide anion production at concentrations below 1 µM, with a strong positive correlation. Conclusions: Associated with the determination of total and individual phenolic compounds contained in fruit and vegetable juices, the PMA–whole blood assay appears better than the ORAC assay for evaluating juice antioxidant capacity.

Ultrasound-Combined Sterilization Technology: An Effective Sterilization Technique Ensuring the Microbial Safety of Grape Juice and Significantly Improving Its Quality.

The effects of ultrasound (US), thermosonication (TS), ultrasound combined with nisin (USN), TS combined with nisin (TSN), and conventional thermal sterilization (CTS) treatments on the inactivation of microorganisms in grape juice were evaluated. TS, TSN, and CTS treatments provided the desirable bactericidal and enzyme inactivation, and nisin had a synergistic lethal effect on aerobic bacteria in grape juice while not having any obvious effect on the mold and yeast. Compared with CTS, the sensory characteristics of grape juice treated with TS and TSN are closer to that of fresh juice, its microbial safety is ensured, and the physicochemical properties are basically unchanged. More importantly, the total phenolic content and antioxidant capacity of juice treated with TS and TSN were significantly increased, and the total anthocyanin and flavonoid contents were largely retained. Taken together, these findings suggest that TS and TSN has great potential application value and that it can ensure microbial safety and improve the quality of grape juice.

Biogenic Amines and the Antioxidant Capacity of Juice and Wine from Brazilian Hybrid Grapevines.

Some biogenic amines (BAs) are used as quality markers in grape-derived products. The prolife of 9 BAs was determined in juices and wines elaborated from hybrid grapes. Low levels of histamine, tyramine and cadaverine were found. Juices elaborated from 'BRS Rúbea' showed the highest tyramine levels (1.56mg/L), while no histamine was found in wines elaborated from 'Seleção 34' and its higher content was detected in 'BRS Carmem' (3.55mg/L). Juices elaborated from 'BRS Violeta' showed elevated content (472.88mg/L) of total phenolic compounds (TPC) and mono-hydrated serotonin (6.20mg/L), and wines elaborated from 'Violeta' presented a high serotonin mono-hydrate content (23.63mg/L) and high antioxidant activity with FRAP test (77.24mmol FeSO4/L). Juices elaborated from hybrid grapes 'BRS Violeta' and wines from 'BRS Violeta', 'Seleção 34' and 'Seleção 13' had high levels of bioactive compounds, emphasizing the great potential of these cultivars for winemaking.

Physicochemical characterization and trait stability in a genetically diverse ex situ collection of pomegranate (Punica granatum L.) germplasm from Cyprus

Proximity to the center of origin and geographical isolation shaped a unique genetic diversity of pomegranate in Cyprus that constitutes a valuable resource for the crop. Physicochemical characters and trait stability were studied for three years in an ex situ collection of 29 pomegranate accessions from Cyprus. Accession signature traits with exceptional yearly stability were titratable acidity and the citrate/malate ratio. Overall, the Cypriot germplasm was characterized by juice of low anthocyanin content (x¯ = 20.6 mg/L) and moderate phenolic content (x¯ = 613.0 mg/L) with glucose (x¯ = 69.1 g/L) and fructose (x¯ = 74.2 g/L) as predominant sugars. Juice antioxidant capacity was associated primarily with total phenolics and less so with juice color and anthocyanin content. Total sugar content was higher in large-fruited accessions with darker juice. In most accessions the titratable acidity was low (<0.50% w/v), with citric (x¯ = 44.7%), malic (x¯ = 39.1%) and succinic (x¯ = 15.8%) being the main organic acid fractions detected. Based on the maturity index (SSC/TA), six accessions were sweet-sour or borderline sweet-sour and 23 accessions were sweet. Cluster analysis of phenotypic characteristics and genetic data revealed a core group of thirteen genetically and phenotypically close accessions constituting the Cypriot pomegranate landrace, characterized by moderate fruit weight, high juiciness, thin rind, moderately hard seeds and light-colored juice low in acidity, anthocyanins, phenolics and antioxidant capacity. The present work advances the understanding of genetic and environmental contribution to the configuration of pomegranate physicochemical fruit composition.

Pasteurization of mixed mandarin and Hallabong tangor juice using pulsed electric field processing combined with heat.

Effects of pulsed electric filed (PEF) processing combined with heating (H-PEF processing) on the inactivation of microorganisms and the physicochemical properties of mixed mandarin and Hallabong tangor (MH) juice were studied. Using a pilot-scale PEF system, MH juice, pre-heated at 55°C, was PEF-treated at 19kV/cm of electric field and 170kJ/L of specific energy and the juice, pre-heated at 70 °C, was PEF-treated at 16kV/cm and 100kJ/L or 12kV/cm and 150kJ/L. H-PEF processing at 70°C-16kV/cm-100kJ/L reduced the aerobe, yeast/mold, and coliform counts of MH juice by 3.9, 4.3, and 0.8 log CFU/mL, respectively, without affecting the ascorbic acid concentration and antioxidant capacity of juice. H-PEF processing changed juice color and browning degree (p<0.05), but not total soluble solid content or pH. By controlling initial juice temperature and electric field strength, H-PEF processing can be an effective pasteurization method for mixed juice with minimal changes in quality.

Characterisation of the flavonoid composition and total antioxidant capacity of juice from different citrus varieties from the Western Cape region

Four citrus varieties, clementine mandarin, satsuma mandarin, navel orange and Valencia orange, grown in the Western Cape of South Africa, were evaluated in terms of their total polyphenol content (TPC), total flavonoid content (TFC), major phenolic compounds and total antioxidant capacity (TAC) of the juice, taking into account seasonal variation (2011, 2012 and 2014). The results indicated that juice from satsuma mandarin had the highest TFC level (748mg/L naringin equivalents) and Valencia orange had the lowest TPC (115mg/L gallic acid equivalents). The data indicated that varieties grown in the same geographical region differed in terms of TPC and TFC content of the juice and that seasonal influence was not significant. Contrary to these results, the major phenolic compounds showed great variation between different seasons. Hesperidin and narirutin were the predominant flavanone-C-glycosides in navel orange and Valencia orange juice, with vicenin-2 and ferulic acid-O-hexoside also present in high quantities. The juice from satsuma mandarin had the highest quercetin-3-O-rutinoside-7-O-glucoside, narirutin and rutin concentrations, whilst clementine mandarin had the lowest in terms of the sum of individual phenolic compounds quantified. Overall the citrus fruit juice samples, collected in 2014, irrespective of variety, had the highest TAC.

Application of abscisic acid (S-ABA) to cv. Isabel grapes (Vitis vinifera × Vitis labrusca) for color improvement: Effects on color, phenolic composition and antioxidant capacity of their grape juice

Hybrid grape Isabel (Vitis vinifera×Vitis labrusca) is the main cultivar used to produce grape juice in Brazil. However Isabel grape is deficient in anthocyanins. Application of abscisic acid (S-ABA), which is responsible for promoting the anthocyanin synthesis, offers a way for color improvement. This study evaluates the changes on the phenolic composition of Isabel grape juice produced from grapes treated with S-ABA, over two consecutive harvest seasons. Application of S-ABA to grapes increased the content of total anthocyanins in the corresponding juices and also the proportion of anthocyanins based on B-ring tri-substituted anthocyanidins. Regarding non-anthocyanin phenolic compounds, total flavonol content was only significantly higher in juices produced from grapes treated in the 2012 season, whereas the treatment did not significantly affect the content of hydroxycinnamic acid derivatives, flavan-3-ols, resveratrol and even the antioxidant capacity of juices. Juice from Isabel grapes treated with S-ABA provides an enhancement of total anthocyanin concentration, mainly when grapes are treated before or at the onset of véraison. As a consequence, the color intensity increased in all the juices obtained from treated grapes.

Phenolic compounds in juice of “Isabel” grape treated with abscisic acid for color improvement

Isabel grape is the main cultivar used to produce juice in Brazil, which has rusticity and high productivity, but it is deficient in anthocyanins, a pigment responsible for the color. Thus, an alternative is the application of abscisic acid (S -ABA), which is responsible to promote the synthesis of anthocyanins. The aim of this work was to evaluate the phenolic compounds composition in “Isabel” grape juice treated with S -ABA, by HPLC-DAD–ESI-MS/MS technique. The results showed the increasing in total anthocyanin concentration in juices, with S -ABA treatments, as well as the proportion of B-ring tri-substituted anthocyanidins. Regarding total flavonols, differences were only significant in juices obtained in 2012 season. S -ABA treatments did not significantly affect the hydroxycinnamic acid derivatives, flavan-3-ols, resveratrol and antioxidant capacity of juices. Juice from “Isabel” grapes treated with S -ABA provides an enhancement of total anthocyanin concentration, mainly when grapes are treated before or at the onset of veraison .

Comparison of the effects of blending and juicing on the phytochemicals contents and antioxidant capacity of typical korean kernel fruit juices.

Four Korean kernel fruit (apple, pear, persimmon, and mandarin orange) juices were obtained by household processing techniques (i.e., blending, juicing). Whole and flesh fractions of each fruit were extracted by a blender or a juicer and then examined for phytochemical content (i.e., organic acids, polyphenol compounds). The antioxidant capacity of each juice was determined by ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. Results revealed that juices that had been prepared by blending whole fruits had stronger antioxidant activities and contained larger amounts of phenolic compounds than juices that had been prepared by juicing the flesh fraction of the fruit. However, the concentration of ascorbic acid in apple, pear, and mandarin orange juices was significantly (P<0.05) higher in juice that had been processed by juicing, rather than blending. The juices with the highest ascorbic acid (233.9 mg/serving), total polyphenols (862.3 mg gallic acid equivalents/serving), and flavonoids (295.1 mg quercetin equivalents/serving) concentrations were blended persimmon juice, blended mandarin orange juice, and juiced apple juice, respectively. These results indicate that juice extraction techniques significantly (P<0.05) influences the phytochemical levels and antioxidant capacity of fruit juices.

Effect of grape seeds on the polyphenol bioactive content and elemental composition by ICP-MS of grape juices from Vitis labrusca L.

The effect of grape seeds on the bioactive content and elemental composition of grape juices from Vitis labrusca L. varieties Concord, Isabel and Bordo, widely cultivated in Brazil, was examined. Grape seeds of each variety were macerated with berries at concentrations of 50, 100 and 200 g/kg of grape, followed by the extraction of varietal juices. The total phenolic content, monomeric anthocyanins and antioxidant capacity were determined in juices, and their correlations with seeds were assessed. The mineral content and metal contamination in juices was determined by ICP-MS. Grape seeds significantly increased the total phenolics and antioxidant capacity of juices, showing high correlations. In Isabel juices, seed addition at concentration of 200 g/kg increased about 8 times the polyphenols concentration. The addition of seeds was poorly correlated with anthocyanins content and positively correlated with minerals (Ca, Mg, Na, K, Mn, Zn). The trace elements Cu, Ni, Sr, As, Cr, Li, Ba and Al were detected. The inclusion of seeds in grape juice comprises a feasible approach to bioactive enrichment of this widely appreciated beverage and also an alternative to reduce vegetable waste in fruit industries.

Pomegranate (Punica granatum L.) fruit response to different deficit irrigation conditions

No information exits on the effects of water stress on pomegranate (Punica granatum L.) fruits. In this paper, the influence of three irrigation treatments on the physical and chemical characteristics of the fruits of adult pomegranate trees was studied. Control (T0) plants were drip irrigated (60% ETo from the beginning of the season to the end of the first half of linear fruit growth phase, 117% ETo during the second half of linear fruit growth phase and 99% ETo during the end of fruit growth and ripening phase) in order to guarantee non-limiting soil water conditions, T1 plants were drip irrigated according to the criteria frequently used by the growers in the area (32% ETo from the beginning of the season to the end of the first half of linear fruit growth phase, 74% ETo during the second half of linear fruit growth phase and 36% ETo during the end of fruit growth and ripening phase) and T2 plants were irrigated as T1, except during the second half of linear fruit growth phase, in which irrigation was withheld. To ensure the recovery of T2 plants re-irrigation was performed at the levels used in T0. T1 plants achieved a moderate water stress level, whereas T2 plants achieved a more pronounced water stress level, from which they completely recovered when plants were rewatered. During ripening the peel of pomegranate fruits changes to show higher luminosity and greater red saturation. Also, the colour of the arils changes to a more perceptible red colour as a consequence of the increasing total anthocyanin content. However, neither the intense red colour of the arils nor their total phenolic compounds content was correlated with the juice antioxidant capacity. Considerable differences were observed in the response of pomegranate fruits to both deficit irrigation treatments. In this sense, fruits from T1 plants showed a decrease in fruit growth, leading to a lower final fruit size and lower total yield, and some changes in colour and chemical characteristics, which reflected earlier ripening. In contrast, a more pronounced water stress during the second half of the fruit growth phase (T2) was more critical for fruit size than for the chemical characteristics of the fruit, probably because under this situation carbon assimilation should be allocated to the synthesis of primary metabolites, which did not exceeded the amount used for fruit growth to the detriment of the synthesis of carbon-based secondary metabolites.

Antioxidant activity and physico-chemical properties of Tunisian grown pomegranate (Punica granatum L.) cultivars

The objective of this study was to compare the physico-chemical characteristics and antioxidant activity of 13 pomegranate cultivars grown in southern Tunisia. Fruit size, skin color, skin thickness, juice yield, juice color, total soluble solids, pH, titratable acidity, total phenolics, total and individual anthocyanin and antioxidant activity were measured in the pomegranate cultivars. The results showed great differences in the characteristics and the composition of the pomegranate cultivars. The considerable variation was consistent with ANOVA and PCA results. Three cultivars were found isolated with particular characteristics; CH8-2 distinguished with large fruit size, MZ2 with red-colored peel, sour sweet juice and high antioxidant activity and GS1 with the smallest fruit, the lowest juice content, highest juice acidity and with its considerable antioxidant activity. In addition, the cultivar RF1was also detached from other cultivars with considerable amounts of phenolics and anthocyanins. Results showed also significant correlations between total phenolics content and antioxidant activity indicating the contribution of phenolic compounds in juice antioxidant capacity. Moreover, significant correlations were found between the red color intensity a* and antioxidant capacity, or total phenolic content and some anthocyanins pigments suggesting the richness of red juices in antioxidants, phenolic compounds and anthocyanin pigments. The correlation observed between the juice visual color and color indices of CIE L*a*b* emphasize the efficiency of the grading color scale to determine the color of pomegranate juice in the absence of the CIE system. These results would be a guide in the selection of potential cultivars which are used in food and chemical industry and fresh market.

Identification of phenolic compositions and the antioxidant capacity of mandarin juices and wines.

This research was undertaken to determine the phenolic composition and antioxidant capacity of juices and wines obtained from Robinson, Fremont and Satsuma mandarins. High-performance liquid chromatography coupled with diode-array detection was used for identifying and quantifying phenolic compounds. The total amount of phenolic compounds ranged from 36.6 to 132.6mg/L for the mandarin juice, and from 14.1 to 54.5mg/L for the wines. In the juices and wines, the major hydroxybenzoic acid was vanillic acid; the major hydroxycinnamic acid was ferulic acid; and the major flavanone was hesperidin. The antioxidant activity was measured using the DPPH and ABTS radical scavenging assays, and the antioxidant capacity of mandarin juices was found to be higher than that of wines. Results of this study indicated that these mandarin wines had a composition similar to other beverages, thus demonstrating that these fruits have the potential to be used to produce fermented beverages.

Changes in bioactive compounds and antioxidant capacity of fresh-cut cashew apple

In this study, ascorbic acid, total polyphenols and proanthocyanidins of fresh-cut cashew apple were quantified. Antioxidant capacity was determined in whole juice and in polyphenols extracts by three methods: 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and β-carotene bleaching. Effect of cutting and storage for 24h at 2°C, 27°C and 40°C on these compounds were also evaluated. Cashew apple presented 163mg of ascorbic acid per 100g of fresh weight (FW). Soluble and hydrolysable polyphenols contents were 12.79mg GAE/100g FW and 18.53mg GAE/100g FW and proanthocyanidins were 9.27mg/100g FW. Antioxidant capacity of juice and polyphenols extract was high for DPPH method. Storage temperatures affected bioactive compounds on cut cashew apple. The content of ascorbic acid decreased in all temperatures. Proanthocyanidins were more sensitive to 40°C than to other temperatures. The content of polyphenols and antioxidant capacity of juice by DPPH assay did not change. However, the reducing power was lower in samples kept at high temperatures. A strong positive correlation between ascorbic acid and FRAP (r=0.99) and a negative correlation between DPPH and FRAP (r=−0.79) were observed. No correlations were found between polyphenols and antioxidant capacity indicating the importance of phenolic composition in the extracts. The results confirm the importance of temperature and injury on the quality of cashew apple.