Comparison of the polyphenolic composition and antioxidant activity of European commercial fruit juices

Thirty six commercial European fruit juices were tested to ascertain their antioxidant capacity and polyphenolic composition. Six of the products were labelled 100% pomegranate juice, the others included 20 brands of diluted pomegranate juice or pomegranate blended with other fruit juices and 10 different non-pomegranate fruit juices. The antioxidant capacity of all the juices was determined while anthocyanin, ellagitannin and ellagic acid profiles of the 26 pomegranate juices and pomegranate juice blends were obtained using HPLC-PDA-MS(2). Additional analysis was conducted on seven of the juices using HPLC with an on-line antioxidant detection system. Three of the "pure" pomegranate juices had the highest ellagitannin content and the highest antioxidant capacity. Only one of these three juices was rich in anthocyanins. The other "pure juices" had differences in their HPLC "pomegranate" fingerprint and also had a lower antioxidant capacity, in some cases lower than that of some of the blended juices. Vitamin C rather than phenolic compounds was the major contributor to the antioxidant capacity for some of the juices. Statistical analysis of both the antioxidant assay and the HPLC on-line antioxidant data demonstrated that the ellagitannins were the major antioxidants in the pomegranate juices. The complexity of the polyphenolic profile of pomegranates necessitates the use of HPLC-PDA-MS(2) for a thorough evaluation of juice composition and authenticity.     

Contributions of phenolics and added vitamin C to the antioxidant capacity of pomegranate and grape juices: synergism and antagonism among constituents

The aim of this study was to examine the contribution of sugar, organic acid, neutral phenol, and anthocyanin fractions and added ascorbic acid to grape and pomegranate‐nectarine juice total phenol, oxygen radical absorbance capacity (ORAC), ferric reducing antioxidant power (FRAP) and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) values. Neutral phenol and anthocyanin fractions contributed ≥75% of the total antioxidant capacity (TAC) for both juices. Intrinsic synergy and antagonism among the fractionated constituents occurred inconsistently in each assay. Sugars and organic acids antagonised pomegranate juice neutral phenols and anthocyanins in the DPPH assay by 50% and the grape juice ORAC value by 21%, but were synergistic to the grape juice FRAP value. The added ascorbic acid was dose‐dependently synergistic with pomegranate and grape juice total phenol, DPPH and FRAP assays, but less so in the ORAC assay. Thus, the interactions between grape and pomegranate juice constituents determine TAC and total phenol values, and synergy in these assays could not be attributed solely to polyphenols.     

Total phenols and antioxidant capacity in 10 Moroccan pomegranate varieties

The study focused on characterizing the 10 major Moroccan cultivars to acknowledge the quality and bioactive compounds of the fruits. The following determinations were assessed: pomegranate fruit maturity index, which truly defines juice taste, as well as organic acids and sugar contents, total phenols, and antioxidant activity of pomegranate juice. The cultivar per se (genotype) behaved as the most influencing factor conditioning pomegranate sugar and organic acids profiles, antioxidant activity, and total phenolics. The assessment of pomegranate chemical compositions implies the great potential of Moroccan cultivars for both fresh market and fruit processing. In fact, the "Hamde" sour cv. seems particularly suitable for juice production because of its high phenolics content. Additionally, the presence of bioactive compounds in pomegranate juices may encourage their consumption for potential health benefits. PRACTICAL APPLICATION: The cultivar per se (genotype) behaved as the most influencing factor conditioning pomegranate sugar and organic acids profiles, antioxidant activity, and total phenolics. Given the divergence observed on bioactive compounds concentrations and antioxidant activity among evaluated cultivars, the genotype factor should be considered as the most influencing factor in future breeding programs to enhance the synthesis of beneficial bioactive compounds.     

Anthocyanin and organic acid profiles of pomegranate (Punica granatum L.) juices from registered varieties in Turkey

This is the first study to analyse the profiles of anthocyanin (ACN) and organic acid (OA) and some physico‐chemical properties of pomegranate juices (PJs) obtained from nine registered varieties in Turkey. HPLC analyses revealed that there were significant differences between ACN contents (28–447 mg L^?1) and profiles (P < 0.01). The PJs contain maximum six ACNs, 3‐glucosides and 3,5‐diglucoside of delphinidin, cyanidin and pelargonidin. The major OA in PJs was citric acid (66–74%), followed by malic (6–12%), succinic (5–19%), nonidentified (0–14%) and tartaric acids (0.1–3.7%). Amongst individual OAs, citric acid had the most significant effects on TA (r = 0.9761), pH (r = 0.9208) values and sourness of PJs. As different from literature, results of this study revealed that malic acid contents of authentic PJs could be higher than 1.5 g L^?1. Consequently, ACN and OA profiles could be successfully used in quality control because all PJs have their own typical ACN and OA profiles.     

喀什甜石榴与会理青皮石榴品质及抗氧化 活性的比较

目的 比较新疆喀什甜石榴和四川会理青皮石榴两个品种的果实品质和抗氧化活性。方法 测定了这两个石榴品种的品质、糖酸含量、总花色素苷、总酚及其抗氧化能力。结果 新疆喀什甜石榴的可溶性固形物含量、籽粒色饱和度、苹果酸含量、总花色素苷含量和总酚含量均高于四川会理青皮石榴;而四川会理青皮石榴的葡萄糖含量和果糖含量则高于喀什甜石榴;喀什甜石榴和会理青皮石榴籽粒的总抗氧化能力分别为211.25 U和178.97 U;DPPH自由基清除率分别为0.87和0.82;石榴籽粒中抗氧化活性分别与总酚、总花色素苷成正相关。结论 两个石榴品种在果实品质和抗氧化活性方面各有特点,这为石榴品种的品质评价和果实加工利用提供了参考依据。     

Antioxidant properties of pomegranate (Punica granatum L.) bagasses obtained as co-product in the juice extraction

The aim of this work was to determine the total phenol (TPC), the total flavonoid (TFC), the tannins contents (TC), organic acids and sugar contents and the antioxidant activity of pomegranate juice extraction bagasses, which were obtained in two different ways: (i) Direct extraction that involved arils and peel (WFB) and (ii) only from arils (AB). Four different test systems were used, namely the 2,2′-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method, the ferric reducing antioxidant power (FRAP); determination of antioxidant activity with thiobarbituric acid reactive species (TBARS) and the ferrous ion-chelating ability (FIC). WFB presented higher total phenolic, flavonoid and tannins contents (10.05 mg gallic acid equivalent/g sample; 7.19 mg rutin equivalent/g sample and 8.18 mg catechin/g sample) than AB. The organic acid detected were oxalic acid, citric acid, malic acid and succinic acid while the sugar identified were fructose and glucose. As regards antioxidant activity, at all concentrations and with all methods, the WFB samples showed a higher antioxidant activity than AB samples. BHT, used as control positive, present higher antioxidant activity than WFB and AB in all antioxidant methods used except in the FRAP assay.The results of this study indicate that pomegranate bagasse obtained as co-product in the process to obtain juice may be considered a good source of natural compounds with significant antioxidant activity which could be suitable for applications on the food industry as potential ingredient for food products.     

A Comparative Study Between Labeling and Reality: The Case of Phytochemical Composition of Commercial Pomegranate‐Based Products

Manufacturers are deeply involved in the development of new pomegranate‐based products, which have acquired great prestige due to many studies proving their potential health benefits. Commercial pomegranate products including capsules and supplements and juices and nectars were assayed. The contents of the key phytochemical compounds (punicalagin, ellagic acid, and total polyphenolic content) and the associated antioxidant capacity (DPPH^?, ABTS^?+, and FRAP) were analyzed. The experimental ranges of punicalagin and ellagic acid contents were 0.96 to 308 mg/g and 0.09 to 13.1 mg/g, respectively. Punicalagin content was positively correlated (P < 0.001) with DPPH^? and total polyphenolic content values. No significant (P > 0.05) correlation was observed among ellagic acid with the antioxidant capacity. The labeling standardization of these products is necessary due to the wide variability among “theoretically” similar pomegranate‐based products.     

Polyphenols,ascorbic acid and antioxidant capacity of commercial nutritional drinks,fruit juices,smoothies and teas

Polyphenols of plant origin have received special interest in the last decade because of their potential health benefits. Consequently, many beverages with words ‘antioxidant’ and ‘polyphenols’ have been developed. However, many of the claims are misleading because some beverages so labelled have either no or minimal levels of polyphenols. The objectives of this study were to quantify polyphenols (TPC) and ascorbic acid contents and antioxidant capacity (AOC) of different beverages; identify major polyphenols in beverages that showed higher TPC; correlate the claim on the label with TPC and AOC; and determine the impact of consumer refrigerated storage on TPC and AOC of aronia, blackcurrant and pomegranate juices which contained the most TPC and AOC. Major polyphenols identified from these juices included anthocyanins, myricetin and epicatechin. TPC of aronia, blackcurrant and pomegranate juices was relatively stable during consumer refrigerated storage, even when the juice had been intermittently exposed to air.     

Sensory and physicochemical characterization of juices made with pomegranate and blueberries, blackberries, or raspberries

The quality parameters of 1 commercial pomegranate juice mixed with 5 different concentrations of blueberry, blackberry, or raspberry juices were studied. The pH, total soluble solids content, titratable acidity, and total phenolic content were determined. To understand the aroma differences of the juices, solid phase microextraction-gas chromatography-mass spectrometry was used to determine the volatile compounds present in the mixtures. A consumer study also was carried out to relate consumer ratings to the instrumental data and to determine acceptance and possible modifications of the designed juices. Four juices received the highest scores in overall consumer liking: pomegranate/blueberry juice with 20% and 50% of blueberry, pomegranate/blackberry with 10% of blackberry, and pomegranate/raspberry with 10% of raspberry. The main characteristics in these juices were: a high maturity index (from 13.9 to 16.5), low acidity (0.79 to 1.09 g citric acid 100 per milliliter juice), and the presence of aromatic compounds typical in blueberries such as 6-methyl-5-hepten-2-one, α-terpineol, and E-nerol. The total phenolic content was significantly higher in the pomegranate/blackberry 90%/10% sample, raising around 3500 mg gallic acid equivalents per liter, and could be a positive determinant for consumers interested in purchasing healthful products. PRACTICAL APPLICATION: The data presented in this article will help the juice industry, in the United States and elsewhere, to understand the consumer's preferences for pomegranate blended juices. Pomegranate juices have high antioxidant content, which makes these juices more desirable for the health-conscious consumer of today.     

Classification of eight pomegranate juices based on antioxidant capacity measured by four methods

The antioxidant capacity of pomegranate juices (PJs) obtained from eight cultivars were determined by the scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) and β-carotene-linoleate model system. Total phenolic content (TPC) and total anthocyanin content (TAC) were also determined and found to vary between the range of 208.3–343.6 mg catechin equivalents and 8.1–36.9 mg cyanidine-3-glucoside equivalents per 100 ml of PJ, respectively. Cultivar Izmir 8 showed the highest scores for trolox equivalent antioxidant capacity (TEAC) as 418.3 ± 5.2 mg/100 ml of PJ, anti-lipid peroxidative activity (ALPA) as 93.5 ± 1.8% and efficient concentration (EC₅₀) as 29.8 ± 2.9 ml of PJ/g of DPPH. The hierarchy of PJs for antioxidant capacity with respect to their TEAC and ALPA values was I8 > I1499 > I10 > I1264 > I1479 > I26 > I23 > Zivzik. Interrelationships among the analyzed parameters and PJs obtained from eight cultivars were investigated by principal component analysis (PCA). Dimension of data set was reduced to two components by PCA accounting for the 93% of the total variance. Eight PJs were classified into three groups by cluster analysis (CA).     

A new drink rich in healthy bioactives combining lemon and pomegranate juices

Nowadays, the interest in dietary antioxidants, mainly present in fruits and vegetables, has prompted research in the field of commercial polyphenol-rich beverages. The main objective of the present work was to produce new polyphenol-rich beverages using lemon and pomegranate juices in different proportions (at 25%, 50% and 75% for both juices). The bioactive composition (flavonoids and vitamin C) of the mixtures as well as its stability, antioxidant capacity and changes in colour over a 70 days storage period were studied. Our results suggest that the new drink made of 75% of pomegranate juice (PJ) and 25% of lemon juice (v:v), has potential for development of new healthy beverages or food products, emphasised by its high antioxidant capacity determined by its phenolic composition – punicalagin isomers, anthocyanins and vitamin C – and improved colour properties.     

Impact of processing and storage on the phenolic profiles and contents of pomegranate (Punica granatum L.) juices

Juices were obtained on pilot-plant scale from untreated, steamed and peeled pomegranate fruits (Punica granatum L.), respectively, by applying increasing pressures and various juice treatments, i.e., enzymatic treatment, filtration, clarification and pasteurization, to determine the influence of process technology on the phenolic profiles and contents of the juices. Polyphenols were characterized and quantified by HPLC-DAD-ESI/MSⁿ, and total phenolics and antioxidant capacity of the juices were determined by Folin–Ciocalteu, FRAP and TEAC assays, respectively. The total amounts of anthocyanins and colorless phenolics in the juices significantly differed depending on the applied technology. Highest phenolic recoveries were obtained from steamed fruits without further treatment. In contrast, lowest phenolic contents were determined in the juices produced from peeled fruits, i.e., the isolated seeds with adherent arils. With increasing pressures, polyphenol recoveries were enhanced, whereas juice treatments such as microfiltration and fining lowered phenolic contents of the juices. Furthermore, the amounts of individual phenolics were determined by HPLC-DAD with ellagitannins dominating the phenolic profiles. Juices solely produced from the edible parts of pomegranate exhibited lower amounts of ellagitannins compared with the juices from entire fruits. In contrast, the former juices were characterized by the highest amounts of gallotannins, hydroxybenzoic acids, hydroxycinnamic acids and dihydroflavonols. These results were consistent with the astringency of the juices. Additionally, storage experiments were performed at 4 °C and 20 °C in the dark and 20 °C under light exposure, revealing significant pigment degradation and concomitant color loss, especially at elevated temperatures and upon illumination, whereas the contents of non-anthocyanin phenolics and antioxidant capacity remained virtually unchanged throughout storage.     

Changes on indigenous microbiota,colour, bioactive compounds and antioxidant activity of pasteurised pomegranate juice

Juices prepared from arils of ‘Mollar’ pomegranates were analysed for naturally occurring microorganisms, CIE Lab colour parameters, total phenols, anthocyanins and punicalagins, ellagic acid content and antioxidant capacity before and after low-, mild- and high-temperature pasteurisations (LTPs, MTPs and HTPs): 65, 80 and 90 °C for 30 or 60 s. Mean aerobic plate count (APC), yeast and mold count (YMC), and lactic acid bacteria (LAB) for fresh juices were 5.7, 5.36 and 4.0 log CFU/mL, respectively. MTPs and HTPs were sufficiently effective to decrease APCs to nil or negligible levels. An increase in CIE a values and decrease in CIE b values were the characteristic colour changes in heat-treated juices. The effect of pasteurisations showed that total phenols, punicalagins and ellagic acid were not much affected by thermal processing. Total anthocyanin content and antioxidant capacity were substantially and significantly influenced by the heat treatment applied. A linear relationship was observed between Trolox equivalent antioxidant capacity (TEAC) values and total anthocyanins, suggesting that they contributed strongly to the antioxidant capacity of pomegranate juice.     

朝鲜蓟花苞汁总酚、总黄酮、抗氧化性比较及体外模拟胃肠消化特性

比较不同部位花苞汁及体外模拟胃肠消化前后总酚、总黄酮质量浓度,并通过总还原力和1,1-二苯基-2-三硝基苯肼自由基、2,2’-联氮-双-3-乙基苯并噻唑啉-6-磺酸阳离子自由基、超氧阴离子自由基清除率4 种方法评价其抗氧化能力。结果表明：花托汁总酚质量浓度为2.46 mg/mL,分别为内苞叶汁、外苞叶汁的1.13、1.94 倍;总黄酮质量浓度为6.53 mg/mL,分别为内苞叶汁、外苞叶汁的1.15、2.06 倍。在4 种抗氧化评价体系中,自由基清除能力强弱顺序均为花托汁＞内苞叶汁＞外苞叶汁,且自由基清除率均随着样品总酚质量浓度增加而增大。在体外模拟胃肠消化实验中,以花托汁为样品,经过模拟胃液处理后,模拟胃液组和胃酸对照组抗氧化性均显著增强（P＜0.05）,但经过模拟肠液处理后抗氧化能力下降,表明胃蛋白酶、胃酸、胰蛋白酶均能促使抗氧化活性因子释放,提高抗氧化能力。     

Quantitative bioactive compounds assessment and their relative contribution to the antioxidant capacity of commercial orange juices

Dietary recommendations for healthy eating include the consumption of fruit juices whose health effects are ascribed, in part, to carotenoids, phenolic compounds and vitamin C. These bioactive compounds have been implicated in the reduction of degenerative human diseases, mainly due to their antioxidant potential. Orange juice is characterized by substantial accumulation (apart from ascorbic acid) of flavonoids and carotenoids. Commercial orange juice is the main human dietary source of antioxidant compounds in developed countries. The qualitative and quantitative determination of carotenoid, flavonoid and vitamin C content of Spanish commercial orange juices was achieved by high‐performance liquid chromatography. The health‐related properties of bioactive compounds contained in orange juice are based on their antioxidant activity. The antioxidant capacity of these juices was assessed by 2,2‐diphenyl‐1‐picrylhydrazyl stable radical scavenging and was compared with a freshly squeezed orange juice. In addition, the relative contribution of the different bioactive compounds to the antioxidant activity of orange juices was calculated. Total vitamin C was found to be the major contributor to the antioxidant potential of the orange juices studied, followed by flavonoid and carotenoid compounds. Ascorbic acid, total vitamin C and β‐cryptoxanthin content correlated positively with the free‐radical scavenging parameters. No significant differences, in terms of antioxidant capacity, were found between commercial traditional pasteurized orange juices and freshly squeezed orange juice. Copyright © 2003 Society of Chemical Industry     

Phytochemical characterisation for industrial use of pomegranate (Punica granatum L.) cultivars grown in Spain

BACKGROUND: The study of 15 pomegranate cultivars was carried out in order to demonstrate the wide diversity among the quality of Spanish pomegranates, and compared to ‘Wonderful’ cultivars, which are used worldwide for industrial purposes. Juice yield, quality parameters, organic acids and sugars, colour, vitamin C, ellagic acid, punicalagins, anthocyanins, total phenolic content, antioxidant capacity, and sensory properties were measured. RESULTS: A considerable variation was found between ‘Wonderful’ and pomegranates of Spanish origin, according to both cluster analysis and principal component analysis. ‘Wonderful’ juices displayed large antioxidant activity and a polyphenol content with very high acidity. In contrast, ‘Mollar de Elche’ showed fewer anthocyanins although it had very superior organoleptical properties. In addition to a high content in ellagitannins, ‘Valenciana’ juices had exclusive colour parameters. CONCLUSION: These useful results can be employed by the juice processing industry to select those properties more interesting for the development of pomegranate juices that are organoleptically attractive and rich in bioactive compounds. Copyright © 2011 Society of Chemical Industry     

Antioxidant capacities of phenolic compounds and tocopherols from Tunisian pomegranate (Punica granatum) fruits

This article aims to determine the phenolic, tocopherol contents, and antioxidant capacities from fruits (juices, peels, and seed oils) of 6 Tunisian pomegranate ecotypes. Total anthocyanins were determined by a differential pH method. Hydrolyzable tannins were determined with potassium iodate. The tocopherol (α-tocopherol, γ-tocopherol, and δ-tocopherol) contents were, respectively, 165.77, 107.38, and 27.29 mg/100 g from dry seed. Four phenolic compounds were identified and quantified in pomegranate peel and pulp using the high-performance liquid chromatography/ultraviolet method: 2 hydroxybenzoic acids (gallic and ellagic acids) and 2 hydroxycinnamic acids (caffeic and p-coumaric acids). Juice, peel, and seed oil antioxidants were confirmed by ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) methods. The highest values were recorded in peels with 25.63 mmol trolox equivalent/100 g and 22.08 mmol TE/100 g for FRAP and ORAC assay, respectively. Results showed that the antioxidant potency of pomegranate extracts was correlated with their phenolic compound content. In particular, the highest correlation was reported in peels. High correlations were also found between peel hydroxybenzoic acids and FRAP ORAC antioxidant capacities. Identified tocopherols seem to contribute in major part to the antioxidant activity of seed oil. The results implied that bioactive compounds from the peel might be potential resources for the development of antioxidant function dietary food.     

基于品质指标的苹果浊汁品种与产地差异性分析

以来自7?个不同主产区的21?个主栽品种,共41?份苹果鲜果为研究对象,对每个品种鲜榨浊汁的出汁率、浊度、果汁颜色、褐变度、透光率、可溶性固形物、可滴定酸、总酚、糖、有机酸、VC、矿物质、抗氧化性等品质指标进行测定。运用描述性分析、逐步线性判别分析进行数据处理。结果表明：不同品种或不同产地的苹果浊汁,品质差异较大。总体来看,a*值、原始浊度、褐变度、可滴定酸、葡萄糖、蔗糖、苹果酸等指标的变幅均较大,分别为94.07%、70.41%、42.86%、35.26%、42.02%、42.40%、37.69%。对于不同品种的苹果浊汁,由于褐变度、总酚、抗氧化性等色泽品质指标以及糖、酸等营养品质指标间具有较大差异,其分布呈现分散状态。其中新红星品种的褐变度、总酚含量、DPPH自由基清除率等品质指标普遍居高,色泽品质差异最显著。富士品种大部分样品的果糖、葡萄糖、蔗糖、苹果酸等指标含量较高,具有较好的营养品质。然而对于不同产地间的样品,其浊度、可滴定酸、可溶性固形物等加工品质指标具有较大差异,样品分布较为分散。河北省样品的出汁率、原始浊度、可滴定酸等指标普遍较低,加工品质较差。来自山东省不同品种苹果浊汁的样品以及来自不同产地富士苹果浊汁的样品间均具有较大差异,并且分别获得了77.8%和72.7%的判别准确率。以上结果表明,不同产地、不同品种苹果原料制得的苹果浊汁存在较大差异,通过对其品质指标进行差异性分析,可为上游育种与种植产业结构调整提供数据基础;通过判别模型的建立实现品种与产地的识别与预测,可以指导企业对苹果原料进行制汁专用化筛选。     

Influence of origin source, different fruit tissue and juice extraction methods on anthocyanin, phenolic acid, hydrolysable tannin and isolariciresinol contents of pomegranate (Punica granatum L.) fruits and juices

To gain more comprehensive knowledge of pomegranate (Punica granatum L.) fruit composition and its impact on juice features, fruits and juices produced from fruits of eleven different provenances were investigated by HPLC–DAD-ESI/MSⁿ for their monomeric phenolic and lignan profiles. Total phenolics and antioxidant capacity were monitored by the Folin-Ciocalteu, ferric reducing antioxidative power and Trolox equivalent antioxidant capacity assays. Peels, mesocarp, seeds and juices obtained from isolated arils (PJAs) as well as from entire fruits were separately analyzed. Ellagitannins were found to be the predominant phenolics in all samples except in PJAs. However, due to the low lignan amounts, only isolariciresinol could be quantitated in peels and mesocarp. The peels and mesocarp revealed highest contents of hydrolyzable tannins (27–172 g/kg and 32–263 g/kg, respectively) and isolariciresinol (4.9–19.8 mg/kg and 5.0–13.6 mg/kg, respectively). To the best of our knowledge, a systematic investigation of monomeric phenolic compounds and isolariciresinol considering diverse pomegranate fruits has been performed for the first time. The study demonstrates that raw material and extraction process have significant impact on juice composition and thus must be carefully selected. Furthermore, pomegranate processors should select juice extraction processes according to the final designation of the product, that is, distinguish between dietary products being rich in phenolic compounds having an astringent taste, and juices for consumption having an appealing taste but lower amounts of phenolics, respectively. This study may further contribute to facilitate authenticity control of diverse pomegranate products and help predict sensory and biofunctional characteristics of pomegranate juices.