Antioxidant capacity changes of 3 cultivar Chinese pomegranate (Punica granatum L.) juices and corresponding wines

This study investigated the antioxidant capacities that included Ferric reducing antioxidant power (FRAP), 1, 1-diphenyl-2-picryl hydrazine (DPPH), ·OH and O(2·)(-)-scavenging abilities, total polyphenols (TP) and total anthocyanins (TA) in pomegranate (Punica granatum L.) juice (PJ) and pomegranate wine (PW). The correlations among them were also analyzed. Both PJ and PW showed significantly high TP and antioxidant capacities, but some differences existed among these cultivars. There was 1596.67 mg/L TP found in sweet PJ, while sour PJ showed the highest titratable acidity of 35.90 g/L and lowest pH value at 2.56. Red PJ was found to have the highest TA (82.26 mg/L) in the 3 cultivars. Sweet PJ showed higher DPPH-scavenging ability and higher FRAP than others. Both PJ and PW exhibited high and relatively stable ·OH-scavenging abilities, in which sour PJ and sour PW had higher O(2·)(-) scavenging capacity than others. Significant positive correlations were observed among TP, DPPH, and FRAP in both PJ and PW. A high correlation between antioxidant capacities and TP indicated that phenolic compounds were major contributors to the high antioxidant activity of PJ and PW.     

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.     

石榴抗糖尿病生物活性的研究进展

体外和体内实验均证实石榴汁、石榴皮、石榴花、石榴籽和石榴叶等具有抗糖尿病的功效,综述了石榴多个部位的降血糖效果、降血糖活性成分及其作用机制的研究进展。石榴中的多酚类是抗糖尿病的主要活性物质,主要通过提高胰岛素受体敏感性、增强PPAR-γ（Peroxisome proliferator-activated receptor,过氧化酶体增殖物激活受体）的表达、抑制α-葡萄糖苷酶活性等作用达到抗糖尿病的功效,为石榴的进一步开发利用提供参考。      

Heavy Metals Bounding Ability of Pomegranate (Punica granatum) Peel in Model System

Pomegranate fruit is an important sources of natural phenolic compounds. In this study, the influence of pomegranate fruit peel on binding of some heavy metals were established by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). Also, the total phenolic content of methanol extract of pomegranate fruit peel was determined with the Folin-Ciocalteu method. Amounts of 1, 2, 3, 10, 20, 40, and 60 g of ground peel were used in this experiment. After pomegranate samples were weighed, they were added into 500 ml baker. Each sample was treated by several solutions contained the heavy metal elements at different concentrations. The heavy metal contents in the solutions prepared with ground material were decreased with increasing of ground material. At the same time, the bounding rate of heavy metals increased with the increase of ground peel amounts. Lead (Pb) with 99.2% rate for solution obtained from 20 g ground sample was the highest bound element. It can be observed from these results that the amount of metal ions bound by the ground material differed from on fraction to others.     

Pomegranate (Punica granatum) supplements: Authenticity,antioxidant and polyphenol composition

Pomegranates contain a complex mixture of gallotannins, ellagitannins, ellagic acid and anthocyanins. However, label claims on pomegranate supplements (PS) may not correlate with actual content of antioxidants, polyphenols or tannins. Nineteen PS were evaluated for their authenticity by determining ellagitannin composition by RP-HPLC and studying the relationship between total polyphenols as measured by the Folin–Ciocalteau assay and antioxidant capacity by oxygen radical absorbing capacity (ORAC), free radical scavenging properties by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and ferric reducing antioxidant power (FRAP). Only a limited number of pomegranate supplements were authentic. Product labels were inconsistent with polyphenol composition and antioxidant content. A majority of the samples (n = 13) contained disproportionately high amounts of ellagic acid and low or no detectable pomegranate tannins. Only six products had tannin composition that resembled pomegranates (punicalagin, punicalin, ellagitannins and gallotannins). PS-01 (natural pomegranate extract) was the most representative of pomegranate fruit polyphenols with 99% total pomegranate polyphenol and the highest antioxidant capacity across all measures. Correlations between total polyphenols and antioxidant content were high (R² > 0.87) in products that had polyphenol composition resembling pomegranates. Products that contained high amounts of ellagic acid and low or no detectable pomegranate tannins had poor correlations between total polyphenols and antioxidant content. The results indicate that reliable labeling information, better standardization, improved manufacturing practices and regulation of the market is required to assure consumers of the quality of pomegranate supplements.     

Volatile composition and sensory quality of Spanish pomegranates (Punica granatum L.)

BACKGROUND: Pomegranate is highly valued for its health‐promoting effects. Fruits of nine pomegranate cultivars were analysed for volatile compounds, antioxidant activity and quality parameters, including maturity index and CIEL*a*b* colour. Volatile compounds were isolated from fresh juices using hydrodistillation; extracts were analysed using gas chromatography/mass spectrometry. Fruit colour was influenced by cultivar and grouping of cultivars according to their taste (sweet, sour‐sweet or sour), with sweet fruits having more intense red colour and higher lightness values. RESULTS: A total of 18 compounds were found in pomegranate aroma profiles, including monoterpenes, aldehydes, alcohols, monoterpenoids and linear hydrocarbons. The most abundant compound were trans‐2‐hexenal, 3‐carene, α‐terpinene and α‐terpineol. The total concentration of volatiles ranged from 1.7 to 10.9 g kg^?1. Overall consumer liking of pomegranate juices was associated with the presence of monoterpenes such as α‐pinene, β‐pinene, β‐myrcene, limonene and γ‐terpinene. The presence of aldehydes such as hexanol, hexanal and cis‐3‐hexenol was correlated with poor overall consumer liking. CONCLUSION: Fruits from the cultivar Mollar de Elche 2 were those most suited for juice processing because they had the highest total concentration of volatiles, which was related to high overall consumer liking, intense and acceptable fresh pomegranate odour and flavour (high scores of satisfaction degree), medium intensity of red colour and low sourness. Copyright © 2010 Society of Chemical Industry     

石榴花色苷的微波辅助提取及抗氧化活性研究

以陕西临潼甜石榴为试验材料,通过正交试验,采用pH 差示法测定石榴总花色苷含量,优化微波辅助提取石榴花色苷的工艺参数。同时,采用DPPH 法、FRAP 法、ABTS 法、螯合亚铁能力法分析石榴花色苷的体外抗氧化活性。结果表明：微波辅助提取石榴花色苷的最佳工艺参数为溶剂pH1、料液比1:13(g/mL)、提取时间210s、乙醇体积分数70%、微波输出功率360W。此条件下,花色苷得率为184.81μg/g。微波输出功率对石榴汁花色苷的提取得率有显著影响(P ＜ 0.05)。石榴花色苷含量与DPPH 自由基清除率、铁还原力、ABTS+ 自由基清除率和螯合亚铁离子有显著的相关性(相关系数R2 分别为0.9928、0.9925、0.9913、0.9945),呈明显的量效关系,IC50 值分别为2.44、1.14、4.08、101.05mg/L。     

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.     

超高效液相色谱-串联四极杆质谱联用法同时测定蒙药全石榴、中药石榴皮及新鲜石榴中7 种成分

采用超高效液相色谱-串联四极杆质谱联用法,同时检测蒙药全石榴皮及籽、中药石榴皮、鲜石榴皮及籽中诃子鞣质A、诃子鞣质B、诃子裂酸、五没食子酰葡萄糖、鞣料云实素、诃黎勒酸和没食子酸7 种成分。选用表儿茶素-4-乙酰半胱氨酸作为内标。石榴样品经粉碎用甲醇（含内标液）溶液超声提取,采用ZORBAX Eclipse XDB-C18柱（2.1 mm×50 mm,1.8 μm）,以甲醇-0.1%甲酸溶液为流动相,梯度洗脱,以电喷雾离子源,采用超高效液相色谱-串联四极杆质谱联用动态多反应监测模式测定。结果表明,7 种成分检出限均小于0.013 5 μg/mL,定量限均小于0.054 2 μg/mL,在0.003 4～13.875 0、0.013 5～13.875 0、0.003 4～13.875 0、0.216 8～55.500 0、0.867 2～55.500 0、0.216 8～55.500 0、0.003 4～13.875 0 μg/mL范围内,峰面积与质量浓度呈良好线性关系,相关系数均大于0.99;方法回收率为99.44%～105.54%;其日内及日间精密度实验的相对标准偏差分别为0.11%～0.95%和0.14%～1.21%。该方法灵敏度高、稳定性强、操作简便、快捷、准确,可用于蒙药全石榴、中药石榴皮、鲜石榴及其相关食品药品的质量控制。     

石榴皮总黄酮的提取工艺及抑制亚硝化反应

目的:研究石榴皮总黄酮的提取工艺及黄酮类物质对亚硝化反应的抑制能力。方法:通过正交试验,探讨影响总黄酮提取率的因素范围和最佳组合,并采用分光光度法测定总黄酮提取液对亚硝酸盐清除能力和亚硝胺抑制能力。结果:石榴皮总黄酮的最佳提取工艺条件为乙醇体积分数60%、料液比1:60(g/mL)、提取时间40min、超声电流强度150mA。在最佳提取工艺条件下,石榴皮总黄酮的平均提取率为84.8mg/g,石榴皮总黄酮提取液对亚硝酸钠的最大清除率为81.2%,对亚硝胺合成的最大阻断率为67.0%。结论:石榴皮总黄酮提取液对亚硝化反应的抑制能力较强。     

Volatile organic compounds in the aril juices and seeds from selected five pomegranate (Punica granatum L.) cultivars

A study was conducted to investigate the distribution of volatile organic compounds in the juice and seed of the most popular five pomegranate cultivars (“Ek?i,” “Devedi?i,” “Hicaz,” “Kat?rba??,” and “Keben”) in Turkey. The volatile organic compounds were analyzed using solid phase micro-extraction and gas chromatography–mass spectrometry. A total of 60 volatile organic compounds, belonging to six chemical groups including aldehydes, alcohols, esters, terpenes, ketones, acids, and phenol were identified. There were 11 volatile organic compounds (1-hexanol, [Z]-3-hexen-1-ol, 1-octanol, α-terpineol, β-myrcene, limonene, [E]-α-bergamotene, β-caryophyllene, hexanal, [E]-2-hexenal, and guaiacol) common to all five pomegranate juices and seeds. Hexalin, phenylacetaldehyde, 3-methyl butanal, and methyl-(1-methylethenyl) benzene were found in seeds only. According to discriminant analysis based on Eigenvalues, volatile organic compounds recovered in the juices could be used to discriminate and classify the pomegranate cultivars. “Devedi?i” and “Hicaz” were the most promising cultivars with respect to the largest volatile organic compounds, high total soluble solid and deep red color.     

云南中蜂与意蜂石榴蜜理化性质及体外抗氧化差异性研究

本文对云南蒙自地区中华蜜蜂与意大利蜜蜂在同一地点采集的石榴蜜进行理化指标及体外抗氧化活性研究,结果表明:中蜂石榴蜜的灰分、酸度、总酚、果糖含量显著高于意蜂石榴蜜,而葡萄糖含量、淀粉酶值、氨基酸总量以及必需氨基酸含量显著低于意蜂石榴蜜。体外抗氧化实验表明,中蜂石榴蜜的羟自由基清除能力和还原力均高于意蜂石榴蜜,而DPPH自由基清除能力低于意蜂石榴蜜。本研究首次报道了同一采集环境下的中、意蜂石榴蜜的差异性,为云南特色蜂蜜的开发利用提供了理论依据。      

Encapsulation of polyphenols and anthocyanins from pomegranate (Punica granatum) by spray drying

Pomegranate (Punica granatum) bioactive compounds (polyphenols and anthocyanins) of juice (PJ) and ethanolic extracts (PE) were encapsulated with maltodextrin (MD) or soybean protein isolates (SPI) by spray drying using a 2² statistical factorial design for each systems studied (PJ–MD, PJ–SPI, PE–MD and PE–SPI) considering the proportion of coating material and the inlet temperature as independent variables. The stability of the bioactive compounds microcapsules powders obtained under optimal conditions for each system was studied at 60 °C in oven for 56 days. The polyphenols encapsulating efficiency was significantly better in SPI matrix whereas for anthocyanins was in MD matrix. By the other hand, during the storage, the MD microcapsules provided a significant greater protective effect on the polyphenols and anthocyanins than SPI, as was shown by the lower degradation rate constants. When the microcapsules were added to yogurt the stability of the bioactive compounds followed a similar behaviour to those without encapsulation, except for PE–MD.     

Phenolics and antioxidant capacity of table grape (Vitis vinifera L.) cultivars grown in Chile

Grapes (Vitis vinifera L.) possess health-promoting effects attributed to their supply of a wide variety of bioactive phenolics. Juice and skin fractions of 4 varieties of table grapes: Red Globe, Crimson Seedless, Autumn Royal, and Ribier were prepared to determine and compare their total phenolics content, antioxidant capacity (DPPH, FRAP, and ORAC), anthocyanins, and specific phenolics (caffeic acid, gallic acid, resveratrol, and catechin) content, since a series of positive health benefits are expected from the intake of any of these fractions. Higher amounts of total phenolics and antioxidant capacity were observed in the skin fractions (P < 0.05). Blue grapes (Autumn Royal and Ribier) exhibited higher phenolics content and antioxidant capacity (P < 0.05) than red grapes. The most abundant phenolic compound observed was catechin (P < 0.05). Significant correlations between the antioxidant capacity and total phenolics were observed in grape juice and skin fractions. Autumn Royal juice provides a very high amount of phenolics, anthocyanins, and exhibits the highest antioxidant capacity, offering the best health promoting properties compared with the other grape varieties studied. PRACTICAL APPLICATION: Grapes possess health-promoting effects attributed to their supply of a wide variety of bioactive phenolics. Grape juice made with blue grapes (Autumn Royal, Ribier) exhibit higher phenolics content and antioxidant capacity than juice elaborated with red grapes (Red Globe, Crimson Seedless). The skin is a good source of phenolics and has a high antioxidant capacity. Specific health-promoting phenolics are more abundant in blue grapes, mainly in their skin fraction, which should not be discarded.     

Evaluation of Dyeing Properties of Carpet Woolen Yarn with Natural and Wild Pomegranate Peel (Punica granatum)

Natural and wild pomegranate peel have been used as colorants for wool yarn because of their high tannin contents. The woolen yarns dyed with pomegranate peel showed different shades of yellow and brown. Wild pomegranate peel has been used traditionally for dyeing wool to obtain brown and darker shades. Both natural and wild pomegranate peel were applied on woolen yarn in presence of four different mordants. Good light fastness was observed in dyed yarns that is due to the formation of complex with the metal which protects the chromophore from photolytic degradation. The values of washing fastness of the dyed samples show very good grades but the rubbing fastness in dyed yarns with wild pomegranate rind are not so good. Therefore, the dyeing potential of wild pomegranate peel as a natural source for wool yarn dyeing is considerable.     

Evolution of juice anthocyanins during ripening of new selected pomegranate (Punica granatum) clones

 For five new clones of pomegranate, cultivated under homogeneous conditions, changes in juice anthocyanin contents during ripening were studied. Six anthocyanin pigments were found to be responsible for the red color of pomegranate juice. These were quantitatively and qualitatively analyzed by high-performance liquid chromatography and identified as delphinidin 3-glucoside and 3,5-diglucoside, cyanidin 3-glucoside and 3,5-diglucoside and pelargonidin 3-glucoside and 3,5-diglucoside. Generally, there was an increase in juice pigmentation during fruit ripening. In the early fruit-ripening stages, delphinidin 3,5-diglucoside was the main pigment, followed by cyanidin 3,5-diglucoside, while in the later stages, the monoglucoside derivatives cyanidin 3-glucoside and delphinidin 3-glucoside increased considerably. The pelargonidin derivatives were always present in small amounts. Received: 1 March 1999     

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.     

超滤对石榴汁抗氧化活性的影响

主要探讨不同截留分子量(100、30、10ku)的超滤膜对石榴汁的澄清效果及抗氧化活性的影响,以确定生产高抗氧化活性澄清石榴汁的最适超滤膜。结果表明,30ku超滤膜对石榴汁的澄清效果较好,可保存其酚类化合物、花色苷、VC等抗氧化活性成分80%左右,使DPPH自由基清除活性和FRAP损失在16%以下。因此,建议采用30ku超滤膜澄清石榴汁,以得到具有高抗氧化活性的石榴汁。