Antioxidant activity,anthocyanins, and phenolics of rabbiteye blueberry (Vaccinium ashei) by-products as affected by fermentation

Basic blueberry processing includes juice processing or winemaking. By-products obtained from the juice and wine industry can be a source of new value-added products such as phenolic antioxidant supplements or ingredients for food processing. The phenolic compositions of products and by-products (pomaces) depend mainly on processing techniques such as duration of skin contact, crushing, pressing, and others. The present study was to evaluate the effects of fermentation type on retention of total anthocyanins, total phenolics, and antioxidant activity of blueberry by-products. Total phenolics (TPH), total anthocyanins (ACY), antioxidant activities (β-carotene bleaching assay and ferric thiocyanate assay), and antiradical activity (DPPH radical-scavenging assay) of rabbiteye blueberry (Vaccinium ashei) by-products (juice, wine, and vinegar pomaces) were determined. The wine pomace (WP) had higher TPH, antioxidant activities and antiradical activity. Vinegar pomace (VP) had the lowest ACY, TPH, antiradical activity, and antioxidant activities. The results indicate that the antioxidant and antiradical activities of blueberry by-products were not significantly affected by the wine making process. Acetification significantly decreased TPH, ACY, antioxidant activities, and antiradical activity. However, VP still maintained an important phenolics concentration and antioxidant activity.     

Storage effects on anthocyanins, phenolics and antioxidant activity of thermally processed conventional and organic blueberries

BACKGROUND: Consumer demand for products rich in phytochemicals is increasing as a result of greater awareness of their potential health benefits. However, processed products are stored for long‐term and the phytochemicals are susceptible to degradation during storage. The objective of this study was to assess the storage effects on phytochemicals in thermally processed blueberries. Thermally processed canned berries and juice/puree were analysed for phytochemicals during their long‐term storage. RESULTS: The phytochemical retention of thermally processed blueberries during storage was not influenced by production system (conventional versus organic). During 13 months of storage, total anthocyanins, total phenolics and total antioxidant activity in canned blueberry solids decreased by up to 86, 69 and 52% respectively. In canned blueberry syrup, total anthocyanins and total antioxidant activity decreased by up to 68 and 15% respectively, while total phenolic content increased by up to 117%. Similar trends in phytochemical content were observed in juice/puree stored for 4 months. The extent of changes in phytochemicals of thermally processed blueberries during storage was significantly influenced by blanching. CONCLUSION: Long‐term storage of thermally processed blueberries had varying degrees of influence on degradation of total anthocyanins, total phenolics and total antioxidant activity. Blanching before thermal processing helped to preserve the phytochemicals during storage of blueberries. Copyright © 2011 Society of Chemical Industry     

Peel Effects on Phenolic Composition,Antioxidant Activity,and Making of Pomegranate Juice and Wine

Pomegranate peel was used in juicing to find out its effects on the juice products’ (storable juice and wine) sensory property, polyphenols composition, and antioxidant ability. Macroporous resin was used to purify the polyphenols, and 6 different in vitro assays were used to comprehensively determine the antioxidant activity of each. The results showed that juicing with peel made the juice bitter and astringent, but contributed better sensory quality to wine. Peel contributed higher total polyphenols and flavonoids, but lower anthocyanins to the juice products, and caused the phenolics content to fluctuate more dramatically during making wine than the storable juice. Polyphenols purified from the juice products containing peel showed higher total reducing ability and 2,2‐diphenyl‐1‐picrylhydrazyl and 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid radical elimination abilities, but their clearance activity of hydroxyl radicals was not positive, and their superoxide anion radical elimination ability showed no significant difference when compared to polyphenols purified from juice products without peel.     

Anthocyanins, Phenolics, and Antioxidant Capacity of Processed Lowbush Blueberry Products

Temperature, pH, and oxygenation of extracted blueberries were examined to determine how processing may affect the antioxidant capacity of blueberry food products. Extraction of fruit at 60 °C resulted in higher recovery of anthocyanins and antioxidant capacity, compared to extracts obtained at 25 °C. Subsequent room temperature storage resulted in losses in anthocyanins and antioxidant capacity only in those extracts obtained at 60 °C. Antioxidant capacity was greatest in pH 1 extracts, compared to extracts at pH 4 and 7. Oxygenation was detrimental to both anthocyanins and antioxidant capacity. Antioxidant capacity of processed products was positively correlated with anthocyanin (R = 0.92) and phenolic content (R = 0.95), and negatively correlated with % polymeric color (R = -0.64). In general, products that had experienced less processing had a higher antioxidant capacity. Simple colorimetric tests for anthocyanins and phenolics proved to be useful indicators of antioxidant capacity in processed products.     

蓝莓汁乳酸菌的发酵特性

蓝莓汁中分别接种干酪乳杆菌、保加利亚乳杆菌、植物乳杆菌和嗜酸乳杆菌进行发酵,比较蓝莓汁发酵过程中乳酸菌活菌数、p H值、总滴定酸、总糖、还原糖、总花色苷、总酚、抗氧化能力和色泽等变化。结果表明,蓝莓汁营养丰富,上述各种乳酸菌均能在蓝莓汁中正常生长,发酵24 h,活菌数达8.10 lg cfu/mL以上;此外,植物乳杆菌和嗜酸乳杆菌产酸能力均强于其它两种乳酸菌,可滴定酸含量均超过10.29 g/L,而植物乳杆菌对蓝莓汁中糖的消耗能力最强,总糖的残留量为40.26%;在花色苷和总酚的保留率以及抗氧化能力等方面,植物乳杆菌和嗜酸乳杆菌也要优于其它两种乳酸菌。植物乳杆菌与嗜酸乳杆菌单独发酵和混合发酵时蓝莓汁营养品质的差异分析表明,单独发酵组与混合发酵组在抗氧化能力和总酚的保留上无明显差异,但混合发酵组在花色苷和色泽的保留方面明显优于单独发酵组。综上所述,蓝莓汁应以植物乳杆菌与嗜酸乳杆菌混合发酵为宜。     

贮藏条件对超高压处理蓝莓汁酚类物质及抗氧化活性的影响

以经超高压处理（400MPa／IOmin）的鲜榨蓝莓汁为对象,研究其5周内在4℃、25℃、37℃贮藏条件下总酚、总黄酮、花色苷含量和抗氧化能力的变化。结果表明：随贮藏时间的延长,在以上三个贮藏温度下,总酚含量和抗氧化能力均呈显著下降趋势（p〈0．05）,总黄酮含量无显著变化,花色苷含量显著下降（p〈0．05）,且其降解过程符合一级反应动力学模型,其反应的活化能Ea为55．75kJ／mol;抗氧化能力与总酚和花色苷含量显著相关。4℃贮藏条件下抗氧化能力与总黄酮含量无显著相关,25℃、37℃下则呈负相关。此外颜色分析显示不同储藏温度下蓝莓汁a·值、b＋值、C值随贮藏时间的延长上升,L＋值下降,37℃下贮藏4周后蓝莓汁的色差△E〉2,已对其感官质量造成影响。由此表明低温短时贮藏有利于保特蓝莓汁中酚类物质含量及抗氧化活性。     

Comparison of polyphenolic composition and antioxidant activity of wild Italian blueberries and some cultivated varieties

Four varieties of cultivated blueberries (Vaccinium corymbosum) and a wild crop (Vaccinium miyrtillus) originating form the Modena region in Italy (Mirtillo nero dell’Appennino Modenese) and protected by the mark of origin, were examined in order to determine their antioxidant activity as related to their phenolic composition. The antioxidant activity was measured as radical scavenging activity, ferric reducing activity, and by an amperometric method; the total phenolics and total anthocyanins were determined by colorimetric methods; individual anthocyanins were evaluated by HPLC. Results showed that total phenolics and total anthocyanin concentrations were, respectively two fold and three fold higher in the wild fruits, which also had a higher anthocyanin-to-total phenolic ratio. Determination of individual anthocyanins put in evidence some differences between the cultivated and wild varieties, in particular the absence of acylated anthocyanins in wild blueberries. The antioxidant activity was much higher in wild blueberries than in the cultivated ones, and it was more related to the total phenolic rather that to the anthocyanin concentration.     

俄罗斯野生蓝莓引种前后营养成分含量及抗氧化活性的比较分析

为了研究引种栽培对于野生蓝莓营养成分及抗氧化活性的影响,选取俄罗斯阿穆尔州腾达市的野生蓝莓（蓝莓RU）和将该种野生蓝莓经引种栽培让其自然生长于中国黑河市二站乡的野生蓝莓（蓝莓HH）为原料,采用福林酚法、pH示差法、亚硝酸钠-硝酸银比色法和电感耦合等离子体-质谱法（ICP-MS）等方法分析比较了两种蓝莓的活性成分（多酚、花色苷、黄酮）、矿物质元素和糖酸含量,并对水提物和醇提物的抗氧化能力进行了比较。结果表明,蓝莓RU的可溶性固形物、还原糖、多酚含量高于蓝莓HH,但总酸、花色苷、黄酮含量低于蓝莓HH。二者的Ca、Mn、P、Zn、Cr元素含量存在显著差异（P＜0.05）,其他的矿物质元素差异不显著（P＞0.05）。蓝莓RU水提物与醇提物的DPPH自由基清除率和Fe3+还原力高于蓝莓HH,但蓝莓HH的羟基自由基的清除率高于蓝莓RU。     

Comparison of anthocyanins and phenolics in organically and conventionally grown blueberries in selected cultivars

Consumption of berries has become popular among health-conscious consumers due to the high levels of valuable antioxidants, such as anthocyanins, and phenolic compounds in berries. Four Rabbiteye blueberry cultivars (i.e., Powderblue, Climax, Tifblue, and Woodward) grown organically and conventionally were compared regarding their chemical profiles and antioxidant capacity in terms of total phenolic content (TPC), total anthocyanin content (TAC) and ORAC activity. Regardless of the high TPC, TAC and ORAC in both organically and conventionally grown blueberries, not all the organic berries showed significantly higher TPC, TAC and ORAC than the conventional berries. The chemical profiles (i.e., the free phenolic compounds and anthocyanins) were determined with aid of HPLC-MS, by which 13 individual anthocyanins and seven free phenolics were identified. This study demonstrated the subtle differences of bioactive phytochemicals between the organically and conventionally grown berries.     

Frozen Wild Blueberry-Tofu-Soymilk Desserts

Both wild (lowbush) blueberries (Vaccinium angustifolium Ait.) and soybeans (Glycine max L.) possess a variety of antioxidants, and both foods appear to have multiple health benefits. Our objectives were to identify whether wild blueberry juice concentrate was more acceptable than puree in frozen desserts with a soy milk‐tofu base; to determine whether fat‐free products were as acceptable as those with 10% added fat; and to compare several levels of blueberry juice concentrate. Four frozen dessert formulations were prepared in duplicate from soy milk, silken tofu, sucrose, stabilizer, BJC or puree, soybean oil or polydextrose, sweetened dried blueberries, salt, and lemon juice. Samples were assayed for total anthocyanins, antioxidant activity using the DPPH method, color, overrun, and solids. Fifty‐five persons evaluated the samples using a 9‐point hedonic scale for color, flavor, texture, and overall acceptability. Samples containing blueberry juice concentrate were darker and less blue. Anthocyanin levels were highest in the puree sample and the fat‐free product with 7.8% blueberry juice concentrate. However, antioxidant activity was highest (28 Trolox equivalents per gram) in the samples made with soybean oil and 7.4% blueberry juice concentrate. The puree formulation received higher hedonic scores than did the low‐fat blueberry juice concentrate formulations. The puree formulation received overall acceptability scores of like very much or like extremely by 45% of the consumers. These findings may aid processors in defining potential formulations that combine 2 healthful food ingredients.     

Juice of New citrus hybrids (Citrus clementina Hort. ex Tan.×C. sinensis L. Osbeck) as a source of natural antioxidants

Fruit juices of pigmented and non-pigmented new citrus hybrids obtained by crossing clementine cv. Oroval with different cultivars of blood oranges were analysed to determine parameters related to fruit quality (total soluble solids titratable acidity, pH), and the content of ascorbic acid, total phenolics, flavanones, anthocyanins and phenolic acids. Antioxidant properties were evaluated by oxygen radical absorbance capacity (ORAC), and inhibition of induced linoleic acid peroxidation (InLAP) assays. The results of this study show that some hybrids with high antioxidant activity owing to considerable polyphenol content may be considered rich sources of phytochemicals. The OTA 9 hybrid was shown to be richest in polyphenols, suggesting that consumption of OTA 9 fruit or juice could be useful in health promotion and a disease-preventing diet. Moreover, the juice of this hybrid could be used as raw material to produce antioxidant ingredients for dietary, pharmaceutical, or cosmetic purposes.     

Effect of thermal treatments on phytochemicals in conventionally and organically grown berries

BACKGROUND: Consumer demand for organic foods is increasing despite a lack of conclusive evidence of nutritional superiority of organically grown produce. The objective of this investigation was to evaluate the effects of thermal treatments on phytochemicals in conventionally and organically grown berries. Two cultivars of conventionally and organically grown red raspberries and blueberries were analysed for total anthocyanins, total and specific phenolic compounds and total antioxidant activity. Fresh berries were thermally processed into cans and juice/puree with and without blanching, and the changes in phytochemicals were monitored. RESULTS: Total anthocyanin and phenolic contents of berries were not influenced by the agricultural production system. Total antioxidant activity of berries was also not influenced by the production system, but antioxidant activity varied significantly between cultivars. After canning, total anthocyanins decreased by up to 44%, while phenolic contents and antioxidant activity of both berries generally increased by up to 50 and 53% respectively. The level of changes in phytochemicals during berry puree/juice processing was influenced by blanching and type of berries. CONCLUSION: Phenolic contents and antioxidant activities of berries increased while total anthocyanins decreased during canning. Blanching prior to puree/juice processing improved the retention of phytochemicals in blueberries. Copyright © 2010 Society of Chemical Industry     

野生蓝莓酒皮渣花色苷及其抗氧化活性研究

该研究比较了蒸馏前后野生蓝莓酒皮渣中的总酚及花色苷含量、花色苷单体的组成和抗氧化活性。结果表明,蓝莓酒皮渣中总花色苷含量为（8.64±0.13） mg/g,总酚含量为（77.24±1.42） mg/g,抗氧化活性为Trolox当量浓度（3.59±0.11） μmol/g;单体花色苷含量较多的是二甲花翠素-3-O-葡萄糖苷（29.90%）、3′-甲基花翠素-3-O-葡萄糖苷（21.31%）和花翠素-3-O-葡萄糖苷（20.44%）。蒸馏后,皮渣中的总酚及花色苷含量分别下降为（68.11±1.20） mg/g和（5.05±0.09） mg/g,其单体降解率变化在21.64%～43.47%。其中,二甲花翠素-3,5-O-二葡萄糖苷稳定性最差,降解率为43.47%;花青素-3-O-葡萄糖苷较为稳定,降解率为21.64%;Trolox当量浓度下降为（3.07±0.07） μmol/g,皮渣抗氧化能力也降低了14.64%。因此,野生蓝莓果酒发酵产生的皮渣具有较高的利用价值,开发时应尽量避免高温处理。     

Improving the Extraction of Juice and Anthocyanins from Blueberry Fruits and Their By-products by Application of Pulsed Electric Fields

Pulsed electric field (PEF) treatments (1–10 kJ/kg at 3 kV/cm) were applied before pressing of blueberry fruits to improve the yield and quality of expressed juice as well as the recovery of anthocyanins from blueberry by-products (press cake) via solid–liquid extraction. A PEF pre-treatment at 1 kJ/kg was sufficient to significantly increase the juice yield (by 32%) with respect to the untreated sample. Higher energy input (10 kJ/kg) was most favorable for the largest increment of anthocyanin content (55%) and antioxidant capacity (36 and 41%, determined by ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) assay, respectively) in juice. Extracts obtained from the press cake of PEF-treated blueberries at 10 kJ/kg possessed an anthocyanin content (75%) and antioxidant capacity (71 and 109%, determined by FRAP and DPPH assay, respectively) higher than that of the extracts obtained from non-treated berries press cake. HPLC analyses revealed the major classes of the detected anthocyanins as glycosides of delphinidin, cyanidin, petunidin, peonidin, and malvidin, and no significant degradation of individual anthocyanins due to PEF application was observed. The present PEF pre-treatment could be a promising approach to facilitate efficient extraction of juice and antioxidants especially anthocyanins from blueberry and their by-products.     

不同产地蓝莓关键品质因子分析及其抗氧化特性

为研究不同产地的同一品种蓝莓品质特性及其花色苷抗氧化特性,以采自南京、湖州、玉溪、贵阳四个不同产地的"灿烂"蓝莓果实为试验材料,测定了总酸、总糖、水分、可溶性固形物、蛋白质和矿质元素含量;并采用体积浓度为60%、pH为3.0的乙醇溶液提取蓝莓花色苷,测定了蓝莓花色苷含量、总还原能力及羟基自由基、DPPH自由基的清除能力,并以V_C为对照,系统评价了不同产地蓝莓花色苷的抗氧化特性。结果表明:不同产地"灿烂"蓝莓的关键品质成分含量不同,贵阳产地蓝莓总酸含量最低为0.39%,总糖含量最高为11.91%,四产地水分含量在80.37%~83.60%,玉溪产地蓝莓蛋白质含量最高为613.50 mg/100 g,可溶性固形物含量由高至低为南京蓝莓、贵阳蓝莓、玉溪蓝莓、湖州蓝莓。不同产地蓝莓提取液花色苷含量和花色苷抗氧化能力由高至低均为贵阳花色苷、湖州花色苷、玉溪花色苷、南京花色苷。     

Efficient sorption of polyphenols to soybean flour enables natural fortification of foods

The present study demonstrated that defatted soybean flour (DSF) can sorb polyphenols from blueberry and cranberry juices while separating them from sugars. Depending on DSF concentration and juice dilution, the concentration of blueberry anthocyanins and total polyphenols sorbed to DSF ranged from 2-22 mg/g and 10-95 mg/g, respectively while the concentration of anthocyanins and proanthocyanidins in cranberry polyphenol-enriched DSF ranged from 2.5-17 mg/g and 21-101 mg/g, respectively. Blueberry polyphenols present in one serving of fresh blueberries (73 g) were delivered in just 1.4 g of blueberry polyphenol-enriched DSF. Similarly, one gram of cranberry polyphenol-enriched DSF delivered the amount of proanthocyanidins available in three 240 ml servings of cranberry juice cocktail. The concentration of blueberry anthocyanins and total polyphenols eluted from DSF remained constant after 22 weeks of incubation at 37 °C, demonstrating the high stability of the polyphenol-DSF matrix. LC-MS analysis of eluates confirmed that DSF retained major cranberry and blueberry polyphenols intact. Blueberry polyphenol-enriched DSF exhibited significant hypoglycaemic activities in C57bl/6J mice, and cranberry polyphenol-enriched DSF showed antimicrobial and anti-UTI activities in vitro, confirming its efficacy. The described sorption process provides a means to create protein-rich food ingredients containing concentrated plant bioactives without excess sugars, fats and water that can be incorporated in a variety of scientifically validated functional foods and dietary supplements.     

两种杀菌条件下蓝莓汁储藏品质变化及动力学研究

为了解经热杀菌和微波杀菌后蓝莓汁在不同储藏温度下品质的变化,采用一级反应动力学模型和Arrhenius经验方程,通过分别将热杀菌和微波杀菌所得的蓝莓汁储藏在不同的温度下,研究了储藏期间热杀菌和微波杀菌所得蓝莓汁中菌落总数、花青素含量、色泽的变化规律,并建立了相关动力学模型。结果表明:在储藏期间热杀菌和微波杀菌蓝莓汁中菌落总数、花青素含量、色泽的变化均符合一级反应动力学模型(R2>0.9),并可用Arrhenius方程拟合(R2>0.98);在较低的储藏温度下,蓝莓汁的菌落总数增长缓慢,花青素和色泽的损失较小,蓝莓汁可长时间保持较好的品质;相比热杀菌,微波杀菌能使储藏期间的蓝莓汁更好地保留花青素和色泽,但其保存期相对较短;各模型预测值与实验值之间相对误差均不超过2%,所有模型的预测准确性均较高。     

圣云蓝莓花色苷不同组分的体外抗氧化性和稳定性

采用制备型高效液相色谱对圣云蓝莓花色苷进行分离,利用体外化学实验模型对分离的3个花色苷组分进行抗脂质体过氧化、还原力、清除羟自由基( ·OH)、DPPH自由基评价,并研究3个花色苷组分的光、热稳定性。结果表明：圣云蓝莓花色苷3个组分(1#、2#、3#)均具有抗脂质体过氧化,还原力、清除 ·OH、DPPH自由基能力。抗氧化性按降低的顺序依次是1#＞2#＞3#,花色苷的抗氧化性和花色苷质量浓度及其结构有关。在3组花色苷中,光、热稳定性最高的是3#,光、热稳定性最低的是1#。圣云蓝莓花色苷不同组分的光、热稳定性也与分子结构有关。因此,圣云蓝莓花色苷是天然的抗氧化剂和食品添加剂。     

High performance liquid chromatography analysis of anthocyanins in bilberries (Vaccinium myrtillus L.), blueberries (Vaccinium corymbosum L.), and corresponding juices

In the present study the anthocyanin content of commercially available bilberry juices and fresh fruits were quantified by using 15 authentic anthocyanin standards via high performance liquid chromatography with an ultra-violet detector (HPLC-UV/VIS). Delphinidin-3-O-glucopyranoside, delphinidin-3-O-galactopyranoside, and cyanidin-3-O-arabinopyranoside were the major anthocyanins found in juices, nectar, and fresh bilberries. In contrast, fresh blueberries had higher concentrations of malvidin-3-O-arabinopyranoside and petunidin-3-O-galactopyranoside. Up to 438 mg anthocyanins per 100 g fresh weight (2762 mg/100 g dry weight (DW)) were detected in blueberries from various sources, whereas bilberries contained a maximum of 1017 mg anthocyanins per 100 g fresh weight (7465 mg/100 g DW). Commercially available bilberry and blueberry juices (n= 9) as well as nectars (n= 4) were also analyzed. Anthocyanin concentrations of juices (1610 mg/L to 5963 mg/L) and nectar from bilberries (656 mg/L to 1529 mg/L) were higher than those of blueberry juices (417 mg/L) and nectar (258 mg/L to 386 mg/L). We conclude that using several authentic anthocyanin references to quantify anthocyanin contents indicated them to be up to 53% and 64% higher in fresh bilberries and blueberries, respectively, than previously reported using cyanidin-3-O-glucoside. This study has also demonstrated that commercially available juices produced from bilberries contain much higher anthocyanin concentrations than those from blueberries. PRACTICAL APPLICATION: We have investigated the contents of a special class of antioxidants, namely anthocyanins in blueberry and billberry fruits and juices commercially available in Germany. To achieve reliable data we have used authentic standards for the first time. We think that our results are important in the field of nutritional intake of this important class of polyphenols and fruit juice companies get a closer insight in the occurrence of these antioxidants in market samples to be used in food composition databases and for nutritional survey.     

蓝莓酵素的体外抗氧化及对秀丽隐杆线虫的氧化应激保护作用

以大兴安岭野生蓝莓为原料,发酵制备蓝莓酵素,研究其发酵过程中总花青素、总酚和总黄酮含量变化,以及体外抗氧化能力变化情况,并以秀丽隐杆线虫为模型,初步探究其抗氧化的相关机制。结果表明:在发酵过程中,总花青素含量呈先上升后下降的变化趋势,于发酵第50 d时,达到了0.52 mg/mL,总酚和总黄酮含量总体呈现上升趋势,均于第300 d时达到最大值2.81、3.17 mg/mL;1, 1-二苯基-2-苦苯肼（1, 1-diphenyl-2-picrylhydrazyl,DPPH）自由基清除能力、还原力、氧自由基吸收能力（oxygen-radical absorbance capacity,ORAC）均呈现先快速增长后趋于平缓的变化趋势。蓝莓酵素能够延长秀丽隐杆线虫寿命,增强其在双氧水刺激下的氧化应激能力,提高超氧化物歧化酶（superoxide dismutase,SOD）、过氧化氢酶（catalase,CAT）和谷胱甘肽过氧化物酶（glutathione peroxidase,GSH-Px）等抗氧化酶的活力,并且降低线虫体内活性氧和丙二醛含量,该结果表明蓝莓酵素可能是通过提高抗氧化酶活力来减缓秀丽隐杆线虫的氧化损伤。