蓝莓花、茎、叶酚类物质含量及抗氧化活性比较

比较蓝莓花、嫩茎、嫩叶及老叶总多酚、总黄酮、原花青素的含量,并研究其抗氧化性能差异。结果表明:嫩叶中总多酚含量最高,为43.77 mg GAE/g(以干质量计,下同),分别是花、嫩茎和老叶的3.45、1.42、1.12倍;老叶中总黄酮、原花青素含量最高,为68.01 mg RE/g、23.29 mg CAE/g,分别是花的2.57倍和4.61倍、嫩茎的1.79倍和1.23倍、嫩叶的1.03倍和1.98倍。抗氧化性能中,老叶的铁还原能力最大,其次是嫩茎和花,嫩叶较差;清除·OH的能力为嫩茎嫩叶花老叶;清除DPPH自由基能力和总抗氧化能力均为嫩茎嫩叶老叶花甲醇提取物,均高于对照品;蓝莓各部分提取物对DPPH自由基的清除能力最强,总抗氧化能力次之,清除·OH能力和铁还原能力较差。     

草莓、黑莓、蓝莓中多酚类物质及其抗氧化活性研究

研究草莓、黑莓、蓝莓3种小浆果的总酚、总黄酮、原花青素含量及其总抗氧化能力。结果表明:蓝莓全果的总酚、总黄酮、原花青素含量在所测3种浆果全果中最高,分别为9.44mg没食子酸/g干质量、36.08mg芦丁/g干质量、24.38mg儿茶素/g干质量;其总抗氧化能力也最强,达14.98mmol Trolox/100g干质量。草莓的总酚、总黄酮、原花青素含量则最低,抗氧化能力也最弱。此外,3种浆果果渣中的总酚、总黄酮、原花青素含量以及总抗氧化能力均高于全果和果汁,即果渣>全果>果汁。总酚含量、总黄酮含量以及原花青素含量与总抗氧化能力之间的相关性分析表明,总酚含量与总抗氧化能力之间存在显著线性相关,相关系数r达到0.9704,表明酚类物质是其抗氧化作用的主要物质基础。     

橄榄中多酚类物质体外抗氧化活性研究

本文对提取纯化后得到的橄榄多酚类物质,通过测定其还原力,对羟基自由基.OH、超氧阴离子自由基(O-2.)和亚硝酸盐的清除能力,及对油脂过氧化的抑制作用,研究了其体外抗氧化活性,并与维生素C和BHT进行了对比。结果表明,橄榄多酚对羟基自由基、亚硝酸盐有较强的清除作用,在一定范围内,清除效果随质量浓度的升高而加强。当添加的橄榄多酚的质量浓度为0.98mg/mL时,对羟自由基的清除率可达82.41%;当质量浓度在1.26mg/mL时,对亚硝酸盐的清除率可达91.3%;橄榄多酚对猪油也有极强的抗氧化作用,能够极显著地抑制猪油过氧化值的升高,这种抑制效果随橄榄多酚质量浓度的升高而增大。另外,在相同浓度下,橄榄多酚对超氧阴离子自由基的清除率低于维生素C和BHT。     

金丝小枣中多酚类物质的体外抗氧化活性研究

采用酒石酸铁法测定金丝小枣枣皮、枣核中的多酚类物质含量。首次利用化学发光分析和紫外-可见分光光度分析相结合的方法测定金丝小枣枣皮、枣核中间苯三酚和邻苯二酚的体外抗氧化活性及其清除自由基保护DNA等能力的变化规律。研究结果表明,间苯三酚和邻苯二酚对·OH、NO2-、DPPH具有较明显的抑制作用,对由·OH引起的DNA损伤也具有较好的保护作用。当间苯三酚和邻苯二酚质量浓度为60μg/mL时,体外抗氧化活性及清除自由基保护DNA作用最佳。本研究可为开发枣副产品的保健功能提供新的研究方向和理论基础。     

不同发酵剂菌种对蓝莓-桑葚复合酵素抗氧化活性的影响

以蓝莓与桑葚为主要原料制备酵素,通过使用不同的发酵剂菌种,即自然发酵、酵母发酵、乳酸菌发酵、复合菌种发酵(酵母+乳酸菌),对发酵过程中感官、可溶性固形物含量、pH值、总酚含量、超氧阴离子自由基清除率、羟基自由基清除率、DPPH自由基清除率以及超氧化物歧化酶(SOD)活力进行测定,从而探究不同发酵菌种对蓝莓-桑葚复合酵素...     

多酚类物质抗氧化活性评价方法研究进展

综述了多酚类物质及其抗氧化活性评价方法的研究进展,同时对该方法的未来发展趋势进行了展望。     

蓝莓叶多酚与蓝莓果渣多酚提取物抗氧化活性研究

通过7种方法比较了蓝莓叶多酚(Blueberry leaves polyphenols,BBLP)提取物、蓝莓果渣多酚(Blueberry pomace polyphenols,BBPP)提取物以及对照品Rutin的抗氧化活性.在ABTS+清除能力、还原力、亚硝酸盐清除能力、FRAP值、ORAC值方面,BBLP与BBPP均高于Rutin或者与其相当.而三种样品DPPH·清除能力顺序为BBLP＞ Rutin＞BBPP,·OH清除能力顺序为Rutin＞ BBLP＞ BBPP.除亚硝酸盐清除能力和ORAC值与BBPP相当、·OH清除能力弱于BBPP外,BBLP在其余4种方法中表现出的抗氧化活性均强于BBPP.结果表明,BBLP与BBPP具有较强的抗氧化作用,可用于开发天然抗氧化剂.     

蓝莓叶多酚与蓝莓果渣多酚提取物抗氧化活性研究

通过7种方法比较了蓝莓叶多酚（Blueberry leaves polyphenols,BBLP）提取物、蓝莓果渣多酚（Blueberry pomace polyphenols,BBPP）提取物以及对照品Rutin的抗氧化活性。在ABTS⁺清除能力、还原力、亚硝酸盐清除能力、FRAP值、ORAC值方面,BBLP与BBPP均高于Rutin或者与其相当。而三种样品DPPH·清除能力顺序为BBLP>Rutin>BBPP,·OH清除能力顺序为Rutin>BBLP>BBPP。除亚硝酸盐清除能力和ORAC值与BBPP相当、·OH清除能力弱于BBPP外,BBLP在其余4种方法中表现出的抗氧化活性均强于BBPP。结果表明,BBLP与BBPP具有较强的抗氧化作用,可用于开发天然抗氧化剂。      

贵州蓝莓蜜的成分分析及其抗氧化活性

以贵州蓝莓蜜为研究对象,对其理化指标、抗氧化活性、多酚成分进行研究。结果显示,贵州蓝莓蜜酸度值44.69 mmol/kg,总糖含量79.30%,葡萄糖含量(40.88%)高于果糖含量(38.41%);总酚酸和总黄酮含量分别为20.27～24.72 mg GAE/100 g和3.88～6.77mg RE/100 g,DPPH和ABTS自由基半抑制率分别为119.04～136.56 mg/mL和140.56～212.34 mg/mL;蓝莓蜜含15种多酚类物质(原儿茶酸、对羟基苯甲酸、香草酸、咖啡酸、对香豆酸、芦丁、阿魏酸、杨梅酮、木犀草素、桑色素、槲皮素、芹菜素、山奈酚、异鼠李素、高良姜素),其中,黄酮类物质含量最高为槲皮素,酚酸含量由高到低为:对羟基苯甲酸对香豆酸阿魏酸咖啡酸香草酸原儿茶酸。研究表明,蓝莓蜜酸度偏高、易结晶,结合槲皮素含量高的特点与酚酸含量高低规律,可作为蓝莓蜜鉴定与检测的参考指标。     

蓝莓叶不同溶剂提取物抗氧化活性研究

研究蓝莓叶不同溶剂提取物中总酚和黄酮的含量以及抗氧化活性。分别用水、甲醇、乙醇、乙酸乙酯、氯仿、石油醚等不同极性溶剂提取蓝莓叶中的活性物质,采用Folin-Cioeaile法、三氯化铝显色法分别测定不同提取物中总酚和黄酮的含量;应用1,1-二苯基-2-三硝基苯肼（DPPH）自由基和2,2-联氮基双（3-乙基苯并噻唑啉-6-磺酸）二铵盐（ABTS）自由基清除体系及β-胡萝卜素-亚油酸体系评价其抗氧化活性,考察活性物质含量与抗氧化活性的关系。结果表明,蓝莓叶提取物的抗氧化活性随提取溶剂极性的减小而减小。水提取物具有较强的抗氧化活性,其清除DPPH·和ABTS+·的EC50分别为（12.78±0.10）、（6.35±0.03）μg/mL,抑制β-胡萝卜素淬灭IC50值为（25.33±0.02）μg/mL。含量测定显示水提物中总酚含量最高,为（264.67±0.29）mg/g,而甲醇提取物中黄酮含量最高,为（68.94±0.08）mg/g,相关性分析表明,不同溶剂提取物抗氧化能力差别较大,总酚和黄酮含量与抗氧化能力具有相关性,提示水可作为蓝莓叶抗氧化活性物质提取的优选溶剂,而总酚和黄酮含量可作为蓝莓叶抗氧化提取物的质量评价指标。      

Phenolic composition,caffeine content and antioxidant capacity of coffee silverskin

Coffea arabica silverskin (CSS), the inner fruit layer surrounding coffee beans, was analyzed for its (poly)phenolic and caffeine content by means of liquid chromatography–tandem mass spectrometry and evaluated for its antioxidant properties by means of the Folin–Ciocalteu and FRAP methods. The most abundant quantified phenolics were caffeoylquinic acids, with the 5- and 3-isomers being the most relevant (199 mg/100 g and 148 mg/100 g, respectively). The three caffeoylquinic acid isomers reached a total concentration of 432 mg/100 g, corresponding to 74% of the total chlorogenic acids detected in CSS. The level of the three feruloylquinic acids detected was 143 mg/100 g, corresponding to 23%, and the two identified coumaroylquinic acids plus the two caffeoylquinic acid lactones were only marginally contributing to the final figure (only 3% of total hydroxycinnamates). No unconjugated phenolic acid was detected. Caffeine content in CSS was equal to 10 mg/g of product, 3.5 times lower than most coffee brews. The total antioxidant capacity (TAC) of CSS was 139 mmol Fe^2 +/kg, a value similar to those of valuable sources of food antioxidants like dark chocolate, herbs and spices. Besides its potential as a food supplement, CSS may represent an innovative functional ingredient exploitable to increase the TAC of a wide range of food products.     

Phenolic content and antioxidant capacity of hybrid variety cocoa beans

Cocoa (Theobroma cacao L.) is a major, economically important, international crop and has been associated with several nutritional benefits including high antioxidant capacity. New cocoa hybrids have been developed in Ghana that exhibit resistance to pest damage during storage. The aim of this work was to assess the phenolic content and antioxidant capacity of these new hybrids in comparison to more traditional cocoa varieties. Total extractable phenolics were similar in all the four hybrids tested ranging from 69.9 to 81.6 FAE g⁻¹. These levels were very similar to that extracted from traditional beans (73.8 ± 2.5 FAE g⁻¹). The “phenolic profile” was determined by HPLC. A total of 25 peaks was observed but there were only minor differences in this profile between traditional and hybrid bean extracts. Antioxidant capacity was determined using the FRAP assay and traditional beans were found to possess 12.4 μmol TE g⁻¹. In comparison the hybrid beans had antioxidant capacities ranging from 21.6 to 45.5 μmol TE g⁻¹, and these were significantly higher than in the traditional beans for three out of the four hybrids. Since the phenolic and antioxidant levels and in these hybrid varieties were either similar to, or higher than, that obtained from traditional beans, the introduction of these new varieties would be unlikely to impact detrimentally on these nutritional components of the beans.     

不同品种蓝莓酚类物质组成特征及抗氧化能力比较分析

以高丛、矮丛、兔眼蓝莓为研究对象,比较了其总酚、花色苷、原花色素、单体酚以及抗氧化力差异。超高效液相色谱检测结果表明,绿原酸为3种蓝莓中含量最多的酚酸;表没食子儿茶素是高丛蓝莓和兔眼蓝莓含量最丰富的黄烷醇,表儿茶素没食酸酯则是矮丛蓝莓含量最高的黄烷醇;在3种蓝莓中含量最高的黄酮醇均为芦丁;矮丛蓝莓单体酚总量显著高于高丛蓝莓和兔眼蓝莓。抗氧化分析结果则表明,无论从DPPH、ABTS还是FRAP测定结果来看,矮丛蓝莓均具有最强的抗氧化能力。相关性分析结果表明,3种蓝莓总酚、总花色苷和原花色素含量均与抗氧化能力存在明显的正相关性。     

Effects of spray drying on antioxidant capacity and anthocyanidin content of blueberry by-products

The effect of spray drying on degradation of nutraceutical components in cull blueberry extract was investigated. Samples collected before and after spray drying were tested for antioxidant capacity using oxygen radical absorbance capacity (ORAC(FL) ) and total phenolics; and for individual anthocyanidins. In Study 1, four different levels of maltodextrin (blueberry solids to maltodextrin ratios of 5: 95, 10: 90, 30: 70, and 50: 50) were spray dried a pilot-scale spray dryer. There was significantly higher retention of nutraceutical components with increased levels of maltodextrin indicating a protective effect of maltodextrin on the nutraceutical components during spray drying. In Study 2, the air inlet temperature of the spray dryer was kept constant for all runs at 150 °C, with 2 different outlet temperatures of 80 and 90 °C. The degradation of nutraceutical components was not significantly different at the 2 selected outlet temperatures. ORAC(FL) reduction for blueberry samples after spray drying was 66.3% to 69.6%. After spray drying, total phenolics reduction for blueberry was 8.2% to 17.5%. Individual anthocyanidin reduction for blueberry was 50% to 70%. The experimental spray dried powders compared favorably to commercial blueberry powders. Results of the study show that use of blueberry by-products is feasible to make a value-added powder. PRACTICAL APPLICATION: Results can be used by producers to estimate final nutraceutical content of spray-dried blueberry by-products.     

Phenolic content and antioxidant capacity of Chinese raisins produced in Xinjiang Province

Raisins of 9 grape genotypes from Xinjiang Province were evaluated for phenolic composition and dietary antioxidant potential by using several assays, including 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, cupric reducing antioxidant power (CUPRAC), nitrite scavenging capacity (NTSC), potassium ferricyanide reducing power (PFRAP), and hydroxyl radical scavenging capacity (HRSC). Desert king had the highest content of total phenolics, total flavonoids, oligo proanthocyanidin, and total flavanols. Significance analysis demonstrated that Desert king had the highest antioxidant capacity in DPPH, CUPRAC, NTSC, and PFRAP. In HRSC, red manaizi showed the highest antioxidant capacity. 3,4-Dihydroxybenzoic acid was the predominant phenolic compound in the majority of raisin samples.     

Relationships between colour parameters,phenolic content and sensory changes of processed blueberry,elderberry and blackcurrant commercial juices

There is an increased interest in the consumption of fruits containing high phenolic concentrations such as berry fruits. Attractive colour of berries plays a vital role for consumer acceptance. The aim of this work was to evaluate colour parameters (a*, b*, L*), phenolic content and sensory changes of blueberry, elderberry and blackcurrant (BC) pasteurised commercial juices during accelerate storage. Initial phenolic concentration was 3.21, 10.06, 10.72 g GAE L^?1 for blueberry, elderberry and BC, respectively. Moreover, phenolic concentration of all juices decreased by approximately 40% throughout the first 30 days. Blueberry exhibited a substantial decrease in a* (40%) in the first 30 days, while elderberry presented a gradual decrease and BC only presented a slight decrease (7%) at the end of storage. Colour preferences decreased when storage time increased. However, when consumers were informed that ‘the juices are a rich source of phenolics, which contribute to reducing risk of suffering chronic diseases’, a high level of purchase intention was obtained.     

Phenolic content and antioxidant capacity versus consumer acceptance of soaked and vacuum impregnated frozen nectarines

Nectarines (Prunus persica L. cv. Maria Laura) were manually selected, cut in slices and divided into four groups: fresh, untreated frozen, soaked in osmotic solution and subsequently frozen, and vacuum impregnated (VI) and subsequently frozen. This investigation was focused on evaluation of consumer acceptance with respect to treated versus untreated frozen nectarine slices. In a preliminary acceptance test of untreated frozen nectarine slices, fruits were generally rejected on the basis of a darkened appearance and “oxidized” taste. These negative attributes were probably linked to the activity of polyphenol oxidase (PPO) and depletion of phenols due to cell rupture during freeze–thaw procedures. For these reasons, in order to evaluate the tendency of fruit to oxidation, several analyses were performed: the antioxidant capacity of phenolic fraction and the o-diphenol content were estimated by spectrophotometric assays, whereas the hydroxycinnamic acid (chlorogenic and neochlorogenic acids) composition was evaluated by high performance liquid chromatography (HPLC). Phenolic content and antioxidant capacity were found to correlate well with the acceptance level of frozen nectarine slices. In this regard a higher phenolic content associated with a higher acceptance level of nectarine samples.     

Phenolic content and antioxidant activity of olive extracts

The phenolic component of freeze-dried olive fruit was fractionated by high-performance liquid chromatography using ultraviolet, atmospheric pressure chemical ionisation (APCI) and electrospray ionisation (ESI) detection. The fractions together with several standards were tested for antioxidant activity in an aqueous and a lipid system. The negative ion mode of APCI and ESI showed less fragmentation than positive ion mode. The latter was generally more useful in obtaining fragmentation data and hence structural information. Some olive phenolics notably tyrosol exhibited a low ionisation efficiency in both APCI and ESI. There was no simple relationship between antioxidant activity and chemical structure. The ranking of antioxidant activity was strongly dependent on both the test system and on the substrate demonstrating the need to examine activity in both aqueous and lipid systems. Significant antioxidant activity was seen in most olive fractions and this was related to phenolic content. The kinetics of the oxidation process are complex and suggest that multiple pathways may be involved at different antioxidant concentrations.     

甜型蓝莓酒的研制及抗氧化能力的评价

通过正交实验对甜型蓝莓酒的发酵工艺进行了优化,最佳工艺参数为:发酵温度24℃,加糖量15%,酵母添加量0.15%。再经陈酿、澄清处理得到风味独特的蓝莓甜酒,成品酒精度16.0%(vol),总糖≥65g/L,总酸6～8g/L。采用FeCl3/K3Fe(CN)6还原力测定体系分析维生素C和葡萄酒样的抗氧化能力,结果显示蓝莓甜酒的还原能力高。