Effect of Polymerization on Antioxidant and Xanthine Oxidase Inhibitory Potential of Sea Buckthorn (H. rhamnoides) Proanthocyanidins

Abstract: Inhibitory potential of sea buckthorn (Hippophae rhamnoides L) seed proanthocyanidins against oxidative stress and xanthine oxidase activity was evaluated. Composition of antioxidant proanthocyanidins was profiled by analyzing the cleavage products obtained by the acid catalyzed hydrolysis in the presence of phloroglucinol. Catechin, epicatechin, gallocatechin, and epigallocatechin were found as the extension and terminal subunits of proanthocyanidins with an average degree of polymerization (ADP) of 14.7. Seed proanthocyanidins showed considerably high antioxidant and xanthine oxidase inhibitory potentials. Antioxidant and xanthine oxidase inhibitory capacity evaluation of proanthocyanidin fractions with varying ADP showed that proanthocyanidins with lower molecular size were more effective as superoxide anion (ADP ≤ 4.2) and hydroxyl radical (ADP ≤ 5.9) scavengers and xanthine oxidase (ADP ≤ 3.1) inhibitors. ADP of the studied proanthocyanidin fractions did not show significant influence on their DPPH and ABTS radical scavenging and ferric reduction capacities.     

微波预处理对沙棘油得率和品质的影响

在2 450 MHz、560 W的微波条件下,分别对沙棘籽、沙棘果肉和沙棘全果进行0~5 min预处理,研究微波不同时间对溶剂法所提沙棘籽油、沙棘果油及沙棘全果油的得率和品质的影响。结果表明,微波预处理能提高沙棘籽油、沙棘果油和沙棘全果油的得率,最高增加比例分别为9.49%、28.35%、18.21%;随着微波时间的延长,沙棘籽油中维生素E含量呈下降趋势,而沙棘果油和沙棘全果油则相反;3种油中植物甾醇含量先增加后减少;沙棘籽油总酚呈先增加后减少的趋势,沙棘果油和沙棘全果油则呈上升趋势;微波也会导致过氧化值和酸价的升高,而微波预处理对脂肪酸组成的影响不大。由此可见,合适的微波预处理时间能同时提高沙棘籽油、沙棘果油和沙棘全果油得率及改善其营养品质。     

香草醛/硫酸比色法测定两种原花色素含量的比较

分别选取儿茶素、葡萄籽原花青素、沙棘籽原花色素为基准物质,考察了三者与香草醛/硫酸反应影响因素的异同,优化了各自的测定条件,结果表明,儿茶素、葡萄籽原花青素和沙棘籽原花色素与香草醛反应动力学有显著差异。儿茶素的适宜反应条件为:30℃反应5min(测定波长500nm),葡萄籽原花青素的适宜反应条件为:20℃反应5min(测定波长500nm);沙棘籽原花色素适宜反应条件为:30℃反应15min(测定波长505nm);反应体系为:1ml样品甲醇溶液加入2.5ml 1%香草醛的甲醇溶液和2.5ml 5mol/L硫酸的甲醇溶液。     

Analysis of carbonyl compounds in sea buckthorn for the evaluation of triglyceride oxidation,by enzymatic hydrolysis and derivatisation methodology

Carbonyl compounds formed in sea buckthorn berry (Hippophae rhamnoides) and oil samples as a result of lipid oxidation were determined by enzymatic hydrolysis followed by derivatisation with 2,4-dinitrophenylhydrazine and analysed by LC–UV and electrospray ionisation (ESI) tandem mass spectrometry (MS/MS). Several classes of carbonyl compounds such as saturated, unsaturated, linear and branched aldehydes and ketones, aromatic aldehyde, dicarbonyls and carboxy aldehydes were identified based on fragmentation pattern, molecular weight and retention time. The lower carbonyls such as formaldehyde, acetaldehyde and acetone were found to be predominant in the berry samples and acetaldehyde was found to be the most abundant carbonyl. In the sea buckthorn pulp oil sample, longer aldehydes and carboxy aldehydes dominated, thus clearly demonstrating the benefit of the enzymatic step when analysing oxidation products originating from triglycerides.     

Differential interaction of seed polyphenols from grapes collected at different maturity stages with the protein fraction of saliva

Grape seed and skin proanthocyanidins undergo significant changes during grape maturation. Those changes have been associated with a decreased astringency of grapes collected at later maturation stages. We have now compared the ability of proanthocyanidin‐rich extracts from Carménère grape seeds collected at two stages of berry development (veraison vs. harvest) both to interact with salivary proteins and to produce astringency. Interaction of proanthocyanidins with the salivary protein was assessed by analysing the concentration‐dependent effect of seed extracts both on inducing salivary protein precipitation and on restricting diffusion of the salivary protein on cellulose membranes. Seed extracts from grapes collected at veraison compared with those of grapes collected at harvest displayed a higher ability both to interact with the salivary protein fraction and to produce astringency. As a whole, our observations show that astringency is closely dependent on the magnitude of the interactions between proanthocyanidins and the salivary protein fraction.     

平欧榛子活性成分含量及抗氧化性比较

榛子中含有多种生物活性成分,不同品种、不同利用部位榛子的活性成分含量存在差异。以8个抗寒优良品种平欧榛子为原料,分别测定其种壳、种皮和种仁中总多酚、总黄酮、单宁及原花青素含量并对种皮中总多酚的抗氧化性进行评价。活性成分含量比较结果表明:种皮中各活性成分含量均显著高于种壳和种仁(P0.05);其中7#品种种皮总多酚含量最高,为185.76 mg/g;6#品种种皮总黄酮、单宁含量均为最高,分别为29.961、3 9.1 0 mg/g;7#品种原花青素含量最高,为7 7.2 8 mg/g;并且种皮中总多酚含量远高于其他3种活性成分(P0.05)。8种平欧榛子种皮总多酚的抗氧化性研究表明:综合考虑了不同质量浓度的处理效果,发现7#平欧榛子种皮总多酚抗氧化性效果强于其他品种,对1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除率可达87.70%,对铁离子还原力为0.450,对超氧阴离子自由基清除率可达53.1%,对脂质过氧化的抑制率达到82.0%。种皮超氧阴离子自由基清除能力、DPPH自由基清除力、抑制脂质过氧化能力、对铁离子的还原能力与总多酚含量之间呈正相关,相关系数分别为0.843、0.793、0.695、0.620。     

沙棘油功效成分及药理功能研究进展

沙棘具有悠久的药用历史,沙棘油根据来源不同分为沙棘籽油和沙棘果油。沙棘果油和沙棘籽油均含有丰富的不饱和脂肪酸、生育酚、β-类胡萝卜素和甾醇类物质。研究表明,沙棘油具有丰富的药理功能,对心脑血管和胃肠道的保护作用,滋润皮肤、促进皮肤组织再生和上皮组织愈合、改善皮肤衰老现象的作用,缓解干眼症和辅助保护化学性肝损伤的作用。除此以外,沙棘油还具有一定的抗炎、抗氧化、增强免疫力的功能。通过对沙棘果油和沙棘籽油的功效成分、药理功能及其开发利用现状等进行综述,以期为沙棘油功能产品开发提供一定的理论基础和依据。     

Anti-obesity effects of highly polymeric proanthocyanidins from seed shells of Japanese horse chestnut (Aesculus turbinata Blume)

Recently, we have shown that seed shells contain a large amount of highly polymeric proanthocyanidins having a series of heteropolyflavan-3-ols with doubly linked A-type linkages as well as single B-type bonds without gallic acid esterified to them. Here, we attempted to evaluate in vivo anti-obesity effects of the polymerized proanthocyanidins in mice. An oral starch or glucose tolerance test in mice revealed that the isolated two fractions of highly polymerized proanthocyanidins with the different degree of polymerization suppressed effectively the elevation of blood glucose from oral starch, but not from oral glucose, suggesting the preferential inhibition of the digestive enzymes of carbohydrates. Moreover, in vivo anti-obesity effects of the total fraction containing the proanthocyanidins as a drink were investigated in mice fed a high-fat diet. Their anti-obesity effects became more evident after 9 weeks as determined by the attenuation of the elevation in body weight, the mass of peritoneal adipose tissues, and the plasma levels of total cholesterol and leptin. Furthermore, the increased size of hepatocytes and the generation of steatosis with micro- and macrovesicles in liver were normalized by the dietary supplementation of the total proanthocyanidin fraction.The findings suggest the usefulness of highly polymeric proanthocyanidins from seed shells in the application to food as a dietary supplement with anti-obesity effects in vivo through the inhibition of digestive enzymes of carbohydrates and fats.     

沙棘蛋白和多肽的提取及功能活性研究进展

沙棘是一种生命力极强的落叶灌木，属于药食同源的植物。沙棘叶及种子中含有大量蛋白质，属于优质植物蛋白资源。沙棘蛋白或沙棘原料经过酶解、电解、酸碱催化等一系列操作后可得到肽。文章归纳整理了已有文献与资料，对沙棘蛋白与多肽不同提取方法的原理及特点进行分析比较，并分析了其蛋白和多肽的氨基酸组成、分子量等内容，介绍其具有的降血糖、抗氧化、醒酒抗炎等活性。总结发现沙棘蛋白和多肽虽然具有多种活性，但是复合法制备蛋白和多肽的应用较少，结构和活性的研究还不够深入，应从以上方面加大研究力度，促进沙棘蛋白资源的开发与利用。     

沙棘果生物活性成分及其功能的研究进展

沙棘果实中含有多种生物活性成分,包括酚类化合物、维生素C、维生素E、类胡萝卜素等;现代多项研究显示,沙棘果具有抗氧化、抑制肿瘤、降低血糖、降低血脂和免疫调节等生物活性功能,在保健食品、医药治疗、美容护肤等领域具有重要的开发价值。该文对沙棘果实的生物活性成分和功能特性研究作总结和归纳,并对其发展前景进行了展望。     

A new technology for extraction and purification of proanthocyanidins derived from sea buckthorn bark

A new technology involving resin purification of proanthocyanidins extracted from sea buckthorn bark has been studied. By investigating single‐factor effects, the main factors affecting proanthocyanidin extraction were identified as extraction temperature, pH and ethanol concentration. A central composite design and response surface analysis were used to determine the optimal parameters of the extraction process (temperature 21 °C, pH 5.13, ethanol concentration 65%). The optimal resin for purification, D3520, was selected from 16 different resins by means of static adsorption and dynamic adsorption/desorption tests. After using this resin to purify the crude extract, a proanthocyanidin extract was obtained whose yield and purity were above 80% and greater than 95% respectively. Procyanidin dimers and trimers predominated among oligomer procyanidins of the proanthocyanidin extract according to analyses by high‐performance liquid chromatography (HPLC) and HPLC/mass spectrometry. Copyright © 2005 Society of Chemical Industry     

Relationships between seed and berry development of Vitis Vinifera L. cv Shiraz: Developmental changes in seed morphology and phenolic composition

Berries were collected regularly from fruit set to berry maturity from irrigated (Shiraz) grapevines in a Barossa valley vineyard. Seeds were removed for detailed study of physical attributes (weight, moisture, colour) and phenolic composition (seed tannins). Three phases of seed growth and development were discerned: (1) a phase of seed growth characterised by a steady increase in both fresh weight and dry weight, biosynthesis and accumulation of flavan‐3‐ols and tannins, and green appearance; (2) a transition phase where seed fresh weight and dry weight reached a maximum, but with continuing enlargement of the basal end. Accumulation of flavan‐3‐ols and seed tannins also reached a maximum during phase 2, and was accompanied by an onset of tannin oxidation, and yellow appearance; and finally, (3) a phase of seed drying and maturation defined by a decrease in fresh weight due to water export, a sustained oxidation of tannins, and overall brown appearance. These phases in seed development correspond to particular stages in berry development. Seeds reached maximum fresh seed weight and full size at the beginning of berry colouring (veraison), while maximum dry seed weight coincided with maximum berry weight. Changes in seed phenolics were linked to berry development and maturation. Changes in seed coat colour were also related to developmental changes in berry anthocyanins and total skin phenolics, indicating that the external appearance and colour of the seed coat may be used as an additional indicator of overall berry ripeness. A graduated colour chart was developed to provide an objective index of seed coat colour and thus developmental status of seeds and berry.     

酸枣仁ACE抑制肽酶解工艺优化

本试验以脱脂后的酸枣仁渣通过碱溶酸沉法提取得到的酸枣仁蛋白为研究对象,以血管紧张素转化酶(ACE)抑制率和水解度为指标,筛选复合酶种类,采用响应面分析法,以中性蛋白酶/碱性蛋白酶比例、pH、底物浓度、酶解温度、酶解时间为试验因素,优化酸枣仁ACE抑制肽最佳酶解工艺参数。结果表明:筛选出中性蛋白酶和碱性蛋白酶作为复合酶,最适酶添加量确定为6000 U/g,5个因素对ACE抑制率和水解度的影响由大到小的顺序为:酶解温度、酶解时间、pH、中性蛋白酶/碱性蛋白酶比例、底物浓度。通过拟合方程分析,得到酸枣仁ACE抑制肽酶解的最佳工艺条件为:中性蛋白酶/碱性蛋白酶比例为2.1:1、酶解温度为54 ℃,底物浓度为3.1%,pH为7.5,酶解时间为62 min。在此条件下,复合酶解酸枣仁蛋白酶解液的实际ACE抑制率和水解度分别为（79.46%±0.49%）和（31.45%±0.85%）,与理论值接近。制备得到酸枣仁ACE抑制肽与阳性对照组卡托普利对比,酸枣仁ACE抑制肽的ACE抑制率大小为（79.46%±0.49%）,与卡托普利的ACE抑制率偏差为（19.28%±0.12%）,证明酸枣仁ACE抑制肽具有显著降压效果。本研究证明了酸枣仁蛋白通过酶解有效得到ACE抑制肽并优化其酶解工艺,旨在为酸枣仁渣废物再利用提供参考方向和理论依据。     

燕麦沙棘酒的研制

以沙棘汁和燕麦为原料,采用发酵法生产燕麦沙棘酒。先确定燕麦粉糖化液的最佳制取工艺条件,再通过正交试验确定燕麦沙棘酒发酵的最佳工艺条件。在燕麦粉糖化液用量17%,沙棘汁用量为27%,酵母接种量1.0‰,发酵温度28 ℃,发酵pH值3.8条件下酿造的燕麦沙棘酒,酒精度12.3%vol,风味纯正,酒体丰满,营养丰富,感官评分为86分。     

Degradation kinetics of grape skin and seed proanthocyanidins in a model wine system

Catechin (monomer), purified grape skin proanthocyanidin (polymer), and purified grape seed proanthocyanidin underwent monitored accelerated oxidation under continuous oxygenation and UV light, at a constant 20 °C. Compounds were dissolved in model wine solutions with (and without) catechol. Solutions were examined and then contrasted by absorbance measurements, phloroglucinolysis, and subsequent HPLC analysis. Oxidation of these monomers and polymers revealed significant colour changes (measurable increase in colour density). The presence of catechol increased the half-life of catechin, but the opposite was observed for total skin and seed proanthocyanidins. Skin and seed proanthocyanidin degradation half-life decreased with the addition of catechol. In general, based on second order rate reactions, total subunits of seed proanthocyanidin solutions degraded faster than that of skin proanthocyanidin solutions. As expected, there were decreases of measurable phenolics in both monomer and polymer solutions. Under the study conditions, flavanol monomer and polymer oxidation was chiefly dependant upon initial solution concentration.     

Analysis of tannins in seeds and skins of Shiraz grapes throughout berry development

The flavan-3-ol and proanthocyanidin composition of both seeds and skin of Vitis vinifera L. cv. Shiraz grapes was determined by reversed-phase HPLC after acetone extraction and acid-catalysis in the presence of excess phloroglucinol. Samples were taken at weekly intervals from fruit-set until commercial harvest. The main period of proanthocyanidin accumulation in grape seeds occurred immediately after fruit-set with maximum levels observed around veraison. Over two seasons there was variation in both the timing and content of proanthocyanidins in seeds. In skin, proanthocyanidin accumulation occurred from fruit set until 1–2 weeks after veraison. Proanthocyanidin subunit composition was different in seeds and skin and changed during berry development but the mean degree of polymerisation of the tannin polymers in skins was higher than in the seeds at all stages of berry development. Proanthocyanidin levels in both seeds and skin decreased between veraison and harvest. Additional proanthocyanidin subunits were released when the residues remaining after acetone extraction were subjected to direct acid-catalysis in the presence of phloroglucinol. In the seeds, these accounted for much of the post-veraison decrease, but not in grape skin. At harvest, 75% of extractable berry proanthocyanidin was in the seeds. Accumulation of proanthocyanidins in the seeds appears to be independent of that in the skins, but in both tissues synthesis occurs early in berry development and maximum levels are reached around veraison.     

Anti-oxidative characterisation of NaN3-induced common bean mutants

The contents of total phenolics, total anthocyanins, total proanthocyanidins and antioxidant activities were measured using 2,2-diphenyl-1-picrylhydrazyl radicals scavenging activity, ferric reducing antioxidant power, lipid peroxidation inhibition ability and ABTS⁻ radical-scavenging activity assays. These were compared in the seed coats of common bean (Phaseolus vulgaris L.) cultivar Hwachia and its eighteen NaN₃-induced mutants. NaN₃-induced mutants generally accumulated more total phenolics (19% more), total anthocyanins (65% more) and total proanthocyanidins (4% more) than Hwachia (containing 29.94 mg g⁻¹ total phenolics, 0.31 mg g⁻¹ total anthocyanins and 12.94 mg g⁻¹ total proanthocyanidins, respectively). Anthocyanidins including delphinine, cyanidin and pelargonidin were detectable in seed coat, each with different levels depending on the tested accessions. Significant correlations (average of 0.847 across all comparisons, p < 0.01) were found between the tested antioxidant activities, total phenolics, total anthocyanins and total proanthocyanidins. Mutants SA-11-2, SA-13-2 and SA-34-2 that are enriched with antioxidants may be useful in food and other applications.     

Sanddorn und Sanddornöle – Neuere Entwicklungen in China und Zentralasien –

Sea buckthorn and sea buckthorn oils – Recent developments in China and Central Asia – Since several years, sea buckthorn and sea buckthorn oils are booming in China, Russia and Central Asia. The background of this development is described and the different species and varieties of sea buckthorn are mentioned. The two different oils obtained from sea buckthorn (pulp oil and seed oil) and their composition is discussed. The use of sea buckthorn and its oils for medical and pharmaceutical purposes has its roots in ancient Tibet. The various “health claims”, particularly by Russian and Chinese medical authorities, could not be discussed here. However, a number of recent papers are quoted here without further comment.     

Antioxidant activity and antimicrobial effect of berry phenolics--a Finnish perspective

In Finland, berries are part of the traditional diet significantly contributing to the intake of flavonoids and other phenolic compounds. Compositional data on phenolic compounds in berries has been rapidly accumulating and included in the national food composition database. Among the different bioactive substances in berries, phenolic compounds including flavonoids, tannins, and phenolic acids have received considerable interest due to their effects in food and health. A great amount of in vitro evidence exists showing that berry phenolics are powerful antioxidants. However, the antioxidant effect of berry phenolics is strongly dependent on the choice of berry raw material, as the antioxidant activity differs between the different phenolic constituents, including anthocyanins, ellagitannins, and proanthocyanidins. In foods, the antioxidant effect is also influenced by the structure of food. Tannin-containing berries exhibit antimicrobial properties against pathogenic bacteria, thus offering many new applications for food industry. Much of the interest in berry phenolics has focused on cranberries and both cultivated and wild blueberries, although also other berries including black currants, cloudberries, lingonberries, and red raspberries possess promising bioactivities that may have relevance to human health. Antioxidant activity of berry phenolics, in addition to other mechanisms, may contribute to human health, but the possible relationship remains yet to be scientifically substantiated.     

Proteolytic regulation of the extent of dietary proteins with skin grape proanthocyanidin and anthocyanidin's interactions

During technological processing, proanthocyanidins and anthocyanidins could be partly lost due to the complexation phenomena, affecting food and beverage nutritional properties, organoleptic properties and health-promoting potentials. A common issue is encountered when processing food and beverage which is binding of phenolics to dietary proteins. The present investigation aims at evaluating the proteolysis contribution, using pure protease (Pepsin, 3000 units g⁻¹), to protein–anthocyanidin and protein–proanthocyanidin interactions. Bovine serum albumin (BSA), ovalbumin (OVA) and casein (CAS) dietary protein models were used. High-performance liquid chromatography coupled to diode array detector (HPLC-DAD) and size exclusion chromatography analyses proved that pepsin treatment significantly (P > 0.05) decreased the ratio of flavonoids’ interaction with tested proteins . The proteolysis reduced anthocyanidin interactions with CAS, OVA and BSA by 64.88%, 57.37% and 42.87% respectively. Similarly, proanthocyanidins interaction with CAS, OVA and BSA were reduced by 34.23%, 13.74% and 2.39% respectively. This study provides the basis to develop innovative technologies to limit protein–flavonoid complexation during food and beverage processing.