Spectral dependence of photosynthesis and light absorptance in single leaves and canopy in rose

Little is known about the effects of leaf pigmentation (related to leaf ontogeny), on the spectral dependence of photosynthesis and most observations have been limited so far to single leaves. This study aimed to investigate photosynthesis and the related optical properties of two types of rose leaves, young reddish leaves and middle age green leaves, and to quantify the spectral dependence of photosynthesis at the canopy level.     

Late season harvest and storage of Rubus berries—Major antioxidant and sugar levels

Late season production of raspberries and blackberries has become more common due to increased consumer demand and new production techniques, but information is scarce regarding the effect on nutritional quality, especially during storage. Antioxidant levels in berries can be influenced by pre-harvest climate conditions (light intensity, day length and temperature) and post-harvest storage time. This study analysed the effect of these factors on the content of different antioxidants (vitamin C, ellagic acid, anthocyanins and total phenolics) in raspberries (Rubus idaeus L. cv. Polka) and blackberries (Rubus fructicosus L. cv. Loch Ness) during storage. The analyses were performed using high performance liquid chromatography (HPLC) with photodiode array detection. Ellagic acid content during storage ranged between 104 and 114 mg/100 g fresh weight in raspberries and 172 and 182 mg/100 g fresh weight in blackberries. Anthocyanin content increased during storage from 64 to 77 mg/100 g fresh weight in raspberries, but decreased from 199 to 162 mg/100 g fresh weight in blackberries. Vitamin C content in raspberries ranged during storage between 22 and 28 mg/100 g fresh weight, but in blackberries values were lower (10–12 mg/100 g fresh weight). Significant changes in total phenolics and sugars occurred during different storage periods (0–9 or 10 days). The results suggest that late season raspberries and blackberries maintain high quality in terms of antioxidant content.     

蓝靛果中花色苷含量的测定及其体外抗氧化性

蓝靛果是具有丰富的花色苷的一种浆果,经常温用60％乙醇提取蓝靛果粉末后,用pH示差法对其干物质中的花色苷含量进行测定,测定得蓝靛果干物质中的花色苷含量为12．232mg／g。并测定其体外抗氧化性,分别对羟自由基、超氧自由基、DPPH自由基和ABTS自由基的清除率进行测定,用VC作为阳性对照,可得蓝靛果花色苷具有极强的抗氧化性,可用于保健食品药品等领域。     

树莓果汁中花色苷降解动力学的研究

通过研究树莓果汁花色苷在不同pH值和贮藏温度下的热稳定性,建立了花色苷降解动力学模型,研究结果表明：树莓果汁花色苷对pH和热不稳定,花色苷的降解符合一级反应动力学,随着pH值和温度的升高,树莓花色苷热降解活化能（Ea）和半衰期（tl／2）显著下降。经验证实验表明,该降解动力学模型有效,可用于树莓果汁贮藏温度的选择和预测不同温度下的贮藏期。     

八种紫甘薯资源原花青素相对含量的比较

探讨不同提取剂和不同物料比对紫甘薯原花青素提取的影响,并比较不同紫甘薯品种原花青素含量的差异。分别用5%的柠檬酸和95%乙醇(1%盐酸)作为提取剂,同时设不同物料比,采用分光光度计比色法测定甘薯原花青素相对浓度,结果表明,不同的提取剂和不用的物料比所测得的甘薯原花青素相对浓度有差异但差异不显著。用5%的柠檬酸作为提取剂,物料比为1:25,测定8种紫色甘薯资源中原花青素相对浓度,结果表明品种间中原花青素含量差异显著,其中原花青素相对浓度最高的是渝紫1号。     

Variation in quality parameters between and within 14 Nordic tree fruit and berry species

Abstract

A 3-year study was carried out to investigate quality parameters in 14 tree fruit and berry species grown in southern Norway. The species were blueberry, apple, aronia, sour cherry, sweet cherry, red raspberry, strawberry, blackcurrant, gooseberry, red currant and elderberry, harvested along with wild bilberry, cloudberry and lingonberry. Significant differences between species were identified for all quality parameters. The coefficient of variation between species was lowest for pH (12.5%), dry matter (18.9%) and soluble solids (25.3%), followed by titratable acids (59.3%), total phenolics (83.8%), antioxidant capacity FRAP (85.7%) and antiradical power by the DPPH-assay (97.8%), total monomeric anthocyanins (132%) and ascorbic acid (137%). Average coefficient of variation within species were lower and ranged from 4 (pH) to 62% (ascorbic acid). Only the FRAP values were significantly affected by harvesting year with lower levels in 2004 than in 2005 and 2006. There were significant interactions between species and harvesting year for dry matter, soluble solids, pH, ascorbic acid and FRAP. The results indicate generic ranges in composition within species independent upon growing location and climate, and the composition of the tree fruits and berries is not likely to deviate from these ranges. It is concluded that desirable composition of tree fruits and berries and their products should primarily be achieved by selection among species rather than searching fors broadened variation within individual species.     

疏穗处理对‘赤霞珠’葡萄果粒大小及花色苷积累的影响

疏穗(花序或果穗)是调节产量和负载量的一项葡萄园田间管理措施,广泛应用于优质葡萄生产中,不同时期和程度的疏穗对果实产量和品质影响不同。本研究于2011年以新疆玛纳斯县广东地和园艺场2个地块2000年定植的‘赤霞珠’葡萄为材料,在果实第1个膨大期(花后约3周)分别进行1穗/新梢(CT1)、1.5穗/新梢(CT2)和2穗/新梢(CT3)3个程度的疏穗处理。在采收期对产量相关指标和花色苷进行测定。结果表明,在广东地,3种疏穗处理间平均果穗质量无显著差异,CT1与CT2、CT3相比,产量分别下降48%和65%;在园艺场,3种疏穗处理间平均果穗质量亦无显著差异,但CT3处理的平均果粒质量低于CT1和CT2。将采收期的果粒按质量分为5级,在广东地,果粒大小主要分布于≤0.84g、0.85~1.14g和1.15~1.44g3个质量级次中,在≤0.84g质量级次中,CT1处理果粒所占百分数分别比CT2和CT3低12.4%和18%;在园艺场,果粒大小主要分布于0.85~1.14g、1.15~1.44g和1.45~1.74g 3个质量级次中,在≤0.84g质量级次中,CT3处理的果粒所占的百分数分别比CT2和CT1高18.3%和15.6%。说明疏穗处理后,果粒有增大的趋势。利用HPLC-MS检测各质量级次花色苷的质量分数和组成,发现不同大小的果粒以及经过不同程度疏穗处理的果粒中花色苷的质量分数间存在差异。随着果粒的增大,甲基化花色苷和酰化花色苷的质量分数及总花色苷的每果粒质量(以mg/kg果实鲜质量表示)逐渐降低。在广东地,随着疏穗程度的提高,总花色苷、甲基化花色苷和酰化花色苷的每果粒质量(以μg/果粒表示)和质量分数(以mg/kg果实鲜质量表示)逐渐增加。对不同疏穗处理下果粒各种花色苷的质量分数进行主成分分析显示,地块对果实中花色苷的积累影响较大。     

蓝莓花青素的抗氧化活性研究

[目的]研究蓝莓花青素的抗氧化活性。[方法]采用酸化乙醇提取蓝莓鲜果中的蓝莓花青素,并通过羟自由基、DPPH自由基、H2O2、超氧阴离子自由基及Fe3+清除率试验评价蓝莓花青素的抗氧化能力。[结果]蓝莓花青素对羟自由基、DPPH自由基、H2O2、超氧阴离子自由基及Fe3+清除率随着浓度的增大而增强,其抗氧化活性高于相同浓度的抗坏血酸。[结论]蓝莓花青素具有很高的抗氧化活性,可以作为天然抗氧化剂进行开发。     

富士苹果果实中突触小泡蛋白基因(MdVAMP)的克隆及其表达

花青素是植物中最广泛存在的次生代谢物之一,是不同颜色花和果实色泽的关键色素。花青苷通常在细胞质中合成,于液泡中积累。虽然花青苷的生物合成途径已被深入研究,但它们从细胞质到液泡的转运以及显示红色的机制仍然不清楚。本试验通过RACE技术成功克隆出富士苹果及其芽变中MdVAMP cDNA序列的总长度。该基因cDNA序列全长994 bp,具有660 bp的开放阅读框(ORF),编码219个氨基酸。同源性分析表明,MdVAMP基因与沙梨同源性最高。定量PCR结果表明,MdVAMP基因在‘长富2’苹果及芽变果实摘袋后表达趋势与其花青苷含量变化相一致,芽变果实中MdVAMP基因表达量和花青苷含量均显著高于‘长富2’苹果。进一步在不同富士品种中研究发现,MdVAMP基因表达水平与花青苷含量密切相关。亚细胞定位结果显示MdVAMP主要定位于细胞质。该研究表明,MdVAMP基因可能参与了花青苷的转运和积累,这为进一步研究苹果果皮着色和花青苷转运提供了一定的科学基础。     

基于次生物质对紫玉米花青素合成模型预测(英文)

通过对与紫玉米花青素合成相关的次生物质总酚、类黄酮、苯丙氨酸解氨酶(PAL)、多酚氧化酶(PPO)的测定,建立了紫玉米花青素合成的最优多元线性回归模型为y=4.38386-0.20545x1+5.479638x2+0.195575x4。经标准偏回系数归检验得出:总酚含量与花青素含量呈负相关,对花青素合成的相对影响为-42.7%;类黄酮含量和PPO活性与花青素含量均呈正相关,对花青素合成的相对影响分别为71.45%和73.32%,且均达到了极显著水平;而PAL活性与花色素合成的相关性不显著。该模型的建立能够为花青素的实验室合成提供理论基础,从而也可为用细胞培养的方法大量生产花青素提供理论依据。