橙皮中类胡萝卜素的提取工艺研究

[目的]确定溶剂法提取橙皮中类胡萝卜素的最佳工艺条件。[方法]以橙皮为原料,采用溶剂法提取其中的类胡萝卜素,通过单因素试验考察浸提溶剂种类、浸提料液比、浸提温度、浸提时间对类胡萝卜素得率的影响,再通过正交试验确定橙皮中类胡萝卜素提取的最优工艺。[结果]单因素试验得出,以丙酮为浸提溶剂,料液比为1∶15 g/ml,浸提温度为60℃,浸提时间为60 min时,类胡萝卜素得率最高。正交试验最终确定影响橙皮中类胡萝卜素提取的因素主次顺序依次为提取温度>料液比>提取时间,最优提取工艺条件为提取温度60℃,料液比为1∶20 g/ml,浸提时间为60 min。在该条件下,类胡萝卜素的得率达到97.3 mg/kg。[结论]该研究可为橙皮的综合利用提供借鉴和依据。     

海洋红酵母的研究进展

海洋红酵母是海洋中广泛存在的一种单细胞酵母品系,富含丰富的蛋白质、类胡萝卜素、维生素和消化酶类等多种活性物质,是极具潜力的食品和饲料添加剂,应用前景广阔.介绍了海洋红酵母的种类与特性、自身营养组成、多样性、代谢产物及开发应用的研究进展,并提出了有关红酵母研究应重点解决的几个关键问题.     

植物类胡萝卜素生物合成及其调控与遗传操作

类胡萝卜素是生物体内通过类异戊二烯途径合成的、自然界广泛存在的一大类天然色素物质的总称。近年来,类胡萝卜素生物合成基因的分离和功能鉴定与有关类胡萝卜素生物合成调控机制研究的新进展,使通过遗传操作调控植物体内类胡萝卜素生物合成途径成为可能。本文主要综述了近年来类胡萝卜素生物合成及其调控研究的进展,并介绍了应用转基因技术改变植物体内类胡萝卜素成分与含量的成功事例。     

观赏植物花色基因工程的研究进展

介绍了观赏植物花色素的种类、显色影响因素、类黄酮类色素和类胡萝卜素的生物合成途径以及利用基因工程改变花色的国内外进展．同时简单阐述了花卉基因工程中存在的问题和应用前景。     

甘薯中类胡萝卜素提取工艺

[目的]探求甘薯中类胡萝卜素的最佳提取工艺,以实现甘薯的综合利用。[方法]采用紫外可见分光光度计测定不同溶剂、料液比、浸提时间、浸提温度条件下提取所得类胡萝卜素溶液的吸光值,并以此作为指标来考察甘薯中类胡萝卜素提取的最佳工艺。[结果]试验得出,甘薯中类胡萝卜素的最佳提取溶剂为乙酸乙酯、最佳料液比为1∶25 g/m L、最佳浸提时间为50 min、最佳温度为50℃,此条件下类胡萝卜素的取得率达到135.5 mg/kg。[结论]该方法简便,试验设备简单、操作方便、安全性较大,而且甘薯在我国分布广泛,来源丰富,价格低廉,可为今后的类胡萝卜素提取研究以及甘薯的综合利用奠定基础。     

“半封闭温室小气候改变对番茄发育及果实产量和保健化合物含量的交互影响”论文评述

针对气候变暖导致温室冬夏两季极端温度多发，尤其是夏季平均温度过高和相对湿度降低的
问题，以及这种小气候变化如何影响温室番茄生长和品质的问题，德国科学家提出一种新的温室小气候调
控策略，并撰文报道了为期2 a 的研究结果，本文介绍和评述了该项研究。在较高环境温度和伴随的高平
均温度情况下，可应用高压雾系统结合CO₂ 施肥的方法降低温室内温度，提高相对湿度和CO₂ 浓度。与
常规气候条件下的番茄相比，新温室小气候调控策略能有效促进植株生长，增加叶片干物质质量，优化每
个花序的产量构成，使总产量提高20%，脐腐病发生程度减轻，在春季试验还能显著增大果实；新温室小
气候调控策略能显著促进次生代谢物的形成，番茄红素、β- 胡萝卜素、酚类化合物含量分别提高49%、
35% 和16%，非水溶性和水溶性组分抗氧化活性分别提高18.5% 和35.4%。因此，新温室小气候调控策
略可提高番茄总产量及品质，有利于保健化合物的形成。     

Changes in pigments and plastid ultrastructure during ripening of green-fleshed and yellow-fleshed kiwifruit

Fruit of Actinidia deliciosa have green flesh when ripe, whereas fruit of Actinidia chinensis often have yellow flesh when ripe. The outer and inner pericarps of A. deliciosa fruit retain their chlorophyll during ripening. In those fruit of A. chinensis that become yellow on ripening, the colour change is caused by the disappearance of chlorophylls unmasking the yellow carotenoids already present, rather than by increased synthesis of carotenoids. In fruit of A. deliciosa and those fruit of A. chinensis that remain green, the chloroplasts retain their typical morphology during ripening, whereas in fruit of A. chinensis that become yellow during ripening the chloroplasts of the immature green fruit are transformed into fully developed chromoplasts.     

The influence of carotenoid biosynthesis modification on the Fusarium culmorum and Fusarium oxysporum resistance in flax

Flax engineering to yield increased resistance to pathogens is the goal of this study. Since carotenoids act as antioxidants it is thus postulated that the accumulation of a higher quantity of these compounds in the transgenic plants might improve their resistance to pathogen infection.Our approach was based on the generation of transgenic flax overproducing carotene and analysis of its susceptibility to Fusarium infection. For transformation bacterial gene – crtB was used. As expected, transgenic plants showed increased resistance against pathogen infection.The impact of carotenoids on plant resistance to infection was verified by generation and analysis of transgenic flax with decreased content of carotene. The transgenic plants were obtained by suppression of endogenous flax gene coding for lycopene β-cyclase. Plant analysis revealed decrease in carotene content, however, an unexpected increase in resistance against Fusarium infection was detected. Further analysis of metabolites in the plants revealed that an increase in accumulation of other terpenoids and tocopherols, squalene and menthol were among them. Thus, it is suggested that repression of carotene synthesis results in the redirecting of substrates to other branches of isoprenoids synthesis.We conclude that a general level of antioxidants rather than the presence of any particular compound is the most important factor in resistance of the flax plant to pathogen infection.     

番茄红素β环化酶基因（Lyc-β）RNAi载体构建及表达鉴定

从番茄(Lycopersicun esculentum Mill)提取总RNA,根据GenBank中番茄红素β环化酶基因(Lye-β)序列(X86452),经mRNA反转录扩增出2段Lyc-β基因高度保守的300 bp DNA 片段,从β-葡萄糖苷酶基因(gusA)中扩增出170 bp的内含子片段.分别将两段不同的Lyc-β片段的正、反向序列与内含子连接,构建出两套干扰Lyc-β基因的植物表达载体.经根癌农杆菌(Agrobacterium tumefaciems)介导转化番茄,22 株转基因植株通过荧光定量PCR分析干扰效果,结果显示,2套干扰载体的干扰效率表现出一定的差异,Lyc-β基因mRNA平均含量分别为对照的11.78%和13.86%,进一步用HPLC分析转化株的番茄红素含量,结果表明,转基因植株中番茄红素的含量最高可达13.84 μg/g FW,是对照的4.26倍.     

不同蜜柚果肉颜色类胡萝卜素成分及含量比较

采用HPLC技术对果肉色泽不同的黄金蜜柚、红肉蜜柚、琯溪蜜柚的类胡萝卜素的组成及含量进行比较分析.结果表明,黄金蜜柚汁胞呈色成分主要为β-胡萝卜素、八氢番茄红素、α-胡萝卜素、β-隐黄质和番茄红素,含量分别为218.83、22.95、4.17、2.96、2.86 μg·g-1,类胡萝卜素总量达到251.77 μg·g-1·dw-1,分别是红肉蜜柚和琯溪蜜柚的2.6倍和287.7倍.