Recent Progress of Flower Colour Modification by Biotechnology

Genetically-modified, colour-altered varieties of the important cut-flower crop carnation have now been commercially available for nearly ten years. In this review we describe the manipulation of the anthocyanin biosynthesis pathway that has lead to the development of these varieties and how similar manipulations have been successfully applied to both pot plants and another cut-flower species, the rose. From this experience it is clear that down- and up-regulation of the flavonoid and anthocyanin pathway is both possible and predictable. The major commercial benefit of the application of this technology has so far been the development of novel flower colours through the development of transgenic varieties that produce, uniquely for the target species, anthocyanins derived from delphinidin. These anthocyanins are ubiquitous in nature, and occur in both ornamental plants and common food plants. Through the extensive regulatory approval processes that must occur for the commercialization of genetically modified organisms, we have accumulated considerable experimental and trial data to show the accumulation of delphinidin based anthocyanins in the transgenic plants poses no environmental or health risk.     

The fate of flavanol–anthocyanin adducts in wines: Study of their putative reaction patterns in the presence of acetaldehyde

Methylmethine bridged flavanol–anthocyanin dimeric adducts (F–A) were synthesised by hemisynthesis using catechin, acetaldehyde and F–A adducts as precursors in order to simulate putative reactions undergoing in red wine. The products obtained, catechin–methylmethine–catechin–malvidin-3-O-glucose and methylmethine-(catechin–malvidin-3-O-glucose)₂, were analysed by HPLC–ESI-MS. The fragmentation patterns allowed the confirmation of the structures. These compounds were investigated and found in wine samples (2-year-old table wine and 10-year-old Port wine), thus confirming their formation in vino as a result of flavanol–anthocyanin adducts transformations.     

提取条件对蓝靛果花色苷抗氧化活性的影响

为研究提取条件对蓝靛果花色苷抗氧化活性的影响,用溶剂浸提法提取蓝靛果花色苷,通过正交试验确定其最佳提取工艺条件,分别采用紫外分光光度法、H2O2/Fe 体系和DPPH 法测定花色苷的提取量及其抗氧化活性。结果表明,提取溶剂为体积分数70% 的乙醇溶液、料液比1:15(g:mL)、提取温度60℃、提取时间90min、pH2、提取3 次为最佳提取工艺参数,在此提取工艺条件下,花色苷含量吸光度为0.789,羟自由基清除率为18.92%,DPPH 自由基清除率为41.57%。     

紫甘薯饮料制备工艺研究

以紫甘薯为原料探讨紫甘薯饮料制备的工艺条件。比较α- 淀粉酶液化和高温液化两种方式对淀粉液化的效果,并进一步添加糖化酶进行淀粉糖化,同时探讨各工序对花色苷的影响,以饮料的可溶性固形物增长率、吸光度及色差值为考察指标。结果表明：鲜薯用两倍水打浆,加入0.020g/100mL α- 淀粉酶于70℃条件下酶解40min,再添加0.04g/100mL 的糖化酶在pH5.0 条件下糖化40min,既可获得理想的淀粉水解效果,又可尽量减少花色苷的损失。较好的饮料配方为30% 甘薯原汁、8% 蔗糖、0.05% 柠檬酸,其余为软水。采用该工艺条件可制备色香味俱佳的紫甘薯饮料。     

Overall Quality and Shelf Life of Minimally Processed and Modified Atmosphere Packaged "Ready-to-Eat" Pomegranate Arils

ABSTRACT:  Minimally processed ready-to-eat pomegranate arils have become popular due to their convenience, high value, unique sensory characteristics, and health benefits. The objective of this study was to monitor quality parameters and to extend the shelf life of ready-to-eat pomegranate arils packaged with modified atmospheres. Minimally processed pomegranate arils were packed in PP trays sealed with BOPP film under 4 atmospheres including low and super atmospheric oxygen. Packaged arils were stored at 5 °C for 18 d and monitored for internal atmosphere and quality attributes. Atmosphere equilibrium was reached for all MAP applications except for high oxygen. As a general trend, slight or no significant change was detected in chemical and physical attributes of pomegranate arils during cold storage. The aerobic mesophilic bacteria were in the range of 2.30 to 4.51 log CFU/g at the end of the storage, which did not affect the sensory quality. Overall, the pomegranate arils packed with air, nitrogen, and enriched oxygen kept quality attributes and were acceptable to sensory panelists on day 18; however, marketability period was limited to 15 d for the low oxygen atmosphere. PP trays sealed with BOPP film combined with either passive or active modified atmospheres and storage at 5 °C provided commercially acceptable arils for 18 d with high quality and convenience.     

杨梅中主要花色苷的组成与结构

采用V(甲醇)∶V(甲酸)=19∶1溶液提取杨梅中的花色苷,并用阳离子交换树脂初步纯化得到杨梅花色苷提取物,然后以水-正丁醇-甲基叔丁基醚(TBME)-乙腈-三氟乙酸(TFA)(体积比5∶2∶1.5∶1∶0.001)为溶剂系统,用高速逆流色谱对杨梅花色苷进行分离。再由C18柱色谱纯化后,得到2种主要的花色苷单体Ⅰ和Ⅱ。经ESI-MS和NMR鉴定为矢车菊色素-3-β-吡喃型葡萄糖苷(Ⅰ)和飞燕草色素-3-葡萄糖苷(Ⅱ)。另外,文中对3个杨梅品种的花色苷组成进行了分析,结果表明,矢车菊色素-3-β-吡喃型葡萄糖苷是杨梅花色苷的主要组成成分,占花色苷总量的90%以上。     

花色苷提取、分离纯化及鉴定的研究进展

花色苷是高等植物中最重要的水溶性色素。因其种类繁多、来源广泛、安全无毒并有一定的营养和保健功效而引起国内外的广泛关注,具有十分重要的开发价值和广阔的应用前景。近年来,有关花色苷的研究一直是国内外研究的热点。文中系统地介绍了国内外花色苷提取、分离纯化及鉴定的研究方法,并对各种方法进行了分析评价。     

黑糯米酒中总花色苷测定方法的研究

以黑糯米酒为研究对象,对黑糯米酒花色苷的测定方法进行了研究。结果表明,pH示差法、单一pH法和差减法所测标准曲线的相关系数R2分别为0.997 7、0.998 5、0.999 4,线性关系均较好,均可用于测定黑糯米酒中总花色苷含量。3种方法测定黑糯米酒花色苷的平衡温度为30 ℃,平衡时间为40 min,测定波长为511 nm。单一pH法和差减法的最适pH值为0.8,pH示差法最适pH值为0.8和4.5。3种方法可直接测定黑糯米酒总花色苷含量,且精密度良好,其中pH示差法精密度最高,相对标准偏差（RSD）为0.83%。pH示差法加标回收率试验结果RSD为0.38%,表明该优化条件后的方法可靠、准确,适用于黑糯米酒中总花色苷测定。