复合酶法制备澄清岗稔汁工艺优化

研究了复合酶系对岗稔果汁澄清效果的影响.采用果胶酶与纤维素酶两种酶对岗稔果浆进行酶解处理,以出汁率为评价指标,在单因素试验的基础上,采用L9(34)正交试验设计,对影响果汁酶解效果的酶比例、酶用量、酶解温度及酶解时间进行优化.结果表明:果胶酶与纤维素酶的合用可明显提高岗稔果浆的出汁率,在酶比例2∶1、酶用量0.4％、酶解温度40℃、时间180 min时,酶解效果最好,出汁率可达56.40％,比空白出汁率33.12％高出了23.28％,可溶性固形物可达14.330Birx,功能因子花色苷的含量可达169.28 mg/g鲜果.     

Anthocyanins from ornamental flowers of red frangipani, Plumeria rubra

Two anthocyanins were isolated from ornamental reddish flowers of Plumeria rubra L. (Apocynaceae) by a combination of chromatographic techniques. Their structures were elucidated mainly by the use of homo- and heteronuclear nuclear magnetic resonance spectroscopy and high-resolution electrospray mass spectrometry. The anthocyanin cyanidin 3-O-β-(2″-glucopyranosyl-O-β-galactopyranoside) (75%), has previously been isolated only from Cornus suecica (Cornaceae) fruits, while the other (20%) was identified as cyanidin-3-O-β-galactopyranoside. This is the first report of the anthocyanins responsible for the attractive colours of the flowers of red frangipani.     

无蜡质芥蓝突变型叶表面蜡质超微结构观察

以亮叶无蜡质紫色芥蓝突变型紫.中花芥蓝和多蜡质紫色芥蓝野生型为试材,对芥蓝叶片发育过程中最外层的表面蜡质进行系统地观察,并对无蜡质突变型紫.中花芥蓝、多蜡质野生型芥蓝和普通绿色芥蓝(CK)的干物质量、VC、可溶性糖、粗纤维、蛋白质、花青苷等主要营养成分含量进行测定分析。结果表明:在叶片发育过程中,多蜡质野生型芥蓝的叶面蜡质明显多于无蜡质突变型紫.中花芥蓝;野生型芥蓝和紫.中花芥蓝叶片背面的蜡质均明显多于叶片腹面;野生型芥蓝叶片背面的蜡质退化速度明显慢于叶片腹面。无蜡质突变型紫.中花芥蓝的VC含量高于野生型芥蓝,而粗纤维(DW)含量低于野生型芥蓝,说明紫.中花芥蓝有利于改良现有芥蓝的营养品质,有望育成高VC含量、高花青苷含量、以生食为主的芥蓝品种。芥蓝叶片的无蜡质性状对多蜡质表现为隐性遗传,紫色对绿色表现为显性遗传。     

NO和H2O2依赖Ca2+/CaM信号调控马铃薯花青素积累

以不同块茎颜色马铃薯品种陇薯8号、陇薯7号、LC310-2和山东彩肉为材料,研究外源NO、H2O2、NO+ H2O2处理对马铃薯块茎花青素合成及其信号物质Ca2+-ATPase和CaM的影响.结果表明:外源NO和H2O2处理后,4个基因型马铃薯薯皮和薯肉花青素积累,Ca2+-ATPase活性升高,CaM含量增加,其效果为NO+ H2O2＞H2O2＞NO＞水(CK),并且花青素的积累量与Ca2+-ATPase活性和CaM含量均呈正相关,其平均决定系数达0.9194和0.8859.说明NO和H2O2对马铃薯花青素合成具有一定的促进作用,而细胞Ca2 +/CaM信号发挥了NO和H2O2对马铃薯花青素合成诱导的信号调节.     

不同花色杜鹃花色素成分与稳定性分析研究

[目的]全面分析不同花色杜鹃花的色素成分与稳定性。[方法]以4种不同花色的杜鹃花花瓣(浅红、紫色、白色和粉红色)为试材,对其花色素提取液进行紫外-可见光光谱扫描检测、特征显色反应和稳定性分析。[结果]试验表明,杜鹃不同花色色素不含叶绿素和类胡萝卜素;粉色、浅红色和紫色杜鹃花色素主要由花色素苷和类黄酮化合物组成;白色杜鹃花色素则含非红色的类黄酮化合物以及其他化合物,其花色素不具备邻二酚羟基或邻三酚羟基结构,揭示了杜鹃花色呈现差异的内在本质。紫外-可见光光谱扫描的结果表明,不同花色素溶液中的花色素种类与含量不同。稳定性研究表明,食品添加剂、低价金属离子对色素色泽无不良影响,但碱性环境、氧化还原剂以及Fe3+、Al3+均对其稳定性影响较大,探明了有利于杜鹃花色素稳定的环境条件。[结论]研究可为杜鹃花色素的分离鉴定奠定基础,同时也为天然杜鹃花色素的科学利用提供理论依据。     

花色苷生物合成关键酶基因在植物基因工程中的应用

文中主要论述了花色苷的合成途径及途径中所涉及的关键酶基因在植物基因工程中的应用,为花色苷在基因工程的应用提供基础资料。     

Metabolite profiling of colored rice (Oryza sativa L.) grains

HPLC analysis of dehulled red, black and non-colored indica and japonica rice subspecies revealed significant differences in the contents of the anthocyanins cyanidin-3-glucoside and peonidin-3-glucoside. The rice materials were subjected to a comparative capillary gas chromatography-based metabolite profiling approach. The employed extraction and fractionation protocol enables the analysis of a broad spectrum of lipophilic and hydrophilic low molecular weight constituents from different chemical classes. The method covers not only primary metabolites (e.g. sugars, fatty acids) but also nutritionally relevant constituents (e.g. α-tocopherol, γ-aminobutyric acid). Statistical assessment of the data via principal component analysis and agglomerative hierarchical clustering revealed a distinct grouping of the different colored rice subspecies on the basis of their metabolite profiles. Compared to non-colored and red rice, black rice exhibited, in particular, higher levels of fatty acid methyl esters, free fatty acids, organic acids and amino acids.     

Isolation and identification of phase II enzyme inductors obtained from black Shawaya sorghum [Sorghum bicolor (L.) Moench] bran

The antioxidant capacity as oxygen radical absorbance capacity (ORAC) and in vitro chemopreventive effect of phytochemicals extracted, partitioned and isolated from the decorticated bran of black Shawaya sorghum (Sorghum bicolor L. Moench) was studied. The chemopreventive effect was evaluated as the induction effect of quinone reductase (QR) using murine hepatoma cells Hepa 1c1c7. The crude methanol extract with an antioxidant capacity of 3.7 μmol Trolox equivalent (TE)/mg was partitioned into 120 fractions with fast centrifugal partition chromatography (FCPC). Fractions with partition coefficients between 0.1 and 0.26 exerted more than 50% of the antioxidant activity of the original crude extract and contained the highest concentration of anthocyanins. No correlation was found for ferulic acid content and ORAC or chemoprevention. A derivative of 7-methoxyapigeninidin at a concentration of 1 μg/ml increased by 31% the QR activity while the original extract reached a maximum of 27% at 40 μg/ml.     

蓝莓果中花青素的乙醇提取工艺研究

[目的]确定蓝莓果中花青素的最佳提取工艺。[方法]以蓝莓果为原料,采用单因素试验考察了乙醇浓度、提取次数、物料比、提取时间、提取温度、pH对花青素提取量的影响。在此基础上,通过正交试验考察花青素的最佳提取工艺。[结果]蓝莓果中花青素的乙醇提取最佳工艺条件为：60%乙醇、提取温度50℃、pH值1、物料比1∶15、提取时间120 min、提取1次,得到的花青素提取量为2.18 g/L。[结论]该工艺操作简单、成本较低、环境友好,具有很好的应用前景。     

A study of biodiversity of flavonoid content in the rice caryopsis evidencing simultaneous accumulation of anthocyanins and proanthocyanidins in a black-grained genotype

Rice genotypes with pigmented caryopses have received increased attention because of their antioxidant properties. Previous works evidenced that the kernel of red rice is characterized by the presence of proanthocyanidins, whereas black rice is characterized by the presence of anthocyanins. In the present study, the total antioxidant capacity (TAC) and the polyphenol content of the caryopsis were evaluated on a set of Italian rice varieties (three white, two black and five red ones). The pigmented rices, on average, had a TAC four times higher than the white ones. As expected, red-grained genotypes contained no detectable anthocyanins and one black rice contained no detectable proanthocyanidins. However, the black-grained cv. Artemide had large amounts of both proanthocyanidins and anthocyanins. This genotype was also characterized by the highest TAC and polyphenol content: its TAC was about twice the TAC of the other pigmented rices, and it had a polyphenol content 2–3 times the content found in the other pigmented rices. Pigmented genotypes are confirmed to be very interesting to breed rice for high polyphenol content and TAC. Furthermore, the possibility to select for genotypes accumulating both anthocyanins and proanthocyanidins provides a way to substantially increase the polyphenol content and TAC of the rice caryopsis.