不同遮阴条件下红花檵木叶色变化与色素的关系

以红花檵木为研究对象,设置全光照、25%遮阴、50%遮阴和75%遮阴四个处理,测定叶片内叶绿素、类胡萝卜素质量分数及花青素质量摩尔浓度和叶色参数(L、a、b值),研究其叶色与色素质量分数(或质量摩尔浓度)间的内在联系。结果表明:红花檵木叶色和色素质量分数(或质量摩尔浓度)在全光照条件下变化不明显;25%、50%和75%遮阴使叶色以不同程度由紫红色向绿色变化,叶色参数a值明显减小,但L值和b值没有明显变化规律。花青素质量摩尔浓度显著下降,叶绿素、类胡萝卜素质量分数以不同速率增加。相关性分析发现,a值与各色素质量分数(或质量摩尔浓度)间均呈极显著相关关系,但L值、b值与各色素质量分数(或质量摩尔浓度)间没有表现出明显的相关性;叶色参数a与色素相对质量分数(或质量摩尔浓度)的回归模型为Y(a值)=10.071+8.006X1(花青素相对质量摩尔浓度)-15.398X2(叶绿素相对质量分数)+13.066X3(类胡萝卜素相对质量分数),F检验达0.01显著水平。     

Enzymatic treatment to enhance carotenoid content in dehydrated marigold flower meal

The effect of enzymatic treatments using a commercial enzyme (Econase-cep at pH 5.0 and 0.1% w/w concentration) at different levels of dehydrated marigold meal (5, 10, 15 and 20% dry weight), to enhance carotenoid extraction, was evaluated. The AOAC method consisting of a simultaneous extraction and saponification by using hexane-ethanol-acetonetoluene (10:6:7:7 v/v) and metanolic KOH (40% w/v) was used to evaluate the carotenoid content. The measurement of carotenoids was also carried out in samples in which the water soluble compounds were previously eliminated (AOAC-H₂O). Total carotenoids ranged from 11.4 to 17. 4 g/kg and 18 to 24.7 g/kg of control and treated marigold meal, respectively. Highest amount of carotenoids were noted when 5% level of treated meal was used.     

Nutritional and toxic factors in selected wild edible plants

Nutritional (ascorbic acid, dehydroascorbic acid and carotenes); antinutritional and toxic components (oxalic acid, nitrate and erucic acid) were determined in sixteen popular species of wild edible plants which are collected for human consumption in southeast Spain. Ascorbic+dehydroascorbic acids contents were very high in several species, especially in Chenopodium album L. (155 mg/100 g). Carotenoid content ranged from 4.2 mg/100 g (Stellaria media Villars) to 15.4 mg/100 g (Amaranthus viridis L.). A range of values was found for oxalic acid from absence to 1100 mg/100 g of plant material. Nitrate contents ranged from 47 mg/100 g ( Salicornia europaea L.) to 597 mg/100 g (Amaranthus viridis L.). Low amounts of erucic acid were found in the Cruciferae family (Sisymbrium irio L. 1.73%; Cardaria draba L. 1.23%) and Plantago major L. 3.45%.     

Composition and variation in vitamin C,carotenoids, protein,nitrate and oxalate contents inCelosia leaves

Twenty two lines/accessions belonging to 5 species ofCelosia were analysed for their nutritional and antinutritional composition. The nutrient contents, vitamin C varied from 18.8 to 53.6 mg/100 g, carotenoids 9.1 to 15.1 mg/100g, protein 2.1 to 5.9%, while the antinutritional factors, nitrate 0.18 to 0.46% and oxalate 0.98 to 3.93%. Moisture ranged 81 to 89%. Variation of these parameters with leaf position and the amino acids profile of some promising lines was also evaluated.     

转苜蓿MsOr基因烟草光合-光响应和光合-CO2响应曲线特征研究

为明确苜蓿（Medicago sativa）Orange基因的表达对植物光合作用的影响,以转Orange（MsOr）基因型烟草（TOR1与TOR2）和野生型烟草（WT）为研究材料,采用盆栽控制试验,比较研究了WT,TOR1和TOR2叶片光响应曲线和CO₂响应曲线,并测定其叶片类胡萝卜素含量。结果表明：直角双曲线修正模型可较好地拟合烟草光响应曲线和CO₂响应曲线;在一定光合有效辐射强度和CO₂浓度范围内,随光强和CO₂浓度增加,TOR1和TOR2的净光合速率均显著高于WT（P<0.05）;TOR1和TOR2的最大净光合速率、光饱和点、CO₂饱和点、羧化效率、暗呼吸速率和光呼吸速率显著高于WT,而CO₂补偿点显著低于WT（P<0.05）;TOR1和TOR2的叶片总类胡萝卜素含量约为WT的2倍。研究表明：苜蓿MsOr基因的表达促进了烟草植株叶片类胡萝卜素的积累,同时提高了其光能和CO₂利用能力,增强了植株对高光强、高CO₂浓度环境的适应能力。     

西瓜瓤类胡萝卜素研究进展

西瓜瓤颜色差异缘于所含类胡萝卜素种类与数量的不同。分析它们在不同品种西瓜中的组成,研究造成这种差异的遗传背景与色素的生物合成途径,可促进西瓜营养育种及其类胡萝卜素应用开发。西瓜类胡萝卜素分析最初是通过开放柱色谱法进行,当前多用高效液相色谱法,由于分辨率低或缺少标准样品,目前,2种方法都还得不到满意结果。色素分析结果表明,红色瓤西瓜主含番茄红素,橙黄色瓤主含ζ-胡萝卜素、前番茄红素与β-胡萝卜素,白色瓜含有六氢番茄红素、β-与ζ-胡萝卜素。基因型、染色体倍数、环境条件及果实成熟度影响西瓜中番茄红素含量。西瓜瓤颜色受几个基因控制,每个基因位点有2或3个等位基因。目前,已从西瓜中分离出类胡萝卜素合成途径几种酶的cDNA全长及基因片段。根据所发现的类胡萝卜素种类与基因分析结果,提出西瓜类胡萝卜素的可能生物合成途径。     

高效液相色谱法测定苹果果皮的类胡萝卜素

用高效液相色谱法测定苹果果皮多种类胡萝卜素。以丙酮与石油醚提取色素 ,用NovapakC18(4 .6mm×15 0mm)色谱柱 ,乙腈∶甲醇∶二氯甲烷 (70∶2 0∶10 )流动相 ,在 45 0nm下检测类胡萝卜素。结果表明 ,玉米黄质、叶黄素、番茄红素与 β 胡萝卜素的回收率分别是94.2 7%～ 99.82 %、84.5 6 %～ 89.41%、87.5 3～ 93.5 4%与 88.0 8%～93 .2 4%。其中富士果仅检测到玉米黄质 (5 .9× 10 -3 μg/mm2 )与 β 胡萝卜素 (5 .4× 10 -3 μg/mm2 ) ;蛇果 (红星 )只有玉米黄质 (9.1× 10 -3 μg/mm2 )。     

Total carotenoid and beta-carotene contents of forest green leafy vegetables consumed by tribals of south India

Seventy edible wild forest green leafy vegetables (GLV) collected andconsumed by tribals of Andhra Pradesh, India were analyzed for totalcarotenoids (TC) and beta carotene (BC) contents using high performanceliquid chromatography (HPLC). The vitamin A activity expressed as retinolequivalents (RE) was calculated based on in vivo conversion factorgiven by WHO. The results of the study indicated that thirty-six GLV werefound to have high vitamin A activity (0.87 to 2.34 RE) with TC and BCcontents ranging from 12.22 to 36.13 and 5.21 to 14.05 mg %,respectively; thirty GLV had moderate vitamin A activity (0.36–0.8 RE)with TC and BC contents ranging from 10.60 to 31.33 and 2.19 to 4.78 mg %.Four GLV contained low vitamin A activity (0.07–0.32 RE); – TC and BCcontents ranging from 5.12 to 13.13 and 0.40 to 1.94, respectively. Thepercent beta carotene in total carotenoids among the three groups of theGLV varied from 19.41 to 73.02, 11.11 to 46.21 and 5.98 to 37.11,respectively.     

Analysis of nutritional components of eight famine foods of the Republic of Niger

In the western Sahel, indigenous plants become important staples when cereal harvests are inadequate to support populations inhabiting that region of Africa. The purpose of this study was to assess the nutrient content of several of these edible wild plants. The leaves of the following seven plant foods were analyzed: Ziziphus mauritiana, Cerathotheca sesamoides, Moringa oleifera, Leptadenia hastata, Hibiscus sabdarifa, Amaranthus viridi, and Adansonia digitata. The fatty acid, vitamin E, carotenoid, selected mineral and amino acid contents of these plant foods were determined. These same analyses were performed on the fruit of the Adansonia digitata. In quantitative and qualitative terms, Amaranthus viridis was found to be an excellent source of protein. Its amino acid composition compared favorably to that of a World Health Organization (WHO) protein standard. It also contained considerable amounts of the two fatty acids that are essential in humans (linoleic and -linolenic) and a number of minerals including iron, magnesium, calcium and zinc. The leaves of Hibiscus sabdarifa contained an appreciable quantity of protein the composition of which was comparable to the WHO standard. The mineral content of the leaves of this plant was also exceptionally high; noteworthy was its high zinc content. H. sabdarifa also contained significant quantities of the two essential fatty acids. Ziziphus mauritiana was an excellent source of the essential fatty acid linoleic acid and several of the metals including iron, calcium, magnesium and zinc. Its content of other essential nutrients, however, was rather low. In general, Adansonia digitata leaves were nutritionally superior to the fruit of the tree; however, the fruit did contain useful quantities of potassium, phosphorus, zinc and -linolenic acid. The Leptadenia hastata leaves were an especially good source of lutein and -carotene. These data should be useful to the people who inhabit the western Sahel in helping them devise healthy diets during times when cereal staples are in short supply.     

Carotenoid composition and heterotic effect in selected Italian maize germplasm

Maize (Zea mays L.) is a promising crop for improving the nutritional quality of foods, because of the presence of broad natural variability for the content of carotenoids. One hundred Italian and nine public lines were screened by PCR to identify the alleles of Hydroxylase3 (HYD3) and Lycopene epsilon cyclase (LCYE) genes, codifying for key enzymes of the carotenoid pathway and associated with high or low β-carotene contents. Nineteen selected genotypes carrying different alleles were grown in 2011 and/or 2012, and used to obtain F1 seeds. HPLC analysis highlighted the richness in zeaxanthin and β-cryptoxanthin of Italian germplasm (mean values 12.63 and 2.88 mg/kg d.m., respectively). The percentage of positive and significant mid parent heterosis (MPH) and best parent heterosis (BPH) values (51% and 29%) indicated the presence of a high heterotic response for carotenoids. The compounds on the same branch of the pathway were found to be positively correlated; on the contrary, no consistent correlation was observed between the different HYD3 alleles and β-carotene content. Finally, total antioxidant capacity (TAC) was also measured. These lines resulted therefore as interesting raw materials for the market of maize-based foods.