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排序方式: 共有106条查询结果,搜索用时 15 毫秒
1.
Mexican pigmented maize (Zea mays L.) landrace kernels have been scantily evaluated regarding potential as functional food. In this study, eight Mexican pigmented (yellow and red) maize accessions of Tuxpeño, Tabloncillo and Chapalote landraces collected in the northwestern region of Mexico were processed into tortilla to determinate carotenoid profiles, as well as their Oxygen Radical Absorbance Capacity for Lipophilic extract (ORAC-L). The total carotenoid content ranged from 3.66 to 5.56 mg LE/kg DW in the yellow maize and from 1.49 to 3.49 mg LE/kg DW in the red maize among all raw genotypes. Lutein and zeaxanthin were major carotenoids in all pigmented maize, accounting for ∼85% of total carotenoids. The traditional nixtamalization and lime-cooking extrusion process significantly (p < 0.05) decrease total carotenoid and ORAC-L assays when compared to raw kernels. Traditional tortillas retained among 72.0–87.6% and 65.1–78.8% of total carotenoids and ORAC-L levels respectively, compared to 68.8–79.5% and 60.3–75.5% assayed in extruded tortillas. Interestingly, traditional and extruded tortillas maintained more 72.7 and 60%, respectively; of the lutein concentration associated with raw grains. Our results suggest that yellow maize landrace could be considered for the elaboration of nixtamalized food products with nutraceutical potential.  相似文献   
2.
Maize kernel color and carotenoid concentration are traits valued by the food industry to ensure the quality of their products. Correlations between color and carotenoid concentration have been extensively reported. Based on the concept that chromaticity is modified differently by opaque and translucent materials, we tested the hypothesis that maize kernel color is not only the result of total carotenoid concentration but also a consequence of kernel hardness. Kernel hardness (test weight, vitreousness, and floaters percentage), carotenoid concentration, and color (HunterLab) were measured in thirteen commercial hybrids. Genotypes showed significant differences in all analyzed kernel hardness traits, carotenoid concentration (24.7–39.4 mg kg−1), and HunterLab color dimensions. Kernel color values and kernel hardness were correlated. Genotype differences in b (yellowness) were observed in kernels with similar total carotenoid concentration but contrasting hardness. For a similar carotenoid concentration harder genotypes always showed lower b values. When whole kernels were milled and color was measured on the resulting flour, genotype differences in yellowness disappeared, further supporting that the kernel vitreous structure affects kernel color. Our results sustain the notion that the genotype capacity to form larger proportions of vitreous endosperm impacts color regardless of total carotenoid concentration.  相似文献   
3.
综述了近年来国内外在类胡萝卜素与草坪草耐荫性研究的进展,阐述了类胡萝卜素的分子结构及分类、生理功能、遗传基因、提取的方法和目前国内外研究草坪草耐荫的进展,探讨了将类胡萝卜素中色素的比值作为一种新的指标的可行性,并对该领域存在的问题和今后的发展趋势作了分析,以期为草坪草耐荫性研究提供参考。  相似文献   
4.
Stress conditions experienced during growth may affect plant responses during post-harvest storage and eventually determine the overall quality of commercial products. In this context, we hypothesized that foliar applications of proline during the growth cycle and light exposure during post-harvest storage could be two important modulators of yield and quality parameters of rocket plants exposed to NaCl stress. Dry matter percentage increased upon NaCl treatment. However, fresh weight loss during storage did not change over time as a consequence of salt stress. High salinity (100 mM NaCl) moderately reduced both leaf nitrate (14%) and nitrite (3%) contents. Lipophilic (LAC) and hydrophilic (HAC) antioxidant activities also decreased by 10% at the highest salinization (average of two growth cycles). In contrast, during storage, LAC decreased whereas HAC increased. Proline applications reduced the leaf nitrate content during storage by 16%, increased carotenoids and chlorophyll contents in salinized plants and also increased the ascorbate leaf concentration in both salinized and non-salinzed plants. Light storage enhanced fresh weight loss in contrast to dark storage. However the exposure to light reduced leaf nitrate levels by 7% (average of two growth cycles) and contributed to maintain high leaf ascorbate concentrations over time.  相似文献   
5.
Aluminum (Al) and cadmium (Cd) are two elements that contaminate soil in different ways as waste products of some industrial processes and that can be tolerated by some plant species in different concentrations. In this study, growth parameters of leaves and stems (fresh and dry weights, stem lengths, leaf surface area, and lamina thickness), anatomical changes in leaves (lower and upper epidermis, stomata and mesophyll tissue), and photosynthetic pigment contents (chlorophyll a and b, total chlorophyll, and carotenoids) were investigated in cotton (Gossypium hirsutum L. cv. Nazilli 84S), which was treated with Al and Cd for 3 months. Cotton seedlings were grown in greenhouse conditions and watered with Hoagland nutrient solutions, which contained 0, 100, and 200 μM aluminum chloride (AlCl3) and cadmium chloride (CdCl2). It was observed that reduced soil pH positively affected many parameters in cotton plants. Aluminum accumulation was greater in leaves than stems while the opposite was true for Cd accumulation. Leaves and stems of cotton plants treated with 100 and 200 μM Al and Cd showed slight growth changes; however, high concentrations of Al (200 μM) caused significant reductions in leaf area and leaf fresh weight, whereas stem fresh weight decreased with 200 μM Cd treatment. Anatomical parameters were mostly affected significantly under both concentrations of Al and Cd solutions (100 and 200 μM). The results revealed that the anatomical changes in the leaves varied in both treatments, and the long-term effect of the tested metals did not include harmful effects on anatomical structures. Moreover, the variations could be signals of tolerance or adaptive mechanisms of the leaves under the determined concentrations.  相似文献   
6.
Carotenoids and flavonoids are the main tomatoes antioxidants, having an important role for human health. This study investigates the effects of different water regime and of the industrial processing on the concentration of these compounds in tomato fruits and in tomato products. Two biotypes of Corbarini small tomatoes were cultivated in the Sarno valley (Salerno, Italy) using three different water regimes. A biochemical characterization of the fresh and of the corresponding canned products was performed. Results show that water regime influenced the antioxidant profile of tomato fruits, with marked differences between the two biotypes. Data obtained highlight that water regime markedly influenced the productivity and the quality of the tomatoes. Results also demonstrated that industrial process increased carotenoids content without causing a significant flavonoids degradation.  相似文献   
7.
’Fuji’ apples (Malus domestica Borkh cv. ‘Fuji’) sometimes develop a discolouration in the peel during cold storage, typically in the periphery of sunburned peel. We refer to this particular postharvest disorder as ‘Fuji’ stain as we have not observed it in any cultivar other than ‘Fuji’ and the discolouration looks like a stain on the peel. Because peel discolouration occurs, peel pigments are thought to be involved. Hence the concentrations of anthocyanins, epicatechin, quercetin glycosides, chlorogenic acid, chlorophylls, and carotenoids in peel disks taken from areas exhibiting ‘Fuji’ stain were compared to concentrations observed in peel disks not exhibiting ‘Fuji’ stain. In 2005, peel from sunburned apples exhibiting ‘Fuji’ stain was compared to peel from three areas of sunburned apples not exhibiting stain [i.e. sunburned peel, the area around the sunburned peel (halo), and the area around the halo (OH)]. Additionally, stained peel was compared to the sun-exposed side of non-stained non-sunburned apples (NSNB). The second year, 2006, we compared stained peel to NSNB peel and the area outside the stained area (OS) on those fruit with stain. The concentrations of idaein, epicatechin, and quercetin glycosides were consistently low in the stained peel both years. This is in contrast to our earlier studies in which sunburned ‘Fuji’ apples had high concentrations of quercetin glycosides and epicatechin and low concentrations of idaein, and non-sunburned apples had low concentrations of quercetin glycosides and epicatechin and high concentrations of idaein. The consistent and unique characteristic of stained peel reported here indicates an association of these compounds with the incidence of stain. In 2005, chlorogenic acid concentrations in the stain peel were lower than other peel types, but in 2006 they were higher. Differences in chlorophyll and carotenoid concentrations were observed among many of the peel types. However, there is not a clear association between stain development and changes in chlorophyll and carotenoid concentrations due to significant differences not being observed in both years. While our research provides insight into pigment changes associated with ‘Fuji’ stain formation, more work is needed to help clarify the inconsistencies observed between the 2 years.  相似文献   
8.
《Journal of plant nutrition》2013,36(10-11):2137-2148
Abstract

The present work is aimed at evaluating some effects induced by different levels of iron availability in the growth medium for two different tomato (Lycopersicon esculentum Mill.) genotypes, the T3238fer (Tfer), unable to activate mechanisms for iron mobilization and uptake known as “strategy I,” and its correspondent wild‐type T3238FER (TFER). By using different iron concentration in the growth solution, the most suitable iron level to induce phenotypic differences between the two genotypes without being lethal for the mutant was found to be 40 µM Fe‐Na‐EDTA. The analyses were carried out also on plants grown with 80 µM Fe‐Na‐EDTA, an iron concentration at which the two genotypes showed no phenotypic differences. A significant decrease in total leaf iron and chlorophyll content was detected in both genotypes following reduction of iron concentration in the nutrient solution, and was particularly evident in Tfer40, which showed symptoms of chlorosis. The photo‐electron transport rate of the whole chain was significantly affected by growth conditions as well as by genotype, the lowest activity being detected in Tfer40 plants. Chlorophyll a fluorescence analysis revealed an increase in non‐photochemical quenching (q NP) of Tfer plants grown at both iron concentrations, indicating the activation of photoprotective mechanisms, which, however, were not sufficient to prevent photoinhibition when plants were grown at 40 µM iron, as indicated by significant reduction in PSII photochemistry (F v/F m) and photochemical quenching (q P). The actual quantum yield of PSII (ΦPSII) and the intrinsic PSII efficiency (ΦEXC) showed the same behavior of q P and F v/F m ratio. A significant effect of mutation and iron supply on all the pigments was detected, and was particularly evident in the mutant grown at 40 µM iron. A different behavior was shown by the three pigments involved in the xantophyll cycle, violaxanthin being less affected than chlorophylls and the other carotenoids, and zeaxanthin even increasing, due to the xanthophyll cycle activation. In conclusion, the interaction between iron deprivation and fer mutation induced functional alterations to the photosynthetic apparatus. Anyway, as far as concerns the photo‐electron transport activity, the influence of fer mutation seemed to occur independently from iron supply.  相似文献   
9.
应用免疫荧光标记法结合激光扫描共聚焦显微镜术对油杉花粉管中的微管、微丝骨架进行观察.结果表明:伸长的花粉管大致可分为3个区,即位于顶端的管细胞区、体细胞区和其后的退化区;花粉管中微管与微丝的分布样式不同;微管骨架主要分布于管细胞区和体细胞区,而退化区的微管较稀疏;管细胞区内微管呈网状结构,微管一直延伸至花粉管极顶端;体细胞具独立的微管系统.花粉管内微丝骨架呈轴向排列于整个花粉管,自花粉粒内一直延伸至花粉管顶端,粗微丝束几乎平行于花粉管的长轴.本研究结果为进一步研究微管与微丝骨架系统在油杉花粉管顶端极性生长中的作用提供依据.  相似文献   
10.
Einkorn (Triticum monococcum L. subsp. monococcum) is an ancient wheat appreciated for its high proteins, carotenoids and tocols content. To better understand its potential for human consumption and food preparation, composition and pasting properties of 65 einkorn accessions, of different geographical origin but cultivated at S. Angelo Lodigiano (Italy), were evaluated. Eight Triticum turgidum and seven Triticum aestivum cultivars, belonging to different subspecies, were assessed as controls.On average, the einkorn samples had light seeds (25.0 mg/kernel), extra-soft texture (238.3 g), high protein content (18.2%), high ash content (2.35%), low SDS sedimentation volume (25.6 ml), high carotenoids (8.36 μg/g) and high yellow pigments (8.46 μg/g). The pasting parameters studied were peak viscosity (average: 2426 cP), breakdown (765 cP), final viscosity (2788 cP) and setback (1126 cP). Total amylose (25.7%) and total starch (65.5%) were also measured. Significant differences from the controls and a broad variation for all the traits analysed were observed. Einkorns from diverse geographical areas showed different mean values for all characters, apart from ash content.The good pasting properties, coupled with high proteins and carotenoids content, suggest that einkorn is particularly suited for the production of baby and specialty foods.  相似文献   
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