Provitamin A Crops: Acceptability, Bioavailability, Efficacy and Effectiveness

Vitamin A deficiency (VAD) is the world’s commonest cause of childhood blindness. More than half of these cases occur in developing countries. Animal sourced foods though good sources of vitamin A are too expensive for poor rural people. Crops biofortified with provitamin A offer a convenient and accessible source of vitamin A. The other micro-nutrient programs of fortification and supplementation require more expensive inputs. Biofortification programs have developed crops that are rich in provitamin A. These crops include: maize, golden rice, cassava and orange fleshed sweetpotato (OFSP). With exception of golden rice, the rest of the biofortified crops have received considerable acceptance among the communities. Both animal and human studies have shown that provitamin A from biofortified crops is highly bioavailable and have capacity to improve vitamin A status. After several years of research and promotion, it is time to fully commercialize provitamin A crops by encouraging farmers to start their large scale production and consumption.

Provitamin D Doped Silica and Polymeric Films: New Materials for UV Biosensor

The original technologies of growing silica films, impregnated with 7-dehydrocholesterol (provitamin D3) on quartz substrates and free transparent films on the basis of polyvinyl alcohol and polyvinyl butyral have been developed. Provitamin D photoisomerization in the films under UVB irradiation was investigated by UV absorption spectroscopy. Remarkable changes in the absorption spectrum of 7-DHC were observed in silica and polyvinyl alcohol films as com-pared with ethanol solution, only in polyvinyl butyral film the spectrum was very nearly, while the spectral kinetics of 7-DHC photoisomerization in all the films was different from ethanol. We suggest that several films have potential as UV dosimeters to measure accumulated ‘antirachitic’ UV dose in the same manner as erythemic UV dose is measured by commonly used polysulphone film.

Genetics of carotenoids for provitamin A biofortification in tropical-adapted maize

Yellow maize contains high levels of β-carotene(βC), making it an important crop for combating vitamin A deficiency through biofortification. In this study, nine maize inbred lines were selected at random from 31 provitamin A(PVA) maize inbred lines and crossed in a partial diallel mating design to develop 36 crosses. The crosses were evaluated in the field in two locations(Samaru and Kerawa) and their seed carotenoid content were determined by high-performance liquid chromatography. The modes of gene action, heritability, and correlations between agronomic traits and carotenoid content were estimated. Additive genetic variances(σ~2a) were lower than non-additive genetic variances(σ~2d) for all the carotenoids, plant height(PH), and grain yield(GY), suggesting a preponderance of non-additive gene action. Broad-sense heritability(H^2) was high(H^2> 60%) for zeaxanthin,days to anthesis, and PH, moderate(30% < H^2< 60%) for lutein and GY, and low(H^2< 30%)for alpha carotene, beta cryptoxanthin, βC, and PVA. Genetic advance as a percentage of mean, considered with H^2, also suggests a preponderance of non-additive gene action for PVA carotenoids. Hybrid variety development is thus an appropriate approach to improving grain yield and PVA. GY showed no significant genotypic correlations with carotenoid content, suggesting that these traits can be improved concurrently. Thus, there is ample scope for improvement of PVA and GY in the sample of tropical-adapted maize.

Photoisomerization of Provitamin D in Hydrogel Matrix

Study of interfacial processes between incorporated biomolecules and hydrogel matrix is of primary importance for the application of synthetic hydrogels as biomaterials, sensors, etc. Their hydrophilic nature, however, hampers fat-soluble biomolecule incorporation. We synthesized N-isopropylacrylamide (NIPAAm)- and Acrylamide (AA)-based hydrogels with hydrophilic-lipophilic balance that under specific conditions permit homogeneous incorporation of provitamins D3(7-dehydrocholesterol) and D2(ergosterol) dissolved in ethanol. Similarity of provitamins D photoisomerization in such hydrogel matrices with the photoreaction in ethanol shows great potential of the novel material for personal dosimetry of biologically active ‘antirachitic’ UV radiation.

Installing the neurospora carotenoid pathway in plants enables cytosolic formation of provitamin A and its sequestration in lipid droplets

Vitamin A deficiency remains a severe global health issue,which creates a need to biofortify crops with provitamin A carotenoids(PACs).Expanding plant cell capacity for synthesis and storing of PACs outside the plastids is a promising biofortification strategy that has been little explored.Here,we engineered PAC formation and sequestration in the cytosol of Nicotiana benthamiana leaves,Arabidopsis seeds,and citrus callus cells,using a fungal(Neurospora crassa)carotenoid pathway that consists of only three enzymes converting C5 isopentenyl building blocks formed from mevalonic acid into PACs,including β-carotene.This strategy led to the accumulation of significant amounts of phytoene and γ-and β-carotene,in addition to fungal,health-promoting carotenes with 13 conjugated double bonds,such as the PAC torulene,in the cytosol.Increasing the isopentenyl diphosphate pool by adding a truncated Arabidopsis hydroxymethylglutaryl-coenzyme A reductase substantially increased cytosolic carotene production.Engineered carotenes accumulate in cytosolic lipid droplets(CLDs),which represent a novel sequestering sink for storing these pigments in plant cytosol.Importantly,β-carotene accumulated in the cytosol of citrus callus cells was more light stable compared to compared with plastidialβ-carotene.Moreover,engineering cytosolic carotene formation increased the number of large-sized CLDs and the levels of β-apocarotenoids,including retinal,the aldehyde corresponding to vitamin A.Collectively,our study opens up the possibility of exploiting the high-flux mevalonic acid pathway for PAC biosynthesis and enhancing carotenoid sink capacity in green and non-green plant tissues,especially in lipid-storing seeds,and thus paves the way for further optimization of carotenoid biofortification in crops.

甜玉米乳熟期籽粒维生素A源和维生素E组分的变异

维生素A和维生素E是人与动物必须从食物中摄取的微量营养物质。甜玉米是人类直接食用的一种鲜食玉米类型。本研究利用高效液相色谱法测定了47份甜玉米自交系籽粒乳熟期的维生素A源和维生素E各组分的含量。结果表明,不同基因型甜玉米材料间维生素A源和维生素E各组分及α/γ-生育酚存在显著差异。非维生素A源的叶黄素和玉米黄质为维生素A组分中的主要成分,γ-生育酚为维生素E组分中的主要成分。相关分析表明多数性状间表现为显著正相关或不相关,其中β-胡萝卜素极显著正相关于玉米黄质、β-隐黄质和α-类胡萝卜素,维生素E各组分两两极显著相关,α/γ-生育酚极显著负相关于δ-生育酚和γ-生育酚,极显著正相关于玉米黄质和α-生育酚,β-胡萝卜素与α-生育酚呈正相关。这些数据为进一步研究甜玉米籽粒中维生素A源和维生素E的代谢和微营养品质的改良提供了有益的表型数据。

导入高VA原玉米种质产量配合力及杂种优势群分析

【目的】研究导入高VA原玉米种质产量配合力,并根据配合力对其杂种优势群归类进行分析。【方法】采用NCⅡ遗传交配设计对25个导入高VA原玉米种质和3个测验种配制75个杂交组合,在云南省3种不同生态环境下对这些杂交组合进行农艺性状和产量配合力分析,评价导入高VA原玉米种质的利用潜力,再根据产量SCA效应分析被测种质的所属类群。【结果】YML1626(L5)、YML1619(L7)、YML16-5(L9)、YML162-3(L13)产量GCA效应值较高。选育过程中要获得产量GCA较高的高VA原玉米育种材料,至少要对4个穗部性状进行优级选择。以SCA正向显著水平临界值(5.49)为阀值划分杂种优势群,有6个被测系归类不确定;以SCA负向显著水平临界值(-5.49)划分杂种优势群,有12个被测系归类不确定。以被测系与3个测验种之间的最小负向SCA效应值为划分标准,可能导致杂种优势群归类出现误差。【结论】导入高VA原玉米种质YML1626、YML1619、YML16-5、YML162-3产量GCA效应值较高,在育种中具有较高的利用价值。一个利用价值较高的自交系至少有4个穗部优良性状。以SCA正向显著水平临界值为阀值划分杂种优势群,更容易解释被测系的杂种优势群归类。

松针维生素原浓缩物中精油化学成分的研究

松针维生素原浓缩物中的精油(90℃～130℃馏份)其量约为维生素原浓缩物的15％。该精油用色谱-质谱-计算机联用仪定性分析和毛细管色谱测定各组分的相对含量,从分离出的59个色谱峰中鉴定出21个化学成分。其中主要成分为反-石竹烯(42.36％),α-蒎烯(10.72％),乙酸龙脑酯(6.81％),长叶烯(6.18％),和α-钴钯烯(5.55％)等,鉴定出的组分占全精油量的90.85％。松针维生素原浓缩物中的精油化学组成和含量,不同于松树嫩枝叶经水蒸汽法蒸馏得到的精油化学组成和含量,引起这种差别的原因,可能是由于生物活性物质在加工时,维生素原浓缩物精油中轻馏份受到损失和中间馏份和重馏份受到氧化之故。

维生素D原体浓度对它的光异构反应的影响

目的：研究乙醇溶液中维生素 Ｄ 原体浓度对它的光异构反应产物产率的影响。方法：用两种紫外光激发光源光照不同浓度的维生素 Ｄ 原体乙醇溶液，使用正相 Ｈ Ｐ Ｌ Ｃ 系统定量测定主要光异构物在溶液中的浓度。结果：数据表明，随维生素 Ｄ 原体浓度的增加，速甾醇产率减少，而光甾醇产率明显增加。维生素 Ｄ 前体产率变化，与所用的激发光源有关。结论：维生素 Ｄ 原体浓度对其光异构反应产物产率的影响较大，特别对速甾醇和光甾醇，利用光自吸收效应有助于设计光化学法合成药物及制备高产率的光异构产物。

High-Yielding and Carotenoid-Rich Clones Identification among Thirty-One Cassava Clones with Colored Flesh

Cassava is the second most important food crop produced and consumed in Côte d’Ivoire, after yam. White-fleshed varieties, which are low in total carotenoids, are widespread, while coloured-fleshed varieties (yellow to orange), carotenoid-rich, are rare. However, the consumption of carotenoid-rich cassava varieties could help to alleviate health problems related to vitamin A deficiency. This study aims to identify high agronomic performance, carotenoid-rich and versatile cassava varieties among 31 clones introduced from IITA. They were compared to three controls, Bocou2, Yacé and Bonou2, according to agronomic and technological parameters. Results found that out of the 31 clones, six (I082425, I084157, I084563, I085894, I083774 and I070520) were more productive than the control Bocou2 (46.01 ± 14.88 t·ha-1);the clone I083774 had the highest yield (55.88 ± 6.16 t·ha-1). Twenty-one clones had dry matter contents, ranging from 37% to 41%, significantly similar to Yacé control (42.70%). Thirteen clones had highest total carotenoid contents than the control Bocou2. Clones I084157 and I082425 recorded the highest total carotenoid contents with 17.57 ± 1.92 and 18.39 ± 1.19 μg·g-1 respectively. Overall 31 tested clones were fibrous to varying degrees while 27 clones had mild or neutral post-cooking flavours and 17 clones had poor cooking. The clone I084157 is the best compromise of agronomic and technological desired traits.

Metabolic Engineering of Carotenoid Formation in Carrot Roots

Carotenoids, a large class of yellow, orange and red pigments accumulate in the chloroplasts of leaves or in the chromoplasts of many flowers and fruits as well as carrot roots. In plants, carotenoids function as

The Power of Integrative Approaches to Develop Markers for Maize Molecular Breeding

Recent advances in genomics and bioinformatics now offer real opportunities for dissecting complex traits into their component sub-traits, which will simplify the process of developing the tools necessary to

The Or Gene Enhances Carotenoid Accumulation and Stability During Post-Harvest Storage of Potato Tubers

Provitamin A carotenoids in staple crops are not very stable during storage and their loss compromises nutritional quality. To elucidate the fundamental mechanisms underlying carotenoid accumulation and stability, we investigated transgenic potato tubers that expressed the cauliflower Orange （Or） gene. We found that the Or transgene not only promoted retention of 13-carotene level, but also continuously stimulated its accumulation during 5 months of cold storage. In contrast, no increased levels of carotenoids were observed in the tubers of vector-only controls or a yellow- flesh variety during the same period of storage. The increased carotenoid accumulation was found to be associated with the formation of lipoprotein-carotenoid sequestering structures, as well as with the enhanced abundance of phytoene synthase, a key enzyme in the carotenoid biosynthetic pathway. Furthermore, the provitamin A carotenoids stored were shown to be stable during simulated digestion and accessible for uptake by human intestinal absorptive cells. Proteomic analysis identified three major functional groups of proteins （i.e. heat shock proteins, glutathione-S-transferases, and carbohydrate metabolic proteins） that are potentially important in the Or-regulated carotenoid accumulation. Our results show that regulation of carotenoid sequestration capacity is an important mechanism by which carotenoid stability is regulated. Our findings suggest that induction of a proper sink structure formation in staple crops may provide the crops with a unique ability to promote and/or stabilize provitamin A accumulation during plant growth and post-harvest storage.

Breeding Major Cereal Grains through the Lens o~ ~iutrition Sensitivity

Cereal grains are the common food staples that collectively provide over 50% of dietary calories and proteins for the world＇s population. Although the Green Revolution has greatly increased the yield of commercial cereal crops, they often lack nutrients essential for human health in the edible tissues. In developing nutrition-sensitive agriculture, the nutritional quality of cereal grains has been a major target for improvement using breeding and biotechnology approaches. This review examines recent progress on biofortification of micronutrients （provitamin A and folates） and an essential amino acid （lysine） in three major cereal grains, wheat, rice, and maize, through plant breeding. In addition, how natural variations, induced mutations, and the advanced genome-editing technologies can be applied to improving the nutrient content and stability in these cereal grains are discussed. High-yield cereal crops pyramided with improved （micro）nutrient contents hold great promise to meet the increasing demand of nutritionally limited popula- tions and to contribute to achieving sustainable nutrition security.

Physicochemical,microbiological and sensory properties of low fat yoghurt fortified with carrot powder

Yoghurt is considered as a healthy food and incorporating carrot powder will make it even healthier.Carrot powder is a good source of beta carotene and provitamin A.The objective of this study was to determine the effects of adding carrot powder on the physicochemical,microbiological and sensory properties of low fat plain yoghurt.Plain and carrot yoghurt were prepared in the laboratory scale production using low fat milk.Carrot yoghurt was prepared by blending low fat milk with 1%,2%and 3%carrot powder before fermentation.Physicochemical analysis revealed a decrease in pH value and an increase in titratable acidity,viscosity and total soluble solids with the increase of carrot powder.On the other hand,protein content decreased with the increase of carrot powder.In terms of the lightness(L*)and the redness(a*),3%carrot yoghurt had low values of lightness while it had higher values of redness.Microbial count showed the significant difference between the 3%carrot yoghurt and 1%and 2%carrot yoghurt.There was a significant difference on the sensory scores of colour and aroma of carrot yoghurt and plain yoghurt as the carrot yoghurt got higher scores than plain yoghurt.There was no significant difference(p<0.05)between the acceptability of the plain yoghurt,1%and 2%carrot yoghurt and a significant difference was there between 3%.Thus,fortifying yoghurt with 1%and 2%carrot powder produced acceptable yoghurt with beneficial health effects.