天然食品添加剂玉米黄色素的研究进展

介绍了玉米黄色素的功能和提取方法的进展,并分析了玉米黄色素的发展趋势。     

玉米黄色素的提取和分析

使用超临界CO2法从水解玉米蛋白粉中提取玉米黄色素.通过单因素实验和正交实验优化了超临界CO2萃取玉米黄色素的工艺条件,并通过HPLC检测提取物中玉米黄素和叶黄素的含量.结果表明:超临界CO2提取玉米黄色素的最佳条件为:萃取时间2 h,CO2流速35 kg/h,萃取压力30 MPa,萃取温度45℃,夹带剂15%无水乙醇,此时玉米黄色素产量为210.97 μg/g.     

微波辅助萃取从玉米中提取黄色素的研究

研究了以玉米为原料,用微波辅助萃取技术从玉米中提取黄色素;通过改变溶剂、玉米目数、微波提取温度、提取时间等条件,考察了对玉米黄色素提取效果的影响。正交实验结果表明:玉米黄色素提取效果受温度影响比较大,时间次之,目数的影响较小;优化工艺条件为以95%乙醇为溶剂,液料比为10∶1mL/g,原料目数80目,浸提温度70℃,提取时间11min。在此条件下,提取液的吸光度可达0.658。     

玉米黄色素的提取工艺研究

研究了以玉米淀粉厂副产品玉米黄粉为原料提取玉米黄色素的工艺 .以无水乙醇为萃取剂一次提取率 >84% ,液体产品吸光度 E1 %1 cm(44 5 nm )为 4.0     

玉米黄色素的提取——玉米渣皮的综合利用之一

玉米渣皮是玉米淀粉加工中的下脚料,含有天然色素和其他可食性成分.本文从浸提溶剂、温度、时间及提取次数等方面探讨了自玉米渣皮中提取玉米黄色素的最佳工艺条件,确定了色素提取的工艺路线.     

玉米蛋白粉综合利用研究

通过对玉米淀粉厂副产品（玉米蛋白粉）酶解,除臭处理后,可以提取食品级天然黄色素和广泛用于食品医药行业的辅料玉米醇溶蛋白,该工艺反应条件温和,易于工业化生产,并可显著提高玉米蛋白粉的附加值。     

巴旦杏壳天然黄色素提取及其稳定性研究

巴旦杏壳是巴旦杏加工过程中的废弃物,利用水/乙醇为浸提剂,在75℃,浸提时间为2 h,料液比为1 g∶15 mL条件下,可提取巴旦杏壳黄色素及木质素。对提取出的黄色素稳定性进行了研究,结果表明,杏壳黄色素在避光条件下的稳定性较好,日光照射会影响黄色素稳定性;杏壳黄色素在一定温度下稳定性较好,但当温度达到85℃时,吸光度明显下降;蔗糖、pH对杏壳黄色素稳定性有影响;Na+、K、Ca2+、Mg2+等金属离子对杏壳黄色素稳定性没有明显影响,而Cu2+、Al3+对杏壳黄色素稳定性影响较大;氧化剂对杏壳黄色素稳定性影响较大;还原剂Vc对杏壳色素稳定性影响不大。     

羟基红花黄色素A稳定性研究

羟基红花黄色素A为红花黄色素制剂中活血化瘀的主要有效成分,为了保证该制剂中有效成分的含量,利用高效液相色谱法研究了温度、光照、抗坏血酸、EDTA、微量金属离子等对羟基红花黄色素A稳定性的影响。结果显示:光照和温度对羟基红花黄色素A的稳定性影响比较大。当温度高于60℃,加热一定时间后,羟基红花黄色素A就会发生水解;在避光条件下,羟基红花黄色素A有较好的稳定性。Fe3+,Fe2+对羟基红花黄色素A的含量都有不同程度的影响;微量的EDTA和抗坏血酸可明显的提高羟基红花黄色素A的稳定性。     

玉米淀粉麸质水的综合利用

生产玉米淀粉,在分离粗淀粉乳后会产生大量的麸质水下脚料。对这些下脚料,经沉降、过滤、干燥处理,可得含粗蛋白40％～60％、淀粉10％～15％、水分约12％的玉米蛋白粉。这种蛋白粉一般均作为优质饲料使用,十分可惜。若以麸质水为原料,通过深加工便可获得植酸钙、植物黄色素、酱油和饲料,效益十分可观。     

油菜花中黄色素的提取及稳定性研究

对不同试剂提取油菜花中的黄色素的效果作了比较，并研究了这种黄色素的稳定性。结果表明用乙醚提取效果最好，这种黄色素耐碱、耐热性好、对Na^ 、Ca^2 、Zn^2 、Mg^2 稳定。．     

Overexpression of beta-carotene hydroxylase enhances stress tolerance in Arabidopsis

Plant stress caused by extreme environmental conditions is already a principal reason for yield reduction in crops. The threat of global environment change makes it increasingly important to generate crop plants that will withstand such conditions. Stress, particularly stress caused by increased sunlight, leads to the production of reactive oxygen species that cause photo-oxidative cell damage. Carotenoids, which are present in the membranes of all photosynthetic organisms, help protect against such light-dependent oxidative damage. In plants, the xanthophyll cycle (the reversible interconversion of two carotenoids, violaxanthin and zeaxanthin) has a key photoprotective role and is therefore a promising target for genetic engineering to enhance stress tolerance. Here we show that in Arabidopsis thaliana overexpression of the chyB gene that encodes beta-carotene hydroxylase--an enzyme in the zeaxanthin biosynthetic pathway--causes a specific twofold increase in the size of the xanthophyll cycle pool. The plants are more tolerant to conditions of high light and high temperature, as shown by reduced leaf necrosis, reduced production of the stress indicator anthocyanin and reduced lipid peroxidation. Stress protection is probably due to the function of zeaxanthin in preventing oxidative damage of membranes.     

Molecular cloning, in vitro expression and enzyme activity analysis of violaxan-thin de-epoxidase from Oryza sativa L.

The violaxanthin de-epoxidase gene was cloned from rice (Oryza sativa subsp. japonica). The full length of the cDNA is 1887 bp, encoding a 446-amino acids protein with the transit peptide of 98 amino acids. The bacterial expression vector pET-Rvde was constructed and the expression quantity of the exogenous protein increased with the induction time by 0.4 mmol/L IPTG. Its molecular weight was similar with that of the native VDE. Western blotting indicated that the expressed protein has immunological reaction with the VDE polyclonal antibody. The absorbance spectrum together with xanthophyll pigments quantification by HPLC demonstrated that the expressed VDE has its enzyme activity, which can de-epoxidate violaxanthin into antheraxanthin and zeaxanthin in vitro.     

Molecular cloning, in vitro expression and enzyme activity analysis of violaxanthin de-epoxidase from Oryza sauva L.

The violaxanthin de-epoxidase gene was cloned from rice (Oryza sauva subsp japonica). The full length of the cDNA is 1887 bp, encoding a 446-amino acids protein with the transit peptide of 98 amino acids. The bacterial expression vector pET-Rvde was constructed and the expression quantity of the exogenous protein increased with the induction time by 0.4 mmol/L IPTG. Its molecular weight was similar with that of the native VDE. Western blotting indicated that the expressed protein has immunological reaction with the VDE polyclonal antibody. The absorbance spectrum together with xanthophyll pigments quantification by HPLC demonstrated that the expressed VDE has its enzyme activity, which can de-epoxidate violaxanthin into antheraxanthin and zeaxanthin in vitro.     

玉米黄素的分析检测

玉米黄素是类胡萝卜素的一种，其分子结构与叶黄素极为相似，且在自然界中以多种构型存在，因此它的定量、定性分析显得较为繁琐。本文对近几年来玉米黄素分析上所用的方法（主要是HPLC）进行了综述，包括样品的预处理、流动相、固定相的选择、所选用的分析系统以及与其它方法的联用情况。     

Phot1 and phot2 mediate blue light regulation of stomatal opening.

The stomatal pores of higher plants allow for gaseous exchange into and out of leaves. Situated in the epidermis, they are surrounded by a pair of guard cells which control their opening in response to many environmental stimuli, including blue light. Opening of the pores is mediated by K(+) accumulation in guard cells through a K(+) channel and driven by an inside-negative electrical potential. Blue light causes phosphorylation and activation of the plasma membrane H(+)-ATPase that creates this potential. Thus far, no blue light receptor mediating stomatal opening has been identified, although the carotenoid, zeaxanthin, has been proposed. Arabidopsis mutants deficient in specific blue-light-mediated responses have identified four blue light receptors, cryptochrome 1 (cry1), cryptochrome 2 (cry2), phot1 and phot2. Here we show that in a double mutant of phot1 and phot2 stomata do not respond to blue light although single mutants are phenotypically normal. These results demonstrate that phot1 and phot2 act redundantly as blue light receptors mediating stomatal opening.     

夏季东海陆架浮游植物类群结构对不同风场条件的响应分析

为探讨东海的主要物理过程对浮游植物生物量和类群结构的时空分布影响,采用高效液相色谱法分析2006年和2011年夏季东海陆架条件下的浮游植物光合色素的组成及含量,并通过CHEMTAX对浮游植物群落的结构进行分析。结果表明,不同风场条件下东海浮游植物生物量和类群结构均有显著差异。在2006年夏季航次,受弱西北风的控制,长江冲淡水向外延伸面积较大,东海陆架叶绿素a的平均浓度为1 228.6ng/L,主要特征光合色素多甲藻素(Peri)、19-己酰基氧化岩藻黄素(19-hex)、19-丁酰基氧化岩藻黄素(19-but)、玉米黄素(Zea)和二乙烯基叶绿素a(DV-Chl.a)相对较高,浮游植物以硅藻(41%)和甲藻(16%)为主要优势类群;2011年夏季航次,受强东南风影响,底层低温高盐水涌升现象明显,东海陆架叶绿素a(Chl.a)的平均浓度(2 677.9ng/L)比2006年高一倍,叶绿素b(Chlb.)、青绿藻素(Prasino)、新黄素(Neo)和别藻黄素(Allo)等光合色素浓度相对较高,硅藻(60%)在浮游植物群落中占主要优势。     

Relationships between D1 protein, xanthophyll cycle and photodamage-resistant capacity in rice (Orysa sativa L.)

Relationships between D1 protein, xanthophyll cycle and subspecific difference of photodamage-resistant capacity have been studied in O. japonica rice varieties 02428 and 029 (photoinhibition-tolerance) and O. indica rice varieties 3037 and Palghar (photoinhibition-sensitivity) and their reciprocal cross F1 hybrids after photoinhibitory treatment. It was shown that PSⅡ photochemical efficiency (Fv /Fm) decreased, and xanthophyll cycle from violaxanthin (V), via anaxanthin (A), to zeaxanthin (Z) was enhanced and non-photochemical quenching (qN) increased accordingly in SM-pretreated leaves of rice when the synthesis of D1 protein was inhibited, and that there was a decrease in qN and, as a result, more loss of D1 protein and a big decrease in Fv /Fm in DTT-pretreated leaves when xanthophyll cycle was inhibited. O. japonica subspecies had a higher maintaining capacity of D1 protein and a decrease of Fv /Fm in a more narrow range, and exhibited more resistance against photodamage, as compared with O. indica subspecies. The above physiological indexes in reciprocal cross F1 hybrids, though between the values of their parents, were closer to maternal lines than to paternal lines. Experimental results support the concept that the turnover capacity for D1 protein is an important physiological basis of photoinhibition-tolerance, and will provide the physiological basis for selection of the photoinhibition-tolerant parents and develop a new approach to breed hybrids with high photosynthetic efficiency.     

Relationships between D1 protein, xanthophyll cycle and photodamage-resistant capacity in rice (Orysa sativa L.)

Relationships between D1 protein, xanthophyll cycle and subspecific difference of photodamage-resistant capacity have been studied inO. japonica rice varieties 02428 and 029 (photoinhibition-tolerance) andO. indica rice varieties 3037 and Palghar (photoinhibition-sensitivity) and their reciprocal cross F₁ hybrids after photoinhibitory treatment. It was shown that PS II photochemical efficiency (F _v /F _m) decreased, and xanthophyll cycle from violaxanthin (V), via anaxanthin (A), to zeaxanthin (Z) was enhanced and non-photochemical quenching (qN) increased accordingly in SM-pretreated leaves of rice when the synthesis of D1 protein was inhibited, and that there was a decrease inqN and, as a result, more loss of D1 protein and a big decrease inF _v/F _m in DTT-pretreated leaves when xanthophyll cycle was inhibited.O. japonica subspecies had a higher maintaining capacity of D1 protein and a decrease ofF _v/F _m in a more narrow range, and exhibited more resistance against photodamage, as compared withO. indica subspecies. The above physiological indexes in reciprocal cross F₁ hybrids, though between the values of their parents, were closer to maternal lines than to paternal lines. Experimental results support the concept that the turnover capacity for D1 protein is an important physiological basis of photoinhibition-tolerance, and will provide the physiological basis for selection of the photoinhibition-tolerant parents and develop a new approach to breed hybrids with high photosynthetic efficiency.     

基于能力源课程套件的遥控小车系统构建

利用能力源课程套件中的结构件、电气组件等构建遥控小车,小车驶离出发区后,其搬运机构变形伸出,增加运载能力。遥控可控制小车前行、后退、转弯、搬运等,指示灯显示小车的运行状态。用连续无故障运行时间表征小车的可靠性。试验数据显示,小车的可靠性大约为12.4小时,其运载能力为5分钟搬运19个球。最终,以5min搬运18个球夺得比赛冠军,比赛数据与前期试验数据吻合。