Characterization of by-products of sunflower culture – commercial applications for stalks and heads     

V. Marechal  L. Rigal 《Industrial Crops and Products》1999,10(3):293-200

The by-products of sunflower production were characterized. The sunflower heads contain a strong smelling essential oil (EO) (0.2%) and pectins (22%). The galacturonic acid (GA.A.) content of the pectins depends on the extraction conditions (water-soluble pectins: 67%, soluble in ammonium oxalate/oxalic acid: 74%, in hydrochloric acid: 33%). They are all slightly methylated (degree of methylation (DM) <20%). The stalks may be readily separated into two parts: fiber (external part, 90%) and the pith (internal part, 10%). The mechanical properties of paper pulp obtained by thermomechanical treatment in a twin-screw extruder of the whole stalks or depithed stems were investigated. The pulps had high values of ring crush test (RCT) and concora medium test (CMT), which make them suitable for the manufacture of cardboard. Low-density materials can be also shaped with ground pith. The role of water-soluble substances in the cohesion of these materials is discussed. Its mechanical properties, which are comparable to those of polystyrene, were determined. They may find application in the packaging and packing industries.  相似文献   

用离子交换法从柚皮中提取果胶的研究   总被引：6，自引：1，他引：6  

戴玉锦  王凤仙  张筱娟 《安徽农业科学》2006,34(3):562-564

通过单因素实验和正交实验,研究了用离子交换法从柚皮中提取果胶的工艺条件。结果表明,离子交换法提取柚皮果胶的最佳工艺条件是:732阳离子交换树脂用量7%,提取液酸度pH值2.0,提取温度85℃,提取时间2.5 h,料液比1∶30。此工艺条件下,果胶得率为22%。  相似文献   

苎麻果胶合成重要酶UGlcAE基因的克隆及组织表达     

刘建新  喻春明  唐守伟  朱爱国  王延周  朱四元  马雄风  熊和平 《作物学报》2008,34(11):1938-1945

以苎麻[Boehmeria nivea (L.) Gaud]中苎1号为材料,采用简并RT-PCR法、RACE技术以及全长cDNA文库筛选,克隆苎麻果胶主要多糖组分的合成关键酶UGlcAE cDNA序列,序列长度为1 257 bp,编码区长723 bp,可编码241个氨基酸序列。实时定量PCR证实,UGlcAE表达量为根部＞叶片＞韧皮部＞木质部,在根部的表达量占优势。该结果对我们后期采用分子生物学方法来调控果胶的合成量具有实际意义。  相似文献   

微波辅助萃取法快速测定苎麻果胶含量的研究     

熊重铎  李海燕  曾庆福 《安徽农业科学》2008,36(7):2610-2612

采用微波辅助萃取法测定苎麻中的果胶含量,研究了苎麻粒径、液料比、微波功率、微波辐照时间、萃取次数等因素对微波辅助萃取果胶的影响。结果表明:苎麻浸泡20 min后,在微波功率450 W、苎麻粒径1.0 cm、液料比为1∶20(g/ml)条件下进行微波辅助萃取,辐照时间每次6 min,连续萃取2次后可达到GB5889-86中苎麻果胶的测定效果。试验将萃取时间从国标法的3 h缩短到12 min,测定的相对标准偏差为2.23%,并采用咔唑比色法对微波辅助萃取液中所含果胶进行了分析。  相似文献   

灵武长枣果实发育成熟期生理生化变化     

魏天军  窦云萍 《农业科学与技术》2008,9(2):18-22

笔者对灵武长枣在采前发育成熟期的果肉硬度、水溶性糖、酸和维生素C、淀粉含量等变化规律以及采后呼吸强度的变化进行研究,旨在为灵武长枣果实发育生理、采后贮藏保鲜、新品种选育和栽培管理提供科学依据。  相似文献   

芦柑皮中果胶提取研究   总被引：2，自引：0，他引：2  

吴环 《安徽农业科学》2012,(7):3982-3983,3991

[目的]研究从芦柑皮中提取果胶的最佳方法。[方法]以烘干的芦柑皮粉末为原料,采用酸水解乙醇沉淀法提取果胶,并应用L9(34)正交试验对提取条件进行了优化。[结果]确定最佳提取条件为pH 2.0、提取温度80℃、提取时间70 min、料液比1∶30 g/ml,在此条件下果胶平均得率为16.60%,果胶纯度为87.6%,甲氧基果胶含量为76.8%。[结论]为芦柑皮的综合利用和我国果胶自主生产提供了参考。  相似文献   

梨黑星病抗性机理的研究进展   总被引：1，自引：0，他引：1  

张海娥乐文全  张新忠 《华北农学报》2007,22(B10):239-242

综述了梨黑星菌的分化类型、侵入机制、抗性遗传及抗性机理的研究进展。梨黑星菌在叶片中寄生的具体位置是果胶层。V．nashicola对抗性、易感和非寄主材料的初期侵染相似，当真菌侵入角质层之后，亚角质层菌丝在易感材料中的增长速率远远高于抗性和非寄主材料，并且在抗性和非寄主材料上出现死亡菌丝，这些都表明抗性是在真菌侵入角质层之后表达的。梨黑星病抗性等位基因和敏感性等位基因定位于不同的连锁基因组上，梨黑星病抗性基因与苹果黑星病抗性基因具有同源性。  相似文献   

Developmental changes in cell wall polysaccharides from sweet cherry (Prunus avium L.) cultivars with contrasting firmness     

《Postharvest Biology and Technology》2013

Firmness is a major quality attribute of fresh cherries, and is also a main factor affecting susceptibility to bruising and postharvest rots. In order to identify the factors determining the textural differences between genotypes, we evaluated the solubilization, depolymerization and monosaccharide composition of pectin and hemicelluloses from two cultivars with contrasting firmness (‘Sweetheart’, firm and ‘Newstar’, soft) at four different developmental stages. Firm ‘Sweetheart’ cherries had higher contents of cell wall material than soft ‘Newstar’ fruit. Moderate depolymerization of hemicellulose and tightly bound pectins was detected irrespective of cultivar firmness. The general pattern and extent of uronic acid solubilization was quite similar in both cultivars. Rhamnogalacturonan I (RG-I) seemed to be preferentially solubilized in firm ‘Sweetheart’ fruit as opposed to tightly bound homogalacturonans (HG) in soft cherries. Pectic polymers with higher neutral sugar to uronic acids ratio were found from early development in soft ‘Newstar’ fruit. Overall, soft ‘Newstar’ fruit had reduced wall content and higher branching of tightly bound pectins than firm ‘Sweetheart’ fruit. These factors may be associated with the varietal differences in cherry firmness.  相似文献   

Changes in enzymatic activity,accumulation of proteins and softening of persimmon (Diospyros kaki Thunb.) flesh as a function of pre-cooling acclimatization     

Edson Luiz de Souza  André Luiz Kulkamp de Souza  Aline Tiecher  César Luis Girardi  Leonardo Nora  Jorge Adolfo da Silva  Luiz Carlos Argenta  Cesar Valmor Rombaldi 《Scientia Horticulturae》2011

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果胶提取中沉淀方法及条件的研究     

戴玉锦  张筱娟  王凤仙 《安徽农业科学》2007,35(9):2732-2732,2744

在柚皮果胶提取中,对醇析法和盐析法2种沉淀方法及条件进行了比较研究.结果表明,用醇析法分离沉淀柚皮果胶的最佳条件是:乙醇终浓度60%,果胶提取液pH值1.5,醇析温度5℃,醇析静置4 h,果胶得率为20.93%.用盐析法分离沉淀柚皮果胶的最佳条件是:Al2(SO4)3饱和溶液∶果胶提取液=1∶1,果胶提取液pH值5.5,盐析温度45℃,盐析静置1 h,果胶得率为20.33%.  相似文献