叶绿素铜钠盐吸附羊毛织物的动力学研究

基于能上染绿色的天然染料很少,文章研究了叶绿素铜钠盐吸附羊毛织物的动力学过程。研究表明,在70～100℃染色温度范围内,叶绿素铜钠盐在染色初期上染羊毛速率很高,随着染色时间增加到20 min后,上染速率降低,60 min后上染百分率、织物上的染料量基本不变,上染达到平衡;叶绿素铜钠盐染后羊毛织物的颜色特征值表观深度与时间的关系与上染百分率趋势基本一致,当染色时间达到120 min后,织物K/S值不再随时间增加而提高;随着染色温度的提高,叶绿素铜钠盐上染羊毛的平衡上染百分率提高,扩散系数提高;准二级动力学模型能很好地描述叶绿素铜钠盐染羊毛织物的染色动力学,该吸附过程以化学吸附为主。     

国外果蔬采后护绿方法研究现状

绿色果蔬易在贮藏的过程中发生叶绿素降解,从而失去绿色,降低产品的质量。本文主要综述了国外关于果蔬采后护绿的一些研究方法及其成果,这些方法包括化学药剂处理、植物生长调节物质处理、低温和热处理、气调包装、辐照等,希望这些研究成果能为国内相关研究提供参考。     

竹叶制备叶绿素铜钠盐的工艺优化研究

以竹叶为原料,石油醚与95%乙醇复合溶剂为提取溶剂提取叶绿素,叶绿素提取液直接经过皂化、酸化、铜代、净化和成盐等步骤制备叶绿素铜钠盐。对影响产品得率和质量指标的提取、铜代两个关键工艺过程,利用L9(34)正交实验进行工艺条件优化。结果表明,竹叶叶绿素的最佳提取条件为复合溶剂中95%乙醇体积分数为15%、液固比8:1(v:w)、提取温度55℃、提取时间2h;铜代过程最佳条件为乙醇体积分数85%、加铜量为理论值的2倍、反应温度60℃、pH2.5。叶绿素铜钠盐得率0.38%,检验结果主要指标符合食品添加剂国家标准。     

Non-destructive evaluation of ripening and quality traits in apples using a multiparametric fluorescence sensor

BACKGROUND: The detection of pigments and colourless flavonoids in apples can provide a useful indication of fruit quality. Optical methods are preferable because they are fast and non‐destructive. In this study, a fluorescence‐based portable sensor was used in order to non‐invasively determine the content of chlorophylls, anthocyanins and flavonols in Fuji, Granny Smith and Golden Delicious apple cultivars. The aim was to define new non‐destructive optical indices of apple quality. RESULTS: The anthocyanin index (ANTH) in Fuji was higher in the sunny (i.e. sun‐exposed) side of the fruit compared to the shady side. For all cultivars, the flavonol index (FLAV) was higher in the sunny side compared with the shady side. The chlorophyll index (CHL) for the shady sides of Granny Smith and Golden Delicious was significantly higher than for the sunny sides. Fine linear regressions were found between the ANTH, FLAV and CHL indices and the actual anthocyanin, flavonol and chlorophyll concentrations, respectively, which were determined destructively on the apple peel extracts. A negative correlation was found between the apple sugar content and the chlorophyll fluorescence in the far‐red spectral band. CONCLUSION: Our results indicate that a single multiparametric fluorescence‐based sensor can provide valuable non‐destructive markers of ripening and quality in apples. Copyright © 2012 Society of Chemical Industry     

脱水甘蓝护色工艺的优化

甘蓝在干燥过程中叶绿素含量降低,产品感官品质下降。采用正交试验方法优化脱水甘蓝护色工艺,以期提高脱水甘蓝的感官品质。正交试验以叶绿素残留率为指标,优化最佳护色工艺。结果显示,采用浓度为1%的Na2CO3溶液浸泡15min,100℃热烫1.5min,脱水甘蓝叶绿素保存率为52.3%,此时过氧化物酶相对酶活小于5%,可以有效保持甘蓝的原有颜色。     

Fractional Separation and Structural Characterization of Chlorophyll and Lignin from Perennial Ryegrass (L. perenne) and Cocksfoot Grass (D. glomerata)

Abstract

One chlorophyll rich fraction and two lignin preparations were separated from perennial grass and cocksfoot grass by sequential three‐stage treatments with 80% ethanol containing 0.2% NaOH, 2.5% H₂O₂?0.2% EDTA containing 1.5% NaOH, and 2.5% H₂O₂?0.2% TAED containing 1.0% NaOH at 75°C for 3 h, respectively, which released 4.6 and 3.6% chlorophyll rich fraction, 2.3 and 5.8%, and 0.9 and 1.0% lignin preparations, except for releasing 8.0 and 10.4%, 79.1 and 77.0%, and 12.9 and 12.5% of the original hemicelluloses, respectively. The lignin fractions obtained from the two different grasses had very similar molecular weights and structural composition. The NMR spectra of the lignin preparations revealed the presence of p‐hydroxyphenyl, guaiacyl, and syringyl structures, and the lignin in chlorophyll rich fraction contained more guaiacyl and syringyl units than p‐hydroxyphenyl unit, whereas the reverse trend was found in the two lignin preparations. The lignin preparations are distinguished with straw and wood lignins by relatively higher contents of p‐hydroxyphenyl unit and lower amounts of condensed units (β‐5 and 5‐5′) and resinol units (β‐β). This difference in distribution of structural units indicated some structural heterogeneity between grass and straw/or wood lignin.     

切分及烹调对叶类蔬菜品质的影响

以芥菜、菜心、生菜等为主要原材料,研究切分方式与烹调方式对叶类蔬菜中维生素C、叶绿素和亚硝酸盐含量的影响,以明确加工条件对叶类蔬菜品质的影响。结果表明,切分后烫漂,叶类蔬菜中维生素C较新鲜蔬菜下降超过40%,亚硝酸盐含量下降超过45%,叶绿素下降不明显,且随细胞液的流失有明显上升趋势;油炒、烫漂和汽蒸三种烹饪方式对叶类蔬菜中叶绿素、维生素C、亚硝酸盐影响的研究表明,汽蒸加工可以保留叶类蔬菜中60~67%的维生素C,可降低40~70%的亚硝酸盐含量,而对叶绿素含量影响不大,是一种较理想的营养烹饪方式。本论文的研究成果具备良好的理论与实践意义,对减少叶类蔬菜烹饪加工过程中营养成分的损失、有害物质的产生、提高叶类蔬菜烹饪品质起到良好的方法借鉴。     

小叶黄杨叶绿素的提取工艺及应用

用正交法考察了温度、时间、浸提剂比[V（乙醇）：V（丙酮）]等因素对小叶黄杨叶绿素提取效率的影响.结果表明：小叶黄杨在浸提温度为45 ℃、浸提时间为4.5 h,浸提剂比[V（乙醇）：V（丙酮）]为1：1的条件下,叶绿素的提取效率最高.探讨用提取的天然色素试制油墨以及用最佳工艺提取其他色素.     

氮、磷、钾营养对白肋烟叶绿体色素、化学成分的影响及相关性分析

通过正交试验研究了氮、磷、钾营养对白肋烟叶绿体色素、化学成分的影响。结果表明,施N水平及氮、磷、钾比例与白肋烟叶绿体色素、内在化学成分关系密切。叶绿体色素含量与施N水平,N:P2O5和N:K2O比例呈正相关,三要素对叶绿素、叶绿素a、叶绿素b及类胡萝卜素的影响作用为N>K>P。施N水平和N:P2O5、N:K2O比例与总氮、烟碱、蛋白质含量呈正相关,而与总糖、还原糖、施木克值、糖/碱、氮/碱呈负相关,三要素对总糖的影响为N>P>K,而对还原糖、烟碱、总氮、蛋白质的影响是N>K>P。