15种提取液对辣椒粉中3种碱性橙染料提取效果比较

通过15种提取液对辣椒粉中3种碱性橙染料即碱性橙2(CDG)、碱性橙21(AOG)、碱性橙22(AOR)提取效果的比较,建立了基于高效液相色谱法(HPLC)的前处理方法。以体积分数1%甲酸甲醇为辣椒粉中碱性橙提取液,以甲醇和20mmol/L乙酸铵(57:43)流动相,STPAKC18-ES(4.6mm×250mm,5μm)色谱柱,CDG检测波长419nm,AOG、AOR检测波长485nm,流速1.0mL/min,柱温40℃为HPLC条件,该方法的检出限为CDG、AOR:0.01mg/kg,AOG:0.005mg/kg。方法回收率60%以上,相对标准偏差小于4%。结果表明,以体积分数1%甲酸甲醇为提取液时,在阳性样品提取率、阴性样品加标回收以及色谱峰形等方面,与现有国家标准相比,均具有显著优势。     

橘皮类黄酮的分离、纯化及结构鉴定研究

柑橘皮内含丰富的类黄酮化合物,具有多种生物学活性,受到医药、食品等行业的关注。本文通过硅胶、聚酰胺及Sephadex HL-20柱对温州蜜桔皮中类黄酮化合物进行反复分离纯化,得到5种类黄酮单体。采用LC-ESI-MS、1H-NMR和13C-NMR及红外光谱等技术对其结构进行鉴定。鉴定结果:化合物A,3,5,6,7,8,3’,4’-七甲氧基黄酮;化合物B,5,6,7,8,4’-五甲氧基黄酮;化合物C,3-羟基-5,6,7,8,3’,4’-六甲氧基黄酮;化合物D,5,6,7,8,3’,4’-六甲氧基黄酮;化合物E,橙皮素芸香糖苷。其中,化合物C是从温州蜜桔皮中首次发现的。     

索氏法与超声波辅助提取甜橙橙皮苷比较研究

为了确定从甜橙果皮中提取橙皮苷的高效方法,比较了索氏法和超声波辅助提取的效果。考虑到不同提取条件,即溶剂浓度、液固比、提取时间、提取次数和超声波功率的影响,采用单因素及正交设计比较这两种方法提取橙皮苷的效果,并用RP-HPLC法测定提取液中橙皮苷的含量。结果表明,超声波法辅助提取3个甜橙品种果皮中橙皮苷的平均含量高于索氏提取法的26.5%～34.6%,用这两种方法提取橙皮苷的数量达到统计学上的显著差异。超声波辅助提取法能真实地反映甜橙果皮中橙皮苷的含量,具有操作简便、省时的优点。建议柑橘果实橙皮苷的测定和提取可采用超声波辅助法。     

胶束增敏光度法测定白酒中汞

在阳离子表面活性剂溴化十六烷基三甲铵(CTMAB)存在下,以二甲酚橙(XO)为显色剂,汞(Ⅱ)-二甲酚橙(XO)在水相中形成稳定的深红色配合物。该配合物在594nm处有一最大吸收波长,汞含量在0～40.0μg/25mL范围内服从朗伯-比尔定律,摩尔吸光系数为4.74×105L/mol·cm,回收率为93.15%～100.2%,该方法用于白酒中汞的测定,结果令人满意。     

R40型转杯纺纱机关键器材的优选配置

为了生产高质量的转杯纺纱线,对立达公司的短流程R40转杯纺生产线的关键纺纱器材,如：阻捻头、假捻器、纺杯和分梳辊等进行了优选。试验结果显示：表面螺旋结构的KS型阻捻头成纱奈干好,毛羽少,强力高;KSNX型阻捻头成纱手感柔软,适纺针织纱;表面带沟槽的K4K型阻捻头成纱蓬松,适纺牛仔布用纱;40-XTC-BD型纺杯适纺83．3tex等粗号纱;33-XT-BD型纺杯适纺29tex等较细号纱;另外,用B20ON-64型分梳辊纺纯棉29tex纱,以8kr／min,排杂补风全关为宜;纺83．3tex补风口开1/2为宜。最后指出,应结合客户要求选择关键纺纱器材和工艺参数才能纺好转杯纱。     

Sorption of Ethyl Butyrate and Octanal Constituents of Orange Essence by Polymeric Adsorbents

Sorption characteristics, rates and capacities of polymeric adsorbents (XAD-4, XAD-7, XAD-16, Duolite ES-865, Duolite S-761, Porapak-Q and XUS-43436) for ethyl butyrate and octanal were determined using model solutions. Sorption of these two principal components of aqueous orange essence, was evaluated utilizing the Freundlich isotherm model. Breakthrough curves were determined using XAD-16 as adsorbent. The capacity of XAD-16 for ethyl butyrate in the column system was 426±212 mg/g. There was no column breakthrough for octanal even after 130 bed volumes. Most (91.4%) of the adsorbed ethyl butyrate was eluted from XAD-16 resin by 95% ethanol elution. Recovery of adsorbed octanal from the resin was 66.4%.     

Studies on non-enzymic browning in orange juice using a model system based on freshly squeezed orange juice

An orange juice based model system was set up wherein variables such as the addition of glucose, lysine, sorbitol and L -ascorbic acid and changes in pH and storage temperature were introduced to study their effects on L -ascorbic acid degradation and on browning. The addition of glucose, lysine and sorbitol did not have a significant effect on L -ascorbic acid degradation, whereas added L -ascorbic acid acted solely as a reserve material. In terms of browning, a change in pH and storage at elevated temperature produced a synergistic effect in the development of brown colour which was enhanced by the introduction of additives. Based on the results obtained, L -ascorbic acid appears to be the precursor in the non-enzymic browning occurring in this type of sample due to the formation of reactive carbonyl compounds produced upon its degradation which tend to polymerise, or to react with nitrogenous compounds, to give brown pigments.     

柑橘皮中果胶的萃取方法研究进展

柑橘在加工生产橘汁和新鲜使用时,约产生30％～50％的皮渣,这些皮渣中有许多有用的成份,果胶是其主要化学成份之一。约占20％～30％。因此将无用橘皮转变为有用的物质,使废弃的天然有机化学资源得到合理利用,可以为国家创造巨大的经济财富。本文主要对目前国内外柑橘皮中果胶的几种萃取研究方法进行了综述。     

复合保健猕猴桃汁的研制

简述了猕猴桃、枸杞、甘草、陈皮的营养价值和生理功能,着重介绍了采用正交试验、感官评价确定饮品配方的过程和复合饮品的加工工艺。据此,开发研制了具有营养保健作用的复合保健饮品。     

Proton spin–spin relaxation time of peel and flesh of navel orange varieties exposed to freezing temperature

Proton spin–spin relaxation times (T₂) of peel (albedo and flavedo) and juice sacs (flesh segments) of navel oranges were measured at 10 MHz using a Bruker Minispec PC 110 NMR spectrometer. The oranges were subjected to chilling (5 °C) and freezing (−7 °C) temperatures for 20 h and warmed to room temperature before peeling for T₂ measurements. The exposure to chilling or freezing temperature did not affect the T₂ values of peel, but freezing caused an appreciable decrease (∼15%) in the T₂ values of flesh segments of the varieties of navel oranges studied. When the peel was exposed to −20 °C, the T₂ showed a drastic reduction suggesting that the peel did not freeze at −7 °C. The possible cause of reduction in the T₂ values when exposed to freezing temperature may be damage to the juice sac membrane and leakage of juice out of the sac. The difference in the T₂ values between juice sacs of freeze-affected and normal oranges can potentially be used for detection of freeze-damaged fruits. Copyright © 2005 Society of Chemical Industry