超临界二氧化碳萃取柿叶黄酮的工艺研究

本文研究了超临界流体萃取柿叶总黄酮苷类化合物的影响因素,并对生产工艺进行了优化设计。试验结果表明:萃取时压力、温度、时间、CO2流量对萃取率的影响程度依次递减。最佳工艺条件为:萃取压力30MPa、萃取温度50℃、萃取时间3h、CO2流量30kg·h-1。用超临界流体萃取法得到的柿叶总黄酮苷类化合物萃取物纯度高,无异味,色泽金黄。  

离子色谱法测定柿叶中有机酸和无机阴离子

以0．75mmol.L^-1邻苯二甲酸和0．35mmol.L^-1三羧甲基氨基甲烷的混合溶液为淋洗液，利用单柱阴离子交换色谱法，直接电导检测，对肺叶的水溶液进行了分析，检测出柿叶中主要含有机酸是琥珀酸和苹果酸，阴离子是H2PO^-4,Cl^-,NO^-3,SO^2-4。方法简便，快速。  

用GC-MS法分析柿树叶中的脂肪酸

用乙醚－己烷混合溶剂抽提柿树叶中的脂肪酸，ＮａＯＨ－ＣＨ３ＯＨ交换法甲酯化，毛细管柱ＦＦＡＰ作为分离柱，进行气相色谱－质谱法测定脂肪酸（以甲酯的形式）的组成。共分离出２１种脂肪酸，鉴定出１９种，占总含量的９８．７２％，其中以肉豆蔻酸（６．６８％）、棕榈酸（３０．００％）、硬脂酸（１０．４２％）、十六碳三烯酸（１．４４％）、亚油酸（１．８４％）、十八碳－烯酸（２２．２２％）、亚麻酸（１．２５％）、花  

Characterization of the surface properties of persimmon leaves by FT-Raman spectroscopy and wicking technique

To fit the request of developing new biomaterials using persimmon leaves as raw material, this paper reported the surface free energy and related components, e.g. the Lifshitz-van der Waals and Lewis acid-base components for persimmon leaves estimated by means of the column wicking technique. Considering this natural material might be varied of its properties with growing area, a characterization of it was initially performed by applying the FT-Raman spectroscopy. Based on the determined results, persimmon leaves have greater surface free energy, gammaS, than cellulose though it has been found rich in this component, e.g. of about 68.28%. Moreover, it was further observed that the persimmon leaves have great Lewis acid-base interactions component, gammaS(AB), contributed by the Lewis acid component, gammaS+. This suggests that the persimmon leaves are available to convert to new biomaterials expected forms.  

超声波辅助提取柿子树叶单宁的研究

以70%的丙酮溶液为提取溶剂,采用超声波辅助提取野柿叶中的单宁,考察了超声波的功率、提取温度、提取时间等因素对单宁提取量的影响.采用响应面法对提取条件进行优化,并建立了二次回归模型.实验结果显示:当提取温度为52℃、超声波功率为80 W、提取时间为42 min,在此条件下单宁的提取量为203.15 mr/g,比无超声波辅助提取提高了38.87 mg/g.  

反相高效液相色谱法同时测定柿叶中齐墩果酸和熊果酸

建立反相高效液相色谱法同时测定柿(Diospyros koki Linn.f.)叶中齐墩果酸和熊果酸的含量.采用Kromasil C18色谱柱(4.6 mm×250 mm,5 μm);流动相:V(甲醇):V(0.2%磷酸水溶液)=87:13;流速:0.8 mL/min;检测波长:210nm;柱温:30℃.齐墩果酸进样量在0.0848～1.696 μg范围内线性关系良好,r=0.9996,平均加样回收率为101.3%;熊果酸进样量在0.1408～2.816 μg范围内线性关系良好,r=0.9995,平均加样回收率为99.0%.3批样品测定结果表明,本法可作为柿叶中齐墩果酸和熊果酸含量测定的方法.  

高效液相色谱法分析柿子中多胺

采用高效液相色谱法,用1,6 己二胺为内标,定量测定柿子中的精胺(Spermine)、亚精胺(Spermidine)、尸胺(Cadaverine)和腐胺(Putrescine)。样品经丹磺酰氯衍生,硅胶柱净化,LichrosorbNH2柱分离后,以氯仿∶乙酸乙酯∶三乙胺(98.4∶1.5∶0.1)为流动相,流速为1 5ml·min-1,荧光检测器检测。激发波长为336nm,发射波长为495nm,精胺、亚精胺、尸胺和腐胺的线性相关系数均大于0.99,其回收率分别为98.99%、94.02%、96.46%和105.44%。  

Culture medium optimization for acetic acid production by a persimmon vinegar-derived bacterium

A new acetic acid-producing microorganism, Acetobacter sp. RKY4, was isolated from Korean traditional persimmon vinegar, and we optimized the culture medium for acetic acid production from ethanol using the newly isolated Acetobacter sp. RKY4. The optimized culture medium for acetic acid production using this microorganism was found to be 40 g/L ethanol, 10 g/L glycerol, 10 g/L corn steep liquor, 0.5 g/L MgSO₄·7H₂O, and 1.0 g/L (NH₄H₂PO₄. Acetobacter sp. RKY4 produced 47.1 g/L of acetic acid after 48 h of fermentation in a 250 mL Erlenmeyer flask containing 50 mL of the optimized medium.  

Production of bacterial cellulose by Gluconacetobacter sp. RKY5 isolated from persimmon vinegar

The optimum fermentation medium for the production of bacterial cellulose (BC) by a newly isolated Gluconacetobacter sp. RKY5 was investigated. The optimized medium composition for cellulose production was determined to be 15 g/L glycerol, 8 g/L yeast extract, 3 g/L K₂HPO₄, and 3 g/L acetic acid. Under these optimized culture medium, Gluconacetobacter sp. RKY5 produced 5.63 g/L of BC after 144 h of shaken culture, although 4.59 g/L of BC was produced after 144 h of static culture. The amount of BC produced by Gluconacetobacter sp. RKY5 was more than 2 times in the optimized medium found in this study than in a standard Hestrin and Shramm medium, which was generally used for the cultivation of BC-producing organisms.  

正交优化微波辅助提取柿子叶中的β-胡萝卜素工艺研究

以柿子叶为原料,采用微波辅助法提取柿子叶中的β-胡萝卜素.在单因素的基础上,通过正交试验对工艺条件进行了优化.结果表明,最佳提取工艺条件为：微波温度25℃,微波时间60 s,液料比17∶1 mL/g,微波功率500W.在此最佳条件下β-胡萝卜素提取率可达31.25％.