低档绿茶对灵芝菌摇瓶发酵的影响

研究了低档绿茶对灵芝菌摇瓶发酵的影响,低档绿茶由于成分多样复杂,一些特殊因子能够促进灵芝菌发酵过程中胞外多糖的合成,但因其多酚类等抗性物质的存在,一定程度上抑制了菌体生长,与对照实验相比,其生物量降低了17.08%,胞外粗多糖增加了42.5%.同时探讨了低档绿茶经过灵芝菌发酵作用后,茶汤中主要呈味成分的变化,实验结果表明:茶多酚降解了64.8%,游离氨基酸总量增加了9.7%、酚氨比降低了67.8%、水溶性灵芝胞外多糖增加,茶汤品质得到很大提高.     

沱茶中茶多酚的分析与鉴定

用索氏提取器以三氯甲烷为萃取剂,在95 ℃下从沱茶中提取茶多酚。用旋转蒸发器将滤液浓缩,有机相中加入三氯甲烷(V(三氯甲烷):V(浓缩液)=3:1)将咖啡因萃取分离、去除。水相中加入乙酸乙脂(V(乙酸乙酯):V(水)=3:1)将沱茶提取物萃取分离。以硅胶G作填充剂,以乙酸乙酯(V(乙酸乙酯):V(乙醚)=4:1)为洗脱剂进行柱层析。用傅里立变换-红外光谱法(FT/IR)测定沱茶提取物待测组分的红外光谱图,提供官能团的有关信息。确定待测组分的可能结构;应用气相色谱-质谱法(GC/MS)对其进行分析与鉴定,由电子电离源质谱(EI/MS)获得待测组分的质谱图和相关数据,进而对子离子裂解途径和特征离子进行辅助解析,确证待测组分为茶多酚。为开发利用沱茶提供了科学依据。     

洞庭碧螺春中咖啡因含量测试

用热水浸提法提取6个洞庭碧螺春茶样品中的咖啡因,采用紫外分光光度法,以咖啡因为标准品,蒸馏水为空白对照,于276 nm波长处分别测定对照品和供试品溶液的吸光度,按标准曲线计算咖啡因含量。回归方程为y=47.945x+0.0015,r=0.9999。平均回收率为99.68%,相对标准偏差RSD为0.23%。该方法简单、快速、准确。     

烘焙提香时间对工夫红茶品质的影响

为提高工夫红茶的甜香度,本文以山东夏季鲜叶加工的工夫红茶初制品为原料,在70℃的烘温下进行不同时间的烘焙提香处理,并通过感官审评、生化成分和香气分析方法研究其对工夫红茶品质的影响,结果表明:烘焙时间的长短不仅影响工夫红茶的香型和高低,而且也影响汤色和滋味,在本试验条件下,烘焙时间以1.0~1.5h的感官品质较好;此外,烘焙时间对工夫红茶各生化成分的影响不同,但对品质有利的生化成分以烘焙1.0h的茶样含量最高;随着烘焙时间的延长,工夫红茶香气的种类、含量以及组分比值发生显著变化,从而可以解释不同烘焙时间工夫红茶香型存在差异的原因。     

Selective elution of tea catechins and caffeine from polyvinylpolypyrrolidone

Desorption of catechins and caffeine from polyvinylpolypyrrolidone (PVPP) was comprehensively investigated. The result showed that caffeine could easily be desorbed from PVPP by the tested solvents except n‐hexane, while catechins could only be thoroughly done by dimethyl sulphoxide (DMSO) and N, N‐dimethylformamide (DMF). Excellent desorption efficiency of DMSO and DMF might be attributed to their high dipole moments and H‐bond potentials. Addition of ethanol was recommended considering the elution efficiency and fluidity, but ethanol volume should be <40% (v/v) for DMSO or 20% (v/v) for DMF. Desorption would get to equilibrium within 1 h and followed the pseudo‐second‐order model. Caffeine and catechins could be separately desorbed through two‐stage elution procedure, that is, water or 20% aqueous ethanol for desorbing caffeine and part of nongalloylated catechins and DMSO/ethanol (8/2, v/v) for eluting the remaining catechins. Highly purified catechins (~95%) with high level (~70%) galloylated catechins would be achieved when the desorption procedure was applied in column chromatograph.     

Analysis of chemical compounds and toxicological evaluation of Forsythia suspensa leaves tea

To determine the compositions of Forsythia suspensa leaves tea (FSLT) and its safety, the chemical compounds were analysed with some methods, and the toxicity was evaluated in Kunming mice and Wistar rats. The results showed that FSLT contained rich flavonoid, lignans, triperpene acids, amino acids, and mineral elements. In the acute toxicity study, none of the mice died, and no obvious poisoning symptoms were observed after 14 days in mice at the dose of 15 mg/g·body weight (bw) FSLT; in the sub-chronic toxicity, no abnormal or dead rat was found at the dose of 1, 3, and 10 mg/g·bw during 90 days feeding administration; there was no significant difference in bw and food consumption; no significant differences were found in each hematology and serum biochemistry parameter and organ/body weight ratio comparing with the control experimental group. The results revealed that the FSLT has low or no toxicity via oral administration. Therefore, FSLT is very suitable and safe to be used as a new resource food.     

茶叶中提取咖啡因实验分析与改进

实验中采用蒸馏后增加过滤步骤,去除易燃有机物;通过焙炒后加无水乙醇,再加入过量氧化钙,除尽水分;以蒸馏装置代替蒸发皿与倒置漏斗组合装置进行升华,通畅升华气流与避免气态咖啡因溢出。结果表明:实验改进措施有利于茶叶中咖啡因的提取。     

Development of Phospholipids Vesicular Nanocarrier for Topical Delivery of Tea Tree Oil in Management of Atopic Dermatitis Using BALB/c Mice Model

This work aims to develop and evaluate the efficacy of tea tree oil (TTO) ethosomal cream with improved deposition in skin layers for treatment of atopic dermatitis (AD). Ethosomes of TTO are developed using phosphatidylcholine (2% and 3% w/v) and ethanol (20%, 30%, and 40% w/v). Ethosomes are evaluated for percent entrapment efficiency (%EE), vesicle size, zeta potential, and in vitro drug diffusion. Ethosomal creams with optimized ethosomal dispersion are developed and evaluated for physicochemical parameters, thermal stability, ex vivo permeation, skin retention, and in vitro cytotoxicity using HaCat skin cell lines in comparison to conventional creams of TTO. In vivo investigations of optimized creams are performed using BALB/c mice model. The %EE, vesicle size, and zeta potential for optimized ethosomes are found to be 76.19 ± 3.26%, 333.6 nm, and –35.3 mV, respectively. Ethosomal creams showed higher deposition in the epidermis and dermis. The optimized creams are non-cytotoxic to HaCat cell lines. The creams significantly reduce the inflammatory response by decreasing the clinical score and infiltration of white blood cells, eosinophils, and IgE antibodies. Overall efficacy of ethosomal cream is higher than conventional cream. In conclusion, optimized ethosomal cream of TTO shows good efficacy for treatment of AD. Practical applications : The method used for the formulation of ethosomes is simple and can be easily scaled up on the industrial level. The loading of TTO within ethosomes can increase the efficiency by enhanced drug deposition in the epidermis and might also improve its stability against oxidative degradation. Topical ethosomal cream of TTO can improve patient compliance by avoidance of adverse effects linked with corticosteroids and could be a possible complementary or alternative therapy in management of AD.