茶叶染料混合染色色彩呈现探析

为了能够最大限度地拓展茶叶染料染色色彩及其应用多样性表现,根据单种茶叶染料染色的基础探究茶叶染料混合染色的色彩呈现.选取3种不同的茶叶染料,以2种媒染剂的介入进行相关试验研究.对3种茶叶染料采取不同的染色顺序、媒染剂在染色过程中介入的先后顺序、不同茶叶染料染液混合染色等方法进行茶叶染料染色,根据不同染色方法对茶叶染料混合染色色彩呈现进行对比分析和规律总结,为茶叶染料染色色彩多样性呈现和创新应用提供参考.     

原料发酵程度及生化基质对茶饮料冷后浑稳定性的影响

将白叶单枞、金萱、鸠坑3个茶树品种鲜叶加工成不同发酵程度的茶原料,通过对其理化成分分析及感官审评,研究不同茶饮料的品质稳定性;深入探讨茶叶原料发酵程度及其生化基质对茶饮料冷后浑稳定性的影响。结果表明:不同品种茶叶原料制成的茶饮料因为生化基质的不同,茶汤冷藏后效果明显不同。透明度:金萱优于鸠坑;白叶单枞最差;絮状沉淀与茶汤的分界线不清晰,随着发酵程度的加重,沉淀物的量明显增加,其沉淀物颜色也逐渐变深。金萱原料制成的茶饮料中能看到明显的灰褐色沉淀和白色沉淀的分层。同一品种,随着发酵程度的增加,冷后浑固形物总量先增加后减少;同个品种的样品中,红茶工艺制作的全发酵茶叶饮料中沉淀物形成总量相对较少,说明红茶较适合于制作茶饮料。沉淀物中茶多酚含量平均为36.47%,说明茶多酚是沉淀物形成的主要控制因子之一;沉淀物中多酚含量不受茶叶中多酚含量的影响;随着茶叶原料发酵程度的加深,沉淀物中的多酚含量先增加后减少。而茶叶中EGC随着发酵程度的加深,其含量先增加后减少;所以EGC有可能是茶汤固形物形成量的主要决定因子。     

不同揉捻程度对单芽红茶生化成分与品质的影响

本实验以“福云6号”单芽茶青为材料进行相同的萎凋处理后,经不同程度的揉捻处理,即分别在相同压力下揉捻20min、30min、40min,后经相同的发酵和干燥程序,得到成品茶.先分析成品茶的细胞破损率与茶叶成条率,后对成品茶进行化学组分的测定与感官审评.结果表明,随着揉捻程度的加重,细胞破损率呈波动上升的变化趋势,茶叶成条率相应提高,水浸出物含量、茶多酚含量、氨基酸含量明显增加,可溶性糖呈现波动性下降,茶黄素含量变化先增加后下降,茶黄素与茶红素比值呈现线性变化规律,揉捻30min比值最大亦最接近最优比值范围.综合来看,揉捻40min的成品茶综合评分最高.     

茶染料的提取及其在服装染色中的应用

使用绿色茶染料,应用茶染技术,不仅是对传统技术的传承创新,同时也为茶叶应用方向拓展提供了重要帮助。随着现代化学技术不断成熟,加上人们对服装设计要求进一步提升,如今探索提取茶染料技术,并探究将茶染料应用于服装染色活动中的价值就更加必要。本文拟从当前茶染料技术应用状况及存在问题分析入手,结合茶染料提取过程分析,结合当前服装染色技术的创新方向及要求,着重探索茶染料在整个服装染色过程中的具体应用思路。     

茶染工艺技术在当代服装设计中的应用

茶在中国有着较为悠久的历史,在长期的历史发展中,以茶为基础衍生出许多与茶相关的茶歌、茶戏、茶染工艺等。其中,茶染工艺是一种利用从茶叶中提取的色素作为染料的一种工艺,其获取十分简单、并且还非常有利于环保。因此,将茶染工艺运用到现代的服装设计中,不但可以达到现代人追求的时尚理念,还可以使得服装的染色更加环保,是现代服装染色发展过程中很好的一种选择。本文首先对茶染工艺进行了介绍,然后探讨了茶染工艺在当代服装设计中应用的价值,最后提出了茶染工艺技术在当代服装设计中的应用思路。     

茶染艺术在现代服装设计中的应用

茶染艺术是一种植物染色工艺,它的优点在于材料获取容易、制作方式简单、有利于环保。茶染艺术在我国得到很好的应用,很大程度上是因为中国的绿茶行业的快速发展。中国是世界生产绿茶最多的国家,所以我国的茶染艺术也尤其发达。本文在分析茶叶染色萃取工艺和现有的服装染色技术的创新方向和要求的基础上,探讨茶染艺术在现代服装设计中的应用。     

外源多糖水解酶提高红碎茶品质技术研究 Ⅵ.红碎茶初制中多糖水解酶酶法制茶配套工艺技术研究

本文通过对不同鲜叶萎凋程度、不同发酵时间、不同干燥温度对多糖水解酶(PSH)制茶效应的影响研究,找出了酶法制茶配套工艺及技术指标。证验结果表明,将酶液在揉切前均匀喷雾加入萎叶,萎叶水分控制在68%左右,茶叶在制品发酵时间比常规制茶工艺延长15～45分钟,干燥采用先高温后低温方式能较好地协调外加酶促反应与茶叶自身内源酶酶促作用,发挥酶法制茶的增质效应,提高红碎茶品质。     

不同萎凋程度处理对单芽红茶品质的影响

以"福云6号"单芽茶青为试材,进行不同程度萎凋处理,即分别失重20%、30%、40%和50%,后经相同的揉捻、发酵和干燥工序,得到成茶。对成茶进行感官审评及化学组分与PPO酶活性测定,结果表明,随着萎凋程度加重,茶叶水浸出物含量、氨基酸和可溶性糖含量都呈现升高的变化趋势。茶黄素(Theaflavins,TFs)和茶红素(Thearubigins,TRs)含量先下降再上升,茶褐素(Theabrownins,TBs)含量则先增高后降低,以失重30%最高,失重50%最低。此外,咖啡碱、儿茶素含量及PPO酶活性,以失重40%萎凋处理最高。综合来看,萎凋失重40%的成品茶综合评分最高。     

普洱茶渥堆发酵的化学成分变化研究进展

本文综述了普洱茶在渥堆发酵过程中各种成分不同程度的变化,从而便于深入了解普洱茶渥堆发酵微生物的作用机理,为提高普洱茶渥堆发酵的转化效率打下理论基础.在普洱茶渥堆发酵过程中,茶多酚、儿茶素、氨基酸、茶黄素、茶红素的含量都呈现下降趋势,而咖啡碱、水溶性果胶、茶褐素则呈现上升趋势;水溶性糖经过一段争议,先普遍认为其在发酵前期含量上升,在发酵后期则大量下降.然而,水浸出物在渥堆发酵过程中的含量变化则仍存在争议,不同的人有不同的看法.     

温差消除措施对茶叶低温贮藏效果的影响

通过对龙井茶和轻发酵铁观音,分成消除温差处理和未消除温差处理设置3个不同的温度进行低温贮藏,在贮藏2个月、4个月、6个月时取出冷藏环境进行处理,在2个月、4个月时茶叶经处理后再包装密封继续低温贮藏;6个月时茶叶经处理后再包装密封待测;随后进行感官审评和理化分析。分析结果表明,在低温贮藏环境下取出茶叶到自然环境时,消除茶叶温差措施对保持龙井茶和轻发酵铁观音的品质,效果非常显著。     

Application of acacia natural dyes on cotton by pad dyeing

Coloration of textiles, traditionally achieved using natural dyes, commonly employs synthetic dyes at the industrial level. A revival of commercial interest in natural dyes has opened several research avenues. This paper investigates the application by padding of cotton fabric with 10 g/l of two natural dyes derived from the Acacia plant family. Three mordanting techniques were studied; of which post-mordanting produced the most even shade. Among the two mordants investigated, the use of copper sulfate resulted in a level beige shade at 15 g/l concentration while ferrous sulfate performed best at 5 g/l yielding a yellow-grey shade. An optimum process-sequence for the copper sulfate mordant was “pad (dye)→dry→steam followed by pad (mordant)→steam→dry”, and for ferrous sulfte it was “pad (dye)→steam→dry followed by pad (mordant)→steam→dry”. Typically a change in mordant resulted in a different shade with the same dye. The study concluded that padding is a readily adaptable process for the dyeing of cotton using natural dyes and acceptable fastness in shades can be obtained.     

Dyeing of cotton and silk yarn with the extracted dye from the fruit hulls of mangosteen,<Emphasis Type="Italic">Garcinia mangostana</Emphasis> linn

The extracted dye from the dried fruit hulls of mangosteen was used as a natural dye for the dyeing of cotton and silk yarn. The optimal conditions for dye extraction were to extract the dried fruit hulls of mangosteen at 80°C for 1 hour with a 15 % w/v citric acid solution in a 1:4 ratio of mangosteen powder to solvent. Cotton dyeing with the extracted dye from the dried fruit hulls of mangosteen was carried out at 60°C for 60 minutes with a material to liquor ratio of 1:25. The effect on dyeing of mordant type with different mordanting methods was studied. The results showed that the dyeing of cotton using the post-mordanting method with ferrous sulfate and calcium hydroxide not only provided better depth of shade but also provided better wash fastness and light fastness than with other mordants (alum; zinc tetrafluoroborate) or without a mordant. Good fastness properties were also obtained using a post-mordanted silk with calcium hydroxide.     

Ultrasound assisted extraction of natural dyes and natural mordants vis a vis dyeing

Most of the natural dyes require mordants for their fixation on textile materials. Natural mordants are thus gaining importance in order to get complete-natural dyeing. In the present work, natural dyes and mordants were extracted using conventional and ultrasound methods and comparative studies were made. The natural mordants namely harda and tamarind seed coat and natural dyes like turmeric, henna were extracted using conventional and ultrasound approaches and various extracts obtained were described in terms of their optical densities. In order to verify the extraction efficiencies, wool fabrics were dyed with extracts of various combinations of mordants/dyes and dyed fabrics were evaluated for their colour strengths and fastness properties. The extent of colour extraction was higher in case of ultrasound assisted extraction as compared to that of conventional method. The fabrics dyed using extracts of ultrasound method showed higher colour values as compared to those dyed using extracts from conventional methods thus confirming ultrasound as more efficient method of extraction.     

Effect of laccase on dyeing properties of polyphenol-based natural dye for wool fabric

Chemical mordants are generally used during the dyeing process, to increase the uptake of natural dyes. Traditional mordants include metal salts, such as copper, iron, aluminum, chromium, and other metal ions. Continuous developments in bio-engineering technology focus on methods that lower the impact on the environment. In this regard, enzymatic processes show great promise in textile field, due to their efficacy, mild conditions, and environment friendly nature. Laccase is a multicopper oxidoreductase that catalyzes in-situ polymerization of small phenolic monomers to form a colorful polymer. In this study, effects of laccase treatment on the dyeing properties of wool fabrics, dyed with natural dyes (turmeric, grape seed extract, and Chinese gallnut), were investigated. The dyeing properties of the dyed wool fabrics were evaluated under different conditions, including laccase stoichiometry, temperature, pH, and reaction time. The structural changes of natural dyes, due to laccase catalyst were also examined by FT-IR. The results showed that laccase greatly influenced the dyeing performance of Chinese gallnut. Moreover, dyeing effects of the samples using post-mordanting method was better than the other two methods, under the same conditions. After laccase treatment, the dyeing properties of Chinese gallnut improved. Finally, factors affecting the dyeing process with Chinese gallnut were studied and the optimized conditions were determined through single-factor experiments.     

A novel eco-friendly colorant and dyeing method for poly(ethylene terephthalate) substrate

Although madder (Rubia tinctorum) has been used as a well-known natural textile dye source for dyeing of natural fibers such as wool, silk and cotton, 100 % polyester dyeing with madder is not common. In this study, polyester samples were dyed with madder at different dyeing temperatures, from 60 °C to 130 °C, in company with 7 chemical and 5 natural mordants. Color properties and rub, light and wash fastness performances were investigated. Different shades of orange, brown, pink and reddish green colors were obtained. Dyeing at 130 °C exhibited the highest color yield, the highest chroma and the lowest lightness values. Overall, chemical mordants exhibited higher color yields than natural mordants. High wash fatness, moderate light and rub fastness levels were observed. The potassium bitartrate and gallnut, a natural mordant, exhibited the best results. The madder dyeing of polyester should be carried out at hot temperature conditions, 130 °C, in order to obtain the highest achievable color yield and chroma with the highest light and wash fastness properties.     

Dyeing of synthetic fabrics in water using azoic dyes based on boronic acid derivatives

Development of water-soluble dyes for the dyeing of different textile fabrics is essential for the textile industry due to ecological and economical reasons. In this study, a series of new azoic dyes were prepared by diazotization reaction between the phenyl boronic acid and different aniline derivatives, and their dyeing capacity in aqueous solution was evaluated. The synthesized boronic azo dyes present good water solubility and can dye polyamide (nylon), wool, silk, and cellulose acetate fabrics. The effect of factors such as concentration of dye, dyeing temperature, and pH on the level of color strength (K/S) was studied. The dyeing results showed that higher color strength K/S (about 16) and fastness properties (about 4/5) with boronic acid dyes were achieved at higher temperatures avoiding the use of surface agents, mordants, and other polluting chemical additives.     

Natural dyeing of cotton with <Emphasis Type="Italic">Xylocarpus granatum</Emphasis> bark extract: Dyeing,fastness, and ultraviolet protection properties

In this research we investigated the dyeing of cotton fabrics with extracts of Xylocarpus granatum, a mangrove plant with a long history of use in leather tanning and textile dyeing. X. granatum bark was extracted and spray-dried, yielding a tannin-rich, reddish-brown powder. This powder proved a suitable colorant for the natural dyeing of cotton with promising color fastness properties to wet treatments (washing, water, sea water, and perspiration), hot pressing, crocking, and light exposure. However, the dye alone produced only weak levels of coloration and therefore metallic salt mordants were employed to improve the color strength, through the formation of insoluble tannate complexes. The resulting fabric K/S values were dependent on the mordant used and exhibited the following trend: ferric sulfate > sodium dichromate > copper sulfate > potassium aluminum sulfate > no mordant, for fabrics exposed to mordants before and after dyeing. Mordanting resulted in slight variations in shade and color fastness. In most cases, the color fastness properties were preserved, except for color fastness to light and hot pressing, for which lowered ratings were found for some mordants. Stiffness and mechanical performance were not greatly affected by dyeing or mordanting, except for sodium dichromate mordanting which significantly stiffened and weakened the fabric. The ultraviolet protection factor (UPF) of all the dyed samples achieved the maximum (50+) level, highlighting the excellent UV shielding properties of the fabric. Overall, X. granatum bark extract is a promising, effective colorant for the natural dyeing of cotton in terms of appearance, fastness, and physical characteristics.     

Eco-friendly dyeing using natural mordant extracted from <Emphasis Type="Italic">Emblica officinalis G</Emphasis>. Fruit on cotton and silk fabrics with antibacterial activity

Emblica officinalis G. dried fruit tannin was extracted and applied as a natural mordant alone and in combination with metal mordant namely copper sulphate for dyeing on cotton and silk fabrics using natural dyes. The color strength, color-coordinates, wash and light fastness were also evaluated for cotton and silk fabrics with and without mordanting. The pre-mordanted cotton and silk fabrics on dyeing gave better color strength, wash and light fastness than those dyeing obtained without mordanting. The total phenolic content of the extract was calculated. Cotton and silk fabrics resulted in good antibacterial activity using the Emblica officinalis G. mordant. When mordant was used along with 0.5 and 1 % copper sulphate mordant and the activity enhanced and was active up to 20 washes.     

Effects of soaking on physicochemical properties of four kinds of rice used in Huangjiu brewing

Rice soaking is an important step in the Huangjiu brewing process. It affects the subsequent fermentation process and the quality of Huangjiu. However, the mechanism and physicochemical variation of rice soaking have been little studied. The physicochemical characteristics of japonica rice (JR), japonica glutinous rice (JGR), indica rice (IR) and indica glutinous rice (IGR) and their properties during the soaking process were studied and compared. The decreased pasting temperature of soaked rice indicated that they were easier to cook and gelatinize after soaking. The four kinds of rice and the soaked water showed different properties after soaking. During soaking, the total acids and amino nitrogen of the four kinds of rice increased slowly at first, then increased rapidly and finally became stable, while the reducing sugar content increased initially and then decreased. The soaking water of JGR showed the highest values of the physicochemical components, showing that it might be more profitable for further Huangjiu fermentation.     

Investigations on C-glycosyl flavonoids from Rhynchosia capitata,its antimicrobial and dyeing properties

Natural dyes extracted from a novel source Rhynchosia capitata (R. capitata) Heyne ex roth were applied to cotton fabric by applying traditional and pad dyeing processes using pre-, post- and simultaneous-mordanting techniques. Both dyeing processes were carried out in the presence of natural mordants: Myrobalan, Pomegranate rind, Rhizhophora mucronata fruits, Manjistha, and eco-friendly metallic mordants such as tannic acid, stannous chloride (SnCl₂), ferrous sulfate (FeSO₄), and copper sulfate (CuSO₄). The range of color developed on dyed materials was evaluated in terms of (L*, a*, b*, C*) CIELAB coordinates and dye absorption concentration on textile materials was studied by using K/S values. Natural mordant Rhizhopora mucronata fruits exhibited good absorption value. It was found that metallic mordants FeSO₄ and CuSO₄ exhibited higher K/S values than SnCl₂. For other mordants except FeSO₄ shade developed on cotton fabric varied from pale yellow to brown. The fastness properties ranged from good to excellent. High pressure thin layer chromatographic analysis for solvents of varying polarity has been investigated and maximum yield was obtained from 80 % aqueous ethanol fraction. Antimicrobial activity was carried out with the aid of two human pathogenic strains, Staphylococcus aureus and Klebsiella pneumonia and the cotton fabric dyed with plain extract of R. capitata shows good activity.