Kamis, 03 April 2014

PEWARNA HERBAL

Natural dyes are dyes or colorants derived from plants, invertebrates, or minerals. The majority of natural dyes are vegetable dyes from plant sources—roots,berries, bark, leaves, and wood—and other organic sources such as fungi and lichens.

Archaeologists have found evidence of textile dyeing dating back to the Neolithicperiod. In China, dyeing with plants, barks and insects has been traced back more than 5,000 years. The essential process of dyeing changed little over time. Typically, the dye material is put in a pot of water and then the textiles to be dyed are added to the pot, which is heated and stirred until the color is transferred. Textilefibre may be dyed before spinning ("dyed in the wool"), but most textiles are "yarn-dyed" or "piece-dyed" after weaving. Many natural dyes require the use of chemicals called mordants to bind the dye to the textile fibres; tannin from oak galls, salt, natural alum, vinegar, and ammonia from stale urine were used by early dyers. Many mordants, and some dyes themselves, produce strong odors, and large-scale dyeworks were often isolated in their own districts.

Throughout history, people have dyed their textiles using common, locally available materials, but scarce dyestuffs that produced brilliant and permanent colors such as the natural invertebrate dyes, Tyrian purple and crimson kermes, became highly prized luxury items in the ancient and medieval world. Plant-based dyes such as woad (Isatis tinctoria), indigosaffron, and madder were raised commercially and were important trade goods in the economies of Asia and Europe. Across Asia and Africa, patterned fabrics were produced using resist dyeing techniques to control the absorption of color in piece-dyed cloth. Dyes such as cochineal and logwood (Haematoxylum campechianum) were brought to Europe by the Spanish treasure fleets, and the dyestuffs of Europe were carried by colonists to America.
The discovery of man-made synthetic dyes in the mid-19th century triggered a long decline in the large-scale market for natural dyes. Synthetic dyes, which could be produced in large quantities, quickly superseded natural dyes for the commercial textile production enabled by the industrial revolution, and unlike natural dyes, were suitable for the synthetic fibres that followed. Artists of the Arts and Crafts Movement preferred the pure shades and subtle variability of natural dyes, which mellow with age but preserve their true colors, unlike early synthetic dyes, and helped ensure that the old European techniques for dyeing and printing with natural dyestuffs were preserved for use by home and craft dyers. Natural dyeing techniques are also preserved by artisans in traditional cultures around the world.


In the early 21st century, the market for natural dyes in the fashion industry is experiencing a resurgence. Western consumers have become more concerned about the health and environmental impact of synthetic dyes in manufacturing and there is a growing demand for products that use natural dyes. The European Union, for example, has encouraged Indonesian batik cloth producers to switch to natural dyes to improve their export market in Europe

Types of Natural Dyes
Natural dyes can be sorted into three categories: natural dyes obtained from plants (indigo), those obtained from animals (cochineal), and those obtained from minerals (ocher). Although some fabrics such as silk and wool can be colored simply by being dipped in the dye, others such as cotton, require a mordant.
A mordant is an element which aids the chemical reaction that takes place between the dye and the fiber so that the dye is absorbed. Containers used for dying must be non-reactive (enamel, stainless steel.) Brass, copper or iron pots will do their own mordanting. Not all dyes need mordants to help them adhere to fabric. If they need no mordants, such as lichens and walnut hulls, they are called substantive dyes. If they do need a mordant, they are called adjective dyes.

Common mordants are: ALUM, usually used with cream of tartar, which helps evenness and brightens slightly; IRON (or copperas) which saddens or darken colors, bringing out green shades; TIN, usually used with cream of tartar, which blooms or brightens colors, especially reds, oranges and yellows; BLUE VITRIOL which saddens colors and brings out greens and TANNIC ACID used for tans and browns.

Natural dyes obtained from plants
One example of a natural dye obtained from plants is madder, which is obtained from the roots of the madder plant. The plants are dug up, the roots washed and dried and ground into powder. During the 19thcentury, the most widely available fabrics were those which had been dyed with madder. The 'turkey red’ that was so popular at that time, was based on madder. This red was considered brilliant and exotic. The madder plant continued to be used for dyeing until the mid-1800s when a synthetic substitute was developed.
Another example of a natural dye obtained from plants is woad. Until the Middle Ages, Europeans used woad to create a blue fabric dye. The woad was a shrub that grew abundantly in parts of Europe. The coloring was in the leaves, which were dried and ground, mixed with water and made into a paste. This dye was supplanted by indigo, an ancient shrub well known to the Egyptians and Indians. Like woad, its color lay in its leaflets and branches. The leaves were fermented, the sediment purified, and the remaining substance was pressed into cakes. 
Indigo prevailed as the preferred blue dye for a number of reasons. It is a substantive dye, needing no mordant, yet the color achieved is extremely fast to washing and to light. The manufacture of natural indigo lasted well into the early 1900s.

In 1905 Adolf von Baeyer (the scientist who also formulated aspirin) was awarded the Nobel Prize for discovering the molecular structure of indigo, and developing a process to produce it synthetically. The natural dye was quickly replaced by the new synthetic, ending an ancient and honored botanical history.

Plant:
Catechu or Cutch tree (brown)
Gamboge tree resin (dark mustard yellow)
Himalayan rubhada root (yellow)
Indigofera plant (blue)
Kamala tree (red)
Larkspurplant (yellow)
Madder root (red, pink, orange)
Myrabolan fruit (yellow, green, black)
Pomegranate peel (yellow)
Weld herb (yellow)

Pewarna alami merupakan bahan pewarna yang bahan-bahannya banyak diambil dari tumbuh-tumbuhan, dapat digunakan untuk memberikan penampilan yang menarik pada makanan atau minuman. Bahan pewarna alami yang banyak digunakan dan berikut cara membuatnya:
  1. Daun suji mengandung zat warna klorofil untuk memberi warna hijau menawan, misalnya pada dadar gulung, kue bika, atau kue pisang. Daun suji biasa dipakai sebagai pemberi warna hijau pada makanan. Karena keindahan bentuk daunnya, tanaman ini seringkali digunakan sebagai tanaman hias. Agar lebih sempurna, daun suji seringkali dicampur dengan daun pandan sehingga selain memberi warna sekaligus juga memberi aroma harum pada makanan, kue dan minuman Anda.
    Cara membuatnya: iris halus daun suji dan daun pandan, haluskan dengan cara ditumbuk atau diblender, peras, dan saring, lalu tambahkan air kapur sirih sebagai pengawetnya. Masukkan ke dalam botol tertutup, lalu simpan di lemari es.
  2. Secang (Caesalpinia sappan L.) adalah tanaman berkayu yang biasa dimanfaatkan bagian batangnya.
    Cara menggunakannya, batang basah diserut dan dikeringkan. Serutan batang kayu secang kering direbus dengan air dan disaring, baru dicampurkan ke dalam adonan atau bahan yang akan diwarnai. Secang memberikan warna merah. Kayu secang dapat diperoleh di toko yang menjual jamu tradisional.
  3. Keluak , bentuk buah keluak ini menyerupai segitiga yang tumpul ujung-ujungnya. Berkulit keras, berwarna abu-abu, dan daging buahnya lunak berwarna cokelat tua kehitaman. Nah, yang dipakai sebagai bumbu dan pewarna adalah bagian dalam yang lunak ini, rasanya sedikit asam, tetapi yang muda rasanya sangat pahit. Triknya, saat membeli pilih yang ringan, goyang-goyangkan keluak, jika terdengar isi yang berguncang berarti keluak berumur cukup tua. Memarkan kulit keluak yang keras, ambil isinya yang lunak dan haluskan bersama bumbu lain. Agar lebih awet simpan keluak bersama dengan kulitnya.
  4. Merang, Air merang atau air abu merang adalah pewarna hitam alami. Diperoleh dengan cara membakar merang kering hingga menjadi abu, lalu merendamnya dalam air. Air abu merang ini biasanya digunakan untuk mewarnai makanan/kue, seperti jongkong Surabaya, bubur suro khas Madura, dll.  Pilih merang yang telah kering benar berwarna kuning agak kecokelatan, kemudian bakar hingga menjadi abu. Untuk 100 gr abu merang, larutkan dengan 250 ml air. Diamkan hingga abu merang mengendap dan airnya hitam jernih. Air abu merang inilah yang digunakan.
  5. Bunga Telang, merupakan tanaman perdu yang tumbuh merambat dan berasal dari kuntum bunga. Cuci bunga talang, remas-remas 5-10 kuntum bunga talang dengan 4-5 sendok makan air lalu saring. Air yang berwarna biru keunguan inilah yang dipakai untuk pewarna makanan atau kue. Cara lain, dengan merebus 20 kuntum bunga telang dalam air secukupnya hingga layu, angkat, biarkan dingin dan saring.
  6. Buah Bit, Buah berwarna merah tua ini mengandung vitamin A (karotenoid), vitamin B1, B2, vitamin C, dan asam folat. Manfaatnya antara lain membantu mengobati penyakit hati dan empedu, penghancur sel kanker dan tumor, mencegah anemia, menurunkan kolesterol, dan membantu produksi sel darah merah.Bit banyak digunakan sebagai bahan pewarna alami makanan. Olah dengan cara mengupas bit, potong-potong kasar, beri sedikit air lalu proses halus dalam blender . Hasil saringannya adalah air yang berwarna merah inilah yang dipakai untuk memberi warna merah pada masakan atau kue.
  7. Buah kakao merupakan penghasil cokelat dan memberikan warna cokelat pada makanan, misalnya es krim, susu cokelat, atau kue kering.
  8. Kunyit (Curcuma domestica) mengandung zat warna kurkumin untuk memberi warna kuning pada makanan, misalnya tahu, bumbu Bali, atau nasi kuning. Selain itu, kunyit dapat mengawetkan makanan. Warna kuning dari kunyit diperoleh dengan cara diparut sampai halus, diperas atau dicampurkan langsung ke makanan.
  9. Cabai merah, selain memberi rasa pedas, juga menghasilkan zat warna kapxantin yang menjadikan warna merah pada makanan, misalnya rendang daging atau sambal goreng.
10.  Wortel, beta-karoten (provitamin-A) pada wortel menghasilkan warna kuning. Wortel bermanfaat dalam menurunkan kadar kolesterol dalam darah, serta membantu pertahanan tubuh dari resiko kanker, terutama kanker peru-paru, kanker larynx (tenggorokan), esophagus (kerongkongan), prostat, kandung kemih, dan leher rahim.
   11.  Gula merah, selain sebagai pemanis juga memberikan warna cokelat pada makanan, misalnya   pada bubur dan dodol. Selain contoh di atas, beberapa buah-buahan juga dapat menjadi bahan   pewarna alami, misalnya anggur menghasilkan warna ungu, stroberi warna merah, dan tomat warna oranye

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