Industrial Crops and Products 43 (2013) 84–86 Contents lists available at SciVerse ScienceDirect Industrial Crops and Products journa l h o me pag e: www.elsevier.com/locate/indcrop Short communication Studies on the application of natural dye extract from Bixa orellana seeds for dyeing and finishing of leather A. Tamil Selvi a , R. Aravindhan b , B. Madhan a , J. Raghava Rao c,∗ a Centre for Human and Organizational Resources Development, Central Leather Research Institute, Council of Scientific and Industrial Research, Adyar, Chennai 600 020, India b Leather Process Technology Division, Central Leather Research Institute, Council of Scientific and Industrial Research, Adyar, Chennai 600 020, India c Chemical Laboratory, Central Leather Research Institute, Council of Scientific and Industrial Research, Adyar, Chennai 600 020, India a r t i c l e i n f o Article history: Received 4 June 2012 Received in revised form 9 July 2012 Accepted 10 July 2012 Keywords: Natural dye Bixa orellana Leather application Dyeing Finishing Eco benign a b s t r a c t The types of dyestuff that are used by tanneries generally vary depending on the product range needed along with the dictates of the fashion world. It is a fact that each tannery uses between 50 and 100 different types of dyestuffs. Leather industry primarily uses dyestuffs such as acid, basic, metal complex, reactive and sulfur dyes. Many of the synthetic dyes used for leather dyeing are difficult to degrade due to their complex structure and xenobiotic properties. Hence, there is a need for development of more degradable or natural materials for use as a coloring agent for leathers, which would eco benign. Thus, the present study aims at extraction of color from Bixa orellana seeds and employing the same in dyeing and finishing of leather. The leathers dyed and finished using the natural dye extract showed better coloring properties. It is the first time, where this material is reported for their use in leather processing. © 2012 Elsevier B.V. All rights reserved. 1. Introduction Nowadays there is a growing demand for eco-friendly/non-toxic colorants, for application in dyeing of food, textile and leathers. Natural dyes and pigments have emerged as an important alter- native to potentially harmful synthetic dyes (Chavan, 1995). In the present study, colorants extracted from the seeds of the Bixa orel- lana tree have been chosen for its dye ability to leather substrate. The fruit of the B. orellana tree consists of bur-like red; similar to sweet chestnut, containing from 10 to 50 seeds at a size of grape seeds covered with a thin layer of soft, slightly sticky vermilion pulp. The extract from the seed is rich in tannin but contains a mix- ture of eight colorants of carotenoids group; the major colorants are bixin and nor-bixin (Gulrajani et al., 2002; Das et al., 2007). The dye extracted from the B. orellana finds a wide range of utility as coloring agent for foods and beverages. Recently, the dye extracted from the seed covering has been used in dyeing of cotton, silk and wool samples (Hallagan et al., 1995). However, the application of these seed extract (B. orellana) for dyeing of leather has not been attempted. The main objective of the present study is extractions of colorants from the seeds (B. orellana) and employs them in the dyeing and finishing of leathers. Very scanty attempts have been ∗ Corresponding author. Fax: +91 44 24411630. E-mail address: rao clri@yahoo.com (J. Raghava Rao). made on the use of natural dyes for leather manufacture (Rao et al., 2008; Velmurugan and Kannan, 2010). 2. Materials and methods 2.1. Materials Dried B. orellana seeds were collected from Forest Department, Dharmapuri district, Tamil Nadu, India. The intact material was stored in the dark at room temperature and used for the exper- iments. All the chemicals used in this study were of laboratory reagent grade. 2.2. Extraction and characterization of colorants from B. orellana seeds The dye from the seed material was extracted using water. Known amount (5 g) of B. orellana seeds were crushed in a mortar and pestle and soaked in water (100 mL) for 10 min and refluxed at 80 ◦ C (in water bath) for an hour. During this period, the colorants get extracted. The extracted solution was filtered through Watt man No. 1 filter paper. The pH of the extracted dye solution is 6.5. The extracted dye solution was subsequently employed for dyeing and finishing of leathers. The water extract of the B. orellana seed has been subjected to col- umn chromatography using silica gel (60–120 mesh) and eluted stepwise using (100:13.5:10) methanol:chloroform:water as a 0926-6690/$ – see front matter © 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.indcrop.2012.07.015