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 alternative to potentially harmful synthetic dyes (Chavan, 1995). In the present study, colorants extracted from the seeds of the Bixa orellana
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 mixture
of eight colorants of carotenoids group; the major colorants are bixin and nor-bixin (Gulrajani et al., 2002; Das et al., 2007)