Extraction and Optimization of Natural Dye from Hambo Hambo (Cassia singueana) Plant Used for Coloration of Tanned Leather Materials

Received May 15, 2017; Accepted Jun 21, 2017

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1. Introduction

Prior to the invention of artificial dyes mankind used natural colorants derived from plants, animals, soil, insects, and minerals. Such colorants were employed for the coloration of human and animal skins, hair, teeth, bones, all types of vegetable fibers, and woods in a wide range of colors [1] (Panhwar and Abro, 2007; Zereen, Khan, and Ajaib, 2013). Starting from 1856 synthetic dyes have been widely used for leather and textile coloration. But since these synthetic dyes are produced from nonrenewable petroleum [2] they do not only destroy the environment during synthesis but also discharge effluents into water bodies during application that affect aquatic life [3, 4]. The leather industry consumes large amount of azo dyes [5] which is a class of harmful synthetic dyes [6]. The adverse features of synthetic dyes advocate the need for benign alternatives for leather coloration.

The aspect of producing leather products with minimal impact on the ecological balance, affecting both human and environmental health, is an important focal point to be pursued. Starting from late 20th century researchers concentrated on using natural colorants in leather dyeing. Investigations have been reported on dye extraction from plant sources such as beetroot [7], henna leaves [8], eucalyptus bark, tea leaves, turmeric rhizomes, walnut bark [9], and Rubia tinctorum roots [10]. Keeping in line with the above efforts, this study was carried out to color chrome tanned sheep skin crust leather using dye extracted from Cassia singueana (Amharic hambo hambo). The use of this plant although known to local dyers as a traditional dye for leather has not been optimized in terms of extraction and dyeing parameters. Available literature however cites the use of the plant in northern Nigeria as an antimicrobial agent and panacea for acute malaria [11, 12]. The purpose of this research is to highlight the use of hambo hambo as...