Extracting and Studying the Factors Affecting the Tanning Material in the Garad Pods

In this study the chemical structure of Garad tan pods (acacia – nilotica) were determined and investigated. It was found that Garad tan is a polyphenol type of structure and consequently it has an antiseptic effect, it is also used as pretaning and retaning agent.

Garad pods need to be disintegrated and ground into fine grains of very small diameter. In its powder form it cannot be used in tannage as the grains may block the sewage, hence, it has to be leached, concentrated and spray dried.

The factors that affect leaching of the tannins from Garad pods were studied, there are: Temperature, solvent to solid ratio, degree of mixing and time were specified and factorial experiments were designed to study the effect and significance of these factors. The levels of these factors were (30 and 50°C), (1:5 and 1:7), (with and without) mixing and (25 and 50) minutes respectively. All these factors were found to be very significant.

Having determined the optimum factors their levels trials were carried out at the following levels:

Temperature: 50°C

Solid to solvent ratio: 1:7

Degree of mixing: With mixing

Time: 50 minutes

The trials made at these conditions were found to be efficient with high yield of the extract. The extract produced was concentration which makes it ready for use in pertannage or retannage or for spray drying to powder.