A Review on Sources, Extractions and Analysis Methods of a Sustainable Biomaterial: Tannins

Abstract

Condensed and hydrolysable tannins are non-toxic natural polyphenols that are a commercial commodity industrialized for tanning hides to obtain leather and for a growing number of other industrial applications mainly to substitute petroleum-based products. They are a definite class of sustainable materials of the forestry industry. They have been in operation for hundreds of years to manufacture leather and now for a growing number of applications in a variety of other industries, such as wood adhesives, metal coating, pharmaceutical/medical applications and several others. This review presents the main sources, either already or potentially commercial of this forestry by-materials, their industrial and laboratory extraction systems, their systems of analysis with their advantages and drawbacks, be these methods so simple to even appear primitive but nonetheless of proven effectiveness, or very modern and instrumental. It constitutes a basic but essential summary of what is necessary to know of these sustainable materials. In doing so, the review highlights some of the main challenges that remain to be addressed to deliver the quality and economics of tannin supply necessary to fulfill the industrial production requirements for some materials-based uses.