Ultrasound Assisted Vegetable Tannin Extraction from Myrobalan (Terminalia Chebula) Nuts for Leather Application

Abstract

Ultrasound (US) assisted preparation of tannins from TerminaliaChebula nuts (myrobalan) through solid-liquid extractionprocess using water as solvent even dispensing with conventionalheating/stirring is presented in this paper. The results indicatethere is a significant enhancement in myrobalan extraction dueto the influence of US, viz., 1.8 to 4.7-fold (US probe: 20 kHz, 80W) and 1.2 to 2.2-fold (US tank: 150 W, 33 kHz) in extract %yieldand tannin contents respectively as compared to differentcontrol processes (static/stirring). Whereas, ultrasound probe at120 W in 50oC water bath gave the best overall %yield andtanning content. Some of the important scale-up parametershave also been studied and found to be useful, suggesting therecould be a significant savings of 427, 184 and 188 kg per ton ofraw material usage as extrapolated values based on Lab-scaleresults in terms of % yield, tannin content and tanning agentoffer respectively due to the use of US as compared to controlprocess. The process involves: i). Clean technology with physicalactivation (US) in aqueous medium at ambient condition – noadditional chemicals ii). Green and Eco-benign process withnatural materials – useful in all extract applications, iii.) Tanninsextract as generic product for better functional properties, iv.)Better diffusion of plant extract through skin matrix in tanningprocess for leather making, v.) Sustainable solution and ecoconservationthrough better yields.