Biotech Studies     (Pages: 025-033)

Optimizing of acidic and alkaline pretreatments for enhanced sugar release of coffee silverskin: a taguchi method approach

Izzet Ozhamamcı 1 ,Bilge Sayın 2

1 Department of Food Engineering, Faculty of Engineering, Ardahan University, 75000, Ardahan, Turkey
2 Department of Gastronomy and Culinary Arts, School of Tourism and Hotel Management, Ardahan University, 75000, Ardahan, Turkey
DOI : 10.38042/biotechstudies.1634773 - Coffee by-products are promising reservoirs of antioxidants and fermentable sugars. Coffee silverskin (CSS) is a significant by-product of coffee bean roasting. In this study, glucose release from CSS was optimized to investigate the pretreatment parameters using the Taguchi method. For this purpose, four different acids (HCl, H2SO4, HNO3, and CH3COOH) and two alkalis (NaOH and KOH) were tested. The factors were acid/alkali type and amount (1, 2, 3, and 4%), CSS amount (2.5, 7.5, 12.5, and 17.5%), and treatment time (15, 30, 45, and 60 min). Sixteen experimental runs were performed using the L16 orthogonal array. The conditions under which maximum glucose release was obtained and the effects of these conditions on the process were examined. The maximum glucose yield (Yg= 0.037 gglucose/gbiomass) was obtained by autoclaving a 4% (v/v) HCl solution containing 17.5% CSS (w/v) for 60 min. This study evaluated the effectiveness of pre-enzymatic CSS treatments to produce fermentable sugars that are valuable for various industrial applications. Keywords : Glucose Optimization Taguchi Coffee by-products Waste management