The garlic (Allium. sativum L.) straw, used as raw material, was discharged from the manufacturing process of conservation of garlic. Sulfuric acid (H2SO4, > 95 wt%) was purchased from Chimie-Plus (France). Sodium hydroxide, sodium chlorite and sodium chloride were purchased from Roth (France). Acetic acid was purchased from Sigma-Aldrich (France). All chemicals were used as received and without further purification.