Biochemical Characterization of Tunisian Cichorium Intybus L. Roots and Optimization of Ultrasonic Inulin Extraction

In this study Cichorium intybus L. roots were tested for its chemical composition, antioxidant activity, and phenolic profile. Optimization of ultrasonic inulin extraction using response surface methodology (RSM) was further investigated. Chicory roots were found to have high value of total carbohydrates (70.43%), soluble fiber (66.93), Neutral detergent fiber (NDF) (33.07%), potassium (380 mg/100g), calcium (540 mg/100g) and sodium (140 mg/100g). Chicory roots exhibit a high content of flavonoids, polyphenols, and tannins. Antioxidant activity measurement reveals the capacity of Chicory roots to scavenge diphenylpicrylhydrazyl (DPPH) radicals. Phenolic acids profile shows the abundance of vanillic acid (19.64%) followed by protocatechuic acid (15.67%). The effect of three independent variables namely extraction time, the ratio of water to raw material and temperature on inulin extraction was studied. Optimum deciding responses were Inulin content, Total Soluble Solids (TSS) content and Water produced inulin yield. The optimal ultrasonic extraction conditions were: extraction time 87 min, liquid to solid ratio 38 (ml/g) and ultrasonic temperature 61 C. Under these conditions, the inulin content, TSS content and produced inulin yield were 35.92%, 24.72%, and 32.53%, respectively. The produced inulin was characterized by the Fourier infrared transformation (FTIR) and observed by means of scanning electron microscopy (SEM).