Enzymatic extraction of pectin from artichoke (Cynara scolymus L.) by-products using Celluclast^®1.5L

The aim of this study was to optimise pectin extraction from artichoke by-products with Celluclast^®1.5L using an experimental design analysed by response-surface methodology (RSM). The variables optimised were artichoke by-product powder concentration (2-7%, X₁), enzyme dose (2.2-13.3 U g^-1, X₂) and extraction time (6-24 h, X₃). The variables studied were galacturonic acid (GalA) (R² 93.9) and pectic neutral sugars (R² 92.8) content and pectin yield (R² 88.6). In the optimum extraction conditions (X₁ = 6.5%; X₂ = 10.1 U g^-1; X₃ = 27.2 h), pectin yield was 176 mgg^-1 dry matter (DM). Considering 27.2 h of treatment as the +α value given by the design, the extraction time was increased up to 48 h obtaining a yield of 221 mg g^-1 DM. The enzymatic method optimised allows obtaining artichoke pectin with good yield, high GalA (720 mg g^-1 DM) and arabinose (127.6mgg^-1 DM) contents and degree of methylation of 19.5%.