Inulin enriched durum wheat spaghetti: Effect of polymerization degree on technological and nutritional characteristics

The flours coming from four ancient Sicilian durum wheat cultivars were used to produce spaghetti enriched with 4% inulin at two degree of polymerization (DP): cardoon roots (CRI, high DP) and chicory (CHI, low DP). The influence of DP on quality, sensory properties, glycaemic index (GI) of enriched spaghetti was investigated; further the release of inulin after simulated in vitro digestion was also assessed. The DP affected most of the sensorial attributes of pasta as overall quality score (OQS), cooking loss and optimal cooking time. Among the cultivars, Timilia and Margherito maintained the OQS scores after inulin addition. Both the presence and the different DP of inulin did not influence the GI values, except a decrease recorded for Timilia spaghetti. Finally, in all the studied cultivars, DP significantly affected the inulin release in the digestive tract highlighting the highest amount of CRI inulin in solid fraction important for potential prebiotic effect.