Effect of dried yam flour (Dioscorea schimperiana) on cooking quality, digestibility profile and antioxidant potential of wheat based pasta

Yam flour (Dioscorea schimperiana) prepared by traditional (TPYF) and modified (MPYF) processes has been used as an ingredient, to develop bio-functionally enriched pasta. The yam flours have been blended with Durum semolina flour at different levels (10, 20, 30 & 60%) to produce pasta. The cooking quality, antioxidant potential, digestibility profile and sensory profile of the blended pasta have been evaluated. Above all the substituted yam based pasta, the cooking loss was within the permissible level (8%). The β-carotene content of MPYF substituted pasta was significantly higher compared to TPYF samples. The incorporation of yam flour substantially improved total phenolic content (2.9 and 1.7 fold for 60% substituted MPYF and TPYF respectively as compared to control). The same trend was observed with the antioxidant capacity (ABTS - 3.80 and 1.41 fold; RSA - 2.21 and 1.72 fold; FRAP - 14.48 and 11.22 fold respectively for 60% MPYF and TPYF sample as compared to control). The in vitro starch digestibility was reduced significantly among the samples (62.35% in control pasta to 46.41% in 60%MPYF and 50.01% in 60%TPYF samples). The starch profile indicated a significant decrease of rapidly digestible starch (62.63% in control to 43.55% in 60%MPYF and 43.04% in 60%TPYF samples). Sensory evaluation revealed that pasta with up to 30% yam flour was acceptable. Dioscorea schimperiana can be used to improve pasta nutritional quality. For better functional potential, modified process yam flour is suitable.