Abstract: In this paper, the effect of added konjac glucomannan (KGM) on the quality and in vitro starch digestibility of noodles was studied. A texture analyzer, a scanning electron micrograph (SEM) and an in vitro starch digestion model were employed to investigate the impact of adding 0–5.00% (m/m) KGM on the texture and cooking properties and in vitro starch digestibility of noodles. The results showed that the water-absorbing capacity and swelling index of noodles increased with the increase of KGM addition, while the cooking loss firstly increased and then decreased, reaching its minimum value with 2.50% KGM addition. The texture profile analysis (TPA) properties of noodles were enhanced with increasing amount of KGM added, while the firmness was reduced. Incorporation of KGM could slow down the release of sugars during in vitro starch digestion, leading to a reduction in the predicted glycemic index (pGI) of noodles. The pGI value of noodles incorporated with 5.00% KGM was reduced by 12.22% when compared to the control. These results suggested that the nutritious quality of noodles could be improved by supplementing KGM, and the best quality was obtained with addition of 2.50% KGM.

Key words: noodles, konjac glucomannan, quality evaluation, starch digestibility