Effect of raw and heat-treated yellow lentil flour on starch-based gluten-free noodle quality

In this study, raw yellow lentil flour (YL) and heat-treated yellow lentil flour (HYL) were used at different levels (0-80%, w/w) to produce lentil flour-enriched noodles. Physicochemical, thermal, and functional properties of the YL and HYL were compared for evaluating the effects of heat treatment. Besides, noodle quality, nutrient composition, textural, sensory, and microstructural analyses were performed. The protein content of YL and HYL was found in the same group (p > .05), although a significant reduction in the water-soluble proteins was observed (p < .05). Similarly, ash, water holding capacity, swelling power, and solubility of HYL were lower than YL. The denaturation peak temperature of YL was found as 116.8 degrees C and shifted to 122.7 degrees C for HYL. Nutritional composition of noodles was improved by increasing the level of YL and HYL. Although an increase was observed in phytic acid by YL/HYL addition, it decreased after cooking of noodles. Overall, all noodles were evaluated as acceptable. Novelty impact statement Gluten-free food formulations are often based on starch-based ingredients; therefore, have low nutritional quality, rich in carbohydrate and fat, low in dietary fiber. Water-soluble protein amount of raw and heat-treated yellow lentil flour-based noodles was significantly higher (nearly 4x and 2x, respectively) than control (potato starch-rice flour-based) noodle. Hardness values were found between 7.1 and 14.0 N and did not show any correlation with the amount of yellow lentil flour. HYL20 noodle had the highest flavor and overall liking score, but for all tested sensory parameters the noodles had scored above 5 point, so they were regarded as acceptable.

Automated summary

This study compared the physicochemical, thermal, and functional properties of raw and heat-treated yellow lentil flour, and evaluated the quality, nutrient composition, texture, sensory, and microstructural analyses of lentil flour-enriched noodles. The results showed that heat treatment reduced the water-soluble proteins and affected the ash, water holding capacity, swelling power, and solubility of the lentil flour. Increasing the level of lentil flour improved the nutritional composition of the noodles, although phytic acid increased initially and decreased after cooking. Overall, the noodles were considered acceptable.