Effect of water requirement and alkali on wheat-rice noodle quality

High protein wheat flour (14.8% protein) was diluted with high AM rice flour to obtain a noodle quality that was comparable to all-purpose wheat flour of 10.6% protein content. Rice flour substitution levels and water addition levels were studied in an attempt to optimize noodle quality using response surface methodology (RSM). Increased substitution of wheat flour with rice flour and increasing water addition levels resulted in the lowering of all textural parameters; maximum tensile strength, maximum distance, maximum cutting force, and cutting curve area. Increased rice flour substitution had a more pronounced effect on textural quality than water addition level. A water addition level appropriate for the level of wheat flour substitution is a critical factor determining noodle quality. The relationship between rice flour substitution level and water addition level was significant for all quality criteria (p0.05). Wheat-rice flour blends exhibited higher peak viscosities and breakdown values, producing noodles with more smoothness, less firmness, and less elasticity. No significant difference in cooking loss of wheat-rice noodles was detected at substitution levels of up to 30% (p0.05). Increasing alkali concentration up to levels of 1.5% can induce protein aggregation by disulphide bonding; resulting in improvement of almost all textural quality metrics.