No abstract

Physicochemical and rheological properties of wheat flour defines its end use and are influenced by variety and environmental factors. New varieties need to be evaluated under different environments to determine the environment and variety best suited desired quality characteristics. This study was designed to evaluate the baking quality performance of 17 advanced stem rust wheat lines and 3 varieties under different environments. Completely Randomized Block Design experiments were set up in five zones in Kenya; Njoro, Narok, Naivasha, Eldoret and Timau where the 17 advanced lines and 3 varieties were grown and different baking quality parameters evaluated. The baking quality parameters were analysed following the approved and AACCI methods as described in the materials and methods section. Protein results ranged from 7.90 to 14.67%, gluten12.30 to 32.20%, and zeleny 10.07 to 56.33% respectively. Dough development time ranged from 1.50 to 7.33 minutes, dough stability0.92 to 15.67 minutes, water absorption60.67 to 70.07% and mixing toleranceindex8.33 to 96.67 B.U. Hectolitre weight ranged from 59.19 to 80.14 Kg/Hl, flour extraction 59.19 to 82.50%, starch47.17 to 75.27, ash0.50 to 1.26% and moisture11.67 to 16.10%. Timau a cooler environment in comparison to the other regions recorded lower protein levels compared to Narok a hotter environment which recorded high protein, gluten and zeleny levels regardless of line/genotype evaluated, confirming the influence of environment on baking quality parameters. K. Ibis and R1290 recorded high protein levels except in Timau which points to the stability of genotypic qualities across the environments. Timau proved to be the best site for soft wheat and Njoro for hard wheat due to the high quality characteristics observed in the lines/genotypes.