Physicochemical and Pasting Characteristics of Local Wheat Flour Grown in the Northern Thailand

Abstract

The study was about the physicochemical and pasting characteristics of 21 local northern wheat flour varieties grown in Chiang Mai (CM), Lamphun (LP) and Mae Hong Son (MH). The objective of this research was to analyze the chemical values in percentages (crude protein, starch, and gluten), physical values (water absorption and dough hardness), and rheological values from starch pasting (peak viscosity, final viscosity, and setback viscosity). The statistical analysis was carried out using cluster analysis of physicochemical characteristics and principal component analysis (PCA) of pasting characteristics. The results showed that all samples of local wheat flour contained two macromolecule components. Gluten helped in dough structure development, and a starch gel occurred when heat starch was in excess water. The higher protein content of wheat flour caused the lower gel viscosity values. PCA revealed that starch and protein were the constituents associated with starch gel formation. Gluten was involved in a network structure formation within the dough by kneading local wheat flour in the presence of water until the dough formed an elastic and sheet-like structure. The natural combination of protein and starch affected the overall quality of local wheat flour. In the northern region, 11 local wheat varieties exhibited medium protein content (CMS2, CMS4, CMF1, CMF3, CMF4, LP2, LP3, LP5, MH1, MH3, and MH4) and four local wheat varieties showing low protein content (CMR1, CMS1, LP4, and MH2). The physicochemical and pasting characteristics of all categorized samples were not statistically different from those of the Thai industrial standard of wheat flour (p>0.05). None of the local wheat flour had a flour quality comparable to that of a high protein content. The research supported future work on local wheat breeding for flour utilization in Thai food products.