Rapid assessment of glutenin and gliadin in wheat by UV spectrophotometer

Traditional breeding of common wheat (Triticum aestivam L.) concentrates largely on the improvement of protein quality because of the importance of protein in end-product functionality, nutritional value, and economic impact. New, rapid, and inexpensive protein quality tests are required to identify premium quality families from large and diverse early-generation breeding populations. In this study, a simple method was designed using organic solvents to divide wheat proteins into monomeric-rich (single-chain, mostly gliadin), polymeric-rich (multichain, mostly low- and high-molecular weight glutenin), and total soluble protein (monomeric and polymeric protein). Monomericrich and total soluble protein fractions were quantified at 280 nm with an ultraviolet (UV) spectrophotometer. Protein fractions were expressed in terms of absolute concentration and as a proportion of total soluble protein. A strong linear relationship between the protein concentration in the fractions and the absorbance reading indicated that the method could accommodate a large range of protein fraction concentrations. The specific relationships between quantity and proportion of monomeric/polymeric protein fractions and dough quality tests allowed for the design of an algorithm eliminating poor quality lines from further breeding assessment. Simplicity, reliability, low cost, and a potential for automation could make this UV-spectrophotometric method suitable for routine use in wheat breeding programs.