Electrophoretic and immunochemical characteristics of wheat protein fractions and their relationship to chapati-making quality

The major portion of wheat produced in India is used in the preparation of traditional foods, such as chapati and its variants. The quality of chapati is mainly influenced by the quality of wheat used. The present study was aimed at predicting the suitability of wheat for chapati-making by assessing the biochemical and immunochemical characteristics of 10 major commercially released Indian wheat cultivars. Wheat proteins and their fractions, such as Soluble proteins (albumin and globulin), gliadin and glutenin, of different wheat cultivars, were isolated and quantified. The albumin and globulin ranged from 0.9 to 2.0%, gliadin 4.0-6.4%, soluble glutenin 0.9-1.1% insoluble glutenin 2.5-46%. The variety DWR 240 had the maximum content of gliadin. The variety NIAW 612 had the maximum percent of glutenin. Wheat varieties having higher amounts of gliadin protein resulted in poor quality chapati (r= -0.68; P<0.05). Albumin and globulin did not have any role in governing chapati-making quality. The proteins subjected to sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that varieties having good chapati-making quality exhibited distinct electrophoretic patterns. For the first time, a dot-blot tecimique was developed, using anti-gliadin antibodies, to differentiate wheat varieties with respect to chapati-making quality. The results indicated that either SDS-PAGE or dot-blot techniques could be conveniently used for identification of wheat varieties suitable for chapati making. (C) 2002 Elsevier Science Ltd. All rights reserved.