Influence of dough porosity and rheology on the quality of chapattis made with wheat and lupin flours

Abstract

Chapattis are a staple in the diet of people living in the subcontinent of India. They are widely made using atta flour in homes and in small scale industries. Atta is flour obtained by grinding wheat grown in the Indian sub-continent. Atta dough is made by mixing flour with only salt and water. It is rolled into circular disks and baked on open hot stoves. High quality chapattis puff during baking and remain soft and pliable over a considerable period of time. Attempts to make chapattis of the same quality have been made in countries outside of the Indian sub-continent using local flours. However, it has not been possible to produce products of a similar quality. The same issue of quality – sub-standard puffing and texture, has also hindered fortifying atta by adding nutritionrich additives, like pulse flours. A project was carried out in our laboratory comparing quality of chapattis made with Indian atta with those made with local wholemeal flour (WW), mixes of local wholemeal flour (L+WW) and lupin flour and 100% lupin flour. Lupin is a legume, high in protein and fibre with no starch. Having no gluten, lupin dough lacks extensibility. All chapattis made from these four different flours, including those made with 100% lupin dough, puffed fully. Qualitatively, the quality of chapattis made with atta was equivalent to those made with the mix of lupin flour and WW flour. To understand these surprising results, doughs were characterized by measurement of true rheological properties and by image analyses of pore structures in doughs using a Skyscan CT scanner. Results showed that atta dough was more porous and
retained more elasticity and porosity compared to other doughs. Dough extensibility was not a requirement for puffing of chapattis. These results provide new methods for characterizing atta dough quality and methods to guide addition of additives atta to improve nutritional profiles.