Chapati, an unleavened flat bread, is a staple in the diet in Pakistan. Wheat in the form of chapati can contribute as much as 90% of the total dietary energy intake to the rural population and generally provides more than half dietary energy and protein. Such a heavy dependence on this cereal food has led to protein malnutrition due to wheat proteins being deficient in lysine, an essential amino acid. The aim of this study was to produce savoury chapati with enhanced nutritional value. Attitudes to a variety of savoury flavours were determined in consumers of Pakistan and in immigrants to Glasgow. Chicken and meaty were most and cheesy least preferred. Amongst chapati quality characters, nutritional value was rated highest followed by flavour. These studies suggested that consumers favoured a product with appropriate flavour, a soft texture and of high nutritional value. Typically chapaties are prepared with wholemeal flours with medium rheological optima. Doughs of British wheat varieties Fresco and Galahad (33+67) and Mercia and Galahad (50+50) had moderate stickiness, high sheeting ability, and were low in shrinkage after sheeting. Such suitable mixtures yielded flours suitable for chapati production. Wheat protein profiles were determined by electrophoresis and relationships between proteins and rheological properties determined with partial least squares regression (PLS2). Dough development time was positively correlated with aggregated values of high molecular weight (HMW) and low molecular weight (LMW) glutenins, ratio of polymeric to monomeric and LMW glutenins, and negatively correlated with the total of gliadin, globulin and albumin fractions. Dough stability showed negative and tolerance index positive correlations with gliadin. Resistance to extension was associated with dough stability and inversely with gliadin content. Such studies reveal that glutenin contributes strength and gliadin imparts weakness to flour. Response surface methodology, used to optimise chapa ties , revealed that a successful savoury product could be produced by incorporating 1.5 to 2.0 % yeast extract without any deleterious effect on dough physical characteristics. Yeast extract enhanced the concentrations of protein from 13.1 % to 14.4 % in chapati. In addition to enhanced nutritional value, yeast extract imparted a desirable savoury flavour to chapati.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:595826 |
| Date | January 1994 |
| Creators | Rehman, Salim-Ur |
| Publisher | University of Strathclyde |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=23309 |
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