EFFECT OF DIFFERENT DOUGH IMPROVERS ON THE PROXIMATE COMPOSITION, MINERALS, VITAMINS AND SENSORY PROPERTIES OF WHEAT BREAD
Comparative evaluation of bread made from wheat flour using five different dough improvers was evaluated. The improvers were ascorbic acid, EDC-2000, (etheylene dough conditioner), egg, STK (screw thread kneading), and azodicarbonamide. The samples were coded A, B, C, D, E and F where sample A with no improver served as the control. The proximate composition of the bread samples analyzed showed that the percentage crude protein content of the samples ranged between 7.06+0.06 to 8.37+0.11 and were significantly different at P<0.05 for all the dough improvers used. The highest value for the crude protein was recorded for bread baked with egg as the dough improver with a value of 8.37+0.11%. The % moisture, % ash and %crude fibre contents were not significantly different at P<0.05 while the fat and carbohydrate contents were significantly different for all the improvers used. The mineral composition of the bread samples analyzed were potassium, calcium, zinc, iron and phosphorus and all were significantly different with all the dough improvers used and the control sample A at P<0.05. The vitamin content analyzed comprised of water soluble and fat soluble vitamins. Vitamin A content of the bread samples ranged between 3.28+0.00mg/100g to 3.45+0.00mg/100g. The water soluble vitamins which comprised of Vitamins C, B1, B2, and B3 were not significantly different with the control sample A at P<0.05 for all the dough improvers used. Bread samples were evaluated for sensory attributes of appearance, texture, crumb color, crust color, taste and general acceptability. Samples B, D, and E were rated significantly higher (P<0.05) for all the attributes except for taste. In terms of general acceptability, sample B (ascorbic acid improver) was rated highest with a mean value of 8.08+0.67 followed by sample D (egg improver) with a mean value of 8.0±0.43 while the least was recorded for bread without improver (control) with a mean value of 6.42±1.08.The bread volume was rated highest for sample B (ascorbic acid) with a value of 3906.25cm 3 while the least volume was recorded for the bread without dough improver (control) with a value of 2310cm 3 . This work showed that acceptable bread could be produced from wheat flour using all the five bread improvers with ascorbic acid and egg giving better results in terms of sensory and physical characteristics of the bread.
Improved nutritional value in wheat bread by fortification with full-fat winged bean flour (Psophocarpus tetragonolobus L. DC)
The nutrient composition of winged bean (Psophocarpus tetragonolobus L.DC) full-fat flour (WBFF), wheat flour (WF) and WBFF-fortified breads was studied. When WBFF fortification was increased from 0 to 20%, there was an increase of 63% in protein, 153% in fat, 130% in calcium, 97% in phosphorus, and 105% in iron contents. WBFF contained greater amounts (g/16g N) of histidine and lysine compared to WF. Except methionine which decreased, all other essential amino acids increased when WBFF was substituted for WF from 0 to 15%. The protein efficiency ratio for 10%-WBFF bread (1.62) was found to be significantly greater (P<0.05) than that of 5%-WBFF bread (1.40) and wheat bread (1.11).
Nutritive value of the winged bean (Psophocarpus palustris Desv.)
1. The winged bean (Psophocarpus palustris Desv.) has been grown successfully for several seasons, on an experimental basis, in the forest belt of Ghana, where earlier attempts to grow the soya bean had proved unsatisfactory. 2. Although botanically different, the composition of the dry seeds was found to be very similar to that of the soya bean, containing 37·3% protein, 18·1% fat, 13·9 ppm thiamin and 1·8 ppm riboflavin. The oil of the seeds contained 125·9 mg tocopherol (γ + β) per 100 g. The amino acid composition of the protein was very similar to that of the soya bean, with methionine as the first-limiting amino acid. The content of unsaturated fatty acids and that of poly-unsaturated essential fatty acids were satisfactory. Active trypsin inhibitor found in the raw seeds could be destroyed satisfactorily by moist heat. No urease activity was detected. The protein efficiency ratio (PER) and net protein utilization (NPU) of the beans determined with rats, were superior to those of groundnuts. The supplementary value of the protein was shown by mixing two parts of the winged bean and three parts of maize flour. When adjusted to either 10% or 16% protein, the PER values of these mixtures were similar to those of skim milk. At the 16% protein level, addition of skim milk or 0·3% DL-methionine to this mixture produced only an insignificant improvement in PER value. The pleasant, sweet taste even when in the raw state is one of the advantages of the winged bean. Although, it is a climber, and should be staked, its cultivation on a small scale in selected areas of Ghana is recommended.