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).
On the fractionation of β-lactoglobulin and α-lactalbumin
Abstract Existing methods for the preparation of α-lactalbumin and β-lactoglobulin are examined critically. It is proposed that the most satisfactory method for the preparation of the whey protein fraction from bovine milk is (NH 4 ) 2 SO 4 fractionation. A number of new gentle procedures for the fractionation of the whey proteins are compared with some existing methods. The distribution of total protein at various stages is determined by total Kjeldahl nitrogen and the kind of protein by starch-gel electrophoresis. The effect of variables, such as pH, salt concentration and temperature on the separation of α-lactalbumin and serum albumin from β-lactoglobulin is studied. Differences in the behavior ( e.g. solubility) of genetic variants of β-lactoglobulin are noted. The solubility of each of the major whey proteins, under similar conditions to those used in the fractionation, is compared with its solubility in the whey protein mixture. The understanding gained of factors important in the fractionation is used in recommending new procedures for α-lactalbumin and β-lactoglobulin isolation.