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.
COMPARATIVE LEVELS OF BROMATE AND METALS IN BREAD LOAVES OBTAINED FROM CORPORATE AND LOCAL BAKERIES IN TWO COMMUNITIES OF LAGOS, NIGERIA
A comparative assessment of potassium bromate and trace/toxic metal levels in bread loaves obtained from selected corporate and local bakeries in two communities of Lagos, Nigeria, was carried out using High Performance Liquid Chromatography (HPLC) and Atomic Absorption Spectrophotometry (AAS). Potassium bromate was present in bread loaves obtained from both corporate and local bakeries, but the bread loaves obtained from local bakeries had significantly higher (p < 0.05) bromate levels. The lowest bromate levels in bread loaves obtained from corporate bakeries was 1.18 ± 0.01 mg/kg, while the highest was 2.26 ± 0.01 mg/kg. The lowest and highest bromate levels in bread loaves obtained from local bakeries were 3.85 ± 0.01 and 11.13 ± 0.00 mg/kg, respectively. The concentrations of metals in the sampled bread loaves were generally below regulatory limits. Bread loaves obtained from corporate bakery 5 had the highest Zn content of 3.26 ± 0.06 mg/kg bread, while the lowest Zn level of 1.18 ± 0.03 mg/kg was found in loaves obtained from local bakery 2. Bread loaves obtained from local bakeries 1, 2 and 3 had Pb contents of 1.26 ± 0.01, 1.26 ± 0.02 and 0.59 ± 0.02 mg/kg, respectively. Bread loaves obtained from corporate bakery 1 had a mean Co content of 0.01 ± 0.01 mg/kg while loaves obtained from local bakeries 3 and 4 had Co contents of 0.08 ± 0.01 and 0.06 ± 0.00 mg/kg, respectively. There is need for regulatory agencies in Nigeria to take adequate steps that will ensure safety compliance among bakers.
Low dose radiation and intercellular induction of apoptosis: potential implications for the control of oncogenesis
Purpose: This review is focused on the potential impact of low dose radiation effects on intercellular induction of apoptosis and the underlying reactive-oxygen species (ROS)-mediated signaling pathways. Results: Transformed cells are subject to ROS-mediated apoptosis induction by non-transformed cells (‘intercellular induction of apoptosis’) and by ROS-mediated autocrine self-destruction. Sensitivity to intercellular induction of apoptosis and autocrine self-destruction are strictly correlated to the expression of the transformed state. Extracellular superoxide anions generated by transformed target cells drive the selectivity and sensitivity of this signaling system which is based on four different signaling pathways. Low dose irradiation of non-transformed cells enhances intercellular induction of apoptosis in transformed cells. This process is controlled by TGF-beta and seems to depend on the induction of peroxidase release. In addition, low dose radiation enhances superoxide anion generation of transformed target cells. Conclusions: Low dose radiation-triggered enhancement of intercellular induction of apoptosis and autocrine selfdestruction might represent a potential control system during carcinogenesis. It might be the underlying mechanism for the well-known inhibitory effect of low dose radiation on detectable transformation events. However, modifications of the complex intercellular ROS-based signaling system may also lead to configurations in which low dose radiation attenuates ROS-mediated apoptosis induction.