effect of ovalbumin and mannose-conjugated ovalbumin on the prevention of salmonella adherence to the intestinal epithelium of chickens

This investigation was designed to determine the effect of intact ovalbumin and mannose-conjugated ovalbumin on the prevention of Salmonella typhimurium adherence to the epithelium of small intestine of chickens. Mannose-conjugated ovalbumin was produced by Maillard-type reaction between chicken ovalbumin and D-mannose at 60[degree]C. The results revealed that incubation up to 96 hrs caused the highest amount of covalent attachment of mannose to the ovalbumin. In order to determine the effect of native ovalbumin and mannose-conjugated ovalbumin on the prevention of S. typhimurium adherence to chicken small intestine, 60 one-day-old chicks were randomly assigned to 3 groups, with two replicates and ten birds per pen. Groups 1, 2 and 3 received normal diet, diet containing 0.5% native ovalbumin and diet containing 0.5% mannose-conjugated ovalbumin, respectively, for 12 days. On day 3, all groups received 1.3 x 10[6] CFU of S. typhimurium orally. On days 4, 7 and 10, two chicks from each group were killed and mean log 10 of CFU [colony forming unit] of Salmonella per 1 g tissues of cecum, liver and spleen was determined. Four chickens from each group were killed on day 12 and were examined as described above. The results showed that in group 3, number of viable Salmonella in cecum, liver and spleen was lower than groups 1 and 2. However, the difference was significant only in cecum on days 4 and 7 [P<0.05]. These preliminary results suggest that mannose-conjugated ovalbumin might be effective in prevention of Salmonella colonization in the epithelium of small intestine if incorporated in the diet of chicks

[Study on activities of some enzymes and protein electrophoretic patterns in heat treated meat products]

Study on some enzymes and protein electrophoretic patterns in order to find an indicator for adequacy of heat treatment in meat products. Experimental study. The activities of some enzymes, including: lactate dehydrogenase [LDH], aspartate amino transferase [AST] and alanine amino transferase [ALT], were assayed in meat and heat treated meat products at different time- temperatures combinations. Extracts of samples were used for electrophoresis by SDS-PAGE method. Analysis of variance and Duncan's test. LDH was active and demonstrated a good stability in samples which were heated up to 65 [degree sign] C for 55 minute. However, its activity started to decline thereafter so that at 70 [degree sign] C no significant activity was observed. ALT and AST were more heat stable than LDH and their activities were still present in heat treated products at 70 [degree sign] C for 30 minutes and vanished at 75 [degree sign]C. Many protein bands disappeared in SDS-PAGE pattern of meatn products which heated at 65 [degree sign] C or above. LDH can be considered as a suitable indicator for meat products that have been heated at 70 [degree sign] C or above