The evaluation of biological value and immunochemical characteristics of the coagulated chicken egg white
The aim of the study was to investigate in vivo the biological value of the coagulated chicken egg white on growing rats and a comparative immunochemical evaluation in vitro of its antigenic power. The experiment was carried out on 50 growing Wistar male rats with a body weight of 80±5 g. The animals were randomly divided into 3 groups (n=16): control group G1 and two experimental groups G2 and G3. The animals of the control group (G1) received a basic isocaloric and isonitrogenous (20% protein of casein by caloric content) semi-synthetic diet. The animals of the experimental groups G2 and G3 received the same semi-synthetic diet in which casein was replaced by chicken egg white (CEW) and coagulated CEW, respectively. The average food intake of group G3 animals, who received the CEW coagulate, was significantly lower (13.7±0.6 g per day, p<0.05) in comparison with the control group G1 (18.4±0.6 g) and the experimental group G2 (19.2±0.5 g). Moreover, body weight gain of animals treated with coagulated CEW didn't differ significantly from the control G1 animals. Already on the 8th day of the experiment, the body weight gain of G2 animals, who consumed native CEW, was significantly higher in comparison with both other groups. The protein efficiency ratio (PER) for animals of the G3 group was significantly higher (1.96±0.04) than the values for the animals of the control group G1 receiving casein (1.49±0.05, p<0.01), and for the animals of the experimental group G2 receiving CEW (1.60±0.02, p<0.05). The results of immune-enzymatic testing of the initial antigenic power of ovalbumin in native CEW indicated that its content was 33.0% relative to the standard ovalbumin value, antigenic power of which was assumed to be 100%. The developed process of coagulation contributed to a decrease in antigenic power to 2.17%. The obtained data indicate a high biological value and low antigenic power of the coagulated CEW, which makes it prospective for the usage in the composition of food products of mass demand and specialized food products.
Keywords:coagulated chicken egg white, biological value, protein efficiency ratio, true digestibility, antigenic power
Voprosy pitaniia [Problems of Nutrition]. 2018; 87 (1): 44-50. doi: 10.24411/0042-8833-2018-10005.