|Budget Amount *help
¥1,000,000 (Direct Cost : ¥1,000,000)
Fiscal Year 1996 : ¥1,000,000 (Direct Cost : ¥1,000,000)
In order to examined the optimum conditions for the Millard reaction between whey protein and glucose-6-phosphate (G6P) were examined, whey protein and G6P were dissolved at various weight ratios at pH 7.0, freeze-dried, incubated at 50ﾟC and 65% relative humidity, and the browning, polymerization of proteins, the phosphorus content of reaction products were measured. The following conditions were appropriate : the ratio of whey protein to G6P,1 to 0.3 ; reaction time, less than 1 day, because brown color development and polymerization of protein exceed rapidly and the phosphorous content of whey protein-G6P conjugates prepared for 0.5 or 1 day of incubation was higher that of casein. The effect of the WPI (whey protein isolate) -G6P conjugate on calcium absorption was examined using rats. The proportions of soluble calcium in the ligated loop of the small intestine of the soy protein, casein, and WPI-G6P conjugate diet groups were 43.2(]SY.+-。[)8.7,72.7(]SY.+-。[)8.0, and 77.7(]SY.+-。[)9.7, respectively. The soluble calcium in the small intestine was significantly higher in the WPI-G6P conjugate diet group than in the soy protein diet group. This indicated that the WPI-G6P conjugate solubilizes calcium to prevent the precipitation of calcium phosphate in the small intestine. The calcium absorption, which was estimated by the disappearance of <@D145@>D1Ca in the ligated loop, of the soy protein, casein, and WPI-G6P conjugate diet groups was 50.7(]SY.+-。[)17.6,58.5(]SY.+-。[)8.3, and 72.6(]SY.+-。[)19.7, respectively. The calcium absorption was also higher in the WPI-G6P conjugate diet group than in the soy protein diet group. These results suggest that WPI-G6P conjugates are useful as food materials.