Studies were conducted to clarify the effect of dietary protein on the development in rats poisoned with lead, and the following results were obtained. (1) The amounts of exogenous lead in the whole brain and blood of low protein group were higher than those of high protein group. (2) Body weight gain per gram of dietary protein in the control group was higher than that in the lead-administered group. To elucidate these mechanisms, the transferred amount of both lead and amino acids were measured. The rat small intestine, to which 1ml of casein solution, 1ml of lead nitrate solution and trypsin were packed, was incubated for 60minutes. The amount of lead transferred from intestinal mucosa to medium was markedly reduced by increasing amounts of protein added, and that of amino acid transferred was also inversely related to the lead concentration used. The activity of proteolytic enzyme was inhibited non-competitively by in vitro addition of lead, which Ki value was obtained to be 0.0015M.
The feeding of high fat diet induced fatty liver, while the feeding of high carbohydrate diet caused hyperlipemia. In the case of the high fat diet, triglyceride was deposited markedly in the liver (namely, deposited type). Elevated levels of serum triglyceride might result from increased secretion of triglyceride from the liver (namely, secreted type). No difference in cholinephosphotransferase activity was observed between the two groups. In contrast, diacylglycerol acyltransferase activity was higher in rats fed the high fat diet than in those fed the high carbohydrate diet. The lipoprotein lipase activities in both the plasma after heparin injection and the adipose tissues were similar in the two groups, suggesting that the delivery of triglyceride from the plasma to the adipose tissue proceeds at a similar rate between the two groups. Morphological examination revealed an increased number or size of lipid droplets in the liver cell cytoplasm of rats fed the high fat diet.
To know the quality of shortening, 29 samples were analyzed. Acid value was in the range of 0.03-0.12 (X 0.060), peroxide value, 0.0-0.93 (X 0.435) and carbonyl value, 0.74-5.14 (X 2.680), indicating no deterioration of oils. Melting point and iodine value varied greatly according to their usig properties, but there was hardly any difference in the saponification value among the samples except for four samples containing coconut oil. Long-chain fatty acids of over C20 were not found in the majority of samples, and shortchain fatty acids of less than C12 were found in four samples. In general, amount of C16 acids was characteristically great, and found in 32.46% on the average. Sterols detected were cholesterol, campesterol, stigmasterol and β-sitosterol. It was found from the features of sterol and fatty acid compositions that four samples consisted of only animal fats, 13 from vegetable oils, and 12 samples mixtures. From the results obtained above, it was noticed that lard was used as a main animal fat and palm oil was the main vegetable oil for shortening.
AOM test and oven test (50°C, 10 weeks) were carried out with 29 samples of shortening for frying and spraying, and the correlation between the stability and the composition of shortening was examined. Even though there was hardly recognized any changes in acid value by oven test with all samples tested, but changes of peroxide vatue separated into two groups, the one showed no change and the other changed rapidly. As the results of AOM test, it was found that there were 9 samples which required more than 100hrs. and 6 samples which required less than 50hrs. In general, samples compounded with coconut oil system and those with low degree of unsaturation tended to prolon, g the AOM time. There were correlations between iodine value or content of unsaturated fatty acids and the AOM time or the peroxide value obtained by the oven test for 10 weeks, but the correlation coefficients with the AOM time was higher than those with the peroxide value.
To investigate the relationship between meat tenderness and content of the CASF (Ca2+-activated sarcoplasmic factor), the CASF was prepared from broiler and culled chicken pectoralis muscles immediately after death. The yield of the crude CASF prepared from broiler was lower than that from culled chicken, while the specific activity of the former was higher than that of the latter. The crude CASF was fractionated into three fractions (A, B and C) by gel filtration on Sepharose 6B, and the fraction B was a main fraction of the CASF activity. The ratio of the fraction B to other fractions was higher for the crude CASF prepared from broiler than that from culled chicken. It seems to be difficult to explain the difference in the tenderness between broiler and culled chicken meats only from the standpoint of the CASF activity.