The mean dietary zinc intake of 8 young women was calculated to be 6.3±0.7mg/day (0.114±0.019mg/day/kg body weight) from the results of a 9-week dietary consumption survey using our own database on the zinc content of food. The mean plasma zinc concentration on the first day of the dietary consumption survey was 0.74±0.10μg/ml, and that on the day after completion of the survey was 0.78±0.13μg/ml. There was a significant correlation betweea zinc intake (per kg body weight) for the 9-week period and the plasma zinc level after the survey (r=0.793, p<0.05). Moreover, the zhlc intake in a selected period of the survey frem 4 to 6 weeks showed a high positive correlation with thle plasma zinc level after the survey (r=0.905, p<0.01).

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A time and motion study was conducted on 142 men having various jobs and 118 male college students during 2 working days and 1 holiday, and obtained 760 valid data, from which energy consumption and the daily activity factor (x) were estimated. Analysis of individual motion time gave average values of relative metabolic rate (RMR) for sitting, standing, walking and running; these values on the working days were 0.34±0.11, 0.80±0.41, 2.34±0.56, and 4.73±1.81, respectively. A simple formula for estimating the value of x was prepared using these averages, and a method for correcting it was devised for a person who showed special activity for more than 60min on that day, as follows: 0.9×sleeping time (min) +1.54×sitting time (min) +2.00×standing time (min) +3.54×walking time (mjn) +Σ [(RMR value for running+1.2) ×running time (min) +correction coefficient×special activity time (min)] =1600 (1+x). The suitability and usefulness of this formula in practice were evidenced by good agreement between the value of x calculated using the formula and the x value obtained from all the data of the time and motion study.

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An investigation was undertaken to determine the ultrastructural changes occurring in refrigerated breast muscle of fowl. Breast muscle (M. pectoralis) of Rockhorn fowl was excised and stored for 1, 3, 5 or 7 days at 5°C. The length of the sarcomeres measured during refrigeration was used as an indicator of post-mortem muscle contraction and relaxation. Cross-striations as a result of contraction were observed in freshly prepared muscle by electron microscopy. After 1 day of storage, the muscle fibers showed maximum rigor mortis. After 3 days of storage, the rigor was gradually resolved. Disappearance of part of the Z-line, destruction of mitochondria and cracks in the I-band were seen in the muscle fibers. Autolysis proceeded rapidly in the muscle fibers after 5 days of storage. Myofilaments were disintegrated and sarcomeres were broken after 7 days of storage. These results suggest that breakdown of the Z-line, mitochondria and I-band is followed by autolysis of myofibrils.

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The effect of an 8% casein diet (low-protein diet, LPD) on the immune system in, mice was compared with that of a 27% casein diet (control diet, CD). Serum protein level, body weight gain and DTH responses to Listeria monocytogenes (L.M) were suppressed in LPD-fed mice. Primary plaqueforming cell (PFC) responses to SRBC in LPD-fed mice remained low because of suppression of an increase in spleen cell number. There was no effect on natural killer cell activity. A low level of phagocytosis of E. coli B by peritoneal macrophages was observed in LPD-fed mice. The mortality of LPD-fed mice due to primary infection with E. coli B or L.M was slightly lower than that of CD-fed mice, but higher in secondary infection with L.M. These results demonstrate a relationship between undernutrition produced by a low-protein diet and some aspects of the immune system in mice.

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Dietary effects of freeze-dried bovine thymus powder (FDT) and a low-molecular-weight fraction of thymus (LMT) on the blood pressure of spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) were studied. LMT was prepared. from acetone-defatted FDT by water extraction, heat treatment, centrifugation and spray-drying of the supernatant solution. SHR and WKY were fed a diet containing 2% LMT or 10% FDT from 3 weeks of age. Systolic blood pressure of these SHR and WKY was measured at 6, 8, 10 and 12 weeks of age. Both FDT feeding and LMT feeding caused suppression of the rise in blood pressure of SHR from 8 weeks of age, whereas the blood pressure of WKY was not affected by dietary FDT or LMT. Several physiological parameters of rats at 14-16 weeks of age were also examined. Liver weight, serum α₁-globulin content, and GPT activity in SHR were increased, and plasma renin concentration was decreased, by dietary FDT. Serum cholesterol levels were decreased by FDT or LMT. Serum angiotensin-converting enzyme activity and mitogen reactivity of spleen cells were not affected by dietary FDT or LMT. These results suggest that bovine thymus contains some factors that affect the mechanism of spontaneous hypertension develogment in SHR.

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The effects of various kinds of mushroom on plasma cholesterol level in rats were investigated with the aim of finding mushrooms from which plasma cholesterol-lowering compounds could be obtained. Each mushroom was added at a level of 5% to a 25% casein diet containing 1% cholesterol and 0.25% sodium cholate. of eleven kinds of mushroom tested, seven had a plasma cholesterol-lowering effect. In addition to shiitake (Leninus edodes), which has been shown to possess a potent plasma cholesterollowering effect, ningyotake (Polyporus confluens) was also found to have an equally potent effect. The ningyotake mushroom, unlike shiitake, did not centain eritadenine or evoke fatty liver. Feeding of ningyotake significantly increased the fecal excretion of cholesterol and bile acids, whereas shiitake did not enhance fecal steroid excretion. The enhancement of fecal steroid excretion was considered to participate, at least in part, to the plasma cholesterol-lowering effect of ningyotake. These results suggest that the ningyotake mushroom is useful for reduction of plasma cholesterol.

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Insufficient intake of calcium is one of the risk factors for osteoporosis. Recently, many studies have investigated calcium sources and various food components influencing calcium metabolism. In this study, the bone mineral density (BMD) of the lumbar spine and tibia was measured by dual energy X-ray absorptiometry (DEXA) in order to examine the effect of globin powder, a polypeptide mixture (average M.W., 8000), on bone metabolism in model rats with postmenopausal osteoporosis. Six-week-old SD-strain female rats were ovariectomized and were fed a low-Ca diet (0.01% Ca and 0.3% P) for 32 days. Thereafter, the rats were divided into 2 groups: a control group fed a control diet (18% casein, 0.3% Ca and 0.3% P) and a globin group fed a globin diet (18% casein, 0.24% globin, 0.3% Ca and 0.3% P) for 27 days. In comparison with the control group, the globin group showed significant increases in (1) the BMD of the lumbar spine and tibia, (2) the Ca content of the femur, (3) the breaking force and energy of the femur, and (4) femoral bone weight. Furthermore, the Ca absorption in the globin group was higher than in the control group. These results suggest that globin powder could be effective for the prevention of bone loss in postmenopausal osteoporotic rats.

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The effects of a dietary fiber preparation isolated from soybean (P.P. 500S) on growth rate, apparent digestibility of certain nutrients and gastrointestinal transit time were compared with those of other dietary fiber preparations in rats. Apparent degradation and fermentation of dietary fiber were also compared. The dietary fibers used were P.P. 500S, okara and wheat bran (WB). The rats were fed diets containing 5% dietary fiber. In experiment I, growth rate, apparent digestibility of certain nutrients and apparent degradation of dietary fiber were determined. None of the experimental diets suppressed the growth of weaning rats, and the apparent digestibilities of starch, protein and fat were almost 100%. However, the rate of apparent degradation of dietary fiber was significantly different in all groups (P.P. 500S 83.5%, okara 62.8%, WB 30.3%). In experiment II, fermentation of dietary fiber in the rat cecum was examined. While cecal pH in the standard (DF-free) group was approximately neutral, those in the other groups were significantly lower. The organic acid content of the cecum showed the order: P.P. 500S>okara>WB>DF-free group, consistent with the order of pH. Addition of P.P. 500S to the diets caused an increase of acetate and butyrate formation. From these results, it is suggested that the useful intestinal microflora population was increased by P.P. 500S. In experiment III, gastrointestinal transit time and fecal moisture were examined. The transit times were 38.0h for P.P. 500S, 34.3h for WB and 53.9h for the DF-free group. By feeding of dietary fiber, the transit times were significantly shortened in comparison with the DF-free group. These results indicate that P.P. 500S is effective for modifying colonic conditions, such as lowering the cecal pH and shortening the transit time, without any harmful influence on growth or digestion of nutrients in rats.

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Deterioration of oil and decomposition of tocopherol (Toc) in oil heated with or without an atuminum float were investigated. Some kinds of oil (soybean, hardend soybean, rapeseed, olive containing α-Toc and whale oil treated with the mixed Toc) were heated in glass tubes (2.7×20cm) at 180°C, and then the content of oxidized fatty acids (fatty substances insoluble in petroleum ether), anisidine, carbonyl and acid values, or amounts of Toc remaining in the oil were measured. The content of oxidized fatty acids, anisidine and carbonyl values of oil heated with the float were clearly lower than these of oil heated without the float, but the acid value for oil heated with the float was much higher. The degree of decomposition of Toc in oil without the float was much higher than that with the float. This result indicates that the decomposition of Toc in oil is not affected by the hydrolysate (free fatty acid) in oil, but by the thermal oxidation products (oxidized fatty acids and carbonyl composition etc.) in the oil.

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The effects of antioxidants and the synergistic effect of ascorbyl palmitate (As. P) on the deterioration of oil and decomposition of tocopherol (Toc) in oil by heating were investigated. Vegetable oil (olive and soybean oils) mixed with antioxidants (BHA, sesamol, eugenol, β-carotene, quercetin, flavone and tert-butylhydroquinone (TBHQ)) or mixed with As. P was heated in glass tubes (2.7×20cm) at 180°C. The degree of deterioration of the heated oil was estimated in terms of the anisidime and carbonyl values of the oil. TBHQ and sesamol showed a greater preventive effect on the thermal decomposition of Toc in oil (especially olive oil) than eugenol, quercetin and BHA, and the preventive effect of TBHQ on the deterioration and decomposition of Toc in heated oil increased as the concentration of TBHQ became higher. ON the other hand, addition of β-carotene and flavone had no effect. The thermal decomposition of Toc in olive oil mixed with BHA or flavone and As. P was prevented to a greater extert than when each of BHA, flavone and As. P was mixed separately.

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