Relationship between maceration and pectic-substance release of vegetable tissues when they were boiled in different pH solutions was studied. The results obtained were as follows :
1. Vegetable tissues were kept firm when cooked at pH 4. They were rapidly softened by cooking either above pH 5 or below pH 3. By prolonged cooking carrot, potato and Japanese radish were considerably macerated even at pH 4. Maceration of lotus and burdock, however, was very slow under the same conditions.
2. Pectic substances released from vegetables during cooking were the least at pH 4 and they increased above pH 5 and below pH 3.
3. Pectic substances released from vegetables during cooking above pH 6 gave positive results by the thiobarbituric acid tests.
These results suggest that the enhanced softening at neutral and alkaline pH is ascribed to the degradation of pectin by a transelimination mechanism but at low pH it is caused by hydrolytic cleavage of pectin and removal of divalent cation from the cell walls of vegetables.
4. The rate of softening of vegetables by cooking depends on their kinds. It is likely that the obstruction to softening of vegetables such as lotus and burdock is caused by heat-resistant and insoluble substances other than pectin of middle lamella, covalent connections between pectin and other insoluble cell wall materials, or rigid structures of the tissues.

View full abstract

The effects of oral contraceptive steroids (OCS) on the tissue concentration of bulk (calcium, magnesium, sodium and potassium) and trace metals (iron, copper and zinc) in the iron-deficient rats were investigated. Weanling Wistar-strain female rats were fed a normal or iron-deficient diet for 8 weeks and OCS were added for the last 4 weeks.
Rats fed on iron-deficient diet decreased hemoglobin value, iron concentration in liver, spleen, kidney, heart and uterus, and calcium and sodium levels in spleen. But those rats increased liver copper, spleen magnesium and potassium, and uterus calcium concentration. OCS treatment elevated the calcium and sodium levels in liver, iron level in spleen, copper level in kidney and magnesium level in brain, but reduced the iron level in kidney.
The OCS treatment in the iron-deficient rat resulted in the reduction of copper concentration in liver and in the elevation of copper concentration of heart and spleen.

View full abstract

In order to know the daily mineral intake (zinc and copper) and its balance value for estimating the mineral requirement, the following two experiments were made. In Experiment I, the zinc and copper balance tests were performed for assessing the nutritional status of 9 male and 10 female preadolescent children (age : 3y 5m-6y 9m) with normal diet. In Experiment II, the balance studies of iron, zinc and copper for 15 preadolescent children (10 male and 5 female children aged between 3y 10m and 6y 5m) receiving two levels of dietary protein were made.
1) Zinc and copper has a retention by daily normal diet. The zinc and copper requirements were estimated to be 236.7 μg/kg and 30.7 μg/kg respectively.
2) Intake of copper was increased and zinc intake was decreased at the lower protein level compared with that of the higher protein diet.

View full abstract

On the 28 kinds of sea fish, 12 of fresh water fish, 18 of shellfish, 5 of cephalopodan, 8 of crustacean, 3 of other marine animals and 8 of seaweed, tocopherol conpositions in their edible portions determined by high performance liquid chromatography.
1) Total tocopherol content in fresh water fish was generally higher (x=1.22mg/100g) than that of sea fish (x=0.66mg/100g) ; and its average values in lipid were 28.91 and 23.18 mg/100g respectively, showing higher values than that in body fat of land animals. As to tocopherol composition, non α-tocopherols were detected from most kinds of fish.
2) Total tocopherol content in tissue of shellfish and cephalopodan showed similar levels to that of sea fish, and its average values in lipid being 62.35 and 64. 26 mg/100g respectively, were higher than that of fish. From most kinds of them non α-tocopherol were detected, while from cephalopodan neither β- nor δ-tocopherol was found.
3) Total tocopherol content in tissue and lipid of crustacean was on the average 1.98 and 190.22 mg/100g respectively, which was higher than that of fish, shellfish and cephalopodan. Non α-tocopherols were detected from all kinds of them.
4) Total tocopherol content in algae and its lipid showed on the average 0.23 and 84.29 mg/100 g respectively. As to tocopherol composition, 10-70% of non α-tocopherols were detected from them except tangle, while β-tocopherol was not found at all.

View full abstract

Fat and mineral absorption and the relationship between these were studied in weanling rats, fed with two formula (A, B) differing in fatty acids composition. The fat of formula A was composed of natural lard which contained high palmitic acid in the 2-position of triglyceride molecule. The fat of formula B was substituted for lard by coconut and corn oils, so that contents of total stearic and palmitic acids and palmitic acid in the 2-position were lower in formula B than those in formula A. Absorption of main fatty acids (C 12 : 0, C 14 : 0, C 16 : 0, C 18 : 0, C 18 : 1, C 18 : 2) were high (90%<) in both formulas, but stearic acid in formula B was more absorbed (p<0.01) than in formula A.
Palmitic acid was well absorbed (95%<) in both formulas. Excreted fatty acid were detected in the forms of neutral fat, free and saponificated fatty acids in feces from all rats. But the content of long chain saturated fatty acids in saponificated form was higher than unsaturated fatty acids in every feces. Especially, content of saponificated stearic acid was higher (p<0.01) in feces in formula A than formula B. Palmitic acid did not show the difference in excreted amount between both formulas. Both formulas showed high mineral absorption (90-97%, Na, K, Ca, Mg, P, C1), though Ca and Mg were better absorbed (p<0.05) in formula B than A. The correlation between mineral (Ca+Mg) and saponificated fatty acid contents (C 16 : 0+C 18 : 0) in feces was high (r=0.83) in formula A but was low in formula B.
It was suggested that mineral absorption was affected by fatty acids absorption, because long chain saturated fatty acids such as palmitic and stearic acids were formed insoluble soap with Ca and Mg during excreting.

View full abstract

The purpose of the present study is to estimate the amount of heat production from fat tissue mass (FTM) and that of essential body mass (EBM) separately on 20 healthy men aged 18-19 in both basal metabolic condition and cold exposure (15°C, 1 clo, 1 hr).
Body density by water displacement method and heat production were measured in winter (Feb.) and summer (Jul.), 1980. The two compartments of FTM and EBM were calculated from the formula used by Chien et al.
Assuming that all the subjects under the same living conditions (diet, work, etc.) have the same amount of heat production per weight of FTM (b) and EBM (a), the values of b and a were calculated by the regression analysis devised by Chirifu.
These experiments were carried out in winter (Feb.) and summer (Jul.) and seasonal variation in heat production was also examined. The value obtained of a in BMR was 26.59 kcal/kg/day in winter and 23.80 kcal/kg/day in summer. The value of a in cold environment was 27.30 kcal/kg/day in winter and 29.85 kcal/kg/day in summer.
Estimated value of b in BMR was 32.00 kcal/kg/day in winter and 37.16 kcal/kg/day in summer. The value of b in cold environment was 28.24 kcal/kg/day in winter and 35.84 kcal/kg/day in summer. The amount of heat production (b×FTM) from FTM per day in BMR was 193.1 kcal/day in winter and 213.4 kcal/day in summer. The value in cold environment was 173.4 kcal/day in winter and 205.0 kcal/day in summer.
The above results suggest that metabolic activity of EBM is considerably high, higher in winter than in summer, and in both seasons, higher in cold environment than in BMR and that metabolic activity of FTM in basal condition is higher in summer than in winter and higher in BMR than in cold environment.
EBM was highly correlated with BMR (kcal/day). However, the amount of heat production (a, b) from EBM and FTM in basal metabolic condition showed a tendency to increase for subjects with lighter EBM (or FTM) and to decrease for subjects with heavier EBM (or FTM).

View full abstract

The influence of konbu (Laminalia japonica) and shiitake (Lentinus edodes) on digestive enzymes and digestive functions of rats were observed. Rats were paired-fed the diet containing 25% of casein and 30% of either konbu or shiitake instead of pregelatinized potato starch of control diet for 8 days. Results obtained are as follows:
1) Total α-amylase activity in pancreas on feeding the diet containing konbu was similar to that on feeding the control-diet, and the activity on shiitake-diet was significantly increased compared with that of the control. Protease activity on either feeding of konbu or shiitake-diet was higher than that on feeding the control-diet.
2) Total lactase and sucrase activities in the small intestinal mucosa on feeding the konbu-diet was higher than those of feeding the control-diet, and total glucoamylase activity of feeding the shiitakediet was lower than that of feeding the control-diet.
3) By scanning electron microscopy, samples of konbu and shiitake recovered from several portions of rat digestive tracts at the end of the experiment suggested that these materials were decomposed by physical and chemical actions in the digestive tracts.

View full abstract

This experiment was carried out to investigate the effects of supplementation with iron, zinc, copper and iodine during total parenteral nutrition (TPN) in trace element-deficient rats.
Trace element-deficient rats were induced by feeding an iron, zinc, copper and iodine poor diet with 1.5% L-histidine solution for 9 weeks. These rats were divided into three groups (A, B and C), which were provided trace element-deficient diet, trace element-deficient TPN and trace element-supplemented TPN, respectively for a week.
The following results were obtained.
1) No significant differences in body weight and nitrogen balance were observed in each group.
2) Plasma concentrations of iron, zinc, copper and protein binding iodine in the Group B were lower than in the Group A, while those in the Group C were not less than the plasma levels of Group A.
3) Comparing with the Group A, the values of ALP, Hct and Hb decreased in the Group B, but significantly increased in the Group C. The values of Hct and Hb in the Group C were almost the same to those in normal rats.
4) In the histopathological findings, increase of fat in bone marrow was observed in the Group A and B, but not in the Group C.
5) The tensile strength of healing wounds decreased especially in the Group B, but had a tendency to increase in the Group C.
These results suggested that the supplementation with iron, zinc, copper and iodine was effective to ameliorate the symptoms of trace element deficiency during TPN in rats.

View full abstract

Komezu is one of brewed vinegar (acetic acid; 4%) obtained from Japanese rice. Komezu is not only simple vinegar but also regarded as a healthful food having a long history in oriental folk medicine. The acute toxicity of Komezu in mice and the pharmacological effects of it on lipid metabolism in mice were investigated and the following results were obtained. 1) The LD₅₀ value of Komezu in male mice was 21.5 ml/kg and equal to that of 4% acetic acid aqueous solution. The cause of death in acute toxicity was the disturbance of upper digestive tracts of mice by acetic acid. 2) Komezu at a dose of over 2.5 ml/kg (p. o.) showed effects of decreasing serum cholesterol levels in both normal and high cholesterol diet-fed mice. Same effect was observed with 4% acetic acid aqueous solution. 3) Komezu (>2.5ml/kg, p. o.) inhibited the increase of lipid peroxide (LPO) levels in mice myocardium induced by adriamycin injection (15mg/kg, i. p.). At a dose of 5ml/kg (p. o.), it also decreased the LPO level of myocardium in normal mouse. But, the effect of 4% acetic acid aqueous solution on LPO levels in mice was weeker than that of Komezu.

View full abstract

Germanium, selenium and manganese were determined for lunch meals. Samples of 27 lunch were collected and each was devided into cooked cereals and the others. Germanium was determined by the modified phenylfluorone method, selenium by the bismuthiol II method, and manganese by the potassium periodate method. The daily intakes of germanium, selenium and manganese were estimated by tripling the average lunch meal values to be 10 μg, 304 μg and 3.2 mg, respectively.

View full abstract

Effects of pH on degradation of pectin, pectic acid, meth-ylester of polygaracturonic acid, acid-insolublepectic acid and acid-soluble pectic acid in hot solution (98°C) were investigated and the following results were obtained.
1) Pectin was broken down rapidly above pH 5 by a transelimination, however, degraded slowly at pH 4. Below pH 3 percent hydrolysis of pectin increased more than that at pH 4 and less than that at alkaline pH.
2) Hardly any degradation of pectic acid occured above pH 5. Below pH 4, however, pectic acid was obviously hydrolyzed and the rate of hydrolysis increased gradually as the pH was lowered. Pectic acid was hydrolyzed more rapidly than pectin in weakly acidic hot solution.
3) Among acid-soluble pectic acid (A), acid-insoluble pectic acid (B) and methylester of polygalacturonic acid (C), A was hydrolyzed most rapidly, B next and C most slowly.
4) Between pH 2 and 5, hardly any de-esteri-fication occured in hot solution (98°C, 30 min). The rate of de-esterification increased above pH 5.5. About 70% of the methoxyl groups of pectin and 28% of them were de-esterified at pH 7 and 1.2, respectively.

View full abstract

The Wassner's method (1980) for determination of Nτ-methylhistidine (τ-Meh) was revised. This method was applied to analyse τ-Meh in rat plasma and urine.
Human plasma and urine were deproteinized with sulfosalicilic acid. Further hydrolysis (with 6N HCl, 100°C for 1 hr) was necessary in rat plasma and urine. Fluorescamine was added to the deproteinized samples and heated with perchloric acid according to the method of Nakamura and Pisano (1976). Reaction mixture (25-100 μl) was injected into HPLC equipped with Zorbax BP-ODS column (∅ 4 mm x 25 cm) and fluorometer. Solvent was 27% acetonitril-10 mM phosphate buffer, pH 7.5. Only two peaks of histidine and τ-Meh was detected. τ-Meh was eluted within 10 min. Regeneration of the column was not necessary. Linearity in standard curve from 33 pmol to 8.5 nmol of τ-Meh was observed. The sensitivity and separation were enough to estimate τ-Meh level in plasma and urine.

View full abstract

Eight healthy subjects (average age 27. 5 years old) were orally administered 200 ml of the control solution (containing 50 g of glucose) or the test solutions (containing 50 g of glucose and 5 g of glucomannan or cellulose), and compared with the suppressive effect on the enhancement of blood glucose level.
Glucomannan delayed the intestinal absorption of glucose and could significantly suppress the maximal level of blood glucose, but cellulose could not. Addition of pullulan of 5 or 10 g to glucose solution also did not show the suppressive effect on blood glucose level.

View full abstract