Nippon Eiyo Shokuryo Gakkaishi (J. Jpn. Soc. Nutr. Food Sci.) 36, 133-140 (1983) In a previous paper the authors reported that the discoloration by the reaction in boiled and dried Euphausia superba among autoxidized unsaturated fatty acid and volatile basic nitrogen (VBN) or non-volatile (Non-VBN) assumed to be influenced by the amounts of nitrogenous substance in VBN and Non-VBN fractions.
In this paper, the influence of pH, some inorganic ions such as Cu²⁺, Fe²⁺ and the water-soluble browning substance separated from boiled and dried E. superba on discoloration was investigated.
The following results were obtained.
(1) The browning intensities of hydrophilic Non-VBN (F-1), lipophilic Non-VBN (F-2), hydrophilic VBN (F-3) and ipophilic VBN (F-4) fractions were measured with E value at 430 nm. The results indicate that the effect of pH (among 5 to 9) on browning intensities was not observed in any fraction even after 120 hr incubation.
(2) The browning intensities of F-1 and F-2 fractions, peroxide value and thiobarbituric acid value increased by addition of 100 or 300 ppm Fe²⁺ and Cu²⁺. Fe²⁺ showed stronger effect than Cu²⁺.
(3) The browning substance which was analyzed by fluorescence intensity, ultraviolet and infrared spectrophotometry, was suggested to be quite similar to melanoidin.

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Effects of training on the hematological values were measured in growing male and female rats. In the condition of normal feeding, body weight in male rats increased gradually as days pass. The increase in the body weight of female rats became moderate after 50 days old. Hemoglobin concentration and hematocrit value in male rats, increased gradually in proportion to the growth of the body weight. But these values in female rats, did not increase as much as that in the male rats. Accordingly, after 70 days of age, sex difference became statistically significant in the hemoglobin and hematocrit value. From 30 days to 100 days of age, the plasma volume per 100 g body weight decreased gradually, and the plasma volume of a female rat was less than that of a male rat of the same body weight.
During such a growing period, the rat fed on 20% casein diet or 5% casein diet were compelled to swim 1 hour per day. The concentration of hemoglobin in a training male rat fed on 20% casein diet and the plasma volume per 100 g body weight, were the same as that of the control male rat. But in the case of the training female rat fed on 20% casein diet, hemoglobin hematocrit, and blood volume, plasma volume, red cell volume and total hemoglobin per 100 g body weight were significantly higher than that of a control female rat. The concentration in hemoglobin and hematocrit value in the training male rat fed on 5% casein diet did not differ significantly from that of the control male rat fed on 5% casein diet, and hemoglobin and hematocrit in the both groups of rats (control and training) were significantly lower than that of the male rat fed on 20% casein diet. In the female rats fed on 5% casein diet, the hemoglobin and hematocrit values in both groups of rats (control and training) were the same, and they did not differ from that of the female control rats fed on 20% casein diet. The volume of blood, plasma, red cell and total hemoglobin in 100 g body weight of the control male and female rats fed on 5% casein diet was significantly smaller than that of the rat of the same body weight fed on 20% casein diet. These values in the training group did not differ from that of the rats of the same body weights fed on 20% casein diet, it was suggested that the lean body mass, red cell volume and total hemoglobin were increased by training even on the low protein diet.

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Lactase was purified from suckling rat jejunal mucosa and the properties were investigated. Lactase of suckling rat jejunum was purified from papain-solubilized jejunal mucosa by the gel filtration (Sepharose 2B, Sephadex G-200) and the chromatography (DEAE-cellulose). The lactase obtained showed a single band in polyacrylamide gel flectrophoresis. The optimum pH of the purified lactase was 5.7. K_m value of the enzyme for lactose was 12.9 mM. The purified lactase was completely inactivated by heating at 58°C for 10 min in 0.1 M sodium maleate buffer, pH 6.0. The molecular weight of the purified lactase was estimated to be 280, 000 by polyacrylamide gel electrophoresis in sodium dodecyl sulphate and 360, 000 in Sepharose 2B column chromatography.

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Riboflavin in the serum of purchased bovine milk was decomposed by exposure to fluorescent light. The amount of photodecomposed riboflavin increased with the intensity of illumination. In the serum exposed to light at low intensity, photogenerated superoxide anion increase quantity, and added superoxide dismutase effectively suppressed the photodecomposition of riboflavin.
The obtained results suggest that the photodecomposition of riboflavin at low light intensity is associated with the photogenerated superoxide anion.

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The present study was undertaken to determine whether indigestible polysaccharides could affect the function of digestion and absorption. Male rats of the Sprague Dawley strain (at 4 weeks of age and weighing 78-88 g) were fed either control diet containing no fiber or experimental diets containing 5% indigestible polysaccharides for 4 weeks. Indigestible polysaccharides used in this experiment were cellulose, agar, κ-carrageenan, Na-alginate, konjac mannan and pectin. The results obtained were as follows :
1. Body weight gain for 4 weeks did not differ in all groups fed the indigestible polysaccharides. The inclusion of Na-alginate, κ-carrageenan, pectin and konjac mannan into the diets induced a significant increase in weight of small intestine, pancreas and caecum. The feeding of Na-alginate, pectin and κ-carrageenan significantly lengthened the small intestine. The most remarkable effect on the digestive organs was observed in the Na-alginate group. However, there was no difference in weight and length of digestive organs between the control group and the groups receiving cellulose and agar.
2. The faecal dry weight increased in the groups receiving cellulose, agar and κ-carrageenan, but not in the groups of konjac mannan, pectin and Na-alginate. The apparent digestibility of dietary protein in the groups fed Na-alginate, κ-carrageenan, pectin and konjac mannan was significantly lower than the value in the control group, whereas it was not changed in the cellulose and agar groups. The apparent digestibility of fat decreased significantly in the groups consuming Na-alginate and pectin.
3. Total activities of amylase and protease in the pancreas were not changed in the groups fed the indigestible polysaccharides except cellulose. In the cellulose group, activity of protease decreased significantly, but that of amylase did not. Activity of amylase in the contents of small intestine tended to be higher in the groups fed the indigestible polysaccharides, especially being significant in the groups of Na-alginate and κ-carrageenan. Activity of protease in the intestinal contents was significantly higher in the group of Na-alginate and lower in the group of konjac mannan than that in the control group.
4. The viscosity of 0.2% solution of konjac mannan and Na-alginate was higher than the other polysaccharides, and that of 5% suspension of the diet containing Na-alginate was the highest. There-fore, the results suggest that the decrease of apparent digestibility induced by the indigestible poly-saccharides is attributed to their viscosity.

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Characteristic of palatinose-hydrolyzing activity was studied in the sucrase-isomaltase complex purified from adult rat intestine.
1) Palatinose-hydrolyzing activity (specific activity) was increased by purification of sucrase-iso-maltase complex in parallel with sucrase and isomaltase activity.
2) Palatinose was hydrolyzed in competition with isomaltose by sucrase-isomaltase complex.
3) Palatinose-hydrolyzing activity, like isomaltase activity, was not inhibited by α-glucosidase inhibitor, acarbose, which inhibits sucrase and maltase activity.
Therefore, we concluded that palatinose is hydrolyzed by the active site of isomaltase of sucrase-isomaltase complex.

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Nocturnal meal-feeding studies on rats with a certain diet at several frequencies per day gave mostly similar results to those previously reported in daytime meal-feeding studies. But, the increased accumulation of body fat, which has been reported in rats fed once at the daytime, could not be observed in rats fed once at the darktime. This suggests the importance of study on nutritional consequences of feeding patterns. Being unsuccessfully conducted, the nutritional consequences were compared between the two different feeding patterns which might daily provide an equal amount of nutrients to rats who had the food life of 3 meals a day ; a feeding of the same diet at 3 meal times vs. an alternate feeding of 3 differently composed diets. The meaning of this type of feeding patterns in nutritional researches was discussed.

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Diurnal variations of the hepatic tyrosine aminotransferase (TAT) activity were studiedin rats treated with streptozotocin which induces hypoinsulinism resulting in diabetes. The rats had free access to a diet during one half of each day and were fasted during another half of the day in the entire period of the experiment.
Clear diurnal variations of the TAT activity were observed in both normal and diabetic rats. The diurnal variations in the TAT activity were not primarily due to a light-dark cycle but in response to food intake : that is, the activity of TAT was high during the feeding period independently of a lightdark cycle. The amplitude of the diurnal variations was higher in diabetic rats than in normal rats. V_max values for tyrosine of TAT remarkably increased during the feeding time in both normal and diabetic rats. In both groups K_m values for tyrosine inclined to decrease during the feeding time. In particular, diabetic rats showed a slight but statistically significant decrease in the K_m values of TAT during the feeding time. The overall evidence demonstrated that diurnal variations of the TAT activity were amplified in streptozotocin-induced diabetic rats and therefore suggests that insulin is not involved in developing the rhythmic rise in the TAT activity which results from food intake.

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Three dietary consumption survey methods, i. e. (1) weighing all foodstuff sprior to cooking (weighing method), (2) purchasing the same oeal asconsued andseparating it into foodstuffs (purchasing method), and (3) asking the housewives who cooked the meal to recall the composition and weight of food stuffs used (recalloethod), were concurrently tested on a total of 30 meals taken by 10 housewives inhabiting an agricultral village in Oita Prefecture in the southen part of Japan. Using the new version of japanese Standard Food Cooposition Table (SupPlement to the 3rd edition), lipid, carbohydrateand protein contents of meals were calculated for eachoethod, and the values obtained were compared with the values measured actually.
Lipid content of oeals was determineded by Soxhlet's method with ether extraction. Aoount of carbohydrate was estimated by subtracting the amount of lipid, pmteinand ash, the latter two of which were separately measured, from the total amountof dried meal. Amount of energy was determined by multiplying the Atwater's coefcients to lipid, carbohydrate and protein amounts.
Good correlation between calculated values and the corresponding actually measured ones was observed, i. e. (1) for lipid content, correlation coecients were 0.802, 0.855 and 0.714 respectively for weighing, purchasing and recall methods, (2) for carbohydrate contet, 0.865, 0.812 and 0.622, and (3) for energy, 0.879, 0.815 and 0.707.

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Japonica waxy and non-waxy and Indica non-waxy rice grains were cooked in excess water. Hardness and stickiness of 3-45 grains of cooked rice were measured by Texturometer with dual arms. Hardness of rice grains attained plateau but stickiness continued to increase with the number of rice grains. Coefficients of variation for stickiness values were much larger than those for hardness. Stickiness values per one grain showed specific curves according to variety and clearance. Effect of measuring voltage was not observed. We suggest that 30-40 cooked rice grains, which correspond to 0. 6 g of raw milled rice grains, are needed for measuring hardness and stickiness of cooked rice grains including Indica and Japonica by Texturometer.

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The mutagenesity of the browning mixtures by amino-carbonyl reaction of glucose with one of 18 kinds of amino acids was investigated using silkworm.
The mutation frequencies induced by 18 kinds of mixtures were lower than 1×10^-3. This result indicates that the mutagenic activities of these mixtures on the pupal oocyte of silkworm were weak.

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Propylene glycol (PG) is allowed to use as a food additive for Chinese noodle at the level less than 2%.
The content of PG in commercial raw Chinese noodles was determined by programmed temperature gas-liquid chromatography.
PG was not detected in seven samples of 16, but PG contents more than 2% were found in 2 samples (2.57 and 3.05%, respectively).

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