The reduced vitamin C contents of 8 kinds of vegetables purchased in market were determined by spectrophotometiic method using 2, 6-dichlorophenol-indophenol for two years since January, 1982. The evaluated values of vitamin C at 10 day intervals were derived from raw data by the operation of interpolation and smoothing. Then the seasonal variation of reduced vitamin C content was illustrated graphically and analyzed statistically with these evaluated data. Significant positive correlations between the corresponding seasonal data of 1982 and 1983 were obtained with five vegetables; cucumber, spinach, eggplant, tomato and lettuce.
Principal component (PC) analysis gave some explanation on the pattern of seasonal variation;
1) Correlation matrix indicated the similarity in profiles of seasonal variation among 5 kinds of vegetables. 2) The first PC characterized an arc type of annual change of reduced vitamin C content. When its factor loading was positive, this curve became concave and vice versa. 3) Five kinds of vegetables could be characterized in two groups; one consists of cucumber, tomato and eggplant, the other spinach and lettuce.
By the time series analysis, it was found that the reduced vitamin C content of cabbage was accompanied with a periodical variation.

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A lectin possessing high hemagglutinability to mouse erythrocyte was purified from Tora beans (Phaseolus vulgaris) and was found electrophoretically homogeneous. The yield was 14 mg from 100 g of beans. The amount of the finally purified lectin required for complete agglutination of 1 ml of 1 % mouse erythrocyte suspension was 2.4 μg and thereby its specific activity was calculated to be 417 unit per mg protein. The lectin was found highly toxic to mouse when injected intraperitoneally. The LD₁₀₀ was approximately 240 μg per g body weight. Tora bean lectin was fairly resistant to the in vitro digestion by pepsin, trypsin and a-chymotrypsin. Histological observation of the organ specimen clearly indicated the occurrence of acute toxicity due to congestion in the lung, heart, liver, kidney and spleen. These results were considered to have ascertained that Tora bean lectin is one of the toxic constituents of plant foodstuffs.

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Antioxidative activity was found in lipid fractions of the extracts (hexane/ethanol, 79 : 21 v/v) from 7 edible sea weeds (1 Chiorophyceas, 3 Phaeophyceas, 3 Rhodaphyceas), as estimated by weighing method and by peroxide determination (thiocyanate method).
Lipid fractions from Aonori and Wakame showed activities comparable with known antioxidants BHA or α-tocopherol, on weight basis. According to TLC, the activity was found in 2 fractions (No. 2 and No. 4) out of 5, for Aonori, Kombu, Hijiki and Wakame. Another fraction (No. 3) of Wakame also showed the activity. Addition of active fractions to the emulsion of mayonnaise and dressing condition showed promising results, but no significant activity was found when they were added to the emulsion of cooky condition.
The active components obtained in this work are found to be different from the known active phospholipids in sea weeds and from tocopherols. The details will be reported in the following paper.

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For the purpose of cooking liver to improve its acceptability, a consciousness survey on 210 female students was carried out, and at the same time, removal of blood from chicken liver by means of an ultrasonic cleaning, and estimation of deodorization effect of this treatment after boiling, sensory tests on cooking aptitudes were also conducted. The following results were obtained.
1) Consciousness survey revealed that an eating rate of liver without ultrasonic irradiation was 65.2 % with high frequency in grilling, frying and boiling. The reasons why liver is not eaten much were due to its taste, odor and appearance.
2) Ultrasonic cleaning method was much more effective in removal of blood and reduction of odor than simple washing method by water. The optimum irradiation time on liver was 10 min from young chicken and 5 min for aged ones, and a 0.5 to 1.5 % sodium chloride solution was most effective for cleaning, and also suitable for boiling which was accepted favorably.

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Effects of heating time and ingredients on blanc mange prepared by using corn starch, milk and sugar were investigated. The rheological properties of the gel were determined by the Rheolograph-gel and Dynagraph. The results obtained are as follows :
1) Increase of the heating time of blanc mange resulted in decrease of the dynamic viscoelasticity and slow increases of the mechanical loss tangent, the rupture stress and energy. The gel without sugar showed the same properties as blanc mange.
2) The starch gel without milk showed slow decrease of the dynamic viscoelasticity and the constant mechanical loss tangent. The rupture properties remarkably increased first by the short time of heating process and after that showed no change.
3) It was found that the gel with sugar made the rupture properties increased compared to the gel without sugar.
4) The results of sensory test corresponded to those of rheological measurement with better relation.

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Nine white sauces with varied frying time (0, 3 or 10 min.) and cooking time (0, 10 or 30 min) were prepared. Their textural properties (hardness and relative adhesiveness) and syneresis before and after frozen storage were investigated. All the white sauces were deteriorated depending on cooking conditions, that is, the longer the cooking time of sauce was, the less the deterioration of white sauce through frozen storage was. This tendency was also shown in a model sauce made with starch or starch-sludge mixture. During frozen storage, the model sauce of starch was more deteriorated than the white sauce and the model sauce made with starch-sludge mixture. Optical microscopic observation showed that no sizes of oil droplets dispersed into any sauces changed during frozen storage, and starch paste eluted from starch granules was coagulated fibriformly. This fibriform starch paste may contribute to the deterioration of sauce by frozen storage.

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The biodegradation behaviors of anionic surfactants, such as sodium linear alkylbenzensulfonate (LAS), sodium dodecyl sulfate (SDS), sodium α-olefinsulfonate, and soap were observed with the river die-away tests using Tama river water.
The course of biodegradation was followed by the measurement of the loss of total organic carbon (TOG), ferroin reagent active substances (FRAS), and the analysis of dissolved oxygen (DO).
The rates of biodegradation of surfactants increased as the test water was stirred by magnetic stirrer to ensure adiguate aeration. In particular, those of LAS markedly increased and TOG almost completely disappeared during 20-25 days. Biodegradation of surfactants also depended upon the incubation temperature. In the case of LAS, lag time at 10 °C was about three times as long as that at 20 °C, and a considerable amount of LAS remained after 50 days at the low temperature.

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[in Japanese]

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