To know the factors for nitrate accumulation in tomato fruits, experiments were conducted in 1968 and 1969 seasons, using three canning tomato varieties with various amounts of nitrogenous fertilizer.
Results showed that there were no significant differences in nitrate content among varieties, and among fertilizer trials. Even in low nitrogen level (2.5kg/10a), high nitrate concentrations (over 10ppm) were found in some fruits.
Spraying plant growth substance (Na 4Cl-2-hydroxymethylphenoxyacetate) gave no effects on nitrate content in fruits.
Apparent seasonal changes in nitrate content were noticed. At the beginning of harvest time, nitrate content was low under the influence of rainy season. In the middle, it became higher being affected by hot and dry weather, and in the end, again it became lower being affected by heavy rainfall and plant senescence.
As for the ripeness, mature green fruits showed generally higher nitrate content than red fruits. As for the fruit portions, it was high in flesh, especially in the portion just under calyx. On the other hand, it was relatively low in placenta, and was negligible in gelatinous pulp.
During 7-10 day storage at room temperature (28°C), nitrate and nitrite contents of fruits were found to be invariable.
It was suggested that the nitrate accumlation in tomato fruits was influenced by weather, soil nitrate-nitrogen and plant vigour.

View full abstract

The tomato purees were stored at 37° for 3 to 6 months to observe the chemical changes as well as surface color of the puree. The results of the analysis on the pigments showed no significant decrease in the amount of lycopene and carotene, although the amount of water soluble pigment increased during storage. The contents of reducing sugar and vitamin c were decreased whereas the amounts of titrable acidity as well as HMF which has absortion peak in ultraviolet region increased. The tomato purees prepared in model system were also stored at 37° in order to find the causes of the color deterioration. Tomato purees which incrude tomato serum part showed color change remarkaby in proportion to the amount of the serum incruded, indicating that the serum part is the principal causes of color change from the viewpoint of constituents of tomato puree.

View full abstract

Chemical compositions of lipids in the salted sea urchin egg were investigated in comparison with that of raw egg.
The lipids in the sea urchin egg were fractionated into non-polar lipids and polar lipids, the ratio of which was 3:1 in the raw egg and 4:1 in the salted. As the main non-polar lipids, hydro- carbon, sterolester, triglyceride, fatty acid, sterol and monoglyceride were found both in the raw the salted one. It was observed that the amount of triglyceride was less egg and in and that of fatty acid was more in the salted egg than in the raw. As the principal polar lipids, phosphatidyl ethanolamine, lecithin (phosphatidyl choline), sphingomyelin and lysolecithin (lysophosphatidyl choline) were detected both in the raw egg and in the salted one. The salted egg contained a smaller amount of lecithin and phosphatidyl ethanolamine and a larger amount of lysolecithin than the raw egg. Unsaturated fatty acids of C₁₈-C₂₂ seemed to be liberated rather easily than the other kinds of fatty acid during curing with salt.

View full abstract

Checking method of the quality of "Wasabi" powder was investigated by gas chromatography.
Column used for gas chromatography were both glass and stainless steel column (0.3 (i.d.)× 225cm) packed with 5% SE-30/Celite 545.
Temperature of column bath was set up to 50-250°C (glass column) or 50-220°C (stainless steel column) at the rate of 9.5°C/min by using programmer. Ratio of peak area of β-phenylethyl isothiocyanate to the one of allyl isothiocyanate was indicated as R (%) value. The R values of twelve "Wasabi" powders (c), horseradish powder (a), and black mustard powder (b) were put into next formula: ax+b (100-x)=100c. In this formula, x indicated the rate of mixing of horseradish powder in "Wasabi" powder. Among the 12 varieties, there were 4 varieties estimated by glass columm and 3 varieties estimated by stainless steel columm of which x values were under 50%.
The contents of both isothiocyanates and ash were also important factors for the check of quality.

View full abstract

In order to measure the ripeness of an apple without cutting, an equipment with a vibrator and a pick-up was devised.
Ripeness of a Starking apple examined by this equipment was compared with that of sensory test to find the result that the maximum value of amplitude possible to be employed as an indicator of ripeness.

View full abstract

An improvement was done with the equipment devised in the former paper. The changes of the ripeness of the Starking apples was measured with the improved equipment during the growth and storage.
A tendency was seen that the value of cycle of the apples was reduced along with the progress of matuation to overmatuarity. A big fruit showed a lower cycle value compared with a small one.

View full abstract

Volatile components in horseradish and black mustard were investigated by head space method of gaschromatography. Nine peaks were detected and 7 of them were identified. A remarkable difference was seen between horseradish and black mustard in the ratio of the hight of peak No. 1 (peak a) to that of isopropylisothiocyanate (peak b); i.e. the ratio of horseradish was fur more than that of black mustard. This fact leads to the finding a way to know the rate of black mustard mixed in horseradish powder product at market. Four ml of water is added to 2g of horseradish powder in 100ml conical flask to be mixed and kneaded well with a glass bar. Thus mixed mash is kept at 37° for 5min. to be taken 5ml of the head space gas for injection to gaschromatography. Percentage of black mustard powder mixed in horseradish can be calculated from the ratio of the hight of peak a and that of peak b.

View full abstract