The effect was investigated of the temperature of water on the foaming property of powdered green tea. Water temperatures of 20,40,60,70,80,90 and 100°C were tested to dissolve powdered green tea with subseqnent stirring of the tea solution. The foam volume, expansion rate and degree of stability of the foam were measured. The amounts of tannin, soluble nitrogen and pectin that could be dissolved at each of these temperatures in 30 seconds and the viscosity of the resulting tea solution werem also measured.
The higher the temperature of the water used to dissolve the powdered green tea, the more chemical elements were dissolved, the more the viscosity increased, the more the foam volume increased and the more the foam became fine and stable.
Evaporation at the surface of the foam membrane became more active, the foam disappeared more easily and the foam stability decreased as the temperature of the water during stirring was increased.

View full abstract

The size and shape of fresh hen egg yolk spheres and dense granules in the yolk sphere were changed by storage (20°C for 20 days) and boiling (15min). These changes were analyzed by the image processing technique. Fresh, stored, and boiled yolk samples were each cut from the outer, middle and inner layers, and from the latebra, and the contents of water and protein were measured. Pieces of each were immersed in a fixation solution and, after sample preparation, were observed by transmission electron microscopy. Binary images of the yolk spheres and dense granules were input to an Excel image processor.
The moisture and protein contents of fresh yolk were higher in the outer layer than in the inner layer. After storing, the moisture content of the yolk was increased, and the protein content was almost unchanged in each layer.
The outer and inner layers of the yolk spheres after boiling had expanded by 1.19 to 1.30 times those of the fresh yolk. The ratio of the long to short dimensions of the yolk spheres after boiling in the middle and inner layer was smaller than that of the fresh yolk.
The proportion of dense granules in the yolk spheres tended to decrease toward the inner layer of the yolk as a result of storage and boiling; therefore, the proportion of dense granules in the yolk spheres was lower than that of the fresh yolk. The transverse sectional area of the dense granules was also greates larger in each region than that of the fresh yolk. The dense granules in the inner layer and latebra were larger and more circular than those of the fresh egg because of granule fusion. Many spots appeared in the internal parts of the dense granules after boiling and storage. Furthermore, the dense particles were dissolved by boiling and their form disappeared.

View full abstract

The stainability of surimi protein in sasakamaboko products and uncooked surimi was examined. The components originating from fish, the amount of mixed starch, and the mingled air bubbles during processing were also studied.
Four brands of sasakamaboko products, each of which were broiled, and their uncooked surimi samples were used in this study. Two samples were taken from both sasakamaboko and uncooked surimi. One was fixed in 10% formalin and another was frozen in a mixture of dry ice and acetone. Paraffin sections or frozen sections were stained with Azan, Hematoxylin-Eosin (H-E), Picrosirius (PS) and acrolein-Schiff (AS) to assess protein stainability. Starch was stained with periodic acid-Schiff (PAS) and iodine. The proportions of starch granules and air bubbles were obtained by measuring their cross-sectional areas present in a fixed area.
With the sasakamaboko products, the superficial thin (ST) layer was stained more intensely with Eosin and AS than the interior. In Azan stain, the ST layer was stained with Azocarmine G, whereas the interior was stained with Aniline Blue. In PS stain, the ST layer was stained with picric acid, whereas the interior was stained weakly with Sirius Red. The uncooked surimi was stained uniformly with Eosin, AS, Azocarmine G in Azan stain, and picric acid in PS stain. The findings show that broiling changes stainability of surimi protein. Collagen fibers stained with Aniline Blue and Sirius Red were dispersed in the sasakamaboko products and uncooked surimi. Gelatinized and swollen or multiform starch granules were dispersed in the products. Round or multiform starch granules were dispersed in the surimi. The round starch granules in the surimi and a few round starch granules dispersed at the center of two brands of the sasakamaboko products showed birefringence. Starch was diffused from some starch granules into surimi protein in the sasakamaboko products and uncooked surimi. The sasakamaboko products contained 1.8∼5.8% starch granules and 12.7∼18.2% air bubbles. Some brand included a very small amount of finely ground scales.

View full abstract

The effect was investigated of the time and speed of stirring on the foaming property of powdered green tea. The foam volume, expansion rate and degree of stability were measured under the following conditions; powdered green tea was stirred at the rate of 300,400,450 times per minute for 0.5,1.0,1.5,2.0,3.0,4.0 minutes. Another experiment was done to investigate how long was needed to produce foam by nine experienced practitioners of the tea ceremony.
Stirring at up to 400 times per minute produced an increasing amount of foam with increasing stirring speed, but less foam was foamed as the stirring speed was increased further to 450 times per minute. As the stirring speed was increased, the foam tended to become finer and less stable.
Stirring for up to 1.5 minutes produced an increasing amount of Foam with increasing stirring time, but over 1.5 minutes of stirring resulted in no change in the foaming characteristics.
The longer the tea was stirred, the finer and less stable the foam became.
Although there were differences between individual tea ceremony practitioner, the average stirring time was 23.3 seconds, the first 13.4 seoconds being at a higher stirring speed.
A high stirring speed was approximately 300∼350 times per minute as judged from the foam volume, foam rate and stirring period.

View full abstract

We analyzed the contents of sodium, potassium and salt, the free amino acids composition, the fatty acid composition, and the bacterial contamination of the typical Indonesian seasonings “Terasi” and “Petis”.
The average contents of sodium, potassium, and salt, and the water activity were 9,978 mg/100g,466 mg/100g,25.3%, and 0.718 in Terasi, and 1,497mg/100g,230mg/100g,3.8% and 0.693, respectively, in Petis.
The average values for the free amino acids in Terasi and Petis were 4,304 mg/100g and 2,547 mg/100g respectively. The major free amino acids of the two seasonings were glutamic acid, alanine, leucine and lysine.
The major fatty acids in Terasi and Petis were C_{18: 0}, C_{18: 2} and C_{20: 5}, and C_{16: 1}, C_{18: 2}, C_{20: 1}, respectively. The bacterial count of the isolate from Terasi was 10³∼10⁵/g, No coliform organisms, like E. coli and Staphylococcus, were detacted in Terasi.

View full abstract