Cucumber was sliced and soaked in solutions containing 10% NaCl (N),20% sugar alcohol (S) and their combination(N+S)at4°C. The hardness, fine structure, external appearance, permeation of the soaking solution, and moisture content of different parts of the cucumber flesh were measured.
The hardness of the outside was reduced by soaking in the N solution, whereas that of the inside was increased in the S solution. In the N + S solution, both these effects proceeded simultaneously.
The damage to the cell structure of the flesh accompanied the decrease in hardness.
The most marked shrinkage of the outside occurred after soaking in the N + S solution. NaCl permeated rapidly through the outside part and penetrated the inside. The Sorbitol permeated relatively more slowly, resulting in an imbalance of the S concentration from the outside to the inside.
Soaking in the N + S solution resulted in a rapid reduction in moisture content from the outside inwards. This reduction in moisture content was relatively slow in the N + S solutions, resulting in an imbalance in the moisture content of the flesh.

View full abstract

Milk jelly samples made with six different gelling substances, agar, gelatin, l-carageenan, corn starch, sodium alginate and LM pectin, were prepared, and the physical properties of these samples were investigated. The rupture stress of all samples was the same. The rupture strain of the agar milk jelly was the lowest, while the values for the elasticity of the Hookean and Kelvin-Voigt bodies, and the viscosity of the Kelvin-Voigt body of the agar milk jelly were the highest. On the other hand, the values for the elasticity of the Hookean body and viscosity of the Newtonean body of the gelatin milk jelly were the lowest. The melting temperatures of the agar, LM pectin, l-carageenan and gelatin milk jelly samples were 84.1°C,55.8°C,52.3°Cand 30.3°C, respectively. While there was marked syneresis of the agar milk jelly, there was little with the alginate milk jelly and LM pectin milk jelly. A sensory evaluation judged the agar and gelatin milk jelly samples to be palatable, while the LM pectin and alginate milk jelly samples were judged to be unpalatable.

View full abstract

The color harmony of Wanmori (a dish used in the Japanese tea ceremony and presented in a lacquered wooden bowl) was analyzed from photographs in books of Kaiseki cooking. V 20 (Toyobo Co. Ltd. ) color-image analyzing computer software, was used. The food materials occupied less than 40% of the whole area of a Wanmori bowl. The color which appeared most frequently and constituted the largest area of the food materials was the white-skin color to show the cooked fish of the season. In the summer, the number of colors per bowl was smaller and the area of the white-skin color was larger than in the winter which gave the effect of coolness. In the winter, warm colors (red and/or yellow) were added to give the effect of warmth. This color harmony is characteristic of Japanese cuisine that respects the sense of the season.

View full abstract

The temperature change patterns were studied for 12 types of pot and pan made from differed materials with different construction and varying bottom thickness. By measuring (1) the temperature distribution from gas heating, (2) the rates of temperature rise and temperature drop during the processes of heating and air cooling, (3) the time for the temperature rise and drop with these processes, and (4) the rate of external temperature rise detected at the heated outside and the difference in temperature between the heated inside and outside surfaces, the temperature change patterns were identified. Strong correlation was found between the rate of temperature change and the thermophysical properties of the main construction materials, although the shape, size, bottom thickness and construction of the pots and pans differed. The pots and pans were classified into three groups by the temperature patterns: (A) aluminum-alloy & copper group, (B) carbon steel &titaniumalloy group, and (C) ceramic group, although the multi-layer types constructed from two materials belonging to different groups were difficult to classify.

View full abstract

Cockle is popular in sushi bars and restaurants, the purple-gray color of the cockle's edible part being a characteristic feature as well as its taste and unique texture. Raw shellfish are generally preferred to cooked ones in Japan, although, raw cockle is not often eaten as sashimi and sushi. The reasons why cockle is blanched and then frozen are that it has unstable color pigments and is difficult to keep freshness.
In this study, we stored raw cockle at low temperature(4°C)when wrapped in a humidity stabilizing sheet containing glycerol, pulp and an absorbing polymer and examined the quality change during storage. The raw sample wrapped in the humidity stabilizing sheet lost weight during storage because of dehydration. Additionally, the surface of the sample increased in toughness and decreased in chewability. The sample stored without wrapping soon decolorized and became faded. Changes in the average amount of ATP and its related compounds and in the freshness indices indicate that the storage wrapped in the sheet were superior to that without wrapping. Sensory tests also show that storage while wrapped kept the sample's fresh appearance for a longer time than without wrapping.

View full abstract

The effects of species and treatment of sesame materials (raw dehulled white sesame seed, roasted white sesame seed, roasted black sesame seed, and defatted sesame flour) on the texture of gomatofu were studied by texture measurement, SEM observation and sensory tests. The amount of lipid in white sesame milk was greater the protein and carbohydrate contents were lower than those in black sesame milk. Values for both the hardness and gumminess of the gomatofu samples increased in the order of DF (defatted gomatofu)>Ro-W (roasted white gomatofu)>Ro-B (roasted black gomatofu)>and Ra-W (raw white gomatofu). The value for the cohesiveness increased in order of Ro-B>Ro-W>Ra-W>and D. F, and the values for the adhesiveness of Ra-W and D. F were higher than th ose for Ro-W and Ro-B. SEM observation revealed that the air cell size in the samples was smaller in order of Ro-W>Ro-B>Ra-W>D. F, and both samples of Ro-W and Ro-B had a uniform cell size and fine structure. The results of a sensory test indicated that the Ra-W prepared with un-roasted dehulled sesame seed had the least hardness, but mouthfeel and viscosity of this sample were the highest. The Ro-B and Ro-W samples were evaluated to have the best palatability because of their superior springiness.

View full abstract

Instructional material for home economics in high-school education was produced from an analysis of residual food components on washed tableware. Color-development reactions for starch, protein and fat respectively with iodine, ninhydrin and curcumin were applied for the analysis on six tableware samples made of porcelain, clay, polypropylene, lacquer, wood and plastic.
Hardly any starch remained on any tableware sample.
The removal of protein and fat was comparatively difficult by a variety of washing methods. In particular, residual fat on a wooden cutting board was the hardest to remove.

View full abstract

We determined the residual surfactants, major components of kitchen detergents, on washed tableware by a simple and rapid method to demonstrate the suitability of this experiment as instructional material for home economics in high-school education.
The residual surfactants were determined by the Ethyl Violet method with a simple, portable spectrophotometer.
Among the six pieces of tableware analyzed, which were respectively made of porcelain, clay, polypropylene, lacquer, wood and plastic, the largest amount of detergents residue remained on the wooden cutting board.
The detergent concentration varied with the washing condition in respect of the dilution of the detergent, temperature of water for rinsing, and flow of water.

View full abstract