Ulva pertusa is a large green, leafy seaweed, containing various vitamins, minerals, and antioxidants, yet it has not been widely used in our daily diet. In our study, samples of loaf bread were prepared by substituting Ulva pertusa powder for bread flour at levels of 1, 2, and 3 wt% and were examined to determine the effects of the substitution level of Ulva pertusa powder on antioxidant, physical, and sensory properties of the bread. In proportion to the substitution level, Ulva pertusa-containing bread showed higher DPPH (1,1-Diphenyl-2-picrylhydrazyl) radical scavenging activity than did the control bread with 0 wt% Ulva pertusa powder substitution. The specific loaf volume and the cohesiveness significantly decreased and the hardness significantly increased at substitution levels of 2 wt% or higher. Scanning electron micrographs showed that, as the substitution level increased, the network structure formation was disrupted, resulting in the development of non-uniform air spaces. As determined by the evaluation of sensory properties, samples of loaf bread with 1 wt% substitution achieved the highest rating for overall quality, while those with 2 wt% or higher substitution received significantly lower rating for overall quality. These results indicate the usefulness of Ulva pertusa as a functional ingredient of bread and its suitability for daily intake.

View full abstract

The purpose of this study is determine the effects of added seasonings (1%) on the texture and vitamin C content of potato (May Queen) under vacuum cooking conditions. We applied the two cooking methods (boiling and vacuum cooking) and added three seasonings (water, 1% salt, and 1% sugar) to the prepared potato samples. We then analysed the texture with EZ Test (Shimadzu, Ltd.), and measured the vitamin C content using the “postcolumn derivatization” method. The hardness of potatoes seasoned with salt was greater than that of potatoes seasoned with sugar under vacuum cooking conditions (p<0.05). Following the addition of salt, the adhesiveness of vacuum-cooked potatoes significantly increased compared to that of boiled potatoes (p<0.01). By 40 min of cooking, vacuum-cooked potatoes had significantly higher levels of vitamin C than boiled potatoes under all three seasoning conditions (p<0.05). These results imply that at 40 min, vacuum-cooked potatoes retained most of the original vitamin C potency, irrespective of the seasoning added, and that potatoes seasoned with 1% salt were harder than potatoes seasoned with 1% sugar under vacuum cooking conditions.

View full abstract

We measured the water absorption of rice grains when it is soaked in warm and cold water, as well as the amount of rice contents suspended in the soaking water. Rice grains were soaked in water with temperatures ranging from 5°C to 50°C, for 5 to 240 minutes. The water absorption curves obtained, crossed each other. At the equilibrium state, rice soaked in cold water showed higher water absorption than rice soaked in warm water. Measurement of suspended rice contents in soaking water showed that warm water adjusted to 40°C and 50°C had the highest rice contents. Subsequently we measured the adjusted water absorption by including the values for rice contents that was suspended in soaking water. The adjusted water absorption curves obtained also crossed each other. Once again, it was observed that at the equilibrium state, rice grains soaked in cold water showed higher water absorption than that soaked in warm water.

View full abstract

In recent years, the consumption of fish and shellfish in Japan has decreased greatly; therefore, the tradition of eating local fish and shellfish could be lost. The objective of this study was to investigate consumer habits of eating fish and shellfish in the following three areas (collected with the help of the Japan Society of Cookery Science): entire Japan, the Chugoku-Shikoku region (excluding Okayama Prefecture), and Okayama Prefecture. The number of Japanese Spanish mackerel dishes consumed per person was highest for residents of Okayama Prefecture (1.57 dishes/person) and lowest in Japan as a whole (0.45 dishes/person). There was a significant association between the cooking methods (raw, boiling, broiling, and frying) and consumption in the three areas (P<0.01). Thus, the tradition of eating local fish and shellfish remains alive in Okayama Prefecture; it is ecologically important that this local production and consumption be maintained.

View full abstract

From 2007 to 2012, surveys were conducted every April to investigate the cooking habits of 1,611 freshmen (ages 18-20) in both college and vocational college. The respondents, 18.5% male and 81.5% female, were categorised into several groups. It was found that their frequency of cooking was low, but they enjoyed cooking and wished to find more opportunities for cooking. It was also found that among boarding students, more than 55% of them cooked every day, while only 5% of the students who commuted from home cooked every day. Furthermore, many students who cooked everyday enjoyed cooking, compared with those who cook rarely. Students who cooked more regularly or with more cooking experience also tended to have their own specialty dish, while those who cooked rarely did not. Therefore, cooking on a regular basis increased the likelihood of enjoying cooking and having a personal specialty dish.

View full abstract