The present study aims to reveal changes in the dietary culture of Japanese farmers since the early Showa era (1926-1988). This study is similar to an investigation of dietary habits that was conducted in 1941. Thirteen women who were residents of Kawahake Kawakami, Nagano, either by birth or marriage were interviewed in 2002. During the 1960s, Kawahake residents changed their occupation from forestry or sericulture to vegetable cultivation. Vegetable cultivation yielded substantial income, yet necessitated a large amount of labor, resulting in an influx of seasonal laborers from the whole country. Intense labor during summer brought about an increase in the consumption of purchased lunches and side dishes. In addition, Kawahake men began to take wives from all over Japan. These changes along with others influenced the dietary habits of the farmers.

The purpose of this study was to determine the dietary habits of the Meshima-Oki district, particularly to obtain an estimate of the consumption of fish and other seafoods prior to the Minamata disease breakout. This small fishing district, which was hard hit by Minamata disease, is located in Ashikita-machi, Ashikita-gun, Kumamoto Prefecture.

For this study, interviews were conducted with 18 informants. The results showed that seafood was the primary food consumed in the subject area together with cooked wheat and Japanese sweet potatoes. Furthermore, the survey determined that the primary seafoods consumed at every meal included anchovies (Engraulidae), hairtail (Trichiuridae), threadfin (Polynemidae), Japanese horse mackerel (Trachurus japonicus), black rockfish (Sebastidae), octopuses, oysters, sea cucumbers, and stomatopods. These were eaten raw, boiled, or in miso soup.

In the meal reproduction survey, the dishes that were typically identified as having been consumed prior to the outbreak of Minamata disease were reproduced and shown to six informants. They were asked to reproduce servings of three types of seafood dishes that were commonly consumed during the purse seine catches of autumn, the purse seine catches of winter, and the non-purse seine catches of winter. Later, the volumes of food consumption, particularly seafood, were measured and recorded.

The net intake volume of the seafood consumed was determined from the calculated values modified using the actual scrappage rate, which was obtained from what remained after eating miso-soup with fish and boiled fish dishes. In addition, the number of calories contained in grains, sweet potatoes, and seafood were calculated afterward to verify the validity of the net intake volume of the seafood.

The results showed that the daily per-person fish and other seafood intake volume ranged from 57 g to 1043 g on a consumption of three meals a day depending on the season and type of work. The results of this study enabled us to make an accurate analysis of the dietary habits of the fishing village in the area along the Shiranui Sea, where “fish and other seafood were consumed as the main food items” prior to the breakout of the Minamata disease.

Despite fact that using “腐” to refer to a food item would be inappropriate, it was nevertheless used to mean “豆腐” (bean curd) in Chinese. What does “腐” mean in this case? Nobody has a clear idea about it as yet.

The author investigated this question, arriving at the following conclusion.

The protein and fibrous portions of the soybean are difficult to digest. During the olden days, people tried to cook soybeans so as to make them more digestible. In 豆腐,there are four processes:(1) soaking soybeans, (2) grinding them in a stone mill,(3) heating and filtrating them to remove the fibrous matter, and (4) curdling the thick liquid obtained after removing the fibrous matter. The processes clearly show that 豆腐 is a food that makes the soybean digestible.

On the other hand, there is a word- “腐熟” -that is used in the field of Chinese medicine. This word refers to the initial digestion of the foods that naturally make their way into the stomach. After the initial digestion takes place in the stomach, these foods turn into a milky color and achieve a thick consistency. This thick liquid resembles the product before the curd-making process in terms of its function and appearance.

It should be noted that “腐” in the word “豆腐” originates from “腐熟.” It is thus possible to assume that “豆腐” means an easily digestible soybean.

To investigate the role of consciousness in the actual process of handing down local dishes from generation to generation, a survey was conducted among 105 inhabitants of the Shonai area in Yamagata prefecture who fix their own daily meals, using a questionnaire that included items about the consciousness in handing down local dishes, eating habits, cooking frequency of local dishes, and concern about them.

The data were compared with respect to the consciousness in handing down local dishes. The results are summarized as follows.

1. In the cluster analysis, the daily dishes were classified into three categories, “dishes that are handed down,” "known dishes that are not easy to hand down,” and "dishes that are not handed down” with respect to their patterns in being handed down. There was no significant difference in the average frequency of cooking in each category between the conscious and unconscious subjects. The cooking frequencies of several dishes were higher in conscious subjects than unconscious subjects.

2. No significant differences were observed between conscious and unconscious subjects with regard to the frequency of cooking special dishes for rituals.

3. There were no significant differences in the eating habits of the two groups.

4. Concern about local dishes was higher in the conscious subjects than unconscious subjects.

In conclusion, this survey revealed that local dishes are handed down from generation to generation irrespective of whether the people were conscious of this process or not.

The phenomenon of food culture at a given time undergoes constant change owing to changes in the natural environment, human technologies, and social norms. Technological developments as well as changes in the societal values also affect the food culture phenomenon.

Therefore, an ongoing study of these phenomena in a specific region is essential in order to verify the interaction between society and change in food culture. The authors are in the process of compiling the food chronology of the U.S., Europe, and Asia, including China, Korea, and Japan, on the basis of numerous historical written material and data. Only those phenomena that subsequently affected the food culture are being considered in the chronology.

In 2009, the food and culture chronology of Japan for the period from the beginning of the Meiji era (1868) to the end of Taisho era (1926) will be published.