Graduate School of Agricultural and Life Sciences, The University of Tokyo

Elucidating the Post-Mortem Conversion of Fish Muscle to Food

Annually, millions of tons of fishery catches are discarded at sea globally. This large volume of discards includes substantial quantities of edible fish, which are often rejected due to low market value or the absence of established culinary traditions. Meanwhile, the world faces the imminent threat of severe food shortages driven by rapid population growth. To address these critical challenges, our research focuses on developing methods for the palatable utilization of underutilized and non-utilized marine resources.
We investigate the post-mortem conversion of fish muscle to food, focusing on the transformation of skeletal muscle (as biological tissue) into meat (as food). Our research examines this transformation from multiple perspectives, including protein degradation, component migration, and textural changes.By quantitatively elucidating the mechanisms of palatability formation (i.e., the development of desirable taste and texture) during this conversion, we aim to optimize cooking and processing protocols for various fish species. Our research encompasses traditional Japanese processed seafoods (e.g., kamaboko, kobujime) as well as modern culinary techniques (e.g., sous-vide cooking). Furthermore, we aim to apply this fundamental knowledge toward the realization of cultured and alternative fish products that closely mimic the texture and flavor of conventional fish meat.

Expanding Horizons through Food

I am responsible for a lecture titled "The Calculus of Kamaboko" (a Japanese surimi product) within an omnibus-style course called "Mathematical Understanding of Agricultural Phenomena." This course introduces various mathematical approaches in the agricultural sciences. In this specific lecture, I cover the behavior of fish proteins during the kamaboko processing, introducing methods for quantifying experimental results, practical simulation exercises, and a gelation model based on differential equations.
Food research necessitates a comprehensive approach, addressing all aspects: the biological processes by which organisms become raw food materials, the industrial processes of manufacturing and distribution, and the human processes of sensory perception, digestion, and absorption. Therefore, our laboratory engages in both "wet-lab" research (e.g., tissue observation, omics analyses) and "dry-lab" research (e.g., simulations using mathematical models, survey data analysis). Furthermore, students have opportunities for industrial field research, including visits to food processing plants and interviews with professional chefs.

Articulating Craftsmen’s Intuition through Science

While food production has become increasingly automated, many fine adjustments are still entrusted to on-site judgment. It is common for artisans to determine processing times, such as mixing or heating, based on empirical rules cultivated over many years. Our laboratory is working to scientifically verify and articulate these uncodified (or tacit) control methods using advanced analytical techniques.
For example, we constructed a mathematical model representing the relationship between the mixing ratios of fish species, heating temperatures, and the resulting texture of kamaboko (surimi products). The optimal conditions calculated by this model were remarkably close to those traditionally determined by master artisans. We are currently expanding this model to predict textures resulting from varied manufacturing conditions. We are also actively engaged in the effective utilization of food processing by-products (residues) and underutilized/non-utilized resources. Our scope is not limited to marine products; we have a proven track record in analyzing other materials, including beef, pork, and chicken liver.
We are actively seeking flexible collaborations aimed at the scientific verification and quantitative interpretation of procedural knowledge and artisanal intuition in food manufacturing (e.g., the empirical belief that "slight aging improves flavor").