Quality of fish sauce products from recycled by‐products from fish gel and kamaboko processing

In order to make effective reuse of kamaboko processing wastes and to minimize the amount of waste disposal, the production of two kinds of fish sauces was tried on a small industrial scale from the wastes with or without the addition of the meat of deepsea smelt (Glossanodon semifasciatus). They were fermented for 6 months at room temperature using salt and koji mold. As a control, a fish sauce was also produced only from the deepsea smelt meat. The recovery of fish sauce from the initial mashed mixture ranged between 75 and 79%, depending on the ingredients in the three fish sauce products. The total nitrogen content of the waste sauce and the mixed sauce was lower than that of the control. The levels of the original additives to kamaboko products, β‐carotene and sorbic acid, were very low in these fish sauces. The taste‐active components of the waste sauce and mixed sauces were lower than those of the control. Sensory evaluation revealed that the former two waste sauces were less bitter and higher in saltiness than the control. However, no difference was found in umami taste between these products. These findings suggest that the wastes from kamaboko processing factories could be reused as fish sauce for food condiments. PRACTICAL APPLICATIONS: Recent development in the food industry in Japan has enabled the surimi‐based products to be mass produced and standardized even in the fish gel, kamaboko trade. However, a serious problem has arisen in the development of kamaboko processing through the discharge of the wastes, i.e., nonstandard products or fragments, from kamaboko processing factories. It is clear that the waste from kamaboko processing factories is transformed effectively into fish sauce by using soy sauce koji mold. As a result, the amount of the discharged wastes from kamaboko factories are able to be minimized because the liquefaction ratio of the fish sauce mushes (moromi) from the wastes after fermentation was high and the products have a high umami taste and agreeable soy sauce‐like flavor.