Article

Background and Purpose: Recently, increasing interest has been focused on food loss, such as non-standard products in food manufacturing plants, and their reuse in Japan. Food loss that occurs during the egg-roasting process can be possibly used as a material and to convert it to fermented seasonings. This study aimed to investigate the quality of various types of fermented seasonings prepared from the food loss using soy sauce brewing technology. Materials and Methods: The food loss produced during the egg-roasting process was chopped with a kitchen knife. The chopped food loss was mixed with three types of koji moulds: rice koji, soy sauce koji and soybean koji, salt-tolerant lactic acid bacterium (Tetragenococcus halophilus), salt, tap water and commercial enzyme in a two-liter crow bottle. Three types of moromis with and without minced chicken meat were fermented at approximately 30℃ for 24 weeks. Soy sauce yeast (Zygosaccharomyces rouxii) was added to each moromi after 2 weeks. Various moromis were heated up to 90℃ at the end of fermentation. The sample obtained after centrifugation and filtration with the heat-treated moromi was tentatively called as final product. Physicochemical properties and extractive components of the final products were investigated. In addition, taste sensor (TS) analyses of the final products were performed. Results and Discussion: The pH levels of all products were in the range of 4.6 to 4.7. The total nitrogen and soluble solids excluding salt levels, were higher in the products with chicken meat than those without chicken meat. The histamine levels of all products were below 20 ppm. Lactic acid, glutamic acid, lysine, leucine and arginine levels were richer in the products with chicken meat than in those without chicken meat, whereas citric and succinic acids and glycine levels exhibited the opposite trend. According to TS analysis, saltiness and sourness were stronger in the product with soybean koji than those with the rice bran and soy sauce koji, and the strength of umami (first taste) was remarkable in the products with chicken meat. Moreover, the product with soybean koji and the chicken meat achieved most well-balanced umami (first taste and aftertaste) in all the products. Conclusion: Food loss, such as non-standard products, produced at egg-roasting process can be effectively reused by converting it to a variety of fermented seasonings using soy sauce brewing technology.

[背景と目的] 現在,食品製造工場では規格外品のような食品ロスへの関心が高まり,その再利用法が求められている。このような食品ロスが食品原料として再利用できれば,卵焼き製造工程で生じる規格外品から発酵調味料への変換が可能となる。本研究では醤油醸造技術を用いて卵焼き製造工程で発生するロス(卵焼き製造ロス)から種々の発酵調味料を調製し,その品質を調査することを目的とした。[材料と方法] 卵焼き製造ロスを細切し,これと3種類の麹(米麹,醤油麹,大豆麹),醤油用乳酸菌(Tetragenococcus halophilus),食塩,水および市販酵素剤を2L容のガラス瓶に入れて良く混合した。次にこれらのもろみを鶏肉添加区と鶏肉無添加区にそれぞれ分けて合計6種類のもろみを調製し,約30℃で24週間発酵させた。2週間目の各種もろみに醤油用酵母(Zygosaccharomyces rouxii)を添加した。発酵終了後,90℃に到達するまで火入れを行い,遠心分離・ろ過後の試料を最終製品とした。各種製品の物理化学的特性と呈味成分を調査した。また,味覚センサー(TS)分析も実施した。[結果と考察] すべて試料で製品のpHは4.6～4.7であった。全窒素分と無塩可溶性固形分は共に鶏肉添加区の方が鶏肉無添加区よりも高かった。ヒスタミンレベルはすべての試料で20ppm未満であった。呈味成分をみると,乳酸,グルタミン酸,リジンおよびアルギニンは鶏肉添加区が鶏肉無添加区よりも高値を示した。一方,クエン酸とコハク酸およびグリシンは逆の傾向であった。TS分析では,塩味と酸味は大豆麹添加区が米麹および醤油麹添加区よりも強く,また,うま味(先味)の強さは鶏肉添加区で顕著であった。さらに,鶏肉と大豆麹添加区はすべての製品の中で最もうま味(先味・後味)のバランスが良かった。[結論] 卵焼き製造工程で生じる規格外品のような食品ロスは醤油醸造技術を用いて効果的に多様な発酵調味料に再利用可能と考えられた。