title: Chemical Composition of Salmon Ovary Outer Membrane and Its Protein Increases Fecal Mucins Content in C57BL/6J and Type 2 Diabetic/Obese KK-AyMice.
abstract: Salmon ovary outer membrane (SOM) is a byproduct of the salmon industry; however, the effective utilization of SOM for food materials and supplements is anticipated as the demand for fish and seafood increases worldwide. The purposes of the present study were to assess the chemical composition of SOM, the characteristics of SOM protein (SOMP), and its effects on serum and fecal biochemical parameters in mice. SOM contained high levels of crude protein (61.9 g/100 g) and crude lipid (18.9 g/100 g). The protein pattern of SOMP was different from those of fish muscle protein and roe; it was abundant in collagen, as calculated from the hydroxyproline content. In addition, SOMP exhibited lower protein digestibility duringin vitrodigestion analyses compared with casein. Male C57BL/6J and KK-Aymice were fed a casein-based semi-purified diet or a diet with replacement of part of the dietary protein (50%) by SOMP for four weeks. Mice fed the diet containing SOMP showed elevated fecal nitrogen and mucins contents and reduced levels of serum liver injury markers and fecal ammonia. These results show for the first time that chemical composition of SOM, and SOMP, contain a resistant protein fraction and a large amount of collagen. Therefore, SOM is a potential source of marine collagen and functional food material for promoting the health of the liver and colon.
authors.affiliation: Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki, Aomori 036-8561, Japan. hayatosp@cc.hirosaki-u.ac.jp.
authors.forename: Hayato
authors.initials: H
authors.lastname: Maeda
authors.affiliation: Division of Food Science and Nutrition, Tottori College, Kurayoshi, Tottori 682-8555, Japan. hryotan123@ns.cygnus.ac.jp.
authors.forename: Ryota
authors.initials: R
authors.lastname: Hosomi
authors.affiliation: Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki, Aomori 036-8561, Japan. uta_f28@yahoo.co.jp.
authors.forename: Utako
authors.initials: U
authors.lastname: Chiba
authors.affiliation: Faculty of Chemistry, Materials and Bioengineering, Kansai University, Suita, Osaka 564-8680, Japan. fukunagk@kansai-u.ac.jp.
authors.forename: Kenji
authors.initials: K
authors.lastname: Fukunaga
keywords: byproducts; collagen; fecal ammonia; mucins; protein digestibility; resistant protein; salmon ovary outer membrane