Glass Transition of Tuna Flesh at Low Temperature and Effects of Salt and Moisture

Authors

  • C. INOUE,

    1. Authors Inoue and Ishikawa are in the Dept. of Food Science & Technology, Tokyo University of Fisheries, 4-5-7 Konan, Minato-Ku, Tokyo 108, Japan.
    Search for more papers by this author
  • M. ISHIKAWA

    1. Authors Inoue and Ishikawa are in the Dept. of Food Science & Technology, Tokyo University of Fisheries, 4-5-7 Konan, Minato-Ku, Tokyo 108, Japan.
    Search for more papers by this author

  • Part of this study was supported financially by SSRF (Salt Science Research Foundation). We thank associate professor Toru Suzuki of Tokyo University of Fisheries for his helpful discussion.

ABSTRACT

Glass transition of fresh red meat of bigeye tuna (Thunnnas obesus) and its filtrate occurred between —71°C and —68°C, independent of cooling rate from 1 K/min up to 50 K/min. Glass transition at low temperature appeared to occur in the liquid part. Neither dilution nor concentration of the filtrate affected the glass transition temperature (Tg) but the solute concentration of the freeze concentrated phase (Cg) was affected. Addition of salt to the filtrate caused a decrease of ∼20 K in Tg. Results suggested the possibility of qualitative improvement in quality of fish by lowering the storage temperature by 15 K below the present storage temperature (—55°C).

Ancillary