Sodium content of tuna

From: John DeBeer (john.debeer@cox.net)
Date: Mon Aug 14 2006 - 10:22:48 PDT

  • Next message: John C. Wekell: "Re: Sodium content of tuna"

    Carlson-Thurston-Stansby-1960-Proximate-Chemical-Composition-Raw-Precooked-C
    anned-Tuna

    If anyone wants a tif or pdf of this paper let me know.

    Raw tuna in tuna directly out of the ocean is about 0.1 to 0.2 percent -
    anything else is added salt.

    How the salt is added depends on the manner of catch or processing.

    1. Tuna caught with purse seiners (generally skipjack or yellowfin) will
    pick up salt because they are chilled and frozen in dense brine. The amount
    depends on the concentration of the brine, the size of the fish, the days in
    brine, temperature of the brine, etc. These factors are well documented.

    2. Tuna caught by longliners and blast frozen contains 0.1 - 0.2 % salt.
    Thus this is the generally the only tuna that can be used in a lo-salt
    canned tuna product.

    3. All modern tuna canneries measure the salt or sodium of the incoming
    fish. If the light meat (SJ or YF) require salt it is added on the canning
    line at the media makeup. The longline fish will have salt added at this
    step as well. If the light meat does not require salt to get it to the
    desired level it is packed as is without added salt.

    4. As Dr. Howgate correctly pointed out in another posting, there are
    purchase specs for salt for purse seine caught fish. Exactly what they are
    depends on the buyer and seller.

    Best Regards
    John DeBeer
     
    e- john.debeer@cox.net

    -----Original Message-----
    From: owner-seafood@ucdavis.edu [mailto:owner-seafood@ucdavis.edu] On Behalf
    Of Richard Chivers
    Sent: Monday, August 14, 2006 3:07 AM
    To: seafood
    Subject: Sodium content of tuna

    I have just received a query regarding the sodium content of tuna.

    According to McCance and Widdowson tuna has the following sodium content:

    Raw tuna 40-50 milligrams/100g

    Cooked tuna in oil 290 milligrams/100g

    Cooked tuna in brine 320 milligrams/100g

    My contact wants to know why the sodium content increases so much through
    cooking.

    Thanks in anticipation

    Richard Chivers
    Seafood Audit International



    This archive was generated by hypermail 2b29 : Mon Aug 14 2006 - 10:28:37 PDT