Did the restaurant really serve me dyed tuna sashimi?

August 30, 2012 1:01 PM

I ordered sashimi at a sushi restaurant a few days ago, and the piece of tuna left red smudges on the pile of daikon it was placed on. Are there any reasonable explanations for this?

The salmon sashimi that came with the tuna sashimi was really good. The tuna tasted a little strange (it wasn't very good). We didn't discuss the smudges with the waitress.

Is there an explanation other than one involving red dye?

posted by leahwrenn to Food & Drink (10 answers total)

It still had over-proteinated fluid on it?
posted by starvingartist at 1:03 PM on August 30, 2012

Rare Tuna: "Besides freezing to prolong the shelf life, there is the growing practice of injecting fish with red dye to make it more eye-catching. Some stores, such as Whole Foods, have taken it upon themselves to alert consumers to this practice. But I’ve never seen any such notice on a restaurant menu."
posted by zippy at 1:09 PM on August 30, 2012 [2 favorites]

Probably definitely dyed.

The bigger question, though, is whether it was actually tuna, and not some lesser fish dyed to mimic tuna. Like escolar, for instance.

You said it tasted strange, and fresh tuna does not, in any way, taste strange. I'm betting you got served a lesser fish dyed to look like tuna. Or, maybe, old-ish tuna that had been given a facelift?
posted by Thorzdad at 1:25 PM on August 30, 2012 [1 favorite]

Umm... blood? It is raw fish after all. Sushi places do tend to wash their fish and meat, but it's not perfect.
posted by valkyryn at 1:25 PM on August 30, 2012

I think this article will help you understand. Toro is very rare in the United States these days inferior ahi is often pawned off as toro, too make matters worse some suppliers are dying the fish red to disguise it. To get the real deal you will pay at least $25 for a serving of toro sashimi two pieces usually about 3/8 of an inch by 1.5 by 3 inches. In Japan you can expect to pay 3 times that.
posted by pdxpogo at 1:27 PM on August 30, 2012

The author of the article called ahi yellow fin, I have always heard yellow fin is hamachi. Yellow fin is good sashimi when fresh and many places will serve that as "tuna" which is true only yellow fin is a different fish than the bluefin where toro comes from. Ahi can refer to bigeye as well as yellow tail both are white translucent fish when served as sashimi.
posted by pdxpogo at 1:40 PM on August 30, 2012

Yellow fin tuna is ahi, yellowtail (a completely different fish) is hamachi.
posted by contraption at 1:51 PM on August 30, 2012 [6 favorites]

(and yellowfin/ahi sashimi will naturally appear dark red, not translucent white like yellowtail/hamachi)
posted by contraption at 2:22 PM on August 30, 2012 [1 favorite]

It might, perhaps, be blood/fluids from a heavily CO-treated batch of tuna, but I'd be tempted to go with dye.
posted by cromagnon at 4:56 AM on August 31, 2012

I bounced this post off Paul Greenberg, who knows more about the fish trade than the Reverend Sun Myung Moon, and he had some interesting links:

NYT: Tuna's Red Glare? It Could Be Carbon Monoxide

Salmon Facts: The Color of Farmed Salmon is No Dye Job. About salmon, but relevant, and this post also covers the "species adulteration" issue a bit, which is rampant in the fish industry.

In salmon aquaculture, the industry endeavors to mimic the diet that salmon would normally get in the wild, so it supplements salmon feed with a synthetic replacement. It's called astaxanthin, and chemically, it's identical to the pigment that salmon get in the wild. Biologically, it's processed and absorbed by wild and farmed fish in exactly the same manner, though some species retain more color than others.


The bottom line is simple here: we're not talking about the sort of food coloring you buy at the supermarket and use in a cake mix. The color of salmon flesh, no matter how it's raised, can't leak. It's physiologically impossible.

posted by jeb at 4:59 AM on August 31, 2012 [1 favorite]