I love tuna and for the past few years have pretty consistently had seared tuna or poke for dinner nearly at least once a week. I used to buy it at H Mart when I was there to buy other things. It has always tasted fine and been cheaper than the other store in my area at which sashimi grade tuna is available so it was often a destination trip. However, with the recent winter, my motivation to go to H Mart 30 miles away has waned and so I've been spending the extra few dollars to buy at Whole Foods. Recently, I had purchased tuna at H Mart but SO and I were quite hungry so wanted to pick up more and only had time to go to Whole Foods. I always noticed that the tuna at Whole Foods and H Mart were different colors, but didn't think too much of it until I recently learned about the use of carbon monoxide to keep tuna a nice pink color. In the picture below, the H Mart filet is on top and is definitely a brighter pink which makes me think that it's the so called "techno tuna." I think it's also pretty consistent with my occasional experiences with freezing - I have frozen the H Mart tuna a few times and the color remains pretty much the same whereas the one time I froze the Whole Foods tuna it turned a lovely shade of brown as you would expect from oxidation.
I just wanted to see if anyone knew if this was the reason for the color difference, and if not is there a reason?
Also, do you avoid the "techno tuna" or don't bother as it doesn't affect the taste or so they say?