crab bait (toxins)

Read an article recently could have been sea angler but they said crabs release a toxin that would deter fish when dead awhile. Fine with fresh crabs but is there a way of knowing if frozen stuff has already been destroyed with these toxins.
Say i order aload of frozen crab how am i to know they were frozen straight away or havnt thawed and been re-frozen?

any give aways?

Best advice I would give you is to find a seller with a good reputation and stick with them, it's not in their interest to sell you rubbish bait.

Paul

smell!! shell a fresh peeler cut it in half and have a GOOD whiff ,now remember that lovely pungent aroma !!!! next peel a dead one ,and have a whiff ,it wont smell rotten! just different. i often smell frozen ones and can tell if it was dead before freezing ,smoothys and bass will normally not go for a dead one but cod and coalies dont seem as fussy in my few years of experience and doggies home in on dead ones and any other bait you have