Wow this takes me back.
I remember a certain sister who used to write to manufacturers to see if the red food colouring (cochineal) was synthetic or made from "crushed up beetles".
There was a bit of a craze for a certain liquid tonic in the 80s as well (Jws are always tired) until a rumour went round that the reason it was so effective was that it contained blood.
One brother wouldn't eat chicken flavoured crisps or noodles in case 'the chicken hadn't been bled'.
And I remember the Ox blood in wine scare. How sacreligious it would be if the wine that represented the blood was made with blood! Truely the devil gets in everywhere.
Anything with pink or red colouring was suspect.