My "new" 1940s novel is either about adulterated candy, Helen Brach or the profits from confectionery business.
Helen Brach was the heiress to the Emil J. Brach & Company family fortune. She was married to Frank Brach, son of the founder of Brach's Candy. Frank invented the concept of Pick-A-Mix (bulk candy at grocery stores) and he latersold the lucrative candy company in 1966.
Helen disappeared in 1977 and was declared legally dead in 1984. Richard Bailey was sentenced to life in jail for conspiring and soliciting the murder of the candy empire heiress.