Me too, here is how I have documented the dreaded fruit cake incidents.
It is definitely the fruitcake. After one of my Sims ate it she immediately started disliking all food everything after that tastes bad even her gourmet dinners. She now has the ability to "Complain about the fruitcake" although when this interaction is chosen, it simply disappears and she doesn't complain. She is an Astronaut and continuously enthuses about space instead of enthusing about other things. Her charisma is maxed. She is also maxed in both cooking and gourmet cooking skills. I think I'll try giving her a dose of remedy medicine and see if it helps.
So, I gave Raven medicine and my Sim got this message "Raven's liberal use of medication when she's not sick has caused some uncomfortable side-effects".
Perhaps not liking her food will eventually wear off.
Another Sim went on vacation and for some reason (she did not cook it) she had a fruitcake plate in her inventory. She ate it while out camping in the forest and now has the ability to "Enthuse about the fruitcake". She still loves her food at home.
Could this be a side-effect of the annoying neighbors that come to call when you buy a new home? If it is, I'm laughing but not really lol.
Had Raven Heart bake another fruitcake with apples as the fruit and had the same effect. The graphic shows its suppose to last 4 hrs so we'll see if it goes away after she sleeps and goes to work.
http://i1381.photobucket.com/albums/ah233/ravenshrt/fruitcake_zps4mqhpbqy.jpg
After 4hrs, she still hates her food, the food notification disappeared to no avail, and I have now decided that I hate fruitcake more than the Sims do.
EDIT: Just adding that I do not use mods or custom content and have all expansion packs and stuff packs. And after 4 days playing (real time) my Ravens Heart Sims4 character still hates her food.
EDIT: July 25, 2015 - Raven Heart sim character continues to hate food at home, visiting, in venues, everywhere. (Side note: she has sworn off fruitcake for good but would love to love her own food and others again soon). I'm being extremely careful to watch for fruitcake being given or taken from sims. Today one of my other sims randomly gave a fruitcake to someone on the street without baking it. Since the last update a lot of things seem very off, like no visitors at all unless called or invited and includes no visits from any friends or romantic relationships, other households "interest earnings notifications" displayed while playing other households, game suddenly lags and causes characters to not respond, sims forget they are in relationships with other sims and suddenly have relationships with sims they haven't encountered, unidentified plants are not being sorted into their own stack of plants in inventory they are hidden inside stacks of other already identified plants which I had to workaround that by going fishing and choosing 'fish with bait" which opened up the stacks so I could scroll through them. There may be more things I've not noticed yet. RavensHrt
EDIT: July 26, 2015 - Since today is my birthday I finally gave in and redid my entire game to get rid of Raven Heart not liking her food. Still noticing lots of lag in the game which was not there prior to the update and haven't played enough to notice anything more going on.
Enjoy your vacation time @crinrict !!!