Some patients lose the ability to taste. Sensation becomes dulled. Try flavor enhancers on food. Chicken broth can marinate chicken to give it extra flavor. Add bacon or cheese flavors to soups and veggies.
Some patients develop tastes for foods they once hated.
For example, someone may have hated brocoli all their life, but suddenly they develop a taste for it. Why, we don't know. Don't serve items with pits, bones, or in the wrapping. The Alzheimer patient may forget to remove the bone or pit or may choke when they eat the wrapper. Try to toilet the patient before you sit them down to eat.