Worth mentioning that unless he has any medical condition that means pineapple is not good for him, you could think about buying fresh pineapple, cutting it up into chunks and freezing them. Sucking frozen pineapple during infusions protects the taste buds and helps to reduce mouth soreness and the awful metallic taste. (Mostly, when people lose their appetite during chemo, it is because food tastes awful rather than because they feel ill.) If he cant have pineapple, sucking ice cubes is an alternative