Human beings can only perceive six different tastes:

1. Salty.
2. Sweet.
3. Bitter.
4. Acidic (sour).
5. Hot (as in pepper)
6. Umami (salts of glutamic acid like mono-sodium glutamate - MSG)
   

However, there are thousands of tastes in the real world. That's because the subjective taste comes not only from the combination of the above six tastes but from many other factors like the consistancy of the food (creamy, crunchy and so on) and other factors.

In most mammles the smell of food is a great part of providing the final subjective taste. It is definitely so in human beings.

When you have a cold or otherwise your nose is blocked the food appears bland and tasteless. You think it's because you are sick but it's mainly because your sense of smell the odors that the food gives off combine with other sensory inputs (like the color of the food) as well as the real taste receptors to give the final subjective taste.

We buy our wet cat food from Costco which means we get thirty two cans at a time (eight of four varieties). We have three indoor cats and also feed two outdoor strays. They mostly eat dry food and have the wet food as a treat.

The challenge has been that one of the four varieties they do not like so much. So I was thinking on how to make them like the variety so we don't end up with extra cans. My academic background includes a B.S. in chemistry and M.S. in biochemistry.

So I remembered the part about the sense of smell being so important in the total subjective gustatory experience (how foods taste to us). I also remembered about volatility of the small chemicals forming most odor. I put some of the food the cats did not like so much in the microwave. I added a little water and heated for between fifteen and twenty five second.

It made a difference. Immediately I could smell the food. I made sure it was cool enough not to burn the cats'  toungs and offered the heated food to the kitties and each one of them who before hand would have turned their nose up at the food (literally it did not have enough odor) now put her nose down into the plate and chow down.

If you try this for yourself be very careful and experiment first. If you put the wet cat food in the microwave for two long it will splatter all over your microwave and rather than having good odor (for kitty) it will stink for the human servant (we companions of cats know that no human will ever own the cat and who is the master and who the servant)....