This year, I took 9th grade chemistry and at the beginning of this school year, August 09, I
started cooking, and I got into the science of food.
Answer: frying foods in oil is obviously very hot and immediately water vapor is created inside the food( in this case tomato). The steam from inside leaves and keeps the oil out, unless you keep it in the oil to long. Although, some of the aroma molecules escape, more water escapes than aroma so you're left with a more intense tomato.
Books to get Some good books I got when I started food science were ones I found in the childrens section of a library. Then I got chemistry for beginners books, and then I got The Fat Duck cookbook by Heston Blumenthal for my birthday. It cost $150 I think, but it's one of the best books you can get for food science. Part 1 tells his road to becoming a chef and working with different chemists, and I really learned a lot. Part 2 is recipes, where he reveals things like hot and iced tea, and ice cream that never melts. And part 3 is all science. You learn about different machines how food works, how the brain reacts with food etc. But no matter what, don't just get food science books, get basic chemistry books and you'll learn important things in cooking like osmosis. When I learned about osmosis, I made about 10 experiments in one week. I hope this helped.