Your Next-Door Neighbor Knows That You Are Taking Food Science

Your next-door neighbor knows that you are taking food science and wants you to explain why her canned fruit cocktail is softer and shinier than her home-made fresh fruit salad. Can you make any suggestions to help her make her fruit salad more like the canned cocktail that she likes so much? Additionally, she would like to know why, after she purchases her bananas, their skins seem to always turn black in color within a few days.