Yes to a certain degree. When the moisture freezes in food it sort of distroys the grain of the fabric or texture. When thawing food, it should be done in the refrigerator, so that bacteria does not grow. This is why they say not to freeze thing twice. In my mind it is better than chucking it out, but maybe some foods can be cooked first before freezing it a second time.
Air is one of the factors in the process of spoiling foods.
So always keep food wrapped with plastic wrap and for best results use vacuumed sealed bags. It is not very difficult to distinguish spoiled or bad foods, look for the following sings. Bad taste with as small sample, use as a last resort. Dip your fish into the batter and when placing it into the oil, don't just drop it in. Hold the piece of fish as close to being submerged as possible, until it wants to float on its own, then release it so that it does not sink to the bottom and get stuck.