There is some science to leaving scent behind, unfortunately I don't have anything scholarly to quote (I'll have to try to dig up the article I read a few years ago):
The gist is that scent is emitted from our bodies in a few different ways - as solid, liquids, and gasses. A basic principle of all matter is that the warmer it is, the faster the molecules move. And vice versa for cold - they slow down. Think boiling water. The more you heat it up, the faster the molecules are moving. You cool it down - say to a freezing - the matter stops moving altogether. Gasses in particular become 'heavier' as they are cooled and 'lighter' as they are warmed up. That's why as the sun warms the earth thermal wind patterns tend to become more active, and when it cools off in the evening, the wind generally dies down a little.
Anyway, the cooler temps will cause your human scent to be 'heavier' and not distribute as much through the wind. It will still drop and accumulate on other matter along your trail. Just not as much as if it were a warm sunny day.
Also, another property of matter is that the colder things get the less they exhibit other properties (such as smell and taste). For example a frozen turd versus a room temperature turd. The frozen turd will be far less fragrant than the room temperature one.
As for taste you can do a simple test at home. Put a beer in your freezer and leave one on the counter (works particularly well with strong craft beers). Take the one in the freezer out when it's very, very cold. Now try sipping on both of them. You will notice that your cold beer simply tastes 'cold' and you might get some of the strong bittering additions (like hops) on the flavor profile with little bouquet, whereas the room temp beer will 'open up' more both in terms of bouquet and flavor profile, and allow you to smell more of the beers fragrance and also experience a more complex depth of flavor with the grains, hops, and other additions.
