How can I recreate canned whipped cream from scratch?

Sigh, I was trying to avoid answering this, but feel compelled to provide some information after all your revisions. I'm answering only this part of the question:

Can someone explain what these are: (maltodextrin, inulin (chicory extract), cellulose, mono- and diglycerides polysorbate 80, artificial flavors, carrageenan)

Let's break that down:

• maltodextrin is a sweetener
• inulin is also a sweetener
• cellulose is a fiber (wood, basically) used as a stabilizer
• mono- and diglycerides are emulsifiers, that make the cream smoother
• polysorbate 80 another emulsifier
• carrageenan algae, also a stabilizer

Now, "artificial flavors" could literally mean anything, which is a big challenge for your recreation experiment. Not only does it not say which flavors they've added, the formula may be a trade secret.

If your trying to imitate the flavor of 'reddi-whip' then you're going to have to play around with the chemistry to get at what you want. If you are wanting to make home-made whip cream come spraying out of a canister, then I have just the thing for you: An NO2 whip cream canister can be purchased at any of several outlets. NO2 Whip Cream Canister Just add whip cream, sugar and give it a good shake then connect an NO2 cartridge (or CO2, cheaper and more readily available but be careful to get food grade, your average 'paint ball' CO2 cartridge can have unpleasant additives) and you have 'ready whip' (you can also add a variety of other flavorings, I enjoy Amaretto... ) Be careful, a little bit of sugar and some flavored syrup can go a long way in here.

Reading the label gives you a long list of stabilizers, sweeteners, emulsifiers, and "artificial flavors", none of which are likely to significantly alter the flavor profile of your homemade replica.

If you are needing to bump the flavor, a (small!) pinch of salt helps accentuate flavor without making things salty. Vanilla extract could help -- however, at that point you're starting to move beyond just whipped cream flavor.

Your biggest challenge is going to be consistency, regardless of the flavor profile you accomplish. Texture, or mouthfeel, can be a big influence on whether something "tastes right," and homemade whipped cream is definitely thicker than its canned counterpart. To replicate texture of Reddi-Whip or similar brands, you need a whipped cream canister that aerates the cream-sugar mixture, and Cos Callis answered that thoroughly.