I'm afraid that my question has still not been answered:

If I now, out of compassion, go to the nearest supermarket and purchase SPC products, will the money go to Australian farmers and producers, or would it go to the American owners?

Yuyutsu,
Quick answer, not wholey.
Cocoa Cola owns 24% of CC Amatil, the rest is held by a variety of
shareholders and you would, like any company on the ASX, have to study
their share register.

CC Amatil owns all of SPC.
The longer answer, 24% would go to Coco Cola.
However a lot more would go into wages and farmers.

Thank you Bazz!

I just wonder what prevents those farmers and employees from packing their own food, so they don't need to give a cent to the Americans. This will certainly affect my preference to buy their products.

SPC used to be a co op in the seventies. There was SPC, Ardmona, KY, and Girgary. SPC and Ardmona became one. KY and Girgary expired.
SPC had a store where you could by damaged stock. Cans with a dent in them, and no label. At 175 cans / minute going through the closer only one had to fall over and you would have a gigantic pile up. The cans are made at the plant at the rate of 750,000 / 24 hour

Yuyutsu, well 579 answered most of your questions.
However the plant is setup for a market that has changed.
The buyer preference is not now so much for cans but for single serve
plastic packs, plastic jars etc.

For a farmers co-op to build a new plant will thanks to the low price
paid by Coles & Woolies, be more than the farmers could raise.
So they are between a rock & a hard place.
If Amatil does not put up the money then it will close for good.
The only alternative I can see is to place a high tariff on imports.
Then the banks might be interested.

No matter what the ATO says, food is an exception.

Dear Bazz,

So if the problem is just the high rental costs of the machinery, can't the farmers ask the public to help them?

What if they offered deals such as "you buy us a machine and we'll deliver you X number of cans/packets for the rest of your life"?

Then Coles & Woolies too will be out of the picture!

Given that financial investments, after tax, are failing the race against inflation, it would be great if I could put some of my savings directly in food instead, so I'll never have to worry about price increases and be assured that I'll have enough to eat for the rest of my life.

While it is not feasible to invest directly in food because there's a limit on the quantity of food that can be preserved for decades, some arrangement like once a year having a truck, directly from the factory, drop say 1000 cans in my shed, can be quite appealing (obviously there should be some variety and an option to exchange certain foods for others, when available).

The government can contribute its part towards helping Australian produce, by assuring that such semi-barter deals will never be taxable or incur red-tape.