Preminced kangaroo is distinctive for a number of reasons. It has an extremely low fat content, but is still ‘marbled’ with connective tissue, which is rather stringy. It has a noticeable gamey odour that you don’t find in beef or lamb.
I had been reading about tenderizers, and noticed that certain fruiting plants contain enzymes (proteases) which break down proteins. One of these is pineapple (it’s enzyme is bromelin). I thought it might be interesting to see how it worked. After all, perhaps the fruity acid of pineapple might give stodgy old roo a flavour lift as well as softening that connective tissue. I noted that the enzyme is activated between 50C and 70C, so there’s no point using it in the 'frig as a marinade. But slow cooking could work. (The enzyme becomes deactivated at 100C, so canned pineapple  is ineffective). Perhaps meatloaf would be worth a try, thought I, giving minced roo another chance. If pineapple does anything it should be quite noticeable in meatloaf. And it would be easy to set up a side-by-side comparison with another mix, free of pineapple, but otherwise identical.

So this is what I did.  Kangaroo mince is readily available in supermarkets in 1 kilogram packs. Each meatloaf would therefore contain 500g mince. They would include onion and mushroom, which seem to commonly accompany game in other recipes. These I would precook, to both add browned flavours and to reduce their liquid content.
In contrast to my failed meatballs, the meatloaf would contain breadcrumbs. They would soak up any released liquid and so keep the loaf moist, and help avoid that rubbery texture that ruined the meatballs.
Some soy and garlic for extra flavour, to help balance the roo meat. And some sweet chilli sauce brushed on the outside of the loaf, to give a nice flavoured crust.
In one batch was 100g chopped pineapple, and in the other 100 grated apple, with a teaspoon of vinegar, to match the acid of the pineapple.
Both were cooked in identical glass terrine-sized dishes, side-by-side in a 170C oven. This would give the pineapple, buried within the meat, inside the glass, in the slow oven, plenty of time at the enzyme activation temperature, in order to do its work.

And it did its work. I took the knife to cut a slice, and tried to get it out of the dish. The loaf collapsed and had to be spooned out. The apple meatloaf, in contrast, sliced obediently and sat neatly beside the nasty mound on the plate.  A bit of probing with the fork, and we noticed how much the pineapple meat resembled canned dog-food. Trying to compare the flavours of both was very difficult, as the texture sensation was hard to get past. I did notice the acid in the pineapple was good, so made a mental note to increase the vinegar in the apple meatloaf.

So the conclusion to this culinary experiment is: pineapple enzyme can be a wicked tenderizer, but is totally unnecessary for minced kangaroo. This does however suggest a further experiment, involving a cut of kangaroo meat which could be rolled around pineapple, and slow roasted. Hmm.

Fortunately, our dog loves the pineapple meatloaf. And the other meatloaf is edible by humans, quite nice in fact. Being quite rich, you don’t need a large serve, which is probably a good thing for all sorts of reasons that I won’t go into here.
Below is the successful recipe, modified a little according to the test results.

Recipe for Kangaroo MeatLoaf,  Being Entirely Edible

500g kangaroo meat, minced
3tbs olive oil
150g mushrooms (3 large swiss browns), chopped in 1cm dice
1 small onion, choppped
1 clove garlic, crushed
1 cup coarse breadcrumbs (around 100g)
1 egg, beaten
1 apple, grated
2 tbs soy sauce
1 tbs white vinegar
½ tsp pepper
sweet chilli sauce

Into a moderately hot sauté pan put 2tbs olive oil with mushrooms. After 2 minutes, add another tablespoon of olive oil and the onion. Stir and cook on moderate heat until the mushrooms have dissipated much of their liquid, and have shrunk considerably. Stir in the garlic. Remove from the pan and let it cool slightly.
Into a large mixing bowl tip breadcrumbs, mushroom mix, apple, vinegar, soy sauce and pepper. Stir until well mixed. Add kangaroo and combine well with your hands, to make a cohesive mixture.
Put a sheet of baking paper into an oven pan. Put the mix into a loaf tin, then invert the shaped loaf onto the baking paper, removing the tin.  Brush all surfaces of the loaf with chilli sauce.
Bake in a 180C oven until the internal temperature reaches 70C, around 45 minutes.
Remove from oven, cover with foil and let sit for 10 minutes before slicing.
Good with crispy sautéd potatoes and green salad.