The answer was these juices from Kagome.
They are no Innocent, it has to be said, and some of the combinations are perhaps a little strange. But you have to give them credit for getting large numbers of different fruits and vegetables into the carton. And they are 100% fruit & veg, unlike many of the cartons in the supermarkets here. So I'm going to give them a bit of free publicity, too.
Here are the ones I have had, with lists of ingredients, and brief comments.
1. 5 fruits and 13 vegetables - “Purple”
That's apple, black grapes, green grapes, blackcurrant, lemon, carrots, purple carrots, purple sweet potato, red cabbage, beetroot, broccoli, kale, spinach, asparagus, green pepper, red pepper, a green leafy vegetable which I haven't got a translation for but which might be a pak-choi, and pumpkin.
This one was very pleasant and got me started on the whole thing. Actually, before I'd tried this one, I did have one with just grape juice and blackcurrant. But once I'd had this one, and realised there were a bunch of these things out there, I started on my project to try as many as I could.
2. 10 vegetables and 9 fruits - “Red”
Tomato, red pepper, beetroot, shiso, parsley, spinach, kale, watercress, asparagus, lettuce, apple, lemon, raspberry, cranberry, strawberry, pomegranate, acerola, grape, grapefruit.
(Although technically tomato is a fruit, of course, as I suppose red pepper would be. And whether shiso, parley and watercress are vegetables or herbs could be a matter of interpretation...)
There was a slight smell and after-taste of tomato, which made this a little strange at first, but otherwise this wasn't too bad. Not that I have a problem with tomato juice per se, but as the predominant taste was sweet and fruity, rather than savoury and vegetably, it was slightly jarring.
3. 18 vegetables and 5 fruits - “Yellow”
Yellow carrot, carrot, pumpkin, yellow pepper, maize, onion, cabbage, aubergine, asparagus, celery, Chinese cabbage, daikon radish, kale, lettuce, watercress, spinach, parsley, beetroot, some kind of angelica which seems to be specific to Japan (known as Ashitaba in Japanese, and which Wikipedia gives as Angelica keiske), apple, mango, banana, lemon, passionfruit.
This was in fact very tasty. I was a little concerned in advance by the presence of onion in the list of ingredients, but there was no hint of that on either the nose or the palate. The nose was, in fact, dominated by mango, although there was certainly more to it than just the mango, and the taste was similarly complex, with the passionfruit lingering most.
4. 21 vegetables and 3 fruits - “Original”
Carrots, spinach, asparagus, red pepper, the one I think might be a pak-choi, watercress, pumpkin, purple cabbage, broccoli, something called petit vert (another Japanese veg, cross between kale and cabbage), beetroot, red shiso, celery, lettuce, Chinese cabbage, kale, parsley, aubergine, onion, daikon radish, cabbage, apple, orange, lemon.
Certainly a citrus-y taste to this one, with something somehow reminiscent of sherbet to it. Apart from the general citus taste, no other fruit of vegetable predominates.
As far as I can tell, that's all the fruit and vegetable ones which Kagome make. There is an all vegetable one, but I'm not so keen on that as an idea, so I probably won't have that one. And there are cheap imitations, too. But unless anyone knows of any fruit and vegetable ones I've missed – and you can let me know by leaving a comment if you do – I think that's my lot. Personally, I'll probably be alternating between “yellow” and “purple”, given the chance.