This is an issue I have aswell. Bags of dried fruit are a pretty good strategy - obviously one can't get one's whole fruit intake in this way, but it's a good way to get maybe a couple of portions a day.
I also find a product called "V Shots" are quite good. Tiny little bottles of pre-mixed really high concentration fruit-and-veg smoothie. They're easy to knock back over breakfast, and count towards at least one portion of fruit/veg and have 100% RDA of vitamin C. They don't take up too much luggage space either. (I'm not working on commission, honest!
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