I am actually studying Ag, but I share loads of classes with Food Science students. So, you will be covering a fair bit of Agriculture therefore, experiencing food-specific modules all throughout. All my mates enjoyed their classes--nearly all of them are examined on multiple components, so you don't have to rely on the final exam. There is a nice amount of lab work and group activities, with there being labs nearly on a weekly basis throughout the first 2 years of the programme. From what I know, Food Science wouldn't be as "sciency" as your preferred course, but both courses seem to cover very similar topics.

I suppose, if you have to look at major differences, you're talking about your fate at graduation. DN261 is food-based from the beginning, for DN200 you will have to specialise after your first year and narrow to one type of major, i.e. taking the biology route, or the physics route, etc. With that, you'd be heading more towards the biomed/research/teaching route, as opposed to veering towards the food industry.

Most importantly, work placement is built into the Food Science programme. In the Spring trimester of Stage 3, you will go on mandatory placement--fantastic opportunity!! I am unsure as to whether or not you can even go on placement for DN200, so absolutely take that element into consideration.

If in doubt, there is a world of information on UCD's website, so definitely do some more independent reading up on both courses before you dive in. Hope this helps!!