I am studying abroad and trying to save money by taking food from home (the US) and not having to buy EVERYTHING once I get there. I have packed ziplock sandwich bags of raw brown basmati rice and ziplocks of protein powder. Will they freak out at the TSA checkpoints?
The TSA does not "freak out" and does not have jurisdiction in the country you are visiting, however you should declare these articles on entry to your arrival country.
If you fail to declare them, you can be liable for a fine or even jail time. The basmaati rice will likely fall under any number of food related prohibition sections (a full list with explanations can be found here for the US however these may be different depending on your arrival country), it may not be banned following a check from officials. Protein powder is usually OK however you should still declare it to the customs official. By declaring your items, the worst that will happen is they will be confiscated, with the best outcome being you can keep them. You haven't actually mentioned where you are going to, however you will find that basmaati rice is not that expensive in most other countries and you may alleviate some of your fears by buying it locally.
Protein powder may freak out an agent when he/she sees your bag going through an xray machine as your powder is organic in nature and having any wires or even ear plugs near that area will certainly make it a case for manual inspection. Once your bag is pulled out for manual inspection, they will ask you what it is and do a quick explosives test by taking a swab to test in their machine before they let you go. Having a labeled sealed packet will make the whole process quicker.
I've often wanted to carry either food for the first ~12 hours (e.g. arriving somewhere slightly remote late in the evening), or snacks (for a trip like a safari with set meal times and minimal chance to stock up). In all cases you will make it easier for yourself if you carry prepared food in its original packaging. Even then I'd steer clear of protein powder (except possibly single-serving sachets) -- if you must have protein supplements, spend the extra on enough bars for a few days until you find a local source (even amazon.wherever). Your luggage is likely to be too full of stuff you really need to take to have room for more than a few days worth of food anyway.