Rise makes alternative flours out of spent grain from the beer-brewing process.

The urban food system is a living organism, and it’s never been changing so quickly. That’s why Robyn Metcalfe started Food + City last year, a part of The University of Texas at Austin that is mostly an incubator for radical technology startups trying to change the food landscape. Last week Food + City announced the finalists in the 2017 Food + City Challenge Prize, and some of the projects are so intriguing that we had to highlight them.

You may recognize Metcalfe’s name for many reasons. She’s married to Bob Metcalfe, the inventor of the Ethernet, and she has a pretty impressive CV of her own: A food historian and research scholar, she’s written three books, taught at universities for years, and is a regular at events like SXSW and Tedx.

Here are five finalists whose companies echo the hottest themes in technology right now.

Food Tracking

Increasingly customers want to know where their food came from, along every step of the supply chain.

Slovenian company Prospeh’s goal is to increase food’s transparency for the end consumer: Its OriginTrail platform traces each meat, dairy, and vegetable product back to the farm, and its Foodko distribution sharing network allows you to order food and have it delivered directly to your door.

Meanwhile Florida-based FreshSurety wants to reduce the amount the fresh produce industry wastes (currently $200 billion) by allowing grocery stores, specialty stores, and the like to track a product’s shelf life by carton for only a few cents per case. Local Libations targets the producers themselves: Barfly, its keg-monitoring system, allows breweries to track their kegs’ location and volume in real time so that they can better serve the restaurants, bars, and so on that offer their beer. All of these remind me to some degree of what Juicero is doing with its juice packs.

Reduce, Reuse, Recycle

The call to be more judicious with our food and food packaging is never ending, and serious, as people increasingly want greener and greener products and systems.

Brooklyn-based Rise makes “beer flour” out of barley mash, a byproduct of the brewing process. They claim their dark-roasted porter and premium ale flours, for example, are gluten free and contain more protein than chicken. People have been using that spent grain to make dog treats, but who knows: Even cricket flour (yes, for human consumption) has become a big thing lately.

On a more serious note, Evaptainers wants to reduce the amount of electricity that we use with its mobile refrigeration technology that employs only sun and water. It’s not super high tech, but it is part of the growing trend to use solar power in the kitchen.

All of the finalists are pretty fascinating; check out the full list here. Over the next 12 weeks they’ll be meeting with mentors to prepare for Showcase Day in February, when one will win a cash prize, among other opportunities designed to jumpstart their business.