There is a place for things like broccoli stalks, onion skins, and orange peels; it’s usually called the garbage. But a friend of mine has been unusually persistent (endearing version of a pain in the butt) in requesting an article on the nutrient content of these vegetable stalks. Well, it turns out that many of the stalks, leaves, and peels that we typically toss bring just as many nutrients (if not more) to the table than the actual fruit or vegetable itself. I guess in this case one man’s trash is a nutritionist’s treasure – those trimmings are garbage no more. We can all start eating a little more “stem-to-root” style and reduce our eco-footprints and bills while we’re at it.
Onion skins: You have to cry to get through cutting it, so why not use the whole thing? Especially considering those papery peels have lots of fiber and even more antioxidants (namely, quercetin and fructan) than the onion itself. Quercetin is a heart-protective flavonoid; it can help reduce blood pressure and arterial plaque. Fructans are prebiotics—great for gut health.
How to use: Onion leftovers can add lots of flavor to soups and stocks. Simmer, then toss the skins before serving.
Stalks and stems (broccoli, cauliflower, chard): Broccoli stalks contain more fiber, vitamin C, and calcium than the florets we’re used to eating, while Swiss chard stems are rich in glutamine, an immune-boosting amino acid.
How to use: Peel and slice broccoli or cauliflower stalks and you have a sweet, crunchy snack, perfect for dipping in hummus – Swiss chard stems are a bit tougher, so simmer in stocks to tenderize, or try baked Swiss Chard Stems with Olive Oil and Parmesan.
Watermelon rinds: August is the best time of year for watermelon, and while the juicy red part might be the tastiest, the white rind is where it’s at, nutritionally speaking. It’s a potent source of citrulline, an amino acid with uses ranging from Alzheimer’s and sickle cell anemia to athletic performance and even erectile dysfunction.
How to use : Make an aguafresca by blending watermelon flesh and rinds with water, fresh lime juice, and mint (and if it’s after 5 p.m., perhaps a splash of vodka).
Leaves/greens (celery, broccoli, turnip, beet greens):While the celery stalks are full of fiber, those celery leaves are the real nutrient powerhouses. The leaves contain FIVE times more magnesium (essential for energy)and calcium (important for bone and muscle health) than the stalks. Similarly, beet greens are also richer in antioxidants, fiber, calcium, and iron than the sweet bulb we’re used to eating.
How to use: Beet and turnip greens sweeten with cooking, so try sautéing them. If you like kale chips, try making broccoli leaf-chips. Celery tops can be tossed into salsas (great for people with an aversion to cilantro).
Citrus peels: The peels contain more flavonoids and four times as much fiber as the fruit. The flavonoids found in citrus fruits, called tangeretin and nobiletin, have anti-inflammatory, anticancer, and cholesterol-lowering benefits.
How to use: Grate the leftover peels into zest for super concentrated flavor – add zest to meat and fish, salads, and drinks.
P.S. Virtual high five to my amigo for helping nutrition, wallets, and garbage situations everywhere.