Is there much difference in nutrition between yellow squash and zucchini?
For the most part, you're getting similar nutrients whether you choose the generally green-skinned zucchini or the generally yellow-skinned crookneck or straightneck squash.
Both are very low in calories (20-25 calories in a cup of raw slices, and 30-35 calories in a cup of boiled slices). And both are good sources of dietary fiber, vitamin C, vitamin B6, folate, magnesium, potassium and manganese.
Yellow squash is generally higher in copper. But zucchini offers more vitamin K and riboflavin. Plus, compared with yellow squash, you'll find zucchini is chock-full of three carotenoids: beta carotene, lutein and zeaxanthin.
For example, a cup of sliced, boiled yellow (crookneck or straightneck) squash has 175 micrograms of beta carotene and 570 micrograms of lutein and zeaxanthin. The same amount of zucchini has 1,200 micrograms of beta carotene and 2,070 micrograms of lutein and zeaxanthin. Lutein and zeaxanthin reduce the risk of cataracts and macular degeneration, one of the leading causes of blindness. Beta carotene is converted to vitamin A in the body, which plays an important role for many functions: vision, bone growth, reproduction, the immune system, and cell division and differentiation.
Whichever kind of summer squash you choose, be sure to eat the skin. That's where most of the nutrients are. Fortunately, the summer squash's thin skin is soft enough to enjoy whether the vegetable is eaten cooked or raw.
One of the best features of summer squash is its versatility. Raw, it can be chopped, sliced or grated for salads, wraps or veggie trays. To serve hot, it can be baked, steamed, boiled, grilled or cooked with tomatoes, onions, peppers, eggplant or other vegetables for ratatouille. Grated squash adds nutrients and moisture to quick breads, muffins and other baked goods.
When choosing summer squash, select ones that are firm and fairly heavy for their size, with bright, glossy skin. Try to avoid any with nicks, bruises or soft spots -- punctures can lead to decay.
Unfortunately, the ideal storage temperature for summer squash is somewhere between 41 and 50 degrees -- too cool for the kitchen counter, and too warm for the refrigerator. Still, experts recommend placing summer squash in a plastic bag, to help it retain its internal moisture, and storing it in your refrigerator's vegetable crisper. Don't wash or cut summer squash it until you're ready to use it. Under these conditions, summer squash should retain its quality for at least three to five days.
Chow Line is a service of Ohio State University Extension and the Ohio Agricultural Research and Development Center. Send questions to Chow Line, c/o Martha Filipic, 2021 Coffey Road, Columbus, OH, 43210-1044, or filipic.3@cfaes.osu.edu.
This column was reviewed by Lydia Medeiros, associate professor of human nutrition in the College of Education and Human Ecology, state food safety specialist with Ohio State University Extension, and researcher with the Ohio Agricultural Research and Development Center.