A normal range for blood urea nitrogen is generally 8 to 24 mg/dL for adult men (2.86 to 8.57 mmol/L) and 6 to 21 mg/dL (2.14 to 7.50 mmol/L) for adult women. However, urea nitrogen levels vary by age. Infants have lower levels than other people do.
Fortunately, freezing zucchini and other summer squash is a snap: All you do is cut it into half-inch slices, blanch it in a pot of boiling water for three minutes, transfer it to a bowl of ice water to cool, drain it, and bag it.
Blanching the Zucchini. 1  1. Fill a large stockpot with water. When blanching slices or cubes of zucchini, you should fill the pot 2/3 full with water and set it to boiling over high heat. 2  2. Fill a large bowl with ice water. Add a dozen or so ice cubes to a large bowl of cold water. 3  3. Blanch the sliced or shredded zucchini.