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.
Keep your zucchini squash in perforated plastic bags in the crisper drawer of the refrigerator. Store-bought zucchini should keep for about a week; freshly-harvested zucchini may last for up to two weeks. Wash the squash just before you use it. You can keep zucchini squash in the freezer for baking for about a year. To prepare for freezing, wash and grate small, tender zucchini. Steam blanch it by placing a single layer of zucchini in a steamer basket at least three inches above several inches of water.