From Purdue Extension:

Nutritional Value & Health Benefits

There are four main types of kale.

Curly: These have bright, dark green or purple leaves. The leaves are ruffled, hence the name. They are sold in bunches, and stalks are fibrous.

Lacianto: These have dark, blue-green leaves with a wrinkled and firm texture.

Red Russian:  These have red-tinted, flat leaves that resemble big oak leaves. Leaf stems are reddish-purple.

Redbor: These have dark red leaves that almost looks purple. Leaf edges are very wrinkled.

Nutrition Facts (1 cup raw)

Calories 8
Dietary fiber 1 grams
Protein 1 grams
Carbohydrates 1 g

Vitamin A 80 micrograms
Vitamin C 19 mg
Calcium 24 mg

Selection & Storage

Choose kale that is dark in color with small to medium leaves. Kale can be stored in a plastic bag in the refrigerator crisper drawer for up to 5 days. Kale can be frozen and dried.

Preparation & Serving

Kale can be steamed, mirowaved, or sauteéd, or added raw to smoothies, salads, and soups.

Steam: Bring water to a boil in a pan with a steamer basket. Reduce heat to low, add kale, and cover. Steam until tender (about 10 minutes).

Microwave: Place kale in a micorwave-safe bowl with about 1 teaspoon of water. Cover the bowl and cook for about 2 minutes for every 2 cups of kale. Drain and serve.

Sauté: Heat 1-2 tablespoons of olive oil in a skillet. Add kale, turn heat to medium-high, stir, cover, then cook for aproximately 5 minutes.

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