From the end of April until the traditional finale on June 24, St. John’s Day, the popular but unfortunately far too short asparagus season lasts. While the healthy asparagus spears were once grown only in monasteries and apothecary gardens as a true panacea and later served as a royal vegetable to the rich and powerful, today the vitamin– and mineral-rich shoots can be found in every supermarket.
Asparagus: white, purple or green?
Depending on the cultivation method, asparagus shows itself in three colors: white, purple or green:
- The shoots of white asparagus – also called pale asparagus – are protected from sunlight by mounded earth and therefore remain white. Due to the complex cultivation process, the white asparagus is more expensive than the green.
- When the asparagus tip breaks through the earth cover, it becomes purple due to the formation of the plant pigment anthocyanin.
- Green asparagus usually grows on flat beds under the influence of full light, thereby forming the green pigment chlorophyll and increased flavor-determining ingredients. Green asparagus thus has a stronger, spicier flavor.
Sprouts rich in vitamins and minerals
Asparagus consists of about 95 percent water and because of this provides very little energy – only 16 calories per 100 grams – unless served with high-calorie fatty sauces (hollondaise, béarnaise, maltaise), buttered breadcrumbs or with a bacon coating. Since it lingers in the stomach for a relatively long time, satisfying hunger for a longer period of time, asparagus has a high satiety value. The proportion of carbohydrates is 1.2 percent. Protein is 1.7 percent, fat only in very small amounts. However, asparagus contains plenty of vitamins and minerals. Especially vitamins C, E and beta-carotene, as well as vitamins of the B-complex. Folic acid, which is found in particularly high concentrations in raw asparagus, prevents malformations in the unborn child and is involved in many metabolic processes in the body. Vitamin C, E and beta-carotene (the precursor of vitamin A) act as antioxidants in the body. The minerals potassium, iron, magnesium, calcium and copper also deserve special mention as beneficial ingredients of asparagus. 5 Facts about asparagus – Pezibear (Pixabay)
Bioactive substances in asparagus
Furthermore, asparagus contains various bioactive substances such as saponins, which are responsible for the bitter-tasting lower part of the asparagus spear, essential oils, and the pigments chlorophyll (green asparagus) and anthocyanin (purple asparagus). Bioactive substances have anticarcinogenic, antimicrobial and cholesterol-lowering effects, among others. The typical flavor of asparagus, which, however, only fully develops during cooking, comes from sulfur-containing essential oils as well as from the amino acid aspartic acid. This amino acid also promotes kidney activity and is thus responsible for the dehydrating effect of asparagus, which is further enhanced by the essential oils and the high potassium content. The typical smell of urine after eating asparagus in almost half of people, is due to sulfur-containing degradation products.
Nutritional information of asparagus cooked
The following nutritional information applies to cooked asparagus (per 100 grams of edible portion):
| Energy: | 16 kcal (52 kJ) |
| Water: | 95 g |
The following distribution applies to the nutrients of asparagus:
| Main nutrients | |
|---|---|
| Protein (protein) | 1,7 g |
| Fat | 0,1 g |
| Carbohydrates | 1,2 g |
| Dietary fiber | 1,0 g |
The following vitamins are contained in asparagus:
| Vitamins | |
|---|---|
| Folic acid (asparagus raw) | 110 µg |
| Vitamin C | 16 mg |
| Vitamin E | 1.8 mg |
| Vitamin B2 | 0.10 mg |
| Vitamin B1 | 0.09 mg |
Asparagus can score with these minerals:
| Minerals | |
|---|---|
| Potassium | 136 mg |
| Iron | 0.6 mg |
| Magnesium | 15 mg |
How to recognize fresh asparagus?
Look for these 9 characteristics to recognize fresh asparagus:
- Fresh asparagus has a tightly closed head.
- The gate should be juicy, fresh and not dried – in the supermarket, the ends of asparagus are often wrapped and thus the gate is hidden. Best to open and check.
- In older asparagus, the cut ends are discolored gray-yellow.
- Fresh asparagus spears produce “squeaky” sounds when rubbed together.
- At the cut, fresh asparagus has an aromatic smell. No longer fresh asparagus smells sour.
- Fresh asparagus shines slightly and looks crisp.
- The stalks should be firm and should not bend.
- Fresh asparagus is easy to score with a fingernail and does not yield to light pressure.
- Short transport routes are important to prevent quality losses. Local asparagus is to be preferred. Especially by buying from the farm you have the certainty to get asparagus fresh.
13 Tips for storage and preparation of asparagus.
- Cool, moist and dark storage is important for asparagus. It is best to store wrapped in a damp cloth in the refrigerator or in a cool pantry.
- Asparagus is to be prepared no later than two to three days after purchase.
- When freezing: Wash asparagus, peel and cut off woody ends. Do not boil or blanch white asparagus.
- Frozen asparagus keeps up to nine months. Subsequently, however, the asparagus should not be thawed – just put frozen in boiling water.
- At a temperature of 0 ° Celsius asparagus should be stored for no more than a week, otherwise the tips will become rubbery.
- Green asparagus is particularly vulnerable to spoilage because of its tenderness.
- Care should be taken that asparagus is always peeled just before cooking to prevent quality losses.
- Always peel the white asparagus about two centimeters, the green asparagus a hand width below the head from top to bottom.
- Towards the bottom peel harder and cut away any woody ends.
- Asparagus is usually steamed or boiled. The cooking time is depending on the diameter and type of asparagus about 20 minutes (white asparagus) and about 15 minutes (green asparagus).
- The less water is used, the lower the loss of nutrients. Therefore, it is preferable to use a sieve insert for vegetables.
- The cooking water can be further used for soups or sauces because of its valuable ingredients.
- A little lemon juice in the cooking water makes the asparagus spears remain white.
Asparagus as a medicinal plant
Asparagus belongs to the group of lily plants and was already used by the ancient Egyptians, Greeks and Romans as a medicinal plant to stimulate metabolism and support liver, lung and kidney function. The word “officinalis”, from the Latin name of asparagus “Asparagus officinalis”, translates as: “medicinal” or “remedy”. It was not until the 16th century that asparagus was systematically planted and used as food due to increasing demand.