Generalities

Asparagus is a food of vegetable origin which can be classified in the group of vegetables. They are sprouts (shoots) of green or white color (depending on whether they are grown in the presence or absence of light), which require a fairly complicated cultivation.

Developed asparagus could be described as a rustic rhizomatous plant, with herbaceous stems without thorns (round bushy with almost needle-like leaves) erect and branched, having white dyocial flowers which turn into red berries; in parallel, asparagus has a horizontal and underground stem (rhizome or leg), from which sprout the shoots or edible sprouts.
Asparagus, besides requiring a totally compatible soil (very draining and tilled), must be picked as soon as the tip of the shoot (which has a total length of about 20cm, almost completely hidden by the soil) comes out. In fact, if one waits for the latter to grow further one will get a thickening of the bark and the consequent reduction of the edibility and pleasantness of the food.
Cultivated asparagus belongs to the Liliaceae family, Genus Asparagus, Species officinalis, of which some varieties can be identified. In Italy (but not only) there is a wild species of asparagus called “Asparagus acutifolius”, vulgarly indicated with the term asparagina (found in spring). Very similar to the latter, is the sprout of the butcher’s broom (binomial nomenclature: Ruscus aculeatus); these are thin and long twigs with an intense and bitterish taste (hence the vulgar term bruschi), which sprout from the ground near the mother plant (therefore similar to the asparagine). Knowing the aspect of adult wild asparagus (filamentous bush) it is however pretty difficult to confuse them with butcher’s broom (bush with flat, wide and pointed leaves).
Asparagus is native to western Asia (perhaps Iran) and is a crop that man has mastered since ancient times. First the Egyptians, then the Romans (quoted by Pliny the Elder in the “Naturalis Historia”), pickers and farmers, have perfected the cultivation of asparagus; asparagus are also mentioned in many Greek texts: “History of Plants” by Theophrastus, “De agricoltura” by Canon etc.. In the Middle Ages, the cultivation of asparagus was prolonged basically in order to use its shoots and roots for medicinal purposes (from here: A. officinalis).
In Italy, besides observing a considerable density of A. acutifolius, in the areas between the Riviera and the sub-mountainous area (Apennine belt) it is possible to find A. officinalis in the wild (absent in Sardinia).
The cultivation of asparagus must also face the infestation of some parasites; in order to produce these vegetables it is therefore necessary to pay attention that in the field do not appear: cryocere beetles, asparagus flies, asparagus rust (fungus), etc.

Useful information

Asparagus boasts extremely good nutritional properties (fiber, vitamins and minerals); in addition, both the edible shoot and the roots of the plant (in decoction) significantly stimulate renal filtration. This aspect, which for many represents a metabolic advantage due to the abundance of certain minerals, for others is the result of the interaction between some molecules present in the asparagus and the kidneys, reason why the vegetable is NOT univocally considered advisable in the diet of the nephropathic.
As if that were not enough, because of the high concentration of purine, asparagus are a food to EVER AVOID absolutely in case of gout or hyperuricemia difficult to compensate, no matter if they boast diuretic properties, they can promote the onset of acute gouty in predisposed subjects and as such are to be EXCLUDED.
Because of the significant concentration of aspartic acid and sulfur groups, asparagus immediately give a pretty intense smell to urine. This characteristic, which apparently is not totally univocal, has been object of some scientific studies. It seems that the discrepancy between the odor of urine in different subjects is not due to the presence or not of certain catabolites, but rather to the ability to perceive them by smell; in this regard, some researchers have found the presence of a segment of the population, corresponding to 40% of the total, which is NOT able to perceive the typical odor of urine after the ingestion of asparagus.
This reaction, which in healthy subjects also occurs after a few minutes, has long been considered a simple method to monitor the efficiency of renal filtration; obviously, the system cannot work in the aforementioned 40% of subjects unable to perceive the smell.

For further information, read: Asparagus in Herbalism – Properties of Asparagus

Preparation and Recipes

The culinary preparation of asparagus is quite simple but still requires some attention.

Purchasing Advice

First and foremost, I would urge readers to eat only fresh asparagus, which is only available in late spring or early summer. This is because frozen asparagus leaves a lot to be desired in terms of taste and flavor.
Secondly, it would be a good rule (having the possibility to choose) to buy asparagus with a quite thick stem (BUT not “past” the bud); this statement derives from the fact that the thinner asparagus of the species A. officinalis have a quite unfavorable ratio between edible part and bark (to the advantage of the first one compared to the second component), while the thicker ones contain a quantitatively greater pulp. Having said this, as it is often the case for many other vegetables, smaller asparagus are characterized by a superior taste and aroma; it will be the consumer, respecting the gastronomical preparation, to prefer thinner or bigger varieties. At the moment of purchase, asparagus shoots must be turgid, straight, elastic and with the bud well tightened.

Cleaning Asparagus

In any case, almost all asparagus requires a peeling process that can be summarized as follows:

  • Wash the asparagus
  • With a potato peeler, remove the portion of bark near the cut (therefore on the lower portion of the sprout) until the product is completely edible
  • Cut the tops off the asparagus, separating them from the stalks, since the tenderest portion of the asparagus can be cooked for a few minutes, while the stalks can be cooked (depending on the variety) for three times as long
  • Boil the stalks in hot water and, eventually, also the tips (adding them at the end of cooking).

From a practical point of view, the procedure is described in this video-recipe, which shows how to clean and peel the asparagus and then prepare the relative sauce.

Microwave Asparagus Gratin

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Asparagus recipes

Numerous Asparagus Video Recipes – such as Asparagus Risotto and Microwave Asparagus Gratin – are available at the following links:

  • Recipes with White Asparagus
  • Green Asparagus Recipes

Nutritional Characteristics

As anticipated, asparagus are the subject of many controversies; they are diuretic but not recommended in case of renal impairment and also in case of hyperuricemia or gout (because of the high concentration of purines).
Asparagus are however very rich in dietary fiber, therefore they are suitable for a diet against constipation; they contain few proteins (of low biological value) and even less carbohydrates (mainly simple, made of fructose). Lipids are almost zero.
Asparagus contains many mineral salts such as potassium; as for vitamins, asparagus is an excellent source of vitamin C (ascorbic acid), carotenoids (pro-vit. A) and some of the B group.

Bibliography:

  • A polymorphism of the ability to smell urinary metabolites of asparagus – M Lison, S H Blondheim, and R N Melmed – Br Med J. 1980 December 20; 281(6256): 1676-1678
  • Fruits and vegetables in Italy – Touring club Italiano – Page 46:49.