Pea is a climbing plant classified in the family of legumes whose fruits, edible green pods, contain small green seeds: peas.
History of pea
It may be the home of the genus Pisum but it wasn’t unique, as it has long thought, but multiple. Central Asia (from northwestern India to Afghanistan) would have been its main place of development, while the Middle East, the Mediterranean Basin and Ethiopia (plateau and mountains) would be secondary places. It would have been domesticated about 10 000 years ago, at the same time as the old wheats and lentils, and probably also the sheep and the goat.
From its center in the Middle East, it will quickly spread westward (Turkey and Greece), then northward. In France, in the debris left by those who lived in what is now called Languedoc, scientists found pea seeds dating from 7 000 years before our age. Three thousand years later, its culture was common in the Rhine valley. It then settled everywhere, especially in China in the first century A.D., and in America from the beginning of colonization.
For a long time, peas would only be grown for its dry seed, with fresh peas being mentioned for the first time in the 12th century in England. You would have to wait for the year 1536 to read a detailed description in a French book. Nevertheless, the food did not appear on the French markets until the beginning of the seventeenth century, coming from Holland, and it was only in 1660 that the pea made its great entry in France. Until the beginning of the next century, the pea remained a rarity commanding such high prices, which only the nobility and the aristocracy were able to afford it.
As it does not keep long, it will only was grown on a large scale with the invention of the (canning technique) in 1821. Finally, thanks to the improvement of the freezing techniques, one can today preserve a good part of the nutritional and taste qualities of this green vegetable.
Pea health profile
Although it belongs to the botanical family of legumes, fresh green pea is an immature seed which is consumed as a vegetable. It contains more protein than most other vegetables. Except in season, green pea is relatively unavailable in its fresh form. Many are frozen or canned. The pea has a pod less tough and sweeter and its seeds are very small. It is therefore eaten whole, pod and seeds, and is more easily found on the shelves in fresh condition. In grains, fresh peas contain a wide variety of vitamins and minerals.
Active principles and properties
For vegetables in general
Several epidemiological studies have shown that high consumption of vegetables and fruit decreases the risk of cardiovascular disease, certain cancers and other chronic diseases. Some mechanisms of action have been proposed to explain these protective effects: the presence of antioxidants in vegetables and fruits could play a role in it.
For fresh peas
Antioxidants. Antioxidants are compounds protecting the body’s cells from damage caused by free radicals. The latter are highly reactive molecules which would be involved in the development of cardiovascular diseases, certain cancers and other diseases related to ageing.
• Lutein and zeaxanthin. Green peas contain a good amount of lutein and zeaxanthin, two antioxidant compounds of the caratenoids family. According to health authorities, 125 ml (½ cup) of raw green peas contain 1 898 μg lutein and zeaxanthin, while 125 ml (½ cup) of boiled green peas contain 2 192 μg. These quantities are much higher than those found in common pods, i.e., 252 μg for ten raw pods and 593 μg for 125 ml (½ cup) cooked. In addition, a study among humans showed that green pea lutein was more bioavailable (better absorbed by the body) than those of other vegetables such as spinach. Lutein and zeaxanthin accumulate in the macula and retina of the eye, thus protecting it from oxidative stress which could cause damage. Moreover, data from a journal of scientific literature indicate a steady intake of lutein and zeaxanthin is associated with a lower risk of macular degeneration and cataract, two eye diseases. It’s also beginning to imply that these compounds could help prevent certain cancers, especially those of the breast and lung, and contribute to the prevention of cardiovascular diseases. It should be noted, however, studies on the cardiovascular level are still limited and sometimes contradictory.
Protein. According to health authorities nutrient file, at equal weight, a portion of green peas can contain nearly twice as much protein as a portion of peas with tiny seeds. Indeed, although green pea is primed and consumed as a vegetable, mature seed is a legume, a family of foods which is one of the most important sources of vegetable protein. Green pea proteins are less digestible and less complete than animal proteins. Cooking can, however, improve their digestibility and the nutritional value of peas. In addition, vegetarians will be able to consume, within the same day, a variety of protein-rich foods which can form a complete healthy intake (legumes, nuts, cereals, dairy products or eggs).
Dietary fibers. With more than 5 g per serving of 125 ml (½ cup, cooked) of dietary fiber, green pea is a high source of it. Food fibers, which are found only in plants, group together a set of substances that are not digested by the body. A diet rich in fiber is associated with a lower risk of colon cancer and can satisfy the appetite by bringing more quickly a sensation of satiety. There are two major types of fibers (soluble and insoluble) having different effects on the body: green peas contain both. Insoluble fibers are given the ability to prevent constipation by increasing stool volume, while soluble fibers can contribute to the prevention of cardiovascular disease and to assist in the control of type 2 diabetes. It’s recommended to consume 25 g of fiber per day for women aged 19 to 50 years, and 38 g per day for men of this same group age.
Oral allergy syndrome
Green pea is one of the foods that can be implicated in oral allergy syndrome. This syndrome is an allergic reaction to certain proteins of a range of fruits, vegetables and nuts. It affects some people with allergies to the pollen of the environment and is characterized by symptoms to the mouth and throat. It’s almost always preceded by hay fever. Local symptoms are confined to the mouth, lips, and throat such as itching and burning sensations can then occur, and usually disappear for a few minutes after consuming or touching the food being implicated. In the absence of other symptoms, this reaction is not serious and the consumption of green peas does not have to be avoided systematically. It is recommended, however, to consult an allergist to determine the cause of the reactions to plant foods. The latter will be able to assess whether special precautions should be taken.
Selection and conservation
Fresh peas begin a process of converting sugar into starch from the moment they are picked. It is therefore necessary to buy them as fresh as possible, preferably on the day of their picking. Their pod must be shiny, green, swollen and firm. The grain of peas should be crunchy and slightly sweet. They will only be Scottish at the last moment.
The snow pea must be green, well flat and small, because too big, it has strings. However, the presence of yarn does not necessarily mean that the pea has exceeded the stage where it has to be harvested. The temperature at the time of maturation of the pods is important. Simply remove the strings by pulling them from the tip to the stalk.
Sugar Snap peas should be green and the grain should fill the pod well. Remove the strings if necessary.
Snow peas and Sugar Snap peas can be eaten raw when they are well fresh and tender. Add them to a salad or soup or present them on a plate of various vegetables for a dip.
The young pea shoots or the ends of the plants are traditionally consumed in Asia: tender, crunchy, they will be added to the salads and hardly be fried in the wok. Still rare in the trade, one can find them in the Oriental markets and some western groceries.
Refrigerator: Fresh peas can be kept two or three days in the cooler part of the refrigerator. If you have to keep them longer, put them in crushed ice without delay.
Freezer: Although, theoretically, the snow pea freezes, it does not always look very good once thawed. On the other hand, the pea and Sugar Snap pea perfectly support freezing, after being bleached for a few minutes and then cooled in icy water.
Dehydrator: Peas dehydrate very well after whitening. On the other hand, the snow pea doesn’t take an interesting texture after drying.
If you have to freeze or dry a large amount of peas, you can use a manual or electric scoter.
Seedlings. Round-grained peas are more resistant to cold and moisture than those with wrinkled grains. On the other hand, the latter are sweeter, remain tender for a longer period, can be harvested larger and tolerate the heat better. Choose the varieties according to the temperatures so as to spread the production throughout the summer and fall. Make a first round pea seeding around April 15 (southern Canada) followed by one or two seed pea seedlings in May. You can try a last round of wrinkled peas at the end of July to get a crop in the fall, however, it is a riskier adventure because powdery mildew and various other fungal diseases may occur at this time of year; choose resistant varieties and treat with sulfur.
Varieties. All varieties of peas (pea, snow pea, Sugar Snap pea) will give dry peas if they are given time, but some varieties have been selected strictly for this purpose. Their seeds are more difficult to find in the retail market, this type of crop is usually large-scale by specialized producers. However, old varieties can be found, giving unsurpassed quality soup peas, through seed exchange groups. By cultivating the varieties with oars (some can climb up to 3 m or 4 m), you will gain a lot of space compared to the dwarf varieties. At least 100 days, or even 120, for most of these varieties.
Soil temperature at the time of sowing. From 4 °C to 14 °C, ideally 10 °C.
ph. From 5.5 to 6.5, ideally the highest measurement. Below 6, add lime and inoculate with rhizobium.
Fungal diseases. In conventional agriculture, seeds are treated with fungicides to limit the damage caused by fusarium, root rot, and seedling melting. In organic farming, it’s imperative to choose resistant cultivars, to ensure the soil is very well drained, to postpone the sowing date if the temperatures are too cold and if it is too humid and, despite all these measures, to accept a certain loss, leaving to sow again a few days later. You can try to treat the seeds at the horsetail, but this is not guaranteed. To counteract powdery mildew, choose resistant varieties and treat with sulfur.
Slugs and birds. Garlic could be effective against slugs, as researchers have recently discovered, but you will avoid planting these two plants next to each other, legumes and alliums experiencing a deep aversion to one another. Use garlic in foliar treatment. To prevent the birds from chipping the seeds just sown or when the young plant emerges, install a scarecrow, aluminum plates hanging from a wire or any other system that will cause them to worry.
Peas as green manure. Sow 2 kilos to 4 kilos per 100 m2 of platform.
Ecology and Environment
A fine example of symbiosis
Rhizobacteria (Rhizobium spp.) are bacteria living in the soil and having the ability to stimulate the formation of small bulges called nodules on the roots of certain plants, especially legumes. Bacteria then colonize these nodules. Once well installed, they transform the nitrogen from the atmosphere, unusable by the plant, into soluble fertilizer which the latter can assimilate and which promotes its growth. Moreover, once the plant has completed its growth cycle, it leaves in the soil nitrogen reserves for the plants that will follow it and which do not have the possibility to enter into symbiosis with the Rhizobacteria. In fact, apart from legumes, a single plant belonging to another family (ulmaceae) is known to host these bacteria.
So it’s a unique phenomenon in nature and a trait that organic farmers use to increase nitrogen reserves in the soil without the use of chemical fertilizers. When used for this purpose, they bury the legumes in the soil before they are fully mature. A few weeks later or the following season, they will be able to sow vegetable plants with high nitrogen needs, such as lettuce or cabbage.