Rutabagas
Brassica napus is a naturally occurring hybrid between the European turnip (Brassica rapa) and an ancestral variety of colewort (Brassica oleracea). The origins of the plant are still very murky, but the first it is estimated to have formed at least 6,500 years ago, possibly much longer ago.
Today, the species is probably known mostly in the form of canola oil (a commercial name for rapeseed oil). It is also planted for the root vegetable rutabaga and for leafy greens similar to kale and collards. Brassica napus is supremely well-adapted to cold weather and its varieties are true winter crops.
Species and varieties
Rutabagas
Rutabaga (Brassica napus)
Root selections
Rutabaga
Greens
Leaf selections
Russian kales
Napini
Seed selections
Rapeseed
Canola
Root selections
Rutabagas are a root vegetable that looks extremely similar to turnips. The first written accounts of rutabagas date from the 17th and 18th centuries; they are thought have been developed in Scandinavia or Russia.
From this region, the rutabaga spread to other parts of northern Europe, including Germany, Scotland, and England, by the 18th century, and then to North America shortly after. Rutabagas, which derive their name from “rotabagge”, a dialectical Swedish name, are also known as “swedes” in the United Kingdom.
Rutabagas are an excellent winter crop for the Pacific Northwest, as one of the cold-hardiest root crops we can grow. Rutabagas will continue to grow throughout winter in the Northwest Coast region and can handle even colder temperatures elsewhere.
In addition to the roots, the primary crop, rutabaga greens can also be picked and eaten.
Leaf selections
Russian and Siberian “kales” are leafy greens that were developed from the Brassica napus plant.
These are not true kales, which are from the colewort, Brassica oleacera. Russian kales are far more cold-hardy; able to handle temperatures well below 0°F , the leaves sweeten with colder weather. They do not keep as well as coles once picked.
When spring hits and temperatures rise, Russian kales, like other mustards, will bolt and attempt to produce seed. The flowering shoots that grow are commonly known as napini. These can be eaten like those from other mustard family plants. The name “napini” is invented from Brassica napus, based on the Italian word “rapini”, which designates a type of turnip shoot (B. rapa).
Seed selections
The primary reason Brassica napus is planted in the world is for its seeds, known as rapeseed. These are processed into rapeseed oil, which has both edible and industrial uses, and ranks as one of the top three vegetable oils in the world by volume.
The unfortunate name “rapeseed”, derived from “rapum”, the Latin for “turnip”, is actually used as a general term for the oil-producing seeds of several different plants in the mustard family, including Brassica rapa, Brassica napus, Brassica juncea, Rhamphospermum arvense, and crosses between these species. Most rapeseed oil was once derived from Brassica rapa, the turnip, but today, in the US, it mostly refers to Brassica napus, which has supplanted the turnip as the main source of rapeseed oil. Because of the ambiguous nature of the term “rapeseed”, it can be difficult to ascertain what exact species was used in the commercial production of culinary mustard oils and rapeseed oils, which are still commonly used in Indian and Chinese cuisines. In India, B. napus is known as “gobhi sarson”.
The best-known version of rapeseed oil is canola oil, a commercial name given to a type of rapeseed oil that was developed in Canada, the largest rapeseed producer in the world today. The name “canola” is an acronym for “Canadian oil, low acid”. “Low acid” refers to erucic acid, a compound found in rapeseed oils that was linked to health issues in mammals (see note).
Notes on erucic acid
Canola oil was developed in Canada in the early 1970s, when studies done on laboratory rats appeared to show that erucic acid had harmful effects on their hearts at high doses. In one such study, rapeseed oils with various levels of erucic acid were fed to rats at 20% by weight of diet for up to 4 months. The more erucic acid in their diets, the greater the incidence of heart issues.
Rats, however, unlike other mammals such as primates or pigs, cannot process erucic acid effectively. Furthermore, no correlation between erucic acid intake and harmful effects in humans has been established, and erucic acid is found in relatively large quantities in wild fish with a high fat content.
Regardless, governments pushed for the removal of rapeseed oils with high levels of erucic acid in 1970s. Technically, Indian mustard oil, which is high in erucic acid, is banned for consumption in the US, but it is still sold through a loophole, with labels stating that it’s “For External Use Only”.
As far as I am personally concerned, I have consumed mustard and rapeseed oils, especially toasted rapeseed oil, and will likely continue to do so. The unrefined oils are both flavorful and excellent for use in high-heat applications.
