3. The Potential for the Introduction of New Asian Vegetables in Europe and the Market Trends
The consumption of fresh vegetables in the EU is barely increasing, and the European vegetable market is highly competitive. However, the current demand for healthy, high-quality and attractive exotic vegetables is growing steadily. Therefore, the market for fresh Asian vegetables has the potential to expand across the EU member states. But, how can we define Asian vegetables?
The meaning of “Asian vegetables” varies and the term is often used ambiguously as “Oriental vegetables” in literature. Asian vegetables can be defined as vegetables that have originated, are cultivated or are commonly consumed in Northeast Asia (China, Korea, and Japan) or in Southeast Asia (Thailand, Indonesia, Vietnam, the Philippines, and Malaysia). In this study, we will use the term Asian vegetables to mean the vegetables from both regions.
A list of Asian vegetables is provided in Table 1, Table 2, Table 3, Table 4, Table 5 and Table 6. In the list, some well-known vegetables that can be found in other countries are not included, such as onions (Allium cepa), potatoes (Solanum tuberosum), sweet potatoes (Ipomoea batatas), tomatoes (Solanum lycopersicum), and okra (Abelmoschus esculentus) even though they are commonly used in Asian cuisines. However, we still included these vegetables if they are unique from their western counterparts, such as Asian green onions (Allium fistulosum), Japanese pumpkin (Cucurbita maxima), and Korean zucchini (Cucurbita moschata). Native Asian vegetables such as soybeans and Chinese cabbage are also included.
Table 1. Sprout vegetables.
Table 2. Tree vegetables.
Table 3. Leaf and Stem Vegetables.
Table 4. Fruit, pod and seed vegetables.
Table 5. Root vegetables.
Due to the limited number of publications and information in Europe, we added some commonly consumed or unique Asian vegetables to the list. Interestingly, some vegetables that had been traditionally gathered in the wild have recently been cultivated to provide more choice for consumers looking for diversity and health benefits. These vegetables are becoming more available in both online and offline markets.
Since vegetables have various common English names in the literature, we use their scientific names to avoid confusion and for better accuracy. The Asian vegetables are categorized under six groups: (i) sprout vegetables (Table 1), (ii) tree vegetables (Table 2), (iii) leaf and stem vegetables (Table 3), (iv) fruit, pod and seed vegetables (Table 4), (v) root vegetables (Table 5), and (vi) mushrooms (Table 6).
For the list of Asian vegetables in Table 1, Table 2, Table 3, Table 4, Table 5 and Table 6, we gathered information from three published sources in English which introduce Asian vegetables, mainly from China, Japan and Southeast Asia. We also referred to information from published literature in Korean from various South Korean government ministries for more specific data. Additionally, we searched for the popularity of each species on the Internet. If the vegetable name did not appear in offline or online markets or in recipes and comments of internet users, we did not include the vegetable name in the list. Furthermore, we discuss four Asian vegetables and their future potential in the European market.
4. Four Recommended Asian Vegetables
Several Asian vegetables that were traditionally gathered wild, harvested from fields or forests, are now sold in online and offline markets in South Korea as ‘Ssam’ or ‘Namul’ vegetables. Vegetable-consuming cultures can also be found in other Asian countries. Pickled vegetables are consumed in China as ‘Pao Cai’ and in Japan as ‘Tsukemono’ and ‘Asazuke’. Additionally, most Southeast Asian countries and China typically consume vegetables by using the stir-fried cooking method. The vegetables are consumed mostly in the forms of ‘Kimchi’, ‘Ssam’ and ‘Namul’ as we explain further below.
‘Kimchi’ consists of salted and fermented vegetables. It is served as a side dish in almost every meal and can be made with various kinds of vegetables such as Chinese cabbage, radish (
Raphanus sativus), cucumber (
Cucumis sativus), and spring onion (
Allium fistulosum). Approximately 300 varieties of ‘Kimchi’ are estimated to exist in Korea
[23]. ‘Ssam’ consists of wrapping fillings such as cooked meat, rice (
Oryza sativa) with fresh leafy vegetables such as lettuce (
Lactuca sativa) and perilla leaves (
Perilla frutescens). Recently, various new leafy vegetables have been introduced for ‘Ssam’ and landed successfully in the vegetable market. ‘Namul’ are seasoned fresh vegetables prepared either blanched or raw as side dishes. Various vegetables, not only cultivated but also gathered wild, are used for ‘Namul’.
4.1. Korean Ginseng Sprouts (Panax Ginseng Meyer)
Korean ginseng is a perennial plant in the
Araliaceae family. Korean ginseng has been used as a medicinal plant in East Asia
[24] for more than 2,000 years
[25]. Ginsenoside (triterpene glycoside saponin) is the main bioactive ingredient in Korean ginseng and is known to have various pharmacological and physiological benefits
[24] such as anti-cancer
[26], anti-diabetic
[27][28], immunomodulatory
[26][29], neuroprotective
[26], radioprotective
[30], anti-amnestic
[26], and anti-stress properties
[31][32].
Korean ginseng sprout
[22] is a new medicinal vegetable recently introduced in the South Korean vegetable market with demand increasing
[22]. Korean ginseng is customarily used only for its roots and should be grown for about 5–6 years before harvest
[33]. Because of this length of time, it is a high-priced product for consumers (
Figure 1). In contrast, Korean ginseng sprout uses all parts of the plant, not only roots, but especially the leaves due to their young tender texture. Leaves contain higher levels of certain types of ginsenosides (Rg1, Rg2+Rh1, Rd, and Rg3) than roots
[34]. It can be grown in a hydroponic cultivation system either without soil
[35][36] or with nursery soil
[22][37] Therefore, ginseng sprouts can be produced all year round without using pesticides in appropriate conditions. It only needs to be grown for 2–8 weeks after transplanting of one-year-old-ginseng-seedlings
[22][35].
Figure 1. Mountain-cultivated Korean ginseng (Panax ginseng Meyer).
These plants are found in mountainous regions (Gangwon-do, South Korea). Compared to intensive field-cultivated plants, mountain-cultivated ginseng is more expensive. Since wild mountain ginseng is rare and Eastern Asians strongly believe in its health benefits, its value is highly appreciated. Intensively cultivated ginseng needs 5–6 years until harvest, while wild mountain ginseng has a slow growth rate and requires a longer time. Mountain ginseng has a smaller size than intensively cultivated ginseng. Korean ginseng is not usually sold in supermarkets, but in particular markets only for Korean ginseng products or online markets (Source: Hong, personal communication)
Korean ginseng sprouts are a small sized vegetable with a mild, bitter flavor. Soil-less ginseng sprouts can provide health benefits and a pesticide-free alternative for consumers. It can be consumed in a variety of ways, including in salads, milkshakes, deep-fried, sushi, soups, and tea. Furthermore, Korean ginseng sprout can be used in health food supplements and cosmetics.
4.2. Ssamchoo (Brassica lee ssp. Namai cv. Ssamchoo) and Red Ssamchoo (Brassica koreana Lee var. Redleaf)
Ssamchoo
[17] is a hybrid plant species. This handle-fan-shaped leafy vegetable was developed by aneuploidy crossing Chinese cabbage with regular cabbage as ‘Ssam’ leafy vegetables
[38][39]. Therefore, Ssamchoo combines the advantages of Chinese cabbage and cabbage
[39]. Red Ssamchoo (
Brassica koreana Lee var. redleaf) is a variety of Green Ssamchoo
[39].
According to a leafy vegetables-agricultural technology guide from the Rural Development Association (RDA) South Korea
[39], Ssamchoo has all the benefits of Chinese cabbage and cabbage, and a very high fiber content making it easier to digest. Overall contents of calcium, iron, vitamin A and ascorbic acid in Ssamchoo are higher than Chinese cabbage, cabbage and lettuce
[39].
Producers can grow Ssamchoo either in soil or hydroponic systems. The method of cultivation is similar to that of lettuce. Ssamchoo can be harvested one month after sowing
[39]. However, this vegetable is intolerant to hot and humid weather
[39].
Ssamchoo has a smaller leaf size (
Figure 2) than those of Chinese cabbage and regular cabbage
[39]. Red Ssamchoo draws attention due to its red leaf and stem color
[39]. Ssamchoo brings together the slight bitterness from Chinese cabbage and nutty sweetness from regular cabbage
[39]. This leafy vegetable is lightly aromatic, sweet, juicy, mini-sized, and can be used in salads and soups and may be deep-fried
[39].
Figure 2. Ssamchoo (Brassica lee ssp. namai cv. Ssamchoo).
Leaves of Ssamchoo can be easily found in open showcases fitted with a cool-mist humidifier in supermarkets. This vegetable is displayed with other various types of fresh leafy vegetables in a ‘Ssam-leafy-vegetables-section’ of supermarkets. Ssamchoo can be purchased in offline or online stores. Some online stores deliver fresh Ssamchoo leaves within 24 h after placing an order, even in the early morning of the next day of purchase (Source: Hong, personal collection).
4.3. Peucedanum Japonicum
Peucedanum japonicum [17][19][20] is a perennial herb
[40] that belongs to the
Umbelliferae family and is used as a medicinal plant
[41]. This herb is found in China, South Korea, Japan, Taiwan, and the Philippines
[42]. Its leaves are consumed traditionally to treat coughs in the Okinawa islands in Japan
[41].
Peucedanum japonicum is reported to possess pharmacological benefits such as anti-obesity
[41][43][44], anti-oxidant
[45], anti-bacterial
[46], anti-diabetic
[44], tyrosinase inhibition
[47], and anti-platelet aggregation
[40].
Peucedanum japonicum is traditionally had been foraged from the wild. However, the plant is now cultivated in South Korea for its health benefits (
Figure 3). The leaves contain a fragrant aroma, a little bitter and sweet taste. This leafy vegetable can be eaten raw as a salad, blanched, pickled or deep-fried.
Peucedanum japonicum can be cultivated in an open field, greenhouse or hydroponic cultivation system
[48][49].
Figure 3. Peucedanum japonicum.
Young leaves with stems, packed in a plastic bag are sold in ‘Namul-leafy vegetable section’ of supermarkets. Peucedanum japonicum can be purchased in offline or online stores. Some online stores deliver this fresh leafy vegetable within 24 h after placing an order, even in the early morning of the day after purchase (Source: Hong, personal collection).
4.4. Aralia Elata (Miq.) Seem.
Aralia elata (Miq.) Seem.
[17][19][22] is a shrub that is found across Northeastern China, Korea, Japan
[50][51] and eastern Russia
[52]. In Chinese traditional medicine, its root cortex has been used as a tonic, anti-arthritic and anti-diabetic agent
[53]. In the leaves and root cortex, many saponins are isolated and reported to possess an anti-diabetic
[53] and a cytoprotective effect
[54]. Additionally, a study found specific anti-tumor activity in the extract of the shoots
[55].
The young shoots of
Aralia elata (Miq.) Seem. have been generally foraged from the wild, but it is cultivated in Japan and South Korea for its expected health benefits (
Figure 4). This young shoot has a mildly bitter and sweet taste, fragrant aroma, and a crunchy texture. This shoot vegetable is enough to be an ornament itself in dishes, and thus this young shoot is used as a garnish in Japanese cuisine
[56]. In South Korea, the shoots are simply blanched and consumed with a spicy-sour sauce. This aromatic vegetable can also be pickled and deep-fried.
Figure 4. Aralia elata (Miq.) Seem.
Young shoots of Aralia, packed in clear transparent disposable plastic containers can be found in the leafy vegetable section of supermarkets. The shoots are still attached to a small part of woody stems to keep the shoots fresh. Consumers should carefully remove woody stems covered with sharp thorns. Young shoots can be purchased in offline or online stores. Some online stores deliver this fresh young shoots within 24 h after placing an order, even in the early morning of the day after purchase (Source: Hong, personal collection).
Young shoots of
Aralia elata (Miq.) Seem. can be harvested (April–May) in open field cultivation from a whole tree
[57][58]. If the shoots are harvested in the greenhouse (February–April), stem cuttings must be prepared
[58]. Shoots will develop naturally from the stem cuttings given appropriate humidity
[58]. Producers following forcing culture practices need a simple cultivation system such as a double-layer plastic greenhouse, heater, and white greenhouse felt for insulation
[58]. Stem cuttings can sprout in immersion cultivation, in which shoots can be harvested after 15 days (30–35 days long)
[57]. This method results in harvest at least two weeks earlier than from forcing cultivation
[57].