Table S1. Description of Representative K-Foods

Table S1. Description of representative K-foods.

K-food Description

Ssalbap SSal means rice. Bap refers to cooked rice and is one of the most basic elements of the Korean diet alongside banchan. Bap is often cooked with other grains such as barley and beans. The murals found in Anak Tomb Number 3 in Kokuryo depict the preparation of bap. These murals suggest that rice has been a staple of the Korean diet for a long time. Although rice contains less protein and more carbohydrates than wheat on a per serving basis, the amount of lysine, an essential amino acid, is higher in rice than in wheat. Brown rice, which has the bran and germ still attached, is very high in phytic acid and fiber that work to prevent constipation and improve immune system functionality. Moreover, high levels of tocopherol, gamma oryzanol, beta-sitosterol, and stigmasterol in brown rice lower cholesterol and increase antioxidant activity.

Okokbap Okok means five grains. Historically, Koreans have enjoyed monthly festivals including special kinds of food. One of these festivals is jeongwol daeboreum, which is celebrated on January 15th of the lunar calendar. This festival is held in the hope of good health and harvests and includes the playing of traditional games and the sharing of meals such as okokbap. Okokbap is a bowl of cooked rice mixed with five grains, such as glutinous rice, red beans, beans, millet, and sorghum; it is often consumed with namul. Okokbap provided essential nutrients that may have been lacking during the winter season. Red beans are rich in potassium, which helps reduce swelling and encourages the discharge of waste from the body. Beans are a plentiful source of isoflavones, which can also help relieve menopausal symptoms. Millet has a diuretic effect and provide minerals that are lacking in rice. Sorghum is a rich source of various phytochemicals such as phenols, proanthocyanidins, and tannins.

Jang (醬) Doenjang is the most well-known fermented soy product in Korea [2]. Doenjang can be — eaten as a seasoning in kuk, namul, or pickles or as a dipping condiment with doenjang vegetables. Although doenjang is an essential food seasoning in Korean cuisine, it was and also an important source of protein intake in the past. Donguibogam, a traditional kanjang Korean text on medicine written in 1613, stated that doenjang aids in reducing fever and detoxifying the body. The fermentation process of doenjang utilizes naturally occurring microbes to enrich the flavors and nutrients in beans, and increase its preservability. Doenjang is a rich source of protease inhibitors, phytic acid, and isoflavones, which help prevent cancer and osteoporosis. Isoflavone glucosides in beans are converted into aglycones through the fermentation process in order to be absorbed in the human body. Doenjang Doenjang-kuk consists of the doenjang broth, vegetables, and meat or shellfish. Not -kuk only does doenjang contain various nutrients from soybeans, but it also has plentiful enzymes and microbes produced in the fermentation process that help with the digestive system. Doenjangkuk has been a popular dish in Korean cuisine for these reasons. Variations of doenjangkuk can be created using assortments of regional and seasonal ingredients, such as spinach or curled mallow, with each variation developing a unique flavor. Dietary fiber, vitamins, minerals, and proteins from various ingredients help make doenjangkuk one of the most nutritious and popular Korean dishes.

Miyok- Miyok (Undaria pinnatifida) is a sea vegetable known as a kind of seaweed. Miyok- kuk kuk is a dish made from meat, shellfish, and miyok. Miyok-kuk is a popular dish in Korea and is frequently consumed by women after giving birth. The calcium and iodine contained in the seaweed help uterine contraction and blood production. Miyok-kuk is also consumed on birthdays as it symbolizes the birth of new life. One serving of miyok-kuk contains 11% of vitamin A, 7% of potassium, and 6.2% of fiber recommended for daily intake. Moreover, the alginic acid and fucoidan in seaweed helps control blood pressure and cholesterol levels, and prevents constipation.

Gomtang Gom (고우다) means making broth. Gomtang is a dish made with various cuts of beef slow simmered on low heat until the broth turns milky-white. Traditionally, gomtang has been regarded as a highly nutritious dish and was served on surasang, the royal table, and paired with patsura. Seollongtang and kalbitang are dishes developed from gomtang. Seollongtang is made with ox leg and back bones and kalbitang with beef short ribs. Gomtang is rich in protein, vitamin B2, and iron, which help relieve fatigue and prevent anemia. As gomtang is high in nutrients that rice lacks, it is one of the most popular summer boyangsik (nutritious medicinal foods).

Samkye- Samkyetang is made from a long-boiled whole chicken filled with various herbs, such tang as garlic, glutinous rice, ginseng, jujube, and milk vetch roots. (蔘鷄湯) Samkyetang is also regarded as boyangsik, a highly nutritious dish, and is popularly eaten on chobok, jungbok, and malbok, which are the three summer solar terms in Korea. In the Chosun dynasty, the boyangsik consumed by the common people was boshintang, which featured dog meat as the primary ingredient. The boyangsik consumed by officials was yukgaejang made from beef. Samkyetang became the representative boyangsik after 1960 and has been widely enjoyed regardless of season both locally and globally. Samkyetang is low in fat and has plentiful amounts of protein, vitamin B2, niacin, phosphorus, and iron. Moreover, the ingredients in samkyetang such as garlic, ginseng, and milk vetch roots are widely used Korean medicinal herbs that are known to strengthen the immune system, relieve fatigue, and prevent cancer. Cheong- Cheongkukjangchigae is made with cheongkukjang broth, beef, tofu, kimchi, and kukjang- vegetables, which are generally cooked in a tukbaeki. Although the primary ingredient chigae for both doenjang and cheongkukjang is fermented soybean, cheongkukjang can be made in 2 or 3 days by fermenting boiled soybeans wrapped with rice straw in warm temperatures whereas doenjang takes a few months to ferment (see [2]). Cheongkukjang has also been called jeonkukjang (戰國醬). Jeungbosanrimgyeongje (增補山林經濟), a book from the Chosun dynasty, included the following instructions on how to make cheongkukjang: “After wrapping boiled soybeans with rice straw, place them in a warm area for 3 days until it starts to ferment.” Rice straw usually contains Bacillus subtilis and this organism hydrolyzes soybeans and initiates the fermentation process, which creates the distinctive aroma and flavor of cheongkukjang. Doenjang, as well as cheongkukjang, were an important source of protein for Koreans and contain high levels of fiber, phosphatide, isoflavones, saponin, trypsin inhibitor, and phytic acid. A sample of 10 g of cheongkukjang contains > 30 billion effective microbes that help with digestion. Research has been conducted to develop supplements based on the health benefits of cheongkukjang. (Ref: Korea Traditional Food Portal, Korea Food Foundation)

Sundubu Sundubu means soft tofu. Korean cuisine includes many soybean-based products such chigae as various jang and tofu. In order to make tofu, soybeans are first soaked in water, then boiled, ground, and finally strained to produce soy milk. Tofu is made by coagulating this soy milk and pressing the curds into blocks. Sundubu is the unpressed and the softest type of tofu that contains the most moisture. Although sundubu does not have a high nutritional value, it is popular with all age groups due to its soft texture and low calories. Sundubuchigae is made with sundubu, vegetables, kimchi, seafood or meat, and various seasoning. It contains high levels of vitamin B1, B2, and iron.

Bossam- Bossam means wrapping. Bossamkimchi is a type of kimchi kimchi made with pickled cabbage filled with green onions, garlic, mushroom, ginger, chestnut, water celery, radish, gat, peppers, mustard leaf, salted seafood, shrimp, and oysters. After adding these ingredients between cabbage leaves, the cabbage is wrapped tightly and fermented. Bossamkimchi is a regional food of Gaesung and is consumed on special occasions.

Dongchi Dongchimi is a type of kimchi fermented in a watery brine with pickled radish, green mi onions, and peppers. Dongchimi has a relatively short fermentation period compared with other types of kimchi. Although it can be made any time of the year thanks to the latest technology, kimchi refrigerators, dongchimi was traditionally made and consumed during the winter to ferment it properly underground in a jar [3]. Dongchimi was also called ‘singkunji’, which means a winter kimchi consumed with water. Radish, the primary ingredient of dongchimi, has been regarded as a beneficial vegetable in both Korea and China. Bonchogangmok (本草綱目), a Chinese text on medicine written in 1596, stated that consuming radish could help reduce excessive stomach acid, the effects of alcohol, and symptoms of cold and urinary disorders. It also strengthens the body, digestive system, and the circulation of qui.

Kongna- Kongnamul, soybean sprouts, are germinated soybeans grown mul- in the dark. Kongnamul-muchim is a dish made with muchim blanched soybean sprouts seasoned with salt, green onion, garlic, sesame seeds, and oil. Kongnamul-muchim is one of the most commonly served dishes in Korea due to the short growth cycle and its affordability. Soybean sprouts contain a high level of protein, fat, fiber, vitamin C, B1, and B2 which complement nutrients often lacking in rice. During the germinating process, soybean sprouts produce vitamin C and it was a valuable vitamin source for Koreans especially during the winter season when vegetables were scarce. A sample of 100 g of soybean sprouts contain 16–20 ㎎ of vitamin C, which is a third of the recommended daily intake. Aspartic acid in soybean sprouts is very effective at improving liver function and relieving hangover symptoms. Soybean sprouts are used as the primary ingredient of haejangkuk. Recent research has suggested that soybean sprouts reduce the incidence of colorectal cancer and the activity of gastric carcinoma cells.

Japchae The word japchae consists of two Chinese characters: jap (mixed and stirred, 雜) and chae (vegetables, 菜). Japchae is made with boiled sweet potato noodles, stir-fried vegetables, mushroom, and beef, and garnished with eggs and pine-nut kernels. Eumsikdimibang (음식디미방), or Gyugonsiuibang (閨壼是議方), a traditional Korean cookbook, shows how japchae has changed over time. The book described japchae as a dish made with various stir-fried vegetables such as bean sprouts, water parsley, balloon flower roots, shitake mushroom, and a sauce made with pheasant broth, doenjang, beef, and flour. Due to its nutritional value and attractive presentation, Japchae was one of the main dishes prepared at celebrations. Japchae is also widely enjoyed among foreigners.

Buchu- Buchu (Allium tuberosum) is garlic chives. Buchu-muchim is muchim a banchan made with garlic chives that are seasoned with red pepper powder, green onions, garlic, and aekjeot, a Korean fish sauce. Garlic chives are a member of the Amaryllidaceae family. The first written reference to buchu appear in Hyangyakgugeupbang (鄕藥救急方), a book written in the Koryo dynasty. Koreans have used garlic chives in buchu muchim, buchu kimchi, oisobaki, japchae, and dumplings. Garlic chives are well-known for their health benefits, mainly the strengthening of the stomach lining and the improvement of the function of the liver. Garlic chives are part of the five strong herbs (garlic chives, garlic, ginger, green onions, and wild rocambole) that are prohibited in Korean Buddhist temples’ food as their strong flavors and invigorating effects were thought to have the potential to distract monks from their mental disciplines. Garlic chives contain vitamin A, C, B1, and B2, and potassium. Betacarotene, chlorophyll, sulfur compounds, and flavonoids contained in garlic chives are very effective antioxidants.

Parae- Parae, sea lettuce, is a member of the edible green algae muchim group. Parae-muchim is made with rinsed sea lettuce, green and red peppers seasoned with kanjang, vinegar, red pepper powder, ground sesame, salt, and minced garlic. Regional variations often include aekjeot and sliced radish. It is a rich source of vitamins and minerals which help with the detoxification of nicotine. There are 720 mg of calcium in 100 g of sea lettuce. Sea lettuce is a popular banchan and is typically consumed fresh due to its attractive aroma and flavor.

Kalbi- Kalbi is ribs of beef or pork. Kalbichim is usually made with chim beef and pork short ribs and is often eaten on special occasions such as Chusok (Korean Thanksgiving day). The short ribs are cooked in knjang, a representative Korean fermented sauce, with jujube, chestnuts, ginkgo nut, pine-nut kernels, shitake mushrooms, and manna lichen, and then garnished with water parsley and eggs. Kalbichim is regarded as a healthy food with high nutritional values and beautiful appearance.

Kimgui Kim, also called laver, is an edible seaweed that belongs to the genus Porphyra. Once harvested, Kim can be eaten either dried or roasted. Kimgui is made with Kim (seaweed) that has been toasted with sesame or perilla oil then sprinkled with salt. The first written reference of kim appears in Samkukyusa (三國遺事) from the Silla era. Kyeongsangjiriji (慶尙地理志) and Dongkukyeojiseungnam (東國輿地勝覽 ) also mentioned kim as a regional product. In the Chosun dynasty, kim was often offered to a king as tribute. Kim is rich in essential amino acids, minerals, and porphyran, which is effective at lowering cholesterol.

Bulgoki Bulgoki is made from thin slices of beef marinated with a mixture of kanjang, green onions, garlic, and sesame oil. Pear juice or honey is added to the marinade to tenderize the meat. Although pan-cooked bulgoki is popular these days, Chosunyorijebeop (朝鮮料理製法, 1939) or Siuijeonseo (是議全書, 1890s) state that bulgoki was traditionally grilled over fire and was referred to as neobiani or maekjeok. Bulgoki is rich in essential amino acids and iron, and has become one of the most popular Korean dishes globally.

Soegoki- Soegoki means beef. Soegoki-jangjorim is a braised beef dish typically made from lean jang- cuts of beef such as shank, round, and rump. Blocks of beef are long-boiled in a jorim kanjang based broth, shredded, then served in a bowl with kanjang poured on top. Sogoki-jangjorim is strongly seasoned for long-term preservation and is a good source of protein on the Korean meal table. Jeyuk- Jeyuk means pork. Jeyuk-bokeum consists of stir-fried slices of bokeum pork loin which are premarinated with gochujang and ginger juice. The dish can be served in Korean ssam style with loose leaf lettuce. Pork is a popular ingredient in Korean cuisine for its soft texture and attractive flavor. Pork has a high level of vitamin B1, B2, and niacin, which promote carbohydrate metabolism. Moreover, the essential fatty acids contained in pork such as oleic and linoleic acids are beneficial for the skin.

Dak- Dakbokkeum-tang is a spicy braised chicken dish made with bokkeum gochujang and vegetables such as potatoes, carrots, and onions. -tang It has gained popularity because the spiciness of dakbokkeum- tang stimulates the appetite. As it includes various vegetables and protein from chicken it is regarded as a nutritionally balanced dish.

Saeng- Saengseon means fish. Saengseonjeon is typically made with a seonjeon white fish, such as croaker, cod, pollack, sea bream, butterfish, or halibut. Saengseonjeon is enjoyed during special holidays and ancestral rites and is served with kanjang or vinegar mixed kanjang. Fish is a rich source of protein and omega-3 fatty acids, which are effective in lowering the risk factors for cardiovascular diseases such as high blood pressure, high cholesterol levels, and infections of the blood.

Haemul- Haemul means fishery products. Haemul pajeon is a pan-fried pajeon dish made from a flour batter, green onions, and shellfish, such as clams, oysters, or mussels. Haemulpajeon is a beloved home- cooked dish and is recorded in Chosunyorijebeop (朝鮮料理製法, 1939). Dongraepajeon, a regional variation of haemul pajeon from Busan, was a famous delicacy often served to kings. Green onions, the primary ingredient in pajeon, contain sulfur compounds such as allicin and vitamin B1, which have sterilizing properties.

Hwayang Hwayangjeok is a dish made with seasoned meat, mushrooms, jeok green onions, water parsley, and carrots, that are cut into 5–6 cm (Pasan- pieces, skewered, and then grilled. The ‘jeok’ in hwayangjeok jeok) literally means ‘grill’, and the name of the dish is derived from its branch-shaped appearance. Chosunmussangsikyorijebeop (조 선무쌍식요리제법), a cookbook from the Chosun era, stated that hwayangjeok is typically served on special occasions. Hwayangjeok, made from meat and vegetables in five colors, is a beautifully presented dish with abundant nutrients.

Pakang- Kanghoe, a type of parboiled dish (熟膾), is a small roll of blanched water parsley or hoe green onions filled with red pepper and cooked beef, and is served with chogochujang (gochujang with vinegar). It is one of the most well-known dishes served during the celebration of the Buddha's birthday. When prepared in the royal court, kanghoe was shaped after the bride's headpiece or the topknot in a private residence. References to kanghoe appear in the Gyugonyoram (閨壼要覽) and Siuijeonseo (是議全書). Siuijeonseo describes kanghoe as below: “Water parsley is blanched and rolled into a shape of a topknot. Pine-nut kernels are placed in the middle of the roll, and eggs, manna lichen, red pepper, and sliced beef brisket are added around the pine-nut kernels. The rolls are served on a plate with chogochujang.” Kanghoe is a beautiful dish made with various colored ingredients.

Bibimbap Bibimbap is made from cooked rice topped with namul and jang served together in a large bowl. Bibimbap is enjoyed on various occasions. According to Dongkuksesigi (東國歲時記), bibimbap was traditionally consumed on the eve of the Lunar New Year in order to get rid of all the leftovers from the previous year. Bibimbap was also eaten after ancestral rituals and was made from the leftovers used in the ceremony. Although traditional Korean meals consist of bap and banchan, bibimbap is a more convenient option as it contains both bap and banchan in one bowl. Bibimbap is a nutritionally balanced dish that contains vitamins, dietary fiber, and minerals from vegetables, fat from sesame oil, protein from meat, and carbohydrates from rice. Due to its nutrient density and convenience, bibimbap has gained popularity internationally and is often served as an in-flight meal on Korean airlines.

Teok-kuk Teok-kuk consists of broth and thin slices of rice cake. It is known that the northern regions of Korea, mainly Hamkyong, Pyongan, and Hwanghae, substituted rice cake with dumplings made of wheat or buckwheat flour when rice production in those regions was low. References to this are found in traditional cookbooks such as Jeungbosanrimgyeongje (增補山林經濟), Jeongjoji (鼎俎志), and Eumsikdimibang (음식디미방). Traditionally, teok-kuk was eaten on Lunar New Year during family gatherings after exchanging sebae, a deep formal bow of respect. It was believed that people would gain a year of life by consuming teok-kuk. Records of seasonal customs such as Dongkuksesigi (東國歲時記), Yeolyangsesigi (洌陽歲時記), and Choseonsangsik (朝鮮常識), suggest that the origin of teok-kuk comes from the custom of partaking in sacrificial food and drink after the celebration of the new year. It was believed that the long shape of the rice cake symbolized longevity and people of all ages and sexes consumed teok- kuk on the Lunar New Year for this reason. Injeolmi Injeolmi is a type of Korean rice cake made by steaming and pounding cooked glutinous rice then covering the mix with pan- fried powdered grains. It has a chewy texture and savory flavor. Injeolmi varies depending on the type of coating used such as beans, red beans, and sesame seeds. Subsidiary ingredients such as mugwort, synurus deltoides, and jujube can also be added into the glutinous rice mix and pounded together. The recipe of Injeolmi is shared in the Jeungbosanrimgyeongje (增補山林經濟,1766): “Soak glutinous rice in hot water for 4–5 days. Steam and pound the rice. Coat the mix with powdered beans. Once hardened, cut into small blocks and serve with honey.”

Baekseol Baekseolki is a variety of white rice cake made with rice flour. ki In the East, white symbolizes purity and auspiciousness. Koreans used white in everyday clothes, in clothes worn during mourning, and in the descriptions of auspicious animals in mythology. In this way, baekseolki was regarded as a sacred food and served during the birthday celebrations of children and ancestral rituals. Even now, baekseolki is a popular rice cake dish served on various occasions regardless of region and season. The variety of baekseolki includes beans, red beans, mugwort, chestnuts, persimmon, and jujube. Jibongyuseol (芝峰類說, 1614) stated that ssukseolkiteok, a variety of baekseolki made with mugwort, was one of the best delicacies made in Koryo.

Sujeong- Sujeongkwa is a traditional cold winter drink and typically kwa consumed on New Year’s Day. It is made from dried persimmons, cinnamon, ginger, sugar, and whole peppers. Chosunyorijebeop (朝鮮料理製法, 1939) provides this description of the preparation of sujeongkwa: “Brew sliced ginger with salt then cool down the brew in a crock. Add dried persimmons into the brew and garnish with cinnamon and pine- nut kernels.” Korean ancestors used the ginger and cinnamon in sujeongkwa to warm up the body. Moreover, the betacarotene and vitamin C found in dried persimmons help promote digestion and prevent colds.

Omija- The word ‘omi’ in omija (五味子) literally means ‘five flavors’: sweetness, sourness, cha bitterness, saltiness, and spiciness. Omija-cha is a red colored tea made from dried omija, Schisandra chinensis, which is a traditional Korean fruit herb. Fruits are often added into the tea, which give it the name omija hwachae. Records from the Hyangyakjipseongbang (鄕藥集成方) and Uibangyuchwi (醫方類聚) suggest that omija-cha has been enjoyed since the Silla period. Omija is used in traditional oriental medicines to treat excessive sweating, dehydration, diarrhea and nausea. The five flavors of omija have distinctive positive effects on specific organs: sourness on the liver, bitterness on the heart, sweetness on the stomach, spiciness on the lungs, and saltiness on the kidneys. Omija contains anthocyanins, a natural antioxidant, which is responsible for the red color of omija. Omija also has schizandrin, an antioxidant lignan, which helps prevent cancer and inflammation.