Yoghurt
From Wikipedia, the free encyclopedia
Yoghurt or yogurt, or less commonly yoghourt or yogourt (see spelling below), is a dairy product produced by bacterial fermentation of milk. Fermentation of the milk sugar (lactose) produces lactic acid, which acts on milk protein to give yoghurt its gel-like texture and its characteristic tang. Natural, unflavored yoghurt is common; fruit, vanilla, and chocolate flavours are also popular. Many yoghurt substitutes such as soy yoghurt are popular.
| Yoghurt, full fat Nutritional value per 100 g |
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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Energy 60 kcal 260 kJ | |||||||||||||
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| (*) Lactose content diminishes during storage. Percentages are relative to US recommendations for adults. Source: USDA Nutrient database |
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[edit] History
There is evidence of cultured milk products being produced as food for at least 4,500 years, since the 3rd millennium BC. The earliest yoghurts were probably spontaneously fermented by wild bacteria living on the goat skin bags carried by the Bulgars (or Hunno-Bulgars), a nomadic people who began migrating into Europe in the 2nd century AD and eventually settled in the Balkans at the end of the 7th century. Today many different countries claim yoghurt as their own, yet there is no clear evidence as to where it was first discovered.
The use of yoghurt by ancient Turks is recorded in the books Diwan Lughat al-Turk by Mahmud Kashgari and Kutadgu Bilig by Yusuf Has Hajib written in the 11th century. In both texts the word "yoghurt" is mentioned in different sections and its use by nomadic Turks is described. The first account of a European encounter with yoghurt occurs in French clinical history: Francis I suffered from a severe diarrhoea which no French doctor could cure. His ally Suleiman the Magnificent sent a doctor, who cured the patient by prescribing yoghurt.
Until the 1900s, yoghurt was part of the common staple diet mainly in South Asia, Central Asia, Western Asia, South Eastern Europe and Central Europe. The Russian biologist Ilya Ilyich Mechnikov had an unproven theory that regular consumption of yoghurt was responsible for the unusually long lifespans of Bulgarian peasants. Believing Lactobacillus to be essential for good health, Mechnikov worked to popularize yoghurt as a foodstuff throughout Europe. It fell to a Spanish entrepreneur named Isaac Carasso to industrialise the production of yoghurt. In 1919, Carasso, who had previously lived in the Balkans, started a small yoghurt business in Barcelona, naming the business Danone ("little Daniel") after his son. Carasso emigrated to the United States during World War II and set up business in New York City under an Americanised version of the name, Dannon.
Yoghurt with added fruit jam was invented to protect yoghurt from decay. It was patented in 1933 by the Radlická Mlékárna dairy in Prague, and introduced in the United States in 1947, by Dannon.
[edit] Etymology of 'yoghurt'
The word derives from the Turkish yoğurt [1] (pronounced [jɔˈurt]) deriving from the adjective 'yoğun', which means "dense" and "thick", or from the verb yoğurmak, which means "to knead" and possibly meant "to make dense" originally -- how yoghurt is made. The letter ğ denotes a voiced velar fricative /ɣ/ but this sound is elided between back vowels in Modern Turkish. Some eastern dialects retain the consonant in this position and Turks in the Balkans pronounce the word with a hard /g/. English pronunciation varies according to the local accent but common pronunciations include /ˈjɒgət/ and /ˈjoʊgɚt/.
[edit] Culture
Yoghurt is made by introducing specific bacteria into milk, which is fermented under controlled temperature and environmental conditions, especially in industrial production. The bacteria ingest natural milk sugars and release lactic acid as a waste product. The increased acidity causes milk proteins to tangle into a solid mass (curd, denature). The increased acidity (pH=4–5) also prevents the proliferation of potentially pathogenic bacteria. In the U.S., to be named yoghurt, the product must contain the bacteria Streptococcus salivarius subsp. thermophilus and Lactobacillus delbrueckii subsp. bulgaricus. Often these two are co-cultured with other lactic acid bacteria for taste or health effects (probiotics). These include L. acidophilus, Lactobacillus casei and Bifidobacterium species.
In most countries, a product may be called yoghurt only if live bacteria are present in the final product. In the U.S., non-pasteurized yoghurt is sold as "live" or containing "live active culture". A small amount of live yoghurt can be used to inoculate a new batch of yoghurt, as the bacteria reproduce and multiply during fermentation. Pasteurized products, which have no living bacteria, are called fermented milk (drink).
In Spain, yoghurt producers were divided between those who wanted to reserve the name yoghurt for live yoghurt and those who wanted to include pasteurised products, the Pascual Hermanos group being the most prominent among the latter. Pasteurized yoghurt has a shelf life of months and does not require refrigeration. Both sides submitted scientific studies supporting their claims. The Spanish government eventually allowed the label yogur pasteurizado to replace the former postre lácteo ("dairy dessert").
People who are otherwise lactose-intolerant often enjoy yoghurt without ill effects, since live yoghurt culture contains enzymes that help break down lactose inside the intestine.[2][3]
Yoghurt is rich in protein, several B vitamins, and essential minerals. It contains as much fat as the milk it is made from.
For women who experience yeast infections, a common cure is the daily ingestion of yoghurt containing L. acidophilus, which combats the imbalance of colonies of the fungus Candida albicans by adding more L. acidophilus.
Many antibiotics cause fungal problems of the mouth, tongue and skin due to a reduction in the number of commensal bacteria in the gut. Eating live yoghurt can stave off these problems before they happen if taken daily after completing a course of antibiotics.
Non-sweetened, drinkable yoghurt is typically sold in the West as buttermilk or cultured buttermilk. This is a misnomer, as the drink has little in common with buttermilk and is, in fact, most similar to kefir.
[edit] Presentation
To offset its natural sourness, yoghurt is often sold sweetened, flavored, or in containers with fruit or fruit jam on the bottom. If the fruit has been stirred into the yoghurt before purchase, it may be referred to as Swiss-style. Most yoghurt in the United States adds pectin or gelatin. Like cream cheese, some specialty yoghurts (e.g., Brown Cow Yoghurt) have a layer of fermented fat at the top. Fruit jam is used instead of raw fruit pieces in fruit yoghurts to allow storage for weeks. "Strained" yoghurt is the concentrated residue (described as a sort of "yoghurt cheese") produced by filtering plain yoghurt (without flavorings, gelatin, pectin, or other additives) in a paper or cloth filter, and allowing water and whey to drain from it.
[edit] Yoghurt types
[edit] Dahi yoghurt
Dahi yoghurt of the Indian subcontinent is known for its characteristic taste and consistency. The English term for a specific yoghurt in Bangladesh, India and Pakistan is curd. A typical Marathi preparation of curd, a dessert called 'shrikhand', is made with curd placed in a soft cloth with very fine holes, such as soft muslin. The cloth is tied up and hung to drain for a few hours while all the water drains out; sugar, saffron, cardamom, diced fruit, raisins, and nuts may then be mixed for taste.
[edit] Dadiah or Dadih
Dadiah or Dadih is a traditional West Sumatran yoghurt made from water buffalo milk. It is fermented in bamboo tubes.
[edit] Labneh or Labaneh
Labneh yoghurt of Lebanon is a thickened yoghurt used for sandwiches. Olive oil, cucumber slices, olives, and various green herbs may be added. It can be thickened further and rolled into balls, preserved in olive oil, and fermented for a few more weeks. It is sometimes used with onions, meat, and nuts as a stuffing for a variety of Lebanese pies or Kebbeh كبة balls.
[edit] Bulgarian ("Кисело мляко")
Bulgarian yoghurt, commonly consumed plain, is popular for its taste, aroma, and quality. The qualities arise from the Lactobacillus bulgaricus and Streptococcus thermophilus culture strains used in Bulgaria and Macedonia. Bulgarian yoghurt producers are taking steps to protect the Bulgarian yoghurt trademark in Europe and to distinguish it from other products that do not contain live bacteria.
Bulgarian and Macedonian yoghurt is often strained by hanging it in a cloth for a few hours to reduce water content. The resulting yoghurt is creamier, richer and milder in taste because of increased fat content. Hanging it overnight creates a concentrated yoghurt similar to cream cheese. Yoghurt is also used to prepare Bulgarian milk salad. Commercial versions of strained yoghurt exist.
A popular cold soup made from yoghurt is popular in the summertime in Bulgaria, Macedonia, and Turkey. Called tarator and cacık, respectively, it is made with Ayran, cucumbers, garlic and ground walnuts in Bulgaria, and generally without walnuts in Turkey.
[edit] Yoghurt Drinks
Lassi is a yoghurt-based beverage originally from Indian Subcontinent ( i.e. India, Pakistan and Bangladesh), usually made salty or sweet. Salty lassi is usually flavored with ground-roasted cumin and chile peppers; the sweet variety with rosewater, lemon, mango or other fruit juice. Another yoghurt-based beverage, a salty drink called ayran, is popular in Azerbaijan, Turkey, Bulgaria, Macedonia, Kazakhstan and Kyrgyzstan. It is made by mixing yoghurt with water and adding salt. The same drink is known as tan in Armenia, "Laban Ayran" in Syria, "Shenina" in Jordan and "Laban Arbil" in Iraq. A similar drink, Doogh, is popular in the Middle East between Lebanon and Iran; it differs from ayran by the addition of herbs, usually mint, and is carbonated, usually with seltzer water. In the United States, yoghurt-based beverages are often marketed under names like "yoghurt smoothie" or "drinkable yoghurt".
They are also popular in Ecuador where the primary form of yoghurt is "bebida de yogurt" or drink of yoghurt.
One popular yoghurt drink in Canada, UK, and Ireland, is called Yop which is sold in supermarkets and select stores.
[edit] Kefir
Kefir is a fermented milk drink originating in Caucasus. A related Central Asian-Turco Mongolian drink made from mare's milk is called kumis, or airag in Mongolia. Some American dairies have offered a drink called "kefir" for many years with fruit flavors but without carbonation or alcohol. As of 2002, names like "drinkable yoghurt" and "yoghurt smoothie" have been introduced.
[edit] Homemade yoghurt
Homemade yoghurt is consumed throughout the world and is the norm where yoghurt has an important place in traditional cuisine, such as Bulgaria, Macedonia, Iran, Turkey, Serbia, Greece[1], Pakistan, Bangladesh and India. It can be made with a small amount of store-bought plain live active culture yoghurt as the starter culture. One recipe starts with a litre of low-fat milk and requires some means of incubating the fermenting yoghurt at a constant 43°C (109°F) for several hours. Yoghurt-making machines are available for this purpose. As an alternative, a heating pad sold in pharmacies for muscle aches may be set at medium with a pot of tepid water on top. Place the milk in the pot. As with all fermentation processes, cleanliness is very important.
- Bring the milk to 85°C (185°F) over a stove and keep it there for two minutes to kill undesirable microbes.
- Pour the re-pasteurised milk into a tall, sterile container and allow to cool to 43°C (110°F).
- Mix in 120 ml of the warmed yoghurt and cover tightly.
- After about six hours of incubation at precisely 43°C (110°F), the entire mixture becomes a very plain but edible yoghurt with a loose consistency.
- The further below 43°C (110°F) the temperature, the longer it will take for the yoghurt to solidify. If a precise means of temperature control is not available, place the culture in a warm place, such as on top of a water heater or in a gas oven with just the pilot flame burning. You may wrap a small towel around the container. An electric oven with the light on may work nicely, depending on the bulb size. It is done when it no longer moves if you tilt the jar.
In Japan, Caspian Sea Yoghurt is a very popular homemade yoghurt. It is believed to have been introduced into the country by researchers in a sample brought back from Georgia in the Caucasus region in 1986. [2] This Georgian yoghurt, called Matsoni, is mostly made up of Lactococcus lactis subsp. cremoris and Acetobacter orientalis[3] and has a uniquely viscous, honey-like texture and is milder in taste than many other yoghurts.
Caspian Sea yoghurt is well-suited for making yoghurt at home because it require no special equipment and cultures at room temperature (20–30°C) in about 10 to 15 hours, depending on the temperature. [4] In Japan, freeze-dried starter cultures are sold in big department stores or online, although many people obtain starter cultures from friends as well.
- General instructions: sterilise all utensils, containers and lids in boiling water prior to use.
- Stir the freeze-dried starter in a container into about 250 ml of milk and cover it with a lid. Incubation time is approximately 12-36 hours from starter. Make the next batch as below using the actual yoghurt as the starter.
- In the winter, use about one part yoghurt to four parts milk. In the summer, use about one part yoghurt to nine parts milk.
- Place the lid gently on top of the container so as to allow some air in, but prevent contamination. Leave in a clean dry place for 10-15 hours or until thick. This may take less than 10 hours in the summer and longer than 15 hours in the winter.
- Some thickening of the yoghurt will occur in the refrigerator.
- The yoghurt can be stored in the refrigerator for a week or longer.
- To reduce contamination, always make the next batch of yoghurt before using the current batch, and use the containers only for making yoghurt.
[edit] Spelling
There are several variations of the spelling of the word. In the U.S., yogurt is the usual spelling and yoghurt a minor variant. In the UK, yoghurt and yogurt are both current, although yoghurt is probably more common, and yoghourt is an uncommon alternative. Canada uses mostly yogurt and yogourt; in Australia and New Zealand yoghurt prevails. Whatever the spelling, the word is pronounced /'jɒgət/ or /'jəʊgət/ in Britain, /'jogɚt/ in the U.S., and /'jəʉgət/ in Australia. See further at American and British English spelling differences.
[edit] References
- ^ Merriam-Webster Online - Yogurt entry
- ^ Yoghurt--an autodigesting source of lactose. J.C. Kolars et al., New England Journal of Medicine, 310:1-3 (1984)
- ^ Yoghurt and gut function. O. Adolfsson et al., American Journal of Clinical Nutrition, Vol. 80, No. 2, 245-256 (2004)
[edit] See also
- Ayran
- Bulla Dairy Foods
- Cacık
- Clabber (food)
- Colombo Yogurt
- Crème fraîche
- Curd
- Dahi
- Danone (Dannon)
- Greek food products
- Kefir
- Kombucha
- Müller
- Probiotic
- Sour cream
- Tzatziki
- Viili
- Yeo Valley Organic
- YoGo
- 'Yoplait' brand yogurt
[edit] External links
- Persian Mast (Yoghurt)
- US National Center for Home Food Preservation: Fermenting Yogurt at Home
- How to make natural Yoghurt at homeNatural way to make Yoghurt at home
