History of yoghurt PDF

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a summary of history and process of yogurt production in microbial environment...

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Marz Jhon V. Patricio 25JAN2018 2014-09915|10062687 B

ChE 172 –

Biotechnological Product: YOGURT History of Yogurt Some mistakes may not turn out to be bad after all. For instance, yogurt is a result of a mistake that is rather considered a success. A theory suggests that the early stores milk in the animal’s intestines. In their attempt to store milk even in warm climate, another result have been obtained. Since the animal’s intestines have enzymes in it, these biological catalysts initiated the fermentation process. Even with an unexpected product which resulted to their mistake of storing milk in an unideal condition, they enjoyed the product. They even continued making it until it has been passed onto several generations. No definite length of time, however, can be claimed for how long yogurt has already existed. Historians date the discovery of yogurt as early as the years between 9000 and 6000 B.C. They claim proof to the New Stone Age man in Central Asia were known to drink the milk of the horses, cattle, and camels, which were domesticated. Yogurt appears in many ancient texts including the ancient Indian Ayurvedic scripts, the Bible and historic texts by Pliny, Herodotus, Homer, and Galen. Even in Genesis 18:8, historians claim that Abraham may have served yogurt and milk to his guests. On the other hand, the great Mongol warrior Genghis Khan is said to have encouraged the drinking of a fermented horse milk (yogurt) called kumis, because he believed that the said drink did not only kept his warriors healthy, but also made them braver. There are many other historical records that tell how yogurt is widely accepted. For another reason to patronize yogurt, in the 16th century, a Turkish doctor saved the life of King Francis I by treating him with yogurt made from goat’s milk. The intestinal illness was not cured by the medicines that the king had taken. But it was cured by the yogurt. With this attributed health benefit of the yogurt, there have been a surge in its popularity. They were not able to explain, however, how yogurt works. It was only until the early 20th century when a Russian scientist, Elie Metchinikoff studied the health benefits of fermented milk on the people of Bulgaria. He explained it in the book he wrote, entitled, The Prolongation of Life: Studies of an Optimistic Philosophy. His book greatly influenced the founding of the yogurt company Danone by Isaac Carasso and his son. Danone is the first company to add fruit to yogurt to the market in 1947. With the food craze at peek in the 1950s and 1960s, yogurt gained its huge

popularity in the United States. Up to this day, yogurt is popular especially among people who are trying to lose weight, to those who want to maintain a healthy lifestyle, or even to those who just love the taste of it. Now yogurt of many types including kefir, Greek style yogurt, Swiss and fruit yogurts can be found at almost any grocery store. With yogurt’s unique taste, and the health benefits that comes with it, it has been widely accepted for centuries. No one could have predicted that a mistake in the past from a simple fermentation process, would be loved by people today. Yogurt Processing Whether the product is set or stirred yogurt, the pretreatment of the milk is the same. Heat treatment, homogenization and standardization of fat and dry matter are done. The dry matter is standardized in the evaporator in the process line while, the fat content is standardized before entering the line. The equipment used in adjusting the dry matter content by adding milk powder, resembles that in processing recombined milk. Stabilizers, vitamins, and other additives are added into the milk before the heat treatment. After preheating and then cooling the yogurt milk to inoculation temperature, the succeeding processes would depend on the type of yogurt that would be produced. This is because the texture and flavor of the yogurt are very important whether it would be set, stirred, drink, frozen, or concentrated yogurt. The preheated milk that cooled to incubation temperature is pumped into the incubation tanks, simultaneous to this, bulk starter is dosed in the milk stream. Agitation begins as the tank is already filled. The temperature remains constant in the incubation tank since it is insulated and the tank is also fitted with pH meters to check the acidity inside the tank. The incubation usually takes 2.5 to 3 hours with a temperature ranging from 42°C to 43°C when using ordinary bulk starter that have 2.5 to 3% inoculums. After the ideal pH value is acquired, the cooling is done within 30 minutes to prevent further growth of bacteria. Gentle mechanical treatment is done to coagulant for the consistency of the product. A special plate is used for cooling at the plate heat exchanger. After cooling, the yogurt is ready for packing. The product is then transferred from buffer tanks to the filling machines that is done continuously with variable speed metering pump that feeds the additional fruits and flavorings into the yogurt to the fruit blending machine. The fruit metering pump and the yoghurt feed pump operate synchronously.

*retrieved from http://dpm.techgenltd.com/yogurt_milk_processing_line_machinery_supplier. html (History of yogurt retrieved from http://www.indepthinfo.com/yogurt/history.htm)...