Sous Vide Cooking Technology (Part One)
Sous Vide, a cooking technique, originated from the French word "vacuum", which is defined as "a cooking method of putting food materials or ingredients into a heat-resistant vacuum bag to accurately control time and temperature". In 1970s, chefs in some top restaurants in the world began to use method of vacuum low-temperature slow cooking. However, it was not until the beginning of the 21st century that vacuum low-temperature slow cooking technology became popular, and it became a new consumption fashion in restaurants and families in recent ten years.
Since 1990s, food scientists have been actively studying the technology of Sous Vide cooking, which focuses on prolonging the shelf life of processed foods by slow cooking in the vacuum and low-temperature condition. These efforts have also been successful in theory and practice. Moreover, there are no explosive food academic literature and food quality accidents to oppose and question this technology.
Vacuum low temperature slow cooking technology includes six basic elements: food and ingredients, packaging materials, vacuum packaging, circulating water boiling and water cooling, time control and temperature control. Compared with traditional kitchen cooking methods, the differences are mainly reflected in two aspects: vacuum packaging of food materials with heat-resistant packaging bags, and precise control of cooking time and temperature. Next, we will briefly introduce sous vide cooking technology below.
Ingredients
For 100,000 years, meat has been an important component of human diet. The history of raising livestock or poultry for meat has been 9000 years. However, in the past few decades, great changes have taken place in meat we eat that it now comes more from young and lean animals, and the meat products may be frozen and transported for half a world before coming to our dining table. Traditional cooking methods are not always suitable for today's tender meat and lean meat, which often results in dried taste. Vacuum low temperature slow cooking technology can make chefs get the best cooking effect, which is tender, juicy and delicious regardless of any type of ingredients.
When cooking eggs, temperature control is always very important, but it is difficult to get better results in traditional cooking methods. Low-temperature slow cooking can make all food materials of eggs keep uniform taste and final result through precise temperature control. At the following temperature, heating an egg with shell until the temperature is balanced (about 30-60 minutes) will get different effects. At 61.5℃, the protein will denature, the egg white will form a loose gel, and the egg yolk will still be in a flowable state, which is very suitable for making sauces; at 63℃, the egg yolk begins to denature and become a flowable viscous shape like honey, which is commonly known as soft-boiled egg in cooking. The sticky egg yolk will bring rich sensory enjoyment; at 70℃, protein denaturation makes egg white form a solid protein gel, and egg yolk solidifies at this temperature.
State of Eggs at Different Heating Temperatures
After cooking, fish and seafood will change their texture, giving them flavor and destroy food-borne pathogens. When the cooking temperature is 46-49℃, collagen in fish meat will be converted into gel, which makes fish meat juicy. Other studies have found that fish cooked in vacuum at low temperature will retain more ω-3 fatty acids and other nutrients than fish cooked by traditional methods.
The State of Salmon at Different Heating Temperatures
Vegetables slowly cooked at low temperature in vacuum condition can completely retain most of the cell walls and dissolve the hard gel components, thus making the vegetables taste more tender. In addition, the beans cooked by Sous Vide can retain most of its water-soluble vitamins and minerals. In terms of ingredients, because of the use of vacuum packaging, there is no loss or loss of flavor substances in ingredients, so the consumption is more economical than that in traditional cooking methods. At the same time, in order to avoid that the evaporation of alcohol will make the vacuum packaging bag surface during heating, it is necessary to heat the ingredients in advance to remove alcohol.