People know that egg whites are very sticky, this is because egg whites are rich in ovalbumin. The protein molecules contained in ovalbumin are originally arranged in a spiral structure with strong tension. When the egg white in the same direction to do mechanical pumping, with the strength of the rotation, the original protein molecules polypeptide chain arrangement of the structure changes, and break to maintain the protein spatial structure of the weak chain, so that the tension is weakened, the overlap of the molecules to unfold.
Then in the continued beating, the overlapping molecules gradually wrapped air, and air molecules and fusion, the emergence of foam, with the increase in the number of times of beating, and air mixed with the foam slowly into a small bubble, the volume of the protein continues to get bigger and bigger, and finally the formation of a new structure of the egg bubble. The whipping of egg whites is actually the process of denaturing the proteins they contain, and the original orderly spatial structure of the proteins becomes a loose and chaotic structure.
Egg whites are commonly used in pastries and batters. Pastries are usually baked cakes, sugar cakes and so on. Wo batter is commonly used in our Chinese food sherry paste, egg foam paste, the use of whipped egg whites and add a certain percentage of starch, you can fry fresh vegetables or meat, the finished product is white, fluffy and full.
Pastry in the whipped egg whites will generally use a whisk, there is nothing technical here, as long as you do a uniform pumping egg whites will be whipped. And Chinese food and paste, the use of egg whites is less, often using manual pumping, which will inevitably be whipped up the situation. The following chef to manually whipped egg whites experience to analyze the reasons why the egg whites are not whipped up:
Reason 1. Eggs are not fresh: egg whites in the egg mucus protein in two kinds, one is insoluble, one is soluble. Eggs during freshness, the tension between the protein molecules is strong and foaming is optimal. With the eggs stored for a longer period of time, the insoluble protein content is reduced, it will lead to a decrease in the concentration of egg white, with such egg white will not be conducive to the formation of protein foam, egg white whipped not up.
Reason 2. Egg white and yolk are not completely separated: egg white mixed with yolk in the pumping process will form an unstable structure, will also lead to egg whites whipped up, of course, a few drops of nothing, more than not.
Reason 3. grease in the container: grease is a very good defoamer, it has a strong surface tension. Egg whites form a bubble when the tension is very small, when the two meet, the tension will be the tension of the foam of the small crack, will be the bubble of the air leakage, the bubble disappeared, the egg whites will not be whipped up.
Reason 4. Not beating in one direction: If there is no rule of random beating, the egg white molecules are not easily denatured, they can not wrap the air, the egg whites can not whip up.
Reason 5. beating is not fast, even speed beating: egg white in the beginning of denaturation, reversible, then if there is no mechanical even speed beating, the egg is easy to change back to the egg white state, and it is difficult to whip again.
Reason 6. beat the hard: after the formation of bubbles, if you continue to beat, the protein molecules will lose the structure of the organization, into the water state, is what we often say, "beat the slack".
The above 6 reasons as long as there is 1 is not done, the egg whites will not be whipped up. In the following time, the chef will share the usual manual whipping of egg whites operation process, I hope that the small partners reference.
~Whipping egg whites operation process~
Raw materials and utensils:
Three eggs, two pairs of chopsticks, stainless steel basin.
Start making:
1. Separate the egg whites from the whites: crack the egg skin into two halves, alternate hands, separate the egg whites from the yolks, and then place the egg whites in an oil-free stainless steel basin.
2. Formal whipping: Tilt the stainless steel bowl, take two pairs of chopsticks, pinch the tops of the chopsticks in the palm of your hand, separate the rest, put the chopstick heads into the egg whites, start whipping according to the oval track, speed up the speed when the egg whites are bubbling until the egg whites are whipped (the best state is to insert the chopsticks into the egg bubbles and not to fall down).
~Tips for Whipping Egg Whites~
1.Manual whisking of egg whites is a physical job, three egg whites need to keep whisking for about ten minutes to whip, then if you are not physically exhausted, the egg whites will be difficult to whip, so it is best to manually whisk the egg whites by alternating between the two people.
2. Chopsticks are the most common tool we use for whipping egg whites, and a whisk is best.
3. When whipping the egg whites, it is best to have the basin inclined so that the egg whites and the whipping tool can fit better.
4. The pumping process can also add a little sugar, sugar has to improve the viscosity of the egg white role, and there is a stabilizing effect of the egg bubble, so that it is not easy to disappear.
5. Sugar should be added after the formation of egg bubbles, if added too early will inhibit the expansion of the bubble. Here the use of sugar is best.
6. Regardless of the application, the egg whites should be used up quickly after whipping, and not left for too long, as they are very easy to slacken off. If you can't use them up, put them in the refrigerator.