Microwave puffing mechanism of protein denaturation during drying
    Protein can depend physical ( such as heat , pressure , freezing, surface tension, and radiation ) , and chemistry ( such as pH , ethanol, heavy metal salts and organic compounds , etc. ) and denatured factors . Proteinaceous material is to extrusion foaming expansion drying , dehydration and protein denaturation of a combination of food processing methods.
    There are three basic molecular structure of the protein forms , one of polyacetal chain amino acid formula to form a protein , the protein is denatured when the chain end and the other end of the CO NH combine to form a ring . 2 for the second form of the protein molecular structure , it has three shapes polycondensation chain amino missing , when these proteins denatured chain hydrogen bonding chain is broken , God straight into a straight short status . 3 is a member of two or more amino acid chain polycondensation combined composition form. Two polycondensation flute acid Pound is connected via ss and magnesium hydroxide formed . When the thermal denaturation of protein binding reversible hydrogen bonding broken, but strong binding of s-s bond is still connected . When the irreversible nature , the hydrogen phase s-s bond both disconnected.
    For the purposes of controlling physical properties of protein , reversible denaturation temperature is extremely narrow in the time zone for the interest , is not conducive to heat treatment , the face of animal protein , fish protein in particular , its reversible denaturation temperature and time of relatively wide area , can be Firstly preheat for cooking, such as cross- border nature can be solidified , and then use the microwave heating irreversibly fixed .
    When the protein denaturation as described above will cause the molecular structure of the three basic forms of arranging the molecular changes. When first denatured (i.e. contravariant ) is disconnected when the combination of the hydrogen , if it continues into the second heat denaturation ( i.e. irreversibly ) phase , the strong binding of the s-s will be destroyed disconnected , thereby completing the the most rapid movement of the chain of amino acids with the column changes. Hydrogen bonds will be destroyed with free water , the free water in the microwave heating technology puffing drying process is discharged radially outward .
    Denatured proteins on the end of the incorporation of additives raw meal thoroughly kneading or mixing wells , is conducive to the formation of the raw meal mixed with air bubbles . Bubble expands when the microwave heating , bubble wrap film on the surface of the protein under tension , simultaneous denaturation heat denaturation and surface tension , so speed up the process of protein denaturation , in a very short time. Clearly then free water should be discharged outside .
    Free water is discharged outside the capacity and the microwave power , the bubble is proportional to the capacity expansion , according to test results show that , compared with no foam was dried products , the discharge of water from the material expansion rate is proportional to the volume ratio of 1.2 to 1.5 times . From the dry time , the ratio of non-foam drying products drying time five or six times , but will never happen because the drying rate accelerated to produce the finished surface of the char, rather than the phenomenon . Visible , this free water formed and discharged outside the situation is conducive to microwave heating puffing dry operation processes.