We will introduce the characteristics of microwave equipment from the following aspects:
An electric wave with a frequency of 300 MHz to 300 GHz is a microwave. The heated medium material contains polar water molecules. Its polarity orientation will change with the change of the external electric field when subject to the influence of a rapidly varying high-frequency electromagnetic field. This results in the mutual friction effect being seen in the movement of molecules. At this point, the microwave field's field energy is converted into heat energy in the medium, raising the material's temperature and causing a number of physical and chemical reactions including heating and puffing to accomplish the microwave heating and drying goals.
Utilizing the combined thermal and biological effects of electromagnetic fields, microwave sterilization is accomplished. Microwaves have a thermal impact on bacteria that causes the protein to alter, resulting in the loss of the bacterium's ability to reproduce, eat, and survive. Microwaves have a biological impact on bacteria by altering the potential distribution of the cell membrane, which in turn alters the concentration of electrons and ions nearby and alters the permeability of the cell membrane. The bacteria are thus undernourished, unable to metabolize correctly, have disordered cell structure and function, and their growth and development are restricted. and passing. Additionally, several hydrogen bonds relax, break, and recombine, leading to genetic mutations, chromosomal aberrations, and even breaks in the nucleic acids (RNA and DNA), which are necessary for bacteria to grow normally and reproduce genetically.
A recently created new technique that speeds up the extraction process by using microwave radiation. The extracted material is heated up in specific areas of the matrix material or components of the extraction system based on differences in how well they can absorb microwaves in the microwave field. This allows the extracted material to be released from the matrix or system and enter the medium. among the extractants with a low electric constant and a weak microwave absorption capability; Microwave extraction features minimal pollution, simple equipment, a broad application range, high extraction efficiency, and good repeatability. It also saves time, reagent, and money. It is mostly employed for environmental sample pretreatment, but it is also utilized in other industries including biochemistry, food, industrial analysis, and the extraction of natural products. There aren't many research studies on the application of microwave extraction technology in Chinese herbal medicine in China.
1.High-frequency electromagnetic waves are used in the microwave radiation process to penetrate the extraction medium and reach the microtubule bundle and adenocyte system inside the material. The temperature inside the cell will quickly increase as a result of the microwave energy being absorbed, beyond the capacity of the cell wall to tolerate expansion. The cell bursts as a result, allowing the active components to easily flow out and disintegrate at a lower temperature. across the extraction medium. The necessary extract can be achieved by further filtering and separation.
2.The molecules of the extracted component can diffuse more quickly from the inside of the solid to the solid-liquid interface thanks to the microwave's electromagnetic field. For instance, when water is utilized as a solvent, the water molecules transform from a high-speed spinning state to an excited state, which is a high-energy unstable state, under the influence of a microwave field. The water molecules either vaporize at this point to increase the driving force of the extracted components or release their excess energy back to the ground state, where it is transferred to the molecules of other substances to speed up their thermal movement, shortening the extracted components. To enhance the quality of the extract, the extraction rate is raised multiple times while the extraction temperature is lowered to account for the time it takes for molecules to diffuse from inside the solid to the solid-liquid interface.
3.Microwave energy is a type of non-ionizing radiation energy that induces molecular motion owing to ion migration and dipole rotation because the frequency of microwave is connected to the frequency of molecular rotation. It can encourage molecular rotation when it interacts with molecules. If the molecule is sufficiently polar, the microwave field's effect can cause immediate polarization and cause the polarity to shift at a rate of 2.45 billion times per second, leading to bond vibration, ripping, and inter-particle contact. A lot of heat energy is quickly produced by friction and impact, which encourages the rupture of cells and leads to the overflow and diffusion of cell fluid into the solvent. In microwave extraction, different parts of the matrix material or specific extraction system components may be selectively heated due to differences in the ability to absorb microwaves, causing the extracted material to be separated from the matrix or system and enter the material with a smaller medium. In extraction solvents with a low microwave absorption capacity and an inadequate electrical constant.
The whole frozen product is heated during microwave thawing, and the temperature rises from below freezing (around -19 to 22 C) to just above freezing (about 0 to 4 C). The overall temperature recovery of the frozen material and the small temperature gradient of the temperature recovery, i.e., good temperature uniformity, short time requirements, and simple control of temperature rise rate, are features of the microwave thawing equipment. Due to these qualities, the frozen product thaws to a more perfect state.
1.It is possible to heat frozen goods at once to minimize temperature differences between the layers as they thaw, and there is no recrystallization of the frozen goods as in the conventional method.
2.The thawing process takes only a short time, making it difficult for bacteria and other microorganisms to grow and multiply.
3.Thermal inertia is absent from microwave heating. The microwave output power, also known as the microwave energy supply rate, regulates the pace at which the frozen material's temperature rises and these two factors are synchronized.
4.The temperature after microwave thawing is typically between -2 and -4 C. The frozen item is now free of leaking water and may be sliced with a knife.