超临界二氧化碳萃取在食品工业中的应用（The application of supercritical carbon dioxide extraction in food industry）Application of supercritical carbon dioxide extraction in food industryApplication of supercritical carbon dioxide extraction in food industry - Application of supercritical carbon dioxide extraction in food industryApplication of supercritical carbon dioxide extraction in food industryAbstract: supercritical CO2 extraction technology as a high and new processing separation technology, in the field of food processing has broadApplication prospect. Many studies have shown that supercritical CO2 has high diffusion and small mass transfer resistance, so it is porousExtraction of compounds in loose solid matter and grease material is especially advantageous: supercritical CO2 for operating conditions (e.g. pressure),Particularly sensitive to changes in temperature etc. This provides operational flexibility and adjustability: supercritical CO2 with solventSolubility and low temperature, non-toxic, solvent-free residue requirements, especially suitable for the food industry. Keywords: supercritical fluid extractionOverview of 1 supercritical CO21.1 definition of supercritical fluidAny substance has three phases - gas phase, liquid phase and solid phase. The point where the three equilibria coexist is called the triple point.The point at which the two phases of liquid and gas equilibrium are called a critical point. The temperature and pressure at the critical point are called the critical pressures. Different thingsThe pressure and temperature required for the critical point are different.At present, supercritical fluid is a kind of carbon dioxide, because it is non-toxic, non burning, and is not suitable for most substancesShould be, cheap and so on, a little, the most commonly used. In the critical state, CO2 fluid has both dual characteristics of gas and liquidHigh diffusivity and low viscosity with gas, with density and material that are close to the liquid, and good solubility.Its density is sensitive to temperature and pressure changes, and is proportional to the solubility in a certain pressure range, so it can be controlledTemperature and pressure change the solubility of a substance.1.2 the basic principle of supercritical fluid extractionThe extraction process of supercritical fluid extraction is based on the relationship between the solubility of supercritical fluid and its density, that is, the utilization of pressureAnd the influence of temperature on the solubility of supercritical fluid. When the gas is in a supercritical state, it becomes a property betweenA single phase between liquid and gas, having a density similar to that of liquids, which is higher than gas but lower than liquid,The diffusion coefficient is 10100 times of the liquid; therefore, the material has better penetrability and stronger dissolving power, and the material can be absorbedCertain ingredients in the material are extracted.The solubility of supercritical CO2In supercritical state, the solubility of CO2 to different solutes varies greatly, which is related to the polarity, boiling point and molecule of soluteQuantities are closely related, in general, by the following laws: lipophilic and low boiling components can be extracted at low pressure (104pa), such as volatilizationOil and esters; the more polar groups are, the more difficult it is to extract; the higher the molecular weight of a compound, the harder it is to extract.Therefore, CO2 is particularly suitable for extraction of active components from natural products.Application of 2 Supercritical CO2 in food industry2.1 extraction of soybean powder phospholipidsSoybean lecithin is widely used in food additives, health care products, cosmetics and other products for its cheap price and various physiological functionsMedicine and other industries. At present, the production of soybean phospholipids mainly adopts organic solvent, in which acetone solvent is the main. AcetoneIts toxicity mainly acts as an anesthetic to the central nervous system. The organic liquid residue in edible vegetable oil is stipulated by the national standardShould not be higher than 50mg/kg, therefore, reduce the amount of acetone residue in edible soy lecithin, and maintain the healthy experience of the human body. It has a heavy weight on the course paper of Jiangsu Food Science CollegeTwoMake sense.Supercritical CO2 was used to extract powder phospholipids, and soybean lecithin was used as the raw materialSolvent, in the absence of any chemical reagents, to achieve high purity soybean powder phospholipid production process.Soybean lecithin is pumped into the extraction vessel through a phospholipid pump and uses supercritical CO2 liquid as a solvent,PressurizeThe pump advances the pressure to the process and regulates the temperature