Study On Fabrication And Properties Of Instant Casein Phosphopeptide Powder

Casein phosphopeptide?CPP?not only promotes the absorption and utilization of calcium,iron,zinc and other minerals in the human body,but also has a wide range of functions in enhancing the body's immunity and anti-oxidation activity.In some developed countries has been applied in food,health products and daily necessities.At present,CPP products with relatively high nutrition and application value?purity?90%?are mainly prepared after the process of separation,purification and drying from the casein enzymolysis solution.Most traditional drying methods,such as hot air drying,fluidized bed drying,spray drying,etc,have some disadvantages,for example,products have some large particles and slow dissolution rate.Vacuum freeze-drying technology can produce products with a faster dissolution rate,but it also has some disadvantages,including long time consumption,high energy consumption,and low production efficiency,and it results in a high production cost.Therefore,the development of a new green and continuous processing technology with high efficiency is vitial important for the wide application of CPP in food and health products.Based on the the interaction mechanism between supercritical fluid and solution,supercritical fluid-assisted atomization technology and the relative processing system,were developed for preparing instant factors of functional food.The relevant characteristics of CPP instant powders prepared by the traditional two-step method?a combination of CO₂ high-pressure treatment with traditional spray drying processing?and the new one-step method respectively,were systmaticaly investigated.The main research points are given below as following:1. Effect of CO₂ high-pressure system on the dissolution behavior of CPP powder.Based on the two-step preparation method,the effects of high-pressure treatment uing CO2and traditional spray drying technology on the dissolution behavior of CPP powder were systematically studied.The results show that during the process of high-pressure treatment,the supersaturation of CO₂ in the solution is closely related to the intensity of the co-solute.When the supersaturation of the solution in the high pressure system is increased,the dissolution rate of the powder obtained is faster.Increasing the pressure,appropriately reducing the temperature and prolonging the treatment time can increase the supersaturation.The optimal reaction conditions are 40?,8.27 MPa,and 40 min.The supersaturation can reach about 8.1%.The dissolution rate of the sample prepared under this condition is 5.6 times that of the original powder,and 2.5 times that of the sample fabricated without high-pressure system treatment.2. Effect of two-step fabrication process on the apparent structure and functional properties of CPP powder.The CPP samples were prepared by the traditional two-step method,and its structure and performance were characterized.As the pressure increases,the co-solute effect improve,and the proportion of particles with a hollow ultra-thin wall structure increases.Due to the larger particle size and surface area of these particles,the average size and ratio of the sample are increased as well as the dissolution rate.Moreover,the results also show that while the dissolution rate of the resulting instant products increased,the functions of calcium holding,antioxidant capacity,hydroxy free radical removal ability and emulsification capacity did not change significantly.3. The design of novel processing system and preparing the instant CPP powder.Since the traditional CPP powder is mainly prepared by two-step method,which presents the properties of low production efficiency,poor solubility,a new processing system with a combition of supercritical fluid physical modification technology and auxiliary atomization media,was designed and developed.The system mainly includes supercritical fluid control unit,reaction behavior regulate unit and spray drying unit.The results show that the instant powder prepared by the novel technology presents an ultra-thin fragmented structure with a large rheumatous surface area.The powder wasquickly dispersed and dissolved in cold water?within54 s?,and its dissolving rate is more than 32 times that of native CPP,and more than 12 times than that prepared by the traditional spray drying.The build-up density and the stop angle of the instant powder are 0.30 g/m L and 33.1?respectively,which meets the requirement of food processing.