Ⅰ.Casein production process
The production of casein is predominantly accomplished through the utilisation of acid precipitation or enzymatic methods, which are outlined below. The two primary production processes are as follows:
Acid precipitation method:
The raw material preparation stage involves the utilisation of skimmed milk as the primary raw material.
Acidification: The skimmed milk is then acidified to the isoelectric point, whereupon precipitation of the casein occurs.
Subsequent separation and washing: The precipitated casein is separated by centrifugation or filtration and washed to remove impurities.
Finally, the washed casein is dried to obtain the final product.
Enzymatic method:
Preparation of raw materials: skimmed milk is used as the raw material.
Enzymatic treatment: Casein in milk is coagulated by adding rennet.
Separation and washing: the coagulated casein is separated by centrifugation or filtration and washed.
Finally, the washed casein is dried to obtain the final product.
Ⅱ.Innovative processes for modern casein production lines
In recent years, membrane separation technology has seen widespread use in the production of casein. The following outlines the application of this technology in a casein production line:
1. Membrane separation technology:
The principle behind this technology is that the components are separated based on their molecular weight or diameter difference, with the separation being achieved by the filtration action of the membrane. The majority of whey proteins, lactose, minerals and water can pass through the membrane and become permeate, while a small portion of the whey proteins, lactose and minerals will remain in the retention solution together with the casein.
The process flow is as follows:
The process begins with raw milk being treated to ensure that its fat content is controlled within 0.07%. This is done by pasteurising and centrifugating the milk.
Membrane separation is achieved through a four-stage continuous dilution filtration process using ceramic membranes with a pore size of 40 nm, with dynamic monitoring of changes in relevant indicator parameters.
Membrane cleaning is performed using a biological enzyme cleaning solution to restore the pure water flux of the membrane.
Evaporation, concentration and spray drying: the retention solution is evaporated and concentrated and spray dried to finally obtain casein micelle powder (MCC).
2. Process optimisation:
Temperature and pressure control: During the membrane separation process, the temperature was controlled at 45 °C and the operating pressure was 1.5 × 10^5 Pa to ensure the efficient operation of the membrane and the stability of whey protein.
The purity and yield of casein were improved by a four-stage continuous dilution filtration process.
Ⅲ.The Future of Casein Production Lines
1. Diversified products
The casein industry is expected to continue introducing new products in order to meet the needs of different consumers. Examples of such products include casein with probiotics, low-lactose or lactose-free casein.
2. Technological innovation
Specifically, advanced membrane separation technology and enzyme digestion technology will be extensively employed in casein production, with the dual objectives of enhancing yield and purity while concomitantly reducing production costs.
3. Environmental protection and sustainability
This is due to an increase in consumer demand for natural and organic foods, which is expected to drive the casein industry towards a greater focus on the selection of raw materials and the environmental friendliness of the production process. It is anticipated that organic casein and non-GMO casein will emerge as the new trend in the market.
4. Market expansion
The continuous opening of the international market and the deepening of exchanges and cooperation between domestic and foreign enterprises will lead to more development opportunities and challenges for the Chinese casein market.
