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The food industry is the largest market for microfiltration in terms of application and development; it is now used for filtering, sterilizing, and clarifying various alcoholic beverages such as beer, liquor, rice wine, wine, and fruit wines； Clarification and filtration of fruit juice beverages, gelatin, glucose, etc ； Filtering and sterilization of milk ； Many fields such as the recycling of beer residues. Since the application of membrane technology in the food industry requires operations such as cleaning and disinfection, and high shear rates are needed when dealing with highly viscous materials, inorganic membranes are a suitable choice. They not only feature a long service life, stable operation, and high separation efficiency, but also allow for in-situ steam disinfection, which is crucial for ensuring food quality. The advancement of membrane separation processes in the food industry: Compared to traditional methods used in this industry, membrane technology offers significant advantages. 1. Energy efficiency: The membrane separation process does not involve phase changes, which gives it the advantage of cold sterilization; it requires less energy compared to separation methods that rely on phase changes or other separation techniques, and it makes use of clean energy – electricity. Therefore, membrane separation technology is also known as energy-saving technology. 2. Preserving color, flavor, aroma, and nutritional components: The membrane separation process takes place at room temperature, making it particularly suitable for the separation, classification, concentration, and enrichment of heat-sensitive substances such as juices, amino acids, vitamins, etc ； At the same time, in membrane separation processes, the materials circulate within a closed loop, which reduces the impact of oxygen in the air; both heat and oxygen have a significant effect on food processing ； The properties of the material do not change either during its migration through the membrane ； Membrane separation processes can also be used for cold sterilization, as an alternative to the traditional heat-based pasteurization method ； Therefore, in membrane separation processes, efforts should be made to avoid altering the color, aroma, taste, and nutritional components of the product, so as to preserve its original qualities. 3. Wide range of applications: Any substance larger than 0.1μm can be filtered out using the inorganic membranes produced by our company; bacteria, yeast, and molds can all be trapped, while most of the active ingredients in food can pass through the membranes. 4. Simplified processes and operations: The membrane separation process is relatively simple to operate, allows for easy automation, requires less space, is easy to maintain, has a long service life, and results in reduced operating costs. Microporous filtration for the sterilization and clarification of alcoholic beverages is used for the precise filtration of such drinks, and it can **improve their clarity. The use of polymer membranes or inorganic membranes, along with diatomaceous earth as a filter aid, for filtering beer in order to remove impurities such as yeast, has a history of many years ； Used to filter low-alcohol and high-alcohol baijiu in order to effectively remove suspended particles from the liquor and improve its clarity ； It is used to filter wines and other fruit-based beverages in order to remove yeast and other impurities, and it is also employed in the filtration of traditional Chinese medicine liquors as a substitute for methods such as asbestos filtration that were previously used. Clarification and separation in the beer brewing process: Filtration is the final and crucial step in beer production to improve product quality, especially when the beer is intended for long-term sale or storage, as it is necessary to ensure its biological safety as well as the stability of its colloidal properties and flavor. Inorganic membranes are used in beer production primarily for removing microorganisms to clarify the beer and for recovering beer from deposits at the bottom of the tanks. (1) Removal of bacterial cells or microorganisms: The presence of bacteria or microorganisms can affect the flavor of beer and shorten its shelf life. Traditional filtration methods involve the use of diatomaceous earth, etc., which can remove yeast and some bacteria; however, they are not very effective at removing bacteria. Therefore, pasteurization is required before bottling to kill these bacteria or microorganisms. Due to the high-temperature treatment involved, some aromatic compounds get oxidized, affecting the flavor of the beer. Meanwhile, bacterial cells remain in the beer after pasteurization. Porous inorganic membranes represent a promising new technology for replacing pasteurization and enabling the direct clarification filtration of beer. By using this technology, it is possible to avoid heat treatment of beer, thereby achieving both sterilization and clarification while preserving its flavor and taste. The comparison of traditional and modern processes for beer clarification is as follows: Traditional process: Fermentation – pre-clarification by centrifugal sedimentation of unfiltered beer – diatomaceous earth filtration – plate and frame filtration – dead-end filter – sterilizing filter. Microfiltration technology: Fermentation – pre-clarification by centrifugal sedimentation of unfiltered beer – microfiltration to produce a sterile filtrate. In the clarification and filtration of beer, it is very important to choose an appropriate membrane pore size; this ensures that suspended particles and microorganisms are retained during filtration, while at the same time preventing changes in the beer’s color, taste, and other quality parameters such as protein content. The 0.2μm membrane has a high retention rate for proteins and pigments in beer, at 12% and 30% respectively; the properties of the beer product change significantly after clarification, which is unacceptable. In contrast, under the same conditions, the 0.5μm membrane can reduce microorganisms to levels below 1 per milliliter, with a removal rate of 99.990%–99.998% for Acetobacter, while its retention rate for pigments is only 3%, and the content of nitrogen and total solids in the retained substances is low. (2) Recovery of yeast and beer from bottom sediment in tanks. Beer production involves four main steps: extracting malted barley and other materials with water; heating the extract to boiling; cooling the extract and adding yeast for fermentation; and clarifying the mixture. Yeast is recovered after fermentation, and the conventional method for this purpose is centrifugation, although inorganic membrane filtration technology holds more potential. The recovery of beer from bottom sediment in tanks represents a potential application area for inorganic membranes in the beer industry. This sediment consists of flocculated liquid extracts that contain suspended solids, collagen particles, yeast, etc., and it contains 90%–99% beer. There are two types of bottom sediment in beer production: sediment from fermentation tanks and sediment from aging tanks, with solid contents of 10–15 grams/liter and 40–50 grams/liter respectively. Traditional treatment methods include vacuum filtration, pressure filtration, and centrifugal separation. Microfiltration technology has become a highly competitive alternative due to its ability to reduce operational costs; it allows for the production of clear beer without the need for filter aids, and membrane filtration can be carried out in a sealed environment, preventing the raw liquid from being exposed to air and thus maintaining a low oxygen content in the beer. The recovery of beer from the sediment at the bottom of membrane filtration tanks is usually carried out after the yeast fermentation process. The clarified beer obtained in this way can account for up to 5% of the total beer production; the residue contains concentrated yeast oils. By using membrane filtration technology, a large amount of diatomaceous earth can be saved, which reduces waste emissions as well as the costs associated with purchasing diatomaceous earth. Compared to traditional diatomaceous earth beer filtration systems, the advantages of membrane filtration are: ■ It enables the production of clear, unsterilized beer from untreated beer, as a replacement for diatomaceous earth filtration ； ■ To produce clear, sterilized beer as a substitute for diatomaceous earth filtration and pasteurization ； ■ Clear, sterilized beer was produced from unfiltered beer and can bottoms to replace diatomite filtration, pasteurization, and can bottom filtration. The economic viability of membrane filtration depends on the cost of the membrane filtration equipment, the membrane area and flux (i.e., production capacity), as well as factors such as water, electricity, and gas consumption as well as maintenance costs. Therefore, in equipment design and production practices, the pore size of the microfiltration membrane should be selected based on the solid content and characteristics of the particles in beer. Membranes with a pore size of 1.3 μm and above are suitable for recovering beer from sediment at the bottom of tanks ； Membranes with a pore size of 0.5–1 μm can replace diatomaceous earth as the primary filtration medium in beer to remove suspended particles from it ； Membranes with smaller pore sizes, such as 0.2–0.5 μm, can replace pasteurization to remove bacteria from beer and produce \"sterile\" beer, thereby reducing costs and expenses. In actual industrial applications, it is often a combination of various types of microfiltration membranes with different pore sizes. Filtering and clarifying baijiu: In recent years, as people’s awareness of health has increased and **wine-making industry policies have changed, there is a greater preference for consuming low-alcohol baijiu, rice wine, wine, and other types of fruit wines. During the reproduction of low-alcohol baijiu, the decrease in alcohol content easily leads to the formation of white turbidity, causing the sensory quality parameters of the baijiu to fail to meet the standards. The main components of these white turbid substances are ethyl palmitate, ethyl linoleate, ethyl oleate, etc. The particles in these turbid substances are small and evenly distributed, resulting in a very slow natural sedimentation rate. Therefore, filtration is necessary to remove these turbidities during the production of low-alcohol baijiu, while it is also important to minimize any loss of flavor compounds in the baijiu during the filtration process. Replacing traditional separation processes and equipment, such as freezing methods, precipitation adsorption, diatomite adsorption, and ion exchange or molecular sieve adsorption, with microfiltration membranes can **reduce production costs and improve economic efficiency. Using inorganic membranes to remove turbidity from baijiu can significantly improve its clarity, preserve its color, aroma, and taste, and extend its shelf life. Baijiu filtered through microfiltration can effectively remove microorganisms. Application in vinegar production: During the fermentation process of producing vinegar from dilute alcohols, the presence of Pseudomonas aeruginosa causes turbidity in the liquid product. Inorganic membrane filtration can remove this bacterium from the concentrate, thereby clarifying the liquid product, significantly improving its transparency, and eliminating bacteria as well. After treatment with an inorganic membrane, good clarification is achieved, with the turbidity of the permeate remaining within the range of 0.2–0.8 NTU. Applications in soy sauce production: Since the production process of soy sauce takes place in an open environment, during the fermentation and decomposition of the raw materials, various microorganisms such as bacteria, actinomycetes, and yeasts grow and multiply. The presence of these fungi not only affects the normal decomposition process carried out by enzymes, but also causes unusual odors and phenomena, leading to the change in flavor or even spoilage of soy sauce. Therefore, it is crucial to kill or remove these unwanted microorganisms promptly after soy sauce is produced, in order to maintain its quality. Moreover, as people’s living standards improve, there are higher demands regarding the color, aroma, taste, and hygiene standards of seasonings such as soy sauce and vinegar, which gives color removal and clarification of soy sauce even greater social and economic value. The types and sizes of bacteria in soy sauce are shown in the table below. As can be seen from the table, membranes with a size of no more than 0.5 μm can completely remove the unwanted bacteria in soy sauce. Bacterial categories: Bacteria, Actinomycetes, Yeasts, Molds. Size in μm: 0.5–5, 1, 5–3, 3–10. Filtration and sterilization of yellow rice wine: Since yellow rice wine is a non-distilled beverage, the raw wine contains large amounts of turbidity-causing substances, colloids, bacteria, and other microorganisms. To improve the quality of yellow rice wine and extend its shelf life, it must be filtered and sterilized before it can be released onto the market. The traditional method involves filtering first with cotton cakes, followed by heating for sterilization. The disadvantages of this processing method include high labor intensity, significant loss of yellow rice wine, and severe environmental pollution. Replacing cotton cake filtration and steam sterilization with microfiltration methods allows E. coli and other contaminants as well as suspended impurities to be removed at lower temperatures, which plays an important role in reducing raw material consumption and production costs and improving the quality of yellow rice wine. The clarification and filtration of fruit juices: The application of inorganic membrane technology is highly beneficial for improving the quality of fruit juices and reducing operational costs. Firstly, it enables the combination of filtration and pressing in a single unit, reducing production costs ； Secondly, inorganic membrane treatment helps to preserve the original flavor of the juice ； Thirdly, in juice filtration, inorganic membranes possess advantages such as high permeation flux, low protein adsorption, good mechanical strength, resistance to high-pressure backwashing and deformation during the process, as well as good thermal stability that allows for in-situ disinfection at high temperatures. One of the most successful applications of microfiltration membranes is in the clarification and purification of fruit juices. Inorganic ceramic membranes are more suitable for this purpose than polymer membranes, as they possess strong antimicrobial properties; the equipment using such membranes can be disinfected with steam, and they can be regenerated through backwashing with high-pressure fluids. In the early 1980s, inorganic membranes were widely used in France’s juice industry; the juices filtered using these membranes had excellent quality, and they possessed a more pleasant aroma compared to juices produced by the traditional diatomaceous earth filtration and pasteurization method. Inorganic membranes are used for clarifying fruit juice primarily to remove bacteria, pectin, and crude proteins that can easily cause the juice to spoil. Traditional juice production methods involve centrifugal separation, diatomaceous earth filtration, and pasteurization; in particular, pasteurization results in the loss of most of the aromatic flavors in the juice. Processing process: Clean fruits – crushing – juicing – coarse filtration – enzymatic clarification – microfiltration – sterilization and packaging. Using these methods, the resulting juice is uniform in texture, clear and transparent, with no suspended particles or stratification. Fresh milk is filtered and sterilized. As people’s living standards continue to improve, their expectations regarding their diet become higher and higher. Fresh milk has become a common nutritional product consumed by people. The main types of fresh milk available on the market today are pasteurized milk, ultra-high temperature sterilized (UHT) milk, and microfiltered milk. Among them, UHT milk has gradually been accepted by people due to its long shelf life, safety and hygiene, good taste, and moderate price, and it has partially replaced pasteurized milk. The application of membrane separation technology in the dairy industry began in the 1970s, initially in cheese production, and later expanded to areas such as the concentration of whey protein, the manufacture of milk powder and curd, the separation of proteins and peptides, the sterilization of skim milk, and the concentration of milk. Microfiltered milk is another type of liquid dairy product that has become popular abroad in recent years. Since microfiltration technology uses microfiltration membranes to remove impurities and bacteria from milk under specific temperature and pressure conditions, it not only requires less energy but also avoids high-temperature heating, allowing the fresh milk to retain its original flavor – which is why it is very popular among consumers. Filtering of vegetable oils and other applications: The crude oils and second-grade oils that were used in cooking in the past have gradually been phased out, replaced by refined first-grade oils and high-quality cooking salad oils. Since vegetable oil is obtained through processes such as pressing plant seeds, alkaline treatment, bleaching, and filtration to remove impurities, crude oil and second-grade oil contain higher levels of free fatty acids, more impurities, higher moisture content, and a darker color. They also contain certain trace elements harmful to the human body, such as phosphorus, arsenic, and lead, as well as carcinogenic substances and aflatoxins. In contrast, refined oil has significantly lower levels of free fatty acids, a lighter color, minimal moisture and harmful impurities, and a longer shelf life. Improving the clarity of vegetable oils has always been a major challenge for oil processing plants. In China, for the solid-liquid separation of raw materials used in the production of edible vegetable oils, whether it is the filtration of crude oil, refined and decolorized oil, or refined oil, plate and frame filter presses or spiral sedimentation centrifuges using filter cloths as the filtering medium are still predominantly employed. In more advanced countries, vane filters or high-speed centrifuges that use metal filters as the filtering medium are used instead. Although these separation devices have their own features, they all share one common drawback: low filtration efficiency and low transparency of the filtrate. Filtering equipment using microporous membranes as the filtering medium was employed to filter crude edible rapeseed oil as well as oil that had been refined and decolorized using clay; the operation was carried out at 70 degrees Celsius. The filtered oil remained clear and transparent after being stored for 18 months, with no particulate deposits present. Microfiltration also finds certain applications in the production of health beverages such as tea drinks, chrysanthemum drinks, and Schisandra chinensis beverages.