Membrane filtration technology transforms dairy foods industry

Membrane filtration technology has revolutionized the food and dairy industry by providing practical, sustainable, and optimal cost solutions, enabling the production of minimally processed dairy foods, new dairy ingredients, and recovering bioactive components. In the membrane filtration process, components are separated based upon molecular size and permeability through a semi-permeable membrane with specific pore size. Based upon selective permeability of the membranes, the membrane filtration process is classified into four categories, viz. Microfiltration (MF), Ultrafiltration (UF), Nanofiltration (NF), and Reverse Osmosis (RO).

Applications of membrane technology in the food industry

In dairy processing, membrane filtration has transformed dairy products and ingredients manufacturing, particularly from milk and whey. Regular MF (1 μm pore size) removes bacteria in various dairy product streams to extend shelf life. Whereas MF with a smaller pore size (~0.14-0.2 μm) fractionates micellar casein from skim milk. UF is used to concentrate milk proteins and separate lactose and minerals. NF helps partial reduction of minerals and concentrate solids to produce high-protein dairy products like milk protein concentrates and isolates. Combination of MF, UF and NF helps to adjust the casein to whey protein ratio and reduce the mineral content of milk to mimic composition of human milk for making infant formula. Combination of MF and UF is used to separate and concentrate milk fat globule membrane and phospholipids from milk, whey and buttermilk, to use them as a dietary supplement.

Venkateswarlu (Venkat) Sunkesula, Ph.D., is leading the research and development department as VP Research and Development at Idaho Milk Products, Jerome, Idaho. He earned his doctoral degree in Dairy Science Manufacturing from South Dakota State University and has more than 20 years of extensive experience in the dairy and food industries.

Gunvantsinh Rathod, Ph.D., is working as a R&D Associate Principal Scientist at Idaho Milk Products, Jerome, Idaho. He earned his doctoral degree in Food Science from Kansas State University. He has more than 10 years of experience in dairy processing and research.

MF and UF are widely used in the beverage industry to clarify and sterilize fruit juices, beer and wine. RO is used to concentrate juices and purify water. UF is used widely in the brewing industry to remove particulate impurities such as yeast, suspended solids, and selected polyphenols without affecting flavor. The meat and poultry industries extensively use a combination of MF-RO and UF-RO for recycling wastewater to reduce organic matter to limit biological oxygen demand (BOD) and chemical oxygen demand (COD) and to recover valuable proteins and peptides from byproducts, contributing to sustainability and reducing waste. The sugar and sweetener industries use UF for clarification (that reduces the operation time and limit use of fining agents) and NF for concentration of fruit sugar from fruit juices, that enhance the production of high-purity sweeteners like high-fructose corn syrup and glucose syrup. A combination of UF and NF decolorize, desalinate, and purify cane sugar and other sweeteners. With the growing demand for plant-based foods, membrane filtration such as UF and RO is used for protein extraction, concentration, and purification from sources like soy, pea and almond. It improves the texture, flavor, and nutritional content of plant-based products due to cold-temperature membrane processing versus traditional processing. Overall, membrane processing is advantageous considering cold temperature separation and minimal effect on the nutritional and functional quality of the components. However, challenges associated with membrane technology, such as membrane fouling, reduced flux rate, and high energy consumption, are still opportunities to improve overall membrane processing performance.

Recent advances in membrane technology

Development in polymers (such as polymer nanocomposite, modified thin film composite, poly sulfone, and polyether sulfone), and advancement in membrane production scale and technology help in developing thinner membranes with reduced pore size distribution. Modern membranes with intelligent sensing technologies adapt to variations in food processing conditions such as pressure, temperature, and contamination levels and improve separation performance by adjusting their pore sizes. Nanomaterials like graphene oxide and carbon nanotubes have been integrated into membrane structures to enhance durability, resistance to fouling, and selectivity. Recent innovations also include bio-inspired and self-cleaning membrane coatings (such as Titanium oxide, polyphenols-tannic acid) that prevent the accumulation of biofilms, proteins, and other contaminants. Recent advancements also focus on low-energy filtration systems to reduce water and energy consumption. The development of forward osmosis (FO) and electrically driven membrane filtration has provided alternative methods that enhance sustainability while maintaining high filtration performance. Combining membrane filtration (UF/RO) with other techniques, such as evaporation, helps to leverage the limitation of retentate concentration, avoiding fouling and higher energy requirements for pumps without compromising final product quality and economy.

Future prospectives of membrane technology

From dairy and beverages to plant-based proteins and sugar refining, membrane filtration continues to be an indispensable tool in modern food manufacturing. As innovation progresses, these technologies will meet global food production challenges and ensure the availability of high-quality, safe, and nutritious food products with better sustainability. DF