The increasing demand for lactose-free milk has given rise to an innovative development by the Shinshu University’s Global Aqua Innovation Centre, investigating the potential application of graphene oxide membranes in this industry. Often studied for water desalination and dye separation, the use of these membranes as a filtration mechanism in the food industry has recently been explored. This article will explore this innovative approach and its potential to revolutionize the food industry’s response to a rising population of lactose intolerance.
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Vijay Sarathi, a lead analyst for food and beverage research within Technavio has outlined the definition of lactose intolerance as the “inability of the body to digest significant amounts of lactose present in milk.” and notes that "lactose intolerance is seen in approximately 90% of adults in East Asia".
The highly digestible nature of lactose-free products makes them a promising healthy substitute for dairy, even for those with lactose sensitivities rather than a complete intolerance. For this reason, lactose-free products are predicted to be on the rise.
The demand for lactose-free food products is driven by the increase in incidences of food allergies and intolerances. The sales of lactose-free products in the US [is] expected to double during the 2016-2020 period and reach revenues worth $700 million.
Vijay Sarathi, Lead Analyst for Food and Beverage Research, Technavio
To develop a promising milk substitute, a research group in Shinshu University’s Global Aqua Innovation Centre, led by Aaron Morelos-Gomez has investigated the use of graphene oxide membranes for milk filtration. The team's research was recently published in the Carbon journal.
Membrane filtration is a separation process that separates a liquid into two streams through a semi-permeable membrane. Different pore sizes allow the separation of specific components of milk and whey, such as lactose. Membrane filtration can be divided into four main types of technology: microfiltration, ultrafiltration, nanofiltration, and reverse osmosis.
Nanofiltration, for instance, uses medium to high pressure and is a type of reverse osmosis with a slightly more open structured membrane. This enables mostly monovalent ions to pass through the membrane, with the entry of divalent ions and lactose rejected by the membrane.
Graphene Oxide Membranes for Lactose Filtration
Graphene oxide membranes can create a porous foulant layer, enabling their characteristic for filtration to be maintained more effectively than commercial polymeric membranes. As graphene is a novel material with a monolayer of carbon atoms bound tightly in the shape of a hexagonal lattice and having a unique chemical and laminar structure, the membrane it forms provides effective filtration.
Enhanced permeation of lactose and water is also enabled, alongside the effective rejection of fat, proteins, and some minerals. Due to this, many differences ensure the value of filtered milk from this method, such as the texture, flavor, and nutritional value which are preserved more efficiently when compared to commercial polymer membranes.
This novel filtration method enables the concentration of lactose and the lactose permeate flux to be significantly higher than the commercial nanofiltration membranes that are currently available due to the porous foulant layer and the unique characteristic of the laminar structure held by the graphene oxide membrane.
The researchers were able to improve the porosity of the fouling layer by using a support membrane with a pore size of 1 μm. As a result, the graphene oxide membrane had an enhanced porous fouling layer, enabling a higher recovery of water flux post-filtration in milk.
With a rising population of lactose intolerance globally, there has become a higher demand for innovative approaches to create lactose-free products. Graphene oxide filtration increases the nutritional value of products due to its ability to preserve other ingredients and remove unwanted sugars. This allows the lactose-intolerant population to experience the nutrients from milk beverages without suffering from digestion difficulties.
The pioneering research by the Shinshu University’s team has illustrated the advantages of using graphene oxide membranes for milk filtration to produce lactose-free milk. The benefits of the antifouling abilities of this technology and the enhanced selectivity for lactose are significant applications for the growing lactose-free market.
This research can also be applied to other sectors. Graphene oxide filtration can be used as a mechanism to treat wastewater and within the medical field.
References and Further Reading
Morelos-Gomez, A., Terashima, S., Yamanaka, A., Cruz-Silva, R., Ortiz-Medina, J., Sánchez-Salas, R., Fajardo-Díaz, J., Muñoz-Sandoval, E., López-Urías, F., Takeuchi, K., Tejima, S., Terrones, M. and Endo, M., (2021). Graphene oxide membranes for lactose-free milk. Carbon, 181, pp.118-129. Available at: https://doi.org/10.1016/j.carbon.2021.05.005
Gea.com. (2021). Membrane filtration in the dairy industry. [online] Available at: https://www.gea.com/en/binaries/membrane-filtration-in-dairy-industry_tcm11-17109.pdf [Accessed 2 August 2021].
Phys.org. (2021). Developing lactose-free milk with graphene oxide based nano filtration membranes. [online] Available at: https://phys.org/news/2021-07-lactose-free-graphene-oxide-based-nano.html [Accessed 2 August 2021].
WIRE, B., 2021. Rising Levels of Lactose Intolerance Predicted to Propel the Global Lactose Free Food Market Until 2020, Says Technavio. [online] Businesswire.com. Available at: https://www.businesswire.com/news/home/20160504005106/en/Rising-Levels-Lactose-Intolerance-Predicted-Propel-Global [Accessed 2 August 2021].