Development of a technology for lactoferrin stabilization with iron ions in a high-efficiency spray drying process

How to preserve the biological activity of lactoferrin during industrial processing?

Lactoferrin is a milk protein with proven immune-boosting and infection-fighting properties. For these reasons, it is widely used as a dietary supplement and added to infant formulas. However, processing lactoferrin isolated from bovine milk often causes it to lose its biological activity - like any protein, it easily undergoes denaturation, primarily due to high temperatures. Dr. Oleksandra Pryshchepa from the Interdisciplinary Centre for Modern Technologies at the Nicolaus Copernicus University in Toruń has found a way to preserve the biological activity of lactoferrin during high-efficiency spray drying. This method is significantly cheaper than freeze-drying (lyophilization), making it far more attractive to industry partners. Under a Proof of Concept grant funded by the European Funds for a Modern Economy 2021–2027 (FENG) through the Foundation for Polish Science, the researcher from Toruń is fine-tuning her lactoferrin stabilization technology.

Lactoferrin is a protein naturally produced by the human body. It is one of the most vital functional proteins, possessing substantial therapeutic potential. It exhibits antibacterial properties (by binding iron, an element essential for bacterial growth, thereby inhibiting their proliferation) and antiviral effects (by interfering with a virus's ability to bind to host cells). Furthermore, it supports the development of the gut microbiome and the immune system - making it especially critical for infants - and regulates iron absorption in the intestine, which is particularly important for individuals with iron-deficiency anemia. Naturally, lactoferrin occurs in saliva, cerebrospinal fluid, bile, and above all, human breast milk. Slightly lower quantities of lactoferrin are present in bovine milk; notably, human and bovine lactoferrin share high structural similarity. Consequently, bovine lactoferrin is utilized to manufacture dietary supplements and medical nutrition products. Lactoferrin is considered well-tolerated and safe, rarely causing adverse effects.

"The key challenge when processing bovine milk-derived lactoferrin through methods such as lyophilization or spray drying is retaining its biological activity. High temperatures trigger protein denaturation - an irreversible destruction of its three-dimensional structure - leading to a loss of biological function. While the lactoferrin remains a nutritional component, it loses the specific bioactive properties for which it is most valued. However, we know that lactoferrin exists in two forms that differ in their susceptibility to thermal denaturation. Apolactoferrin (the iron-free form) denatures at approximately 60°C, whereas hololactoferrin (the iron-bound form) exhibits greater stability, withstanding temperatures up to roughly 90°C. This demonstrates that binding with iron stabilizes lactoferrin. Hence, our concept involves not only saturating existing iron-binding sites in naturally unsaturated lactoferrin, but also inducing additional iron-binding sites within the protein molecule. Packing it more densely with iron ions enhances its thermal resistance during industrial processing," says Dr. Oleksandra Pryshchepa. The researcher has already demonstrated that generating new iron-binding sites within the lactoferrin molecule is achievable by treating it with non-toxic salts, such as citrate.

Ongoing research into creating new iron-binding sites opens up new avenues for designing stable forms of lactoferrin that can be more broadly integrated into the food, pharmaceutical, and medical industries. Such stabilization allows lactoferrin to undergo more demanding processing techniques, including spray drying, without forfeiting its biological activity.

"Spray drying is substantially cheaper than freeze-drying, making it the preferred method across many industrial settings, particularly for large-scale production. Nevertheless, the main challenge in spray drying is maintaining the biological activity of proteins like lactoferrin due to the higher temperatures involved and the elevated risk of denaturation. If our method of stabilizing lactoferrin with iron ions proves successful, it will allow high biological activity to be preserved within this more cost-effective technology, serving as a highly attractive solution for manufacturers," notes Dr. Pryshchepa.

Dr. Oleksandra Pryshchepa earned her PhD in Chemical Sciences from Nicolaus Copernicus University in Toruń in 2023. She previously completed a Master's degree in Cosmetic Chemistry at NCU and a Master's degree in Chemistry at the National University of Kyiv-Mohyla Academy in Kyiv. She currently works as an Assistant Professor at the Interdisciplinary Centre for Modern Technologies at NCU in Toruń, carrying out research projects funded by NCN (National Science Centre), NCBiR (National Centre for Research and Development), and FNP (Foundation for Polish Science). She brings extensive laboratory experience from both research and industrial settings in Poland and abroad, including Ukraine, Spain, and Norway. Her track record includes participation in numerous scientific conferences and active collaboration with industry, particularly the dairy sector. Authoring multiple publications in reputable scientific journals, her research focuses on isolation and modification methods for milk proteins with a special emphasis on lactoferrin, d-metal and small-molecule protein modifications, and the creation of protein-silica nanobiocomposites for potential applications in the food, pharmaceutical, and cosmetic industries.