Cheese is a nutrient‑dense food that concentrates high‑quality proteins, calcium and phosphorus, and fat‑soluble vitamins such as vitamin D, while offering a remarkable range of textures and flavors shaped by milk composition, starter cultures, and ripening. Its value goes beyond nutrition: cheese is strongly tied to tradition, regional identity, and economic relevance, with many protected or heritage varieties relying on unique characteristics and manufacturing practices.
Despite its long tradition, cheese is not immune to microbiological spoilage and food safety hazards, especially when contamination occurs after curd formation or during handling and packaging. Recent market events in the United States highlight a global risk:
- In 2024, there were six market recalls and two foodborne outbreaks with 37 hospitalizations and 2 deaths linked to cheese consumption.
- In 2025, an increase in market recalls was reported, rising to eight.
The presence or potential presence of pathogens such as Listeria monocytogenes, enterohaemorrhagic Escherichia coli, or Salmonella spp. was behind these outbreaks and market recalls. Against this backdrop, High‑Pressure Processing (HPP) has emerged as a practical, nonthermal intervention to improve safety and stability while helping preserve the sensory traits consumers associate with “fresh” or traditionally crafted products.
HPP to Ensure Food Safety
HPP improves cheese safety mainly by inactivating vegetative pathogens in the packaged product, reducing risk from post‑packaging contamination. In fresh, high‑moisture cheeses, this is especially relevant for L. monocytogenes, which can persist and grow under refrigeration.
- For example, in a commercial starter‑free fresh cheese, Evert‑Arriagada et al. (2018) evaluated monocytogenes at 6000 bar (87 kpsi) for 5 min and reported a 4.4 log10 reduction following HPP treatment.
- In Queso Fresco, Tomasula et al. (2014) found that processing at 6000 bar (87 kpsi) for 3 min achieved a 3 and 4.1 log10 reduction of L. monocytogenes when the curd and the surface of the final cheese were artificially inoculated with the pathogen, respectively (Figure 1).
- Studies on raw-milk ripened cheeses produced with milk deliberately inoculated with coli and L. monocytogenes demonstrated that processing at 5000 bar (72.5 kpsi) for 5 min, following 50 days of ripening, resulted in a reduction of both pathogens by 5 to 6 log₁₀ (Arqués et al. 2005; Rodríguez et al. 2005).
HPP to Extend Shelf Life
Shelf life in cheese is often limited by spoilage yeasts and molds, growth of residual bacteria, and defects such as gas formation (i.e. late blowing) or off‑odors. Multiple studies show HPP can delay these outcomes by reducing spoilage populations and, in some products, slowing biological activity during refrigerated storage.
- Fresh lactic curd cheese made from pasteurized cow’s milk was treated at 6000 bar (87 kpsi) for 5 min, resulting in a reduction of the starter culture (Lactococcus) by more than 6 log10 (Daryaei et al. 2008). HPP stopped yeast growth for up to 60 days in cold storage, while untreated cheese had over 5 log10 CFU/g after just 20 days.
- For fresh goat’s milk cheese inoculated with coli, Capellas et al. (1996) found that no surviving E. coli (>8 log10 reduction) was detected at 15, 30, or 60 days after HPP at 5000 bar (72 kpsi) for 5 min, and that aerobic mesophilic counts remained in the 2-3 log CFU/g range.
- Queso Fresco made from pasteurized cow’s milk subjected to 6000 bar (87 kpsi) for 3 min achieved a shelf life of up to 84 days at 4 °C (39 °F), whereas unprocessed controls reached an aerobic mesophile concentration of more than 5 log10 CFU/g after 54 days. Therefore, HPP extended the shelf life by 50% (Figure 2) (Tomasula et al. 2014).
- In semi‑hard industrial cheeses artificially inoculated with Clostridium tyrobutyricum, Ávila et al. (2016) reported that processing at 3000 bar (43.5 kpsi) for 10 min prevented late blowing symptoms, with organic acid and volatile profiles comparable to controls.
Potential New Applications: When Tradition Meets Innovation
Beyond preservation, HPP can be used to treat milk before cheesemaking to modify protein interactions and improve curd formation and moisture retention, potentially increasing yield while maintaining desirable sensory traits.
- Voigt et (2010) manufactured Cheddar from whole milk treated at 4000 or 6000 bar (58 to 87 kpsi) for 10 min and reported yield increases of 1.2% (4000 bar / 58 kpsi) and 7.8% (6000 bar / 87 kpsi) alongside increased incorporation of β‑lactoglobulin into the curd, indicating that pressure‑induced whey protein/casein interactions can contribute to higher moisture (Figure 3).
- In fresh cheese production, Molina et al (2000) found that using milk treated with both heat pasteurization (65 °C / 149 °F for 30 min) and HPP (4000 bar / 85 kpsi for 15 min) increased cheese yield by 20% over heat pasteurization alone, with better coagulation and texture also noted.
Moreover, as highlighted by Nuñez et al. (2020) in a comprehensive review, HPP can be used as a ripening modulator:
- Mild pressures (2000-4000 bar / 28-58 kpsi), especially when applied early on fresh and young cheeses, tend to promote faster ripening biochemistry by enzyme release and restructuring proteins.
- More intense pressure levels (>5000 bar / >72.5 kpsi), particularly when applied later, tend to slow over‑ripening by suppressing microorganisms and inactivating key enzymes.
These findings suggest that HPP can serve not only as a post‑packaging safety and shelf‑life tool, but also as a process lever to improve efficiency, support product innovation, and develop new texture and flavor profiles, although the effects can vary with cheese type, enzymes involved, and microorganisms present.
Conclusions
Across cheese styles, HPP demonstrates strong potential to enhance food safety by inactivating pathogens. It also supports shelf‑life extension by controlling spoilage microorganisms and mitigating defects like late blowing when applied appropriately. Finally, when applied to milk prior to cheesemaking, HPP can drive yield improvements through protein interactions and moisture retention. This opens innovation opportunities without relying on high‑temperature treatments, which aligns with the demand for improved sensory and nutritional quality.
