{"id":66563,"date":"2026-01-15T13:50:39","date_gmt":"2026-01-15T12:50:39","guid":{"rendered":"https:\/\/www.hiperbaric.com\/?p=66563"},"modified":"2026-02-26T12:19:47","modified_gmt":"2026-02-26T11:19:47","slug":"high-pressure-processing-hpp-for-milk-preservation-safety-shelf-life-and-raw%e2%80%91like-quality","status":"publish","type":"post","link":"https:\/\/www.hiperbaric.com\/en\/high-pressure-processing-hpp-for-milk-preservation-safety-shelf-life-and-raw%e2%80%91like-quality\/","title":{"rendered":"High-Pressure Processing (HPP) for Milk Preservation: Safety, Shelf Life, and Raw\u2011Like Quality"},"content":{"rendered":"

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Milk is one of the most nutrient-dense everyday foods<\/strong>, providing high-quality proteins, minerals, and vitamins. Yet, when consumed raw, it can also carry biological hazards<\/strong>, with outbreaks historically linked to pathogens such as Listeria monocytogenes<\/em>, Salmonella<\/em> spp., Campylobacter<\/em> spp., and Shiga toxin-producing Escherichia coli<\/em> (STEC).<\/p>\n

For over a century, the dairy industry has relied on thermal pasteurization<\/strong> to ensure safety, but heat can also drive quality trade-offs and contribute to sensory alterations.\u00a0 This is why emerging nonthermal technologies are gaining momentum. Among them, High-Pressure Processing (HPP)<\/strong> stands out as a promising route to reduce microbial risk while preserving a more raw-like sensory profile and much of milk\u2019s nutritional value. Turning that promise into routine commercial practice, however, still depends on meeting regulatory expectations for validation and verification.<\/p>\n

Milk and Nutritional Properties<\/h2>\n

Recent data in raw cow milk suggest that nutritional value can be largely preserved<\/strong> immediately after HPP, with vitamins and minerals remaining comparable to untreated milk under intense conditions (6000 bar\/87 kpsi, 10 min) (Figure 1)<\/strong>. Importantly, vitamin stability is still governed by storage: some vitamins (A, B3, B5, B6, C) decline gradually over refrigerated storage after HPP, but untreated raw milk can degrade even faster.<\/p>\n

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Figure 1<\/strong>. Vitamin and mineral concentrations in raw vs HPP milk (Lim et al. 2023)<\/a><\/figcaption><\/figure>\n

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The Potential of HPP to Inactivate Pathogens and Ensure Safety<\/h2>\n

Raw milk safety remains a public-health concern. A US analysis (2013\u20132018) reported around 75 outbreaks<\/strong> linked to raw milk, with most occurring where sales were permitted, especially where retail sale was allowed (Koski et al. 2022)<\/a>.<\/p>\n

Multiple challenge studies indicate that HPP at 6000 bar (87 kpsi) can deliver several log reductions of key vegetative pathogens, including L. monocytogenes<\/em>, Salmonella<\/em> spp., and E. coli<\/em> (Figure 2)<\/strong>. However, a recurring limitation in published research is that post\u2011process pathogen evolution during storage is often not monitored, and some studies use UHT milk for inoculation, which may not fully represent raw milk behavior.<\/p>\n

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Figure 2.<\/strong> Pathogen inactivation in raw milk (Stratakos et al. 2019)<\/a><\/figcaption><\/figure>\n

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HPP may also help address emerging hazards such as avian influenza. While its effectiveness against H5N1 in milk remains uncertain, results for other subtypes (e.g., H7N7) in other matrices suggest that sufficiently intense pressure treatments can markedly reduce viral titers (Isbarn et al. 2007).<\/a><\/p>\n

The Potential of HPP to Extend Shelf Life by Controlling Spoilage Microorganisms<\/h2>\n

Beyond safety, HPP can meaningfully reduce spoilage microbiota in milk. For example, 6000 bar (87 kpsi) for 3 min achieved a 4 log reduction of total viable counts and >2.7 log reduction of Enterobacteriaceae<\/em>, followed by delayed growth under refrigeration compared with untreated milk, which extended shelf life up to 21 days under refrigeration (Figure 3).<\/strong><\/p>\n

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Figure 3<\/strong>. Evolution of total viable counts in raw milk after HPP (Stratakos et al. 2019)<\/a><\/figcaption><\/figure>\n

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Across studies, shelf life outcomes vary with conditions and initial microbiota, but reports include:<\/p>\n