1. Why pressure alone cannot select a process

High-pressure processing (HPP) transfers hydrostatic pressure through a liquid medium. Read acidity, composition, target organism, pressure, hold time, temperature and subsequent storage together. Copying a pressure/time combination to another product cannot guarantee the same result.

2. What the juice experiment lets you compare

Cheng, Usaga and Worobo inoculated apple, orange and white grape juices with E. coli O157:H7, Salmonella and Listeria. Original pH values were 3.7, 3.7 and 3.4. Treatment at 550 MPa for one minute at 5°C produced more than a 5-log reduction of all three pathogens immediately in original-pH juices.

Samples with increased pH did not necessarily respond the same way at that pressure. For example, the paper reports Salmonella reduction in orange juice at pH 5.00 below the required 5-log level. If added ingredients change a new product's acidity, the successful original-juice result cannot simply be transferred. This interprets an experimental comparison; it is not a manufacturing recipe.

3. Relating 5-log reduction to storage safety

A 5-log reduction means reducing the target count to one hundred-thousandth, not eliminating every microorganism. Hypothetically, 1,000,000 becoming 10 is 5-log. These illustrative numbers are not product validation.

21 CFR 120.24(a) requires covered US juice processors to include HACCP controls consistently producing at least a 5-log reduction in the pertinent microorganism for at least the product's shelf life under normal and moderate abuse conditions. The provision also specifies exemptions. Section F of FDA's Q&A explains the pertinent pathogen and identifies HPP as one possible control measure. Distinguish immediate from storage results and review changes in formulation, packaging and storage.

4. Reading a consumer label

EFSA's explanation of its 2022 assessment describes the importance of food- and pathogen-specific time/pressure combinations. It is not certification of every HPP product. The term nonthermal alone does not establish perfect nutrient, color or flavor retention or long ambient storage. Follow the product's refrigeration and use-by instructions.

5. Sources

Cheng et al.: inoculated juice/pH comparisons. FDA: US Juice HACCP performance requirements. EFSA: institutional explanation of safety and efficacy assessment. These sources have different scopes.