High pressure processing for food safety.

TLDR

High‑pressure processing is a promising, non‑thermal food preservation method that can extend shelf life, preserve nutrition, and maintain organoleptic qualities, but its effectiveness depends on pressure level, temperature, duration, microorganism type, and food matrix. The study investigates the effect of high pressure on the survival of Listeria monocytogenes, Aeromonas hydrophila, and Enterococcus hirae in cooked ham, ripening hard cheese, and fruit juices. The authors applied high‑pressure treatments to artificially contaminated samples of these foods and measured bacterial survival. High pressure reduced the counts of the tested pathogens proportionally to pressure and treatment time, with both factors having a statistically significant effect.

Abstract

Food preservation using high pressure is a promising technique in food industry as it offers numerous opportunities for developing new foods with extended shelf-life, high nutritional value and excellent organoleptic characteristics. High pressure is an alternative to thermal processing. The resistance of microorganisms to pressure varies considerably depending on the pressure range applied, temperature and treatment duration, and type of microorganism. Generally, Gram-positive bacteria are more resistant to pressure than Gram-negative bacteria, moulds and yeasts; the most resistant are bacterial spores. The nature of the food is also important, as it may contain substances which protect the microorganism from high pressure. This article presents results of our studies involving the effect of high pressure on survival of some pathogenic bacteria -- Listeria monocytogenes, Aeromonas hydrophila and Enterococcus hirae -- in artificially contaminated cooked ham, ripening hard cheese and fruit juices. The results indicate that in samples of investigated foods the number of these microorganisms decreased proportionally to the pressure used and the duration of treatment, and the effect of these two factors was statistically significant (level of probability, P