High pressure processing for food safety.

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

High Hydrostatic Pressure Processing of Cheese

“…Ding and others (2001) observed that higher pressure conditions (345 and 550 MPa) and longer exposure times (10 and 30 min) achieved a greater reduction in numbers of undesirable bacteria in the natural microflora of Swiss cheese slurries (coliforms, presumptive coagulase‐positive Staphylococcus , yeasts, and molds) and in starter LAB added to milk for acid production and flavor development. Fonberg‐Broczek and others (2005) found that A. hydrophila strains (Państwowy Instytut Weterynaryjny N.98, Państwowy Inspekcja Sanitarna N. 98, Inspekcja Sanitarna N. 95) in samples of Gouda cheese treated at 100 MPa and 50 °C had a D‐value of 32.05 min, while at 200 MPa the D‐value fell to 12.97 min, and to 2.43 min when subjected to 300 MPa. More recently, in raw milk Cheddar cheese, an increase in pressure intensity from 250 to 350 MPa applied at 25 °C resulted in a decrease of D‐values from 23.5 to 1.4 min for L. monocytogenes Scott A (Shao and others 2007).…”

Effect of High Pressure on Selected Properties and Shelf-Life of Poultry Burgers

“…Formy wegetatywne drobnoustrojów są bardziej wrażliwe na działanie wysokiego ciśnienia, natomiast przetrwalniki można zniszczyć tylko w fazie kiełkowania lub stosując bardzo wysokie ciśnienie (powyżej 800 MPa) i ewentualnie podwyższoną temperaturę, co jest opisywane w piśmiennictwie. Szczególnie podkreślana jest skuteczność stosowania HPP jako procesu zapewniającego eliminację z mięsa i jego produktów bakterii z rodzaju: Salmonella, Campylobacter jejuni, Listeria monocytogenes, a także Aeromonas hydrophila [1,2,4,11,28].…”

Advanced Methods for the Elimination of Microorganisms in Industrial Treatments: Potential Applicability to Wastewater Reuse

“…However, it has certain limitations because it is only possible to use it in batch and/or semi-continuous processes (Hayashi, 1989;Vachon et al, 2002). Fonberg-Broczek et al (2005) reviewed the high-pressure processing for food safety. High pressure is a viable alternative to thermal processing.…”