Combined use of high pressure and salt or sodium nitrite to control the growth of endogenous microflora in raw pork meat

International audienceThe interaction of high pressure (up to 500 MPa at 20 degrees C for 6 min) with sodium chloride (0%-3%) or sodium nitrite (0 mg/kg-100 mg/kg) on the outgrowth of four endogenous flora of pork meat was investigated during storage after a cold-chain break. First, the effect of high pressure was investigated. Next, high-pressure treatments at 350 MPa were combined with the addition of salt or sodium nitrite. Interesting results were observed for the lactic acid bacteria of the salted samples. Whereas salt or 350 MPa processing alone was not sufficient to delay the growth of these bacteria until the end of storage, the combination treatment resulted in low microbial counts (below 2 log CFU/g) at the end of storage. The results of this study suggest the existence of a synergy between salt and high pressure that could result from pressure sensitization of bacterial cells. Industrial Relevance: Meat products must contain enough hurdles to inhibit the growth of pathogenic or spoilage microorganisms. The existence of synergy between high pressure and salt or nitrite is promising for the manufacture of meat products. In fact, the use of high-pressure processing could be an approach to limit the addition of salt and nitrite while ensuring extended shelf life, as consumers demand simpler and healthier formulations. (C) 2012 Elsevier Ltd. All rights reserved

Hautes pressions et sel : impact sur la qualité technologique et microbiologique de la viande de porc

Une étude, menée conjointement par le CTCPA et les UMR GEPEA et SECALIM d’ONIRIS, s’est intéressée à la caractérisation de l’effet des hautes pressions hydrostatiques sur la viande de porc, en combinaison avec le sel. L’intérêt était d’évaluer le potentiel de ce procédé innovant pour diminuer l’ajout de sel dans la formulation des produits de la fi lière viande, tout en conservant des caractéristiques organoleptiques optimales

Hautes pressions et sel : impact sur la qualité technologique et microbiologique de la viande de porc

Une étude, menée conjointement par le CTCPA et les UMR GEPEA et SECALIM d’ONIRIS, s’est intéressée à la caractérisation de l’effet des hautes pressions hydrostatiques sur la viande de porc, en combinaison avec le sel. L’intérêt était d’évaluer le potentiel de ce procédé innovant pour diminuer l’ajout de sel dans la formulation des produits de la fi lière viande, tout en conservant des caractéristiques organoleptiques optimales

Combined use of modified atmosphere packaging and high pressure to extend the shelf-life of raw poultry sausage

International audienceThe contribution of modified atmosphere packaging (MAP) in extending the shelf-life of high-pressure treated raw poultry sausages was examined by considering microbial and oxidative stability (TBARs) aspects. Raw poultry sausages packaged under air or modified atmosphere (50% CO2–50% N2) were pressurized at 500 MPa during 5 min at a maximum temperature of 10.5 °C, subsequently allowed to refrigerated storage during 22 days. During storage, samples were tested at time intervals for headspace gas composition, pH, TBARs, Aerobic Mesophilic Counts (AMC) and Lactic Acid Bacteria (LAB) counts. The high pressure treatment could represent an efficient means of extending the microbiological shelf-life, insofar as it reduced and stabilized the AMC and LAB counts. However, the MAP did not further improve the microbial quality. But, still, by limiting lipid oxidation, it remains an essential technology for the control of the organoleptic quality, another important characteristic to consider in shelf-life determinations.Industrial relevanceRaw poultry meat and especially raw ground poultry meat, such as raw poultry sausages are highly perishable.Economic challenges and busier lifestyles have consumers seeking out products with longer and longer shelf-lives. Manufacturers have to respond to this demand by improving processes. The use of alternative preservation techniques such as high hydrostatic pressure represents a promising strategy to enhance the shelf-life of meat products and is preferred by consumers to addition of food additives. Modified atmosphere packaging is largely used to extend the shelf-life of processed meat products. Manufacturers may question the relevance of maintaining MAP while introducing a new step of high pressure treatment in their process. This study showed that MAP significantly reduced lipid oxidation. In that way, MAP remains necessary to maintain organoleptic quality of pressurized raw poultry sausages

Assessment of Salmonella and Listeria monocytogenes level in ready-to-cook poultry meat: Effect of various high pressure treatments and potassium lactate concentrations

International audienceThe objective of this study was to develop a probabilistic model in order to determine the contamination level of Salmonella and Listeria monocytogenes in ready-to-cook poultry meat, after a high pressure (HP) treatment. The model included four steps: i) Reception of raw meat materials, mincing and mixing meat, ii) Partitioning and packaging into 200-g modified atmosphere packs, iii) High pressure treatment of the meat, and iv) Storage in chilled conditions until the end of the shelf-life. The model excluded the cooking step and consumption at consumer's home as cooking practices and heating times are highly variable. The initial contamination level of Salmonella and L. monocytogenes was determined using data collected in meat primary processing plants. The effect of HP treatment and potassium lactate on microbial reduction was assessed in minced meat, using a full factorial design with three high pressure treatments (200, 350 and 500 MPa), three holding times (2, 8 and 14 min) and two potassium lactate concentrations (0 or 1.8% w/w). The inactivation curves fitted with a Weibull model highlighted that the inactivation rate was significantly dependent on the HP treatment. From the literature, it was established that Salmonella was not able to grow in the presence of lactate, under modified atmosphere and chilled conditions whereas the growth of L. monocytogenes was determined using an existing model validated in poultry (available in Seafood Spoilage and Safety Predictor software, V. 3.1).Once implemented in the Excel add-in @Risk, the model was run using Monte Carlo simulation. The probability distribution of contamination levels was determined for various scenarios. For an average scenario such as an HP treatment of 350 MPa for 8 min, of 200 g minced meat containing 1.8% lactate (pH 6.1; aw 0.96), conditioned under 50% CO2, the prevalence rate of Salmonella and L. monocytogenes, after a 20-day storage at 6 °C was estimated to be 4.1% and 7.1%, respectively. The contamination level was low considering that the product is going to be cooked by the consumer afterwards: the 99th percentile of the distribution was equal to − 2.3 log cfu/g for Salmonella and 0.5 log cfu/g for L. monocytogenes. More generally, the model developed here from raw material reception up to the end of the shelf-life enables to recommend combinations of HP treatment and lactate formulation to guarantee an acceptable microbial concentration before cooking

Traitements par hautes pressions hydrostatiques des denrées alimentaires : état de l’art

National audienceHigh Pressure has traditionally been used for many years in the fields of geology and chemistry. This technique was first applied in the food industry, in Japan, in the late 1980s. This technology, also named pascalization, consists in maintaining the product at very high hydrostatic pressure (100-1000 MPa) for a definite time and temperature. The high hydrostatic pressure treatment is considered as a nonthermal process capable of inactivating and eliminating pathogenic and food spoilage microorganisms. This novel technology has great potential improving food safety and extending food products shelf-life while preserving their organoleptic properties. Today, more than 160 industrial vessels are under work and more and more high-pressure-treated products are available in the market. In this paper, effects of high hydrostatic pressure treatment on food constituents and microorganisms are reviewed.L’utilisation de la pression, bien connue dans le monde de la géologie, de la géochimie et de la chimie, a fait son apparition dans les Industries Agro-Alimentaires il y a moins d’une vingtaine d’années en Europe. Le traitement d’aliments par Hautes Pressions Hydrostatiques (HPH), quelquefois dénommé Pascalisation, connaît aujourd’hui un fort et constant développement partout dans le monde. De cette période initiale pionnière, au début des années 1990, à l’existence aujourd’hui de plus de 160 installations industrielles dans le monde et de plus en plus de produits traités par Hautes Pressions Hydrostatiques dans les linéaires de la grande distribution, le chemin parcouru est riche de très nombreuses publications scientifiques ou de vulgarisation s’intéressant le plus souvent aux effets du traitement sur les caractéristiques organoleptiques et technologiques des aliments ou sur les microorganismes d’intérêt. Il nous semble nécessaire et utile, aujourd’hui, d’effectuer une synthèse bibliographique sur ces deux principaux sujets