Effect Of High Pressure Treatment Research Articles

Effect of high pressure treatment on the aging characteristics of Chinese liquor as evaluated by electronic nose and chemical analysis.

Several high pressure (HP) treatments (100–400 MPa; 15 and 30 min) were applied to Chinese “Junchang” liquor, and aging characteristics of the liquor were evaluated. Results from the principal component analysis and the discriminant factor analysis of E-Nose demonstrated that HP treatment at 300 and 400 MPa resulted in significant (p < 0.05) changes in aroma components of the liquor. An increase in total ester content and a decrease in total acid content were observed for all treated samples (p < 0.05), which was verified by gas chromatography analysis. In addition, a slight decrease in alcohol content was found for HP treatment at 400 MPa for 30 min. These changes and trends were in accordance with the natural aging process of Chinese liquor. However, HP treatment caused a slight increase in solid content, which might be somewhat undesirable. Sensory evaluation results confirmed that favorable changes in color and flavor of Chinese liquor were induced by HP treatment; however, overall gaps still existed between the quality of treated and six-year aged samples. HP treatment demonstrated a potential to accelerate the natural aging process for Chinese liquor, but long term studies may be needed further to realize the full potential.

Quality changes in high pressure processed cod, salmon and mackerel during storage

High pressure (HP) treatments inhibit spoilage and thereby increase the shelf life of fresh fish. However, studies comparing the effect on the biochemical changes in different fish species are lacking. The current study investigated the effect of HP treatments at 200 and 500 MPa for 120 sec. (8-days on texture, liquid loss, water holding capacity and protein denaturation in cod, mackerel and salmon. At 500 MPa hardness increased,and the fish became lighter and less red in all species. Severe protein denaturation was induced by HP treatment in all species. It was concluded that the effect on the measured quality parameters were not much affected by fish species, which suggests that HP induced changes in structural proteins and thereby affects only parameters like texture, lightness and water holding capacity, and do not depend on amounts of fat or the muscle composition.

Effects of High-Pressure Treatment on Functional, Rheological, Thermal and Structural Properties of Thai Jasmine Rice Flour Dispersion

Effect of high-pressure (300–600 MPa) and flour to water (F/W) ratio (1:1-1:4) on functional, rheological, thermal and structural properties of Thai Jasmine rice flour were investigated. Water holding capacity and water solubility index of high-pressure-treated rice samples increased linearly with pressure intensity. Pressure treatment significantly influenced the particle size distribution of flour. Thermal transitions and the mechanical property of pressure-treated samples were measured by DSC and rheometry, respectively. Starch gelatinization of rice flour is affected by both applied pressure and F/W ratio. The mechanical rigidity G′ of rice flour decreased with increasing F/W ratio and increased with the pressure level. The peak viscosity, hot paste viscosity and final viscosity decreased significantly with increasing pressure intensity. Fourier-transform infrared (FTIR) spectroscopy showed changes in the secondary structure of rice proteins and the sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) showed changes in the protein subunits that occurred after the pressure treatment. Practical Applications High pressure is a novel processing technology that transforms sol to gel and produces a desirable gel which is relatively softer than the thermal gel. Rice flour is currently studied extensively for development of food products for celiacs and an increasing demand from Asian consumers' for preparation of ethnic foods. Therefore, an application of pressure as a processing method to improve the quality of rice starch products would be possible.

Effect of High Pressure Treatment and Degree of Milling on Gelatinization and Structural Properties of Brown Rice

Brown rice (BR), medium-milled rice (MR), and fully milled white rice (WR), with different degrees of milling (DOM), 0, 6.6, and 10.4 %, respectively, were high pressure (HP) treated at 200 to 500 MPa for 5 to 15 min. Water absorption, swelling, and gelatinization properties, and microstructural changes were investigated. HP treatment (≥200 MPa) or partial milling (DOM 6.6 %) resulted in water absorption comparable with that of white rice. Swelling behavior was affected by milling and processing temperature. Both HP treatment and milling promoted gelatinization properties. In addition, partial milling reduced the pressure resistance of rice grain, while differences in water absorption, swelling behavior, and gelatinization properties due to milling were reduced by HP treatment. Further, the degree of gelatinization (DG) increased with HP treatment with 400 MPa and 10 min defined as the threshold values for pressure and holding time, respectively. DG values, observed with 400 MPa-10 min treatments, were 41.2, 50.2, and 39.9 %, respectively for BR, MR, and WR. Results demonstrated that HP treatment, combined with milling, is technically feasible and produces rice and rice flour with enhanced DG and swelling behavior. These basic data can be used to improve the processing efficiency and quality of brown rice-based product.

Effect of high-pressure treatment on the structural and rheological properties of resistant corn starch/locust bean gum mixtures

In this study, effects of a 30min high pressure (HP) treatment (200–600MPa) at room temperature on the rheological, thermal and morphological properties of resistant corn starch (RS) (5% w/w) and locust bean gum (LBG) (0.25, 0.50 and 1.0% w/v) dispersions were evaluated. Results showed that the storage modulus (G′), loss modulus (G′′), and apparent viscosity values of starch/gum (RS/LBG) mixtures were enhanced with an increase pressure level, and demonstrated a bi-phasic behavior. HP treated RS/LBG samples were predominantly either solid like (G′>G′′) or viscous (G′′>G′), depending on the pressure level and LBG concentrations. Differential scanning calorimetry (DSC) analysis of the pressurized mixtures showed a major effect on gelatinization temperatures (To, Tp,), and it was observed that RS/LBG mixtures gelatinized completely at ≥400MPa with a 30min holding time. Confocal laser scanning microscopy (CLSM) images confirmed that at 600MPa, RS/LBG mixtures retained granular structures and their complete disintegration was not observed even at the endpoint of the gelatinization.

Effect of high pressure treatment on the structural, mechanical and rheological properties of glucomannan gels

The influence of high hydrostatic pressure (HHP) of 100 (C100), 200 (C200), 400 (C400) and 600 MPa (C600) on the structural, physicochemical, and thermo-rheological properties of aqueous glucomannan dispersions (AGD) was studied. Each AGD was prepared with a 5% concentration of deacetylated glucomannan (GM) at pH = 11 for use in the preparation of restructured fish products. The control (0 MPa) AGD (C0) exhibited a partially crystalline GM network with a glass transition temperature (Tg) of ∼75 °C. C0 gels at 25 °C were rigid, with high breaking force (BF), fracture constant (Kf) and complex modulus (G*) and low tanδ values due to the large number of physical junctions produced by complete deacetylation of the GM chains. This structural response was reflected in high water binding capacity (WBC) and colour (L*) and low cooking loss (CL). Specifically, 200 MPa reduced close packing ability in the crystalline regions, evidenced in the lower Tg∼65 °C and resulting in lower gel strength (S), Kf, G* and a higher viscous component (high tanδ), thus reducing the L* value. Conversely, 600 MPa increased the degree of cross-linking in C600, reinforcing the number and extent of crystalline regions, resulting in the broadening of the O–H stretching band in the FT-IR spectrum and producing a thermoset physical network with no glass transition region. Thus, C600 gel was firmer (higher G*) with greater S, and less flexible (lower strain amplitude-γmax). Consequently, depending on the textural properties desired in the final restructured fish product, the most appropriate pressure would be 200 MPa for softer final gels and 600 MPa for firmer and less deformable gels.

Effects of high pressure treatment and EDTA‐2Na on lipid oxidation and color properties of Altay sheep body fat

Autoxidation during storage is one of the major causes of food spoilage that decreases the nutritional quality of food and generates potential toxic products. Oxidation process involves the degradation of PUFAs, vitamins, and other tissue components, which lead to the development of rancid and changes in color and texture of foodstuffs. Investigations to analyze lipid autoxidation products and factors influencing their production suggest that temperature and time for food processing, conditions for transport and storage, other factors including pH, light, oxygen, water activity, or a combination of these factors, and particularly heat processing all contribute to fat autoxidation and fatty acid degradation. Lipid oxidation also was a major problem in the high‐pressure processing and long storage times of Altay sheep fat. The present study investigates the variations in fatty acid composition and lipid oxidation in pressurized Altay sheep fat during storage. The lipid oxidation and composition of fatty acids in Altay sheep body fat, a high‐quality component, after high‐pressure (0.1–600 MPa) and EDTA‐2Na (0.05%) treatment were mainly investigated at 4 °C for up to 20 d. The TBARS values increased with higher pressure treatment (from 0.1 to 600 MPa). Compared with TBARS of 200 MPa at 4 °C, the treatment of 600 MPa at 4 °C+EDTA‐2Na increased the TBARS value. A significant decrease at the end of storage was observed in the PUFA/SFA values for all samples, and larger decrease (p &lt; 0.01) in the PUFA/SFA values under the 600 MPa. The results showed that high pressure significantly affects the PUFA/SFA ratios during storage, which can be a potential method to regulate the PUFA/SFA level.600 MPa treatment produced darker and higher a* value (p &lt; 0.05), and the redness of samples was affected by the pressure level and storage time. Therefore, higher‐pressure and EDTA‐2Na treatment were important in catalyzing lipid oxidation and the evolution of fatty acids from Altay sheep body fat.Support or Funding InformationThis research was supported by the Natural Science Foundations of China (No. 31401559 and No. 31460401).

Effect of high-pressure processing on moisture sorption properties of brown rice

ABSTRACT The effect of high-pressure treatment (0.1 to 500 MPa for 10 min) on the moisture sorption properties of brown rice (Feng Liang You Xiang No. 1) was investigated. Air was maintained at selected conditions (temperature between 20°C and 40°C, equilibrium relative humidity between 11% and 75%) and equilibrium moisture content was measured. The control attained a higher equilibrium moisture content than treated samples, while the 300 MPa treated sample had the lowest. The area of hysteresis of the 300 MPa test sample was the largest and the BET model was applied to determine the monolayer moisture content.

Effect of high-pressure treatment on hard cheese proteolysis

The application of high hydrostatic pressure (HHP) treatment has been proposed to reduce the ripening time of cheese via modifications in the enzymatic activities or the substrate reactivity. Investigations on the effect of HHP on cheese proteolysis have been undertaken with either encouraging results or little effect according to the treatment conditions and the type of cheese, but information concerning the effect of HHP on the ripening of hard cooked cheese is still lacking. In this report, we describe the effect of HHP treatment on Reggianito cheese proteolysis. For that purpose, 1-d-old miniature cheeses (5.5-cm diameter and 6-cm height) were treated at 100 or 400MPa and 20°C for 5 or 10min, and control cheeses in the trial were not pressurized. All cheeses were ripened at 12°C during 90d. The HHP did not affect gross composition of the cheeses, but microbial load changed, especially because the starter culture count was significantly lower at the beginning of the ripening of the cheeses treated at 400MPa than in controls and cheeses treated at 100MPa. Cheeses treated at 400MPa for 10min had significantly higher plasmin activity than did the others; the residual coagulant activity was not affected by HHP. Proteolysis assessment showed that most severe treatments (400MPa) also resulted in cheeses with increased breakdown of αS1- and β-CN. In addition, nitrogen content in soluble fractions was significantly higher in cheeses treated at 400MPa, as well as soluble peptides and free AA production. Peptide profiles and individual and total content of free AA in 60-d-old treated cheese were as high as in fully ripened control cheeses (90d). Holding time had an effect only on pH-4.6-soluble nitrogen fraction and plasmin activity; cheese treated for 10min showed higher values than those treated for 5min, at both levels of pressure assayed. We concluded that HHP treatments at 400MPa applied 1d after cheesemaking increased the rate of proteolysis, leading to an acceleration of the ripening process in Reggianito Argentino cheese, whereas 100-MPa treatments did not lead to significant changes.

The effect of high-pressure treatment on functional components of shrimp ( Litopenaeus vannamei ) cephalothorax

Abstract High-pressure (HP) technology has been applied to extend the shelf life of shrimps by inhibiting enzymes with PPO activity or microorganisms. However, there is very little information on its effect on relevant compounds from a nutritional or functional point of view, such as fatty acids, α-tocopherol, astaxanthin, and hemocyanin, which constitutes the main objective of the present work. Shrimp cephalothoraxes were HP processed at 200, 400, or 600 MPa/18 °C/15 min or three consecutive 5 min cycles. It was found that hemocyanin was partially denatured at pressures up to 400 MPa, resulting in lower PPO activity, and it was totally denatured at 600 MPa, although 20% residual PPO activity remained. Astaxanthin, α-tocopherol, and total antioxidant activity were stable whichever HP treatment was applied, whereas 600 MPa caused a slight reduction of eicosapentaenoic acid (C20:5n3, EPA) and docosahexaenoic acid (C22:6n3, DHA). Despite this reduction, the ω -6/ ω -3 fatty acids ratio was very low (1). Industrial relevance Shrimps are high-value fishery products with a very short shelf life under refrigeration, mainly because of microbial growth and development of melanosis. Thermal treatment is effective for extending shelf life, but it affects the nutritional quality of shrimps through degradation of bioactives such as polyunsaturated fatty acids, tocopherols, or astaxanthin, which are mainly located in the cephalothorax. High pressure is a non-thermal processing technology that has been proved to extend shrimp shelf life, but very little information can be found on its effect on the above-mentioned compounds as well as on the melanosis-inducing hemocyanin. Such basic knowledge is very important for industrial application of high-pressure technology to extend the shelf life of shrimps.

High pressure effect on photosynthetic properties of green plant leaves

We investigated the effects of high pressure treatment on green plant leaves of two species, red rose (Rosa rubiginosa L.) and silver birch male (Betula pendula Roth). Both species were treated with pressure up to 100 bar in order to explore stress reactions, including desirable or undesirable metabolites in plant. When increasing the pressure, chlorophyll (Chl) fluorescence maximum shifts to the wavelength of about 680 nm for both red rose and silver birch, with shift rates–0.062 nm/bar and–0.082 nm/bar, respectively. High pressure induces the changes of the position for the second fluorescence maximum at approximately 730 nm in both species with the same shift rate–0.083 nm/bar. When increasing pressure the change of the photosynthetic apparatus efficiency decreases for both plant species slowly and nonlinearly. High-pressure treatments irreversibly damaged the leaf tissue and at this way induced changes of Chl fluorescence and photosynthetic efficiency.

Effect of high pressure treatment on rapeseed protein microparticle properties and gastrointestinal release behavior of the encapsulated peptides

ABSTRACT This study investigated the high pressure (HP) modifications of rapeseed protein isolate (RPI) to improve its functional properties as wall materials for rapeseed peptides (RPs) microencapsulation by spray-drying. Results indicated that the surface hydrophobicity of HP-treated RPI microparticles was increased at 400 MPa and 5–15 min but decreased when extended to 20 min. Microparticles obtained with HP-treated RPI showed lower spray-drying yield than native RPI microparticles (67 ± 1.0% and 73 ± 1.4% respectively). Conversely, HP-treated RPI (400 MPa, 15 min) formed microparticles that enabled significantly higher encapsulation efficiency of up to 94.7 ± 1.8% (91.4 ± 1.4% for control samples). Morphological characterization indicated that microparticles with 6.1–8.5 μm diameters were spherical without fissures or cracks. Release profiles revealed that the core of microparticles (especially the 400 MPa, 15 min) achieved controlled release without an initial burst when exposed to the simulated intestinal environment; meanwhile they were resistant to gastric release-stimuli, such as extremely low pH and pepsin.

The effects of high-pressure treatments on Campylobacter jejuni in ground poultry products containing polyphosphate additives

Marinades containing polyphosphates have been previously implicated in the enhanced survival of Campylobacter spp. in poultry product exudates. The enhanced Campylobacter survival has been attributed primarily to the ability of some polyphosphates to change the pH of the exudate to one more amenable to Campylobacter. In this study a ground poultry product contaminated with a 6 strain Campylobacter jejuni cocktail was utilized to determine if the efficiency of high-hydrostatic-pressure treatments was negatively impacted by the presence of commonly utilized polyphosphates. Two polyphosphates, hexametaphosphate and sodium tripolyphosphate, used at 2 concentrations, 0.25 and 0.5%, failed to demonstrate any significant negative effects on the efficiency of inactivation of C. jejuni by high-pressure treatment. However, storage at 4°C of the ground poultry samples containing C. jejuni after high-pressure treatment appeared to provide a synergistic effect on Campylobacter inactivation. High-pressure treatment in conjunction with 7 d of storage at 4°C resulted in a mean reduction in C. jejuni survival that was larger than the sum of the individual reductions caused by high pressure or 4°C storage when applied separately.

High-pressure processing of milk alleviates atopic dermatitis in DNCB-induced Balb/c mice

High pressure (HP) is recognized as the alternative process technology of heat treatment in food production. Although milk was the first food product to be treated with HP, the allergenicity of HP-treated milk remains to be elucidated. Thus, this study was conducted to investigate the effects of HP treatment on the alleviation of atopic dermatitis (AD) caused by milk in a mouse model. To investigate the effect of HP treatment on the alleviation of AD, Balb/c mice were fed HP-treated milk orally for 7 days following induction of AD with 1-chloro-2,4-dinitro-benzene (DNCB). Mice fed with HP-treated milk exhibited markedly lower serum IgE level than DNCB-treated mice. These results suggest that HP may be applicable as an alternative process for the development of hypoallergenic milk products.

Effect of high pressure treatment on inactivation of vegetative pathogens and on denaturation of whey proteins in different media

Cell suspensions of Listeria monocytogenes 5366, Staphylococcus aureus 976 and Pseudomonas aeruginosa 110T were exposed to high pressure treatment from 200 to 600 MPa for 5, 10 and 15 min at an initial temperature of 20 °C in raw skimmed bovine milk, whey and phosphate buffer, pH 7.0 in order to determine their degree of inactivation. S. aureus was the most baroresistant bacteria followed by L. monocytogenes and P. aeruginosa. A treatment at 600 MPa for 15 min was needed to obtain a reduction of 7 log10 cycles of S. aureus in all media. This treatment was selected to determine the degree of denaturation of the main whey proteins. Lactoperoxidase activity was not affected by pressure treatment applied to milk, whereas a denaturation of 80%, 70%, 44% and 7% was obtained for β-lactoglobulin, lactoferrin, immunoglobulin G (IgG) and α-lactalbumin, respectively. The effect of the treatment media on denaturation was not noticeable for lactoperoxidase, α-lactalbumin and IgG whereas β-lactoglobulin was more sensitive when treated in milk and lactoferrin in whey. Treatment of milk at 75 °C for 15 s induced a lower denaturation of β-lactoglobulin, lactoferrin and IgG compared to pressure treatment, whereas produced a higher decrease of enzymatic activity of lactoperoxidase.

Application of High-Pressure Treatment to Enhancement of Functional Components in Agricultural Products and Development of Sterilized Foods.

In 1988, the late Prof. Rikimaru Hayashi had first proposed "Use of High Pressure in Food", introducing his views, i.e., "heat and pressure are independently capable of transforming the state of a substance, and such state transforming factors are only heat and pressure in nature." Sc. D. Masaru Nakahara stated in his note that he had been impressed by the unique starting point of Prof. Hayashi's idea. Prof. Hayashi had explored some good method for food processing without using heat, so he alternatively thought of high-pressure treatment (Hayashi R (1989) Use of high pressure to food processing and preservation. In: Hayashi R (ed) Use of high pressure in food. San-Ei Publishing Co, Kyoto, pp 1-30; Nakahara M (1990) Water and ions at high pressure: their fundamental properties relevant to the pressure treatment to food. In: Hayashi R (ed) Pressure-processed food--research and development. San-Ei Publishing Co, Kyoto, pp 3-21). Since the start-up of Japanese research group of high pressure in biological field (the present "Japanese Research Group of High Pressure Bioscience and Biotechnology (JHPBB)") and "International Association of High Pressure Bioscience and Biotechnology (IAHPBB)", we have continued to research into the industrial use of high-pressure treatment over a period of 25 years to realize our dream, that is, the same as Prof. Hayashi's dream. Although heat and pressure were found to be independent factors capable of transforming the state of a substance, use of heat has been overwhelmingly more frequent in food processing up to now. However, the pressure treatment has the advantages of instantaneous transmission, uniform distribution in vessels, and ability of inducing uniform change in quality. The high-pressure treatment does not cause cleavage of the covalent bond in the substance, thereby lessening the decomposition of nutrients, the generation of offensive smell, and the production of abnormal materials when compared with the heat application. In addition, energy consumption in the high-pressure treatment is less than that in the heat treatment. For the reasons mentioned above, the high-pressure treatment has thus been regarded as suitable for future food processing, and much attention has been paid to the researches of high-pressure treatment again. Then, we reviewed the previous researches in which little interest had been taken because of imperfectness of non-heat sterilization. Surprisingly, we discovered some novel findings about the effect of high-pressure treatment, that is, pressure history on the subsequent event. Then, we decided to present two theses on the themes, "Application of High-pressure Treatment to Enhancement of Functional Components in Agricultural Products" and "Application of High-pressure Treatment to Development of Sterilized Foods".

Effect of High Pressure Treatment on Rheological Characteristics of Egg Components

The objective of this study was to evaluate the effect of high pressure treatment on rheological properties of various egg components (i.e., egg white, egg yolk, and whole liquid egg). A five-level central composite design with three independent variables (pressure, 281.8–618.2 MPa; temperature, 8.2–41.8°C; pressure holding time, 1.6–18.4 min) was employed. Samples were packed in plastic pouches, heat sealed, and subjected to pressure treatment in an isostatic press. Shear and time-dependent rheological properties were evaluated using a 3-segment (each 5 min) program with the shear rate initially increasing from zero to 100 s−1 (upward curve), then held at 100 s−1 (hold curve), and finally decreasing from 100 to 0 s−1 (downward curve) using a parallel plate rheometer. Power law model was fitted to the upward (virgin) and downward curves while Weltman time dependency model was fitted for the hold curve (R2 > 0.90). Rheological properties were most significantly affected by pressure followed by holding time and temperature for all egg components. In general, they showed thixotropic shear thinning behavior and reduction in time dependency, which was dependent on the level of processing treatment used (combination of pressure, time, and temperature level). The high pressure treatment resulted in a progressive transition of egg components from flowable liquid-like behavior (218–350 MPa) to semi-viscous (350–500 MPa) to highly-viscous (500–618 MPa) behavior. Rheology-based optimal conditions satisfying HP pasteurization needs were identified.

Effect of high hydrostatic pressure treatments on volatiles of berry purées

High hydrostatic pressure (HHP) technology, as a promising alternative of thermal-treatment and chemical preservatives, can be used to produce minimally processed foods. It has the advantage of affecting only non-covalent bonds of macromolecules in foods, and thus preserves nutritional components, taste, and flavour exceptionally well. However, HHP also influences enzymatic reactions of food. Although some of these changes are often beneficial, monitoring the potential effects of high pressure treatments — especially in the field of product and technology development — is essential. The aim of this study was to point out some parameters of high hydrostatic pressure technique (pressure, temperature, build-up time, holding time, number of cycles) that can substantially impact the sensory properties of treated products.

Effect of high pressure treatment on microbiological quality of Indian white prawn (Fenneropenaeus indicus) during chilled storage

High pressure treatment of 250 MPa for 6 min at 25 °C was applied to headless Indian white prawn (Fenneropenaeus indicus) to evaluate changes in microbiological characteristics of the species during chilled storage. Changes in load of mesophilic bacteria, psychrotrophic bacteria, proteolytic bacteria, Enterobacteriaceae, Pseudomonas spp., H2S producing bacteria, lactic acid bacteria, Brochothrix thermosphacta and yeast & mold were estimated in pressurized and un-pressurized samples during chilled storage. All microbes were reduced significantly after high pressure treatment and there was significant difference in microbial quality of control and high pressure treated samples in the entire duration of chilled storage (p < 0.05). There was delay in the growth of Enterobacteriaceae and H2S producing bacteria up to 6th and 9th day of storage, respectively in high pressure treated samples. In high pressure treated sample, no lag phase (λ) was observed for psychrotrophic bacteria, H2S producing bacteria, B. thermosphacta, Pseudomonas spp. and lactic acid bacteria; however, other bacteria showed a reduced lag phase during chilled storage. Kinetic parameter such as specific growth rate (μmax) in high pressure treated samples was significantly reduced in most of the bacterial groups except for psychrotrophic bacteria, Enterobacteriaceae and lactic acid bacteria. Mesophilic bacterial count of control samples crossed the marginal limit of acceptability on 12th day and unacceptable limit on 18th day of storage, whereas high pressure treated samples never breached the acceptability limit during entire duration of chilled storage. The present study indicated that application of high pressure processing can be used to improve microbial quality of Indian white prawn and extend the chilled storage life.

Effect of high pressure treatment on the characteristics of a model emulsion

The aim of this study was to investigate the use of HP (high pressure) technology as a possible alternative method for decontamination of non-food medium. HP (500 MPa) did not modify significantly the physicochemical characteristics of a model non-food emulsion. A 10 min HP treatment inactivated totally Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Aspergillus niger and Candida albicans even if all the five microorganisms were inoculated together, regardless of the initial load. No recovery was observed until six months of storage at 25°C.