Effect Of High Pressure Treatment Research Articles

Effects of high pressure treatment on the quality of cooked pork ham prepared with different levels of curing ingredients

The aim of this study was to define the effects of high-pressure treatment (600 MPa, 10 min, 20 °C) on the quality of cooked pork ham prepared with two different levels of curing ingredients in brine. Physical, chemical, microbiological, and sensory tests were performed 24 h after high pressure processing (HPP), as well as after 6 and 8 weeks of storage in refrigerator conditions. The results indicate that HPP causes significant improvement of shelf life of vacuum packed ham, including the samples with reduced level of curing ingredients in brine to 8 weeks in refrigerator conditions (4–6 °C). HPP did not have significant effect on the texture or color of ham. However, it significantly increased the drip loss during storage in the packed samples. This may indicate that HPP has negative effects on water holding capacity of cooked products.

Effects of high-pressure treatment on some physicochemical and functional properties of soy protein isolates

The effects of high-pressure (HP) treatment on some physicochemical and functional properties of soy protein isolates (SPI) were investigated. Surface hydrophobicity ( H o), free sulfhydryl (SH) content, differential scanning calorimetry characteristics, protein solubility, emulsifying activities, and heat-induced gelling property were evaluated. HP treatment at 200–600 MPa resulted in a slight but gradual decline in solubility, and a significant ( P<0.05) increase in H o. Free SH content of SPI was significantly ( P<0.05) increased after HP treatment at 200 MPa, but was gradually decreased with further increase in pressure. HP treatment at 200–600 MPa significantly ( P<0.05) increased emulsification activity index, but decreased emulsion stability index. The heat-induced gelling property of SPI was also decreased by HP treatment. The influence of HP treatment on these properties was closely dependent on the protein concentration at which the SPI solutions were HP-treated. These results suggest that HP treatment could be used to modify the properties of soy proteins by appropriate selection of pressure level and protein concentration.

Effect of high-pressure treatment on various starch-in-water suspensions

This study investigated the high-pressure-induced gelatinization of different starches, namely normal rice, waxy rice, normal corn, waxy corn, tapioca and potato starches. The high-pressure-treated starch solutions were characterized by pasting behaviour, degree of swelling and changes in birefringence. Potato starch was found to be less affected by pressure treatment than the other starches, as it retained birefringence after a pressure treatment of 600 MPa for 30 min. Waxy and tapioca starches showed complete gelatinization after the same treatment, whereas normal starches were only partially gelatinized. The pasting curves of the normal starches showed an increase in the initial viscosity after pressure treatment, whereas the initial viscosities of the waxy starches after the 600 MPa for 30 min treatment were already equal to their respective peak viscosities.

Effect of high-pressure treatment on rheological, thermal and structural changes in Basmati rice flour slurry

Rheological, thermal and structural changes in high pressure (HP) treated Basmati rice flour dispersions were studied as function of pressure level (350–650 MPa), slurry concentration (with 1:5, 1:3 and 1:2 flour-to-water ratios) and holding time (7.5–15 min). Rice flour dispersions exhibited a gradual liquid–solid gel transformation as they gelatinized and/or denatured and behaved as viscoelastic fluid following HP treatment. Mechanical strength ( G′) of pressurized gel increased with applied pressure and rice concentration. Differential scanning calorimeter (DSC) thermograms of rice slurry measured after pressure treatment indicated a reduction in peak enthalpy in proportion with the extent of gelatinization and/or denaturation of starch and proteins. Pressure-treated rice samples had a progressively lower gelatinization temperature. A 15 min pressure treatment at 550 MPa was found sufficient to complete gelatinization of protein free isolated rice starch while the slurry required 650 MPa. The presence of proteins might have been responsible for the slower starch gelatinization in the rice slurry during pressure treatment. The sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Fourier-transform infrared (FTIR) spectroscopy results indicated some minor changes in protein subunits and secondary structure of rice protein. This study has provided complementary information on pressure-induced changes in physical (thermal stability, overall structure) and molecular level (secondary structure) of rice protein.

Influence of high pressure processing on the linear viscoelastic properties of egg yolk dispersions

The effect of high-pressure treatments on the gelation of egg yolk dispersions was studied by using differential scanning calorimetry (DSC) and small ampli- tude oscillatory shear (SAOS). The influence of pressure of processing and pH were analysed. The DSC results suggest a progressive decrease in thermal denaturation enthalpy as pressure level increases related to protein denaturation. SAOS was used to evaluate the effect of different pressure levels on the linear viscoelastic behaviour of egg yolk dispersions. An increase in the pressure level produces a dramatic change in the linear viscoelastic behaviour under- going a sol-gel transition. High hydrostatic pressure (HHP) processing was also analysed as a function of pH and solids content. The results obtained confirm that the impact of high pressure on aggregation and network formation can be modulated by pH. HHP processing of egg yolk systems is highly affected by protein concentration particularly when it is compared to heat processing.

Effect of high-pressure treatment on the electrospray ionization mass spectrometry (ESI-MS) profiles of whey proteins

The effects of different high-pressure (HP) treatments (pressures ranging between 450 and 650 MPa) on β-lactoglobulin and α-lactalbumin and on two commercial whey protein isolates (WPI) were examined by electrospray ionization mass spectrometry (ESI-MS). HP treatment resulted in substantial changes in the charge-state distribution (CSD) of pure β-lactoglobulin, attributable to exposure of side chains of buried amino acids to solvent, whereas the CSD of pure α-lactalbumin was largely insensitive to HP treatment. The changes in the CSD of these proteins effected by HP treatment differed between the two commercial WPI samples examined, perhaps due to the different production methodologies employed by the two suppliers. These findings illustrate the important role of interactions between the various components in WPI in the response of whey proteins to HP treatment and underscore the difficulty of obtaining consistent rheological and nutraceutical properties by HP treatment of WPI, particularly when different sources of WPI are employed. The information provided by ESI-MS may be useful in monitoring the effects of HP treatment to verify that such consistency is achieved.

Effects of High Pressure Treatment on Volatile Profile During Ripening of Ewe Milk Cheese

The effect of high-pressure treatment on the volatile profile of ewe milk cheeses was investigated. Cheeses were submitted to 200, 300, 400 and 500MPa at 2 stages of ripening (after 1 and 15 d of manufacturing) and volatile compounds were assayed at 15 and 60 d of ripening. High-pressure treatment altered the balance of volatile profile of cheeses, limiting the formation of acids, alcohols, ketones, aldehydes, and sulfur compounds and enhancing the formation of 2,3-butanedione. In general, cheeses pressurized at 15 d of ripening were more similar to untreated cheeses than those treated at 1 d. Cheeses treated at 300MPa after 1 d of manufacturing were characterized by higher levels of free amino acids, ethanol, ethyl esters, and branched-chain aldehydes, whereas cheeses treated at 500MPa after 1 d of manufacturing had lower microbial populations, showed the highest abundance of 2,3-butanedione, pyruvaldehyde, and methyl ketones, and the lowest abundance of alcohols.

Inactivation of a calicivirus and enterovirus in shellfish by high pressure

Abstract This study demonstrates the potential of high pressure (HP) processing to reduce viral contamination in shellfish. Bovine enterovirus, which is structurally similar to hepatitis A virus, was more pressure-resistant than feline calicivirus, a surrogate for norovirus. Both viruses were more pressure-resistant when treated in “naturally” contaminated mussels and oysters, compared to seawater and culture medium, suggesting that the medium can have a significant protective effect against HP treatment. Treatment at pressures of 250 MPa showed only a limited inactivation of either virus in shellfish, suggesting that relatively mild HP treatments (approximately 260 MPa) currently used for the commercial processing of oysters, principally to assist the shucking process, may be insufficient to ensure the safety of shellfish for human consumption, particularly in relation to human pathogenic viruses. Industrial relevance High pressure (HP) processing is increasingly being used in the commercial processing of oysters, principally to assist the opening or shucking of oysters. Little is known about the effect of HP treatment on pathogens in shellfish, particularly human enteric viruses, which are the predominant cause of shellfish-borne disease. This article demonstrates the inactivation of surrogate animal viruses, as potential models for noroviruses and hepatitis A virus, by HP processing and compares the efficacy of inactivation when viruses are treated in culture medium, seawater and shellfish. The potential of HP processing to reduce viral contamination in shellfish is discussed in light of these findings.

The effects of high pressure treatment and of storage periods on the quality of vacuum-packed “salchichón” made of raw material enriched in monounsaturated and polyunsaturated fatty acids

Abstract This study investigates the effects of high-pressure processing on the microbiological, physico-chemical and sensory properties of 3 fermented Spanish dry sausages (salchichon), all high in unsaturated fatty acids. The products, manufactured from the sausage meat and back fat of pigs fed on high-oleic and high-linoleic diets and a control diet, were vacuum-packed prior to high hydrostatic pressure (HPP) treatment (500 MPa, 5 min), and storage at 6 °C for up to 210 days. High-pressure treatment slightly inhibited certain microorganisms, especially yeasts and moulds, and psychotrophic and anaerobic bacteria. Consequentially, microbial counts fell, although injured microorganisms recovered during storage except in the case of the high-linoleic salchichon, in which they remained inactive causing it to register the lowest counts. High-pressure treatment had no noticeable effect on the physico-chemical and sensory properties of the three samples suggesting that it improves the food safety of salchichon with no detrimental effects on organoleptic properties. Industrial relevance The problem of safe preservation is increasingly complex for the meat industry as today's products require longer shelf lives and greater assurance of protection from microbial spoilage. High pressure processing is finding increased use in products such as sliced cured meats, where microbial contamination can occur during the slicing process and develop over storage. This study evaluates the microbiological, physicochemical and sensory characteristics of vacuum-packed slices of dry fermented sausage – control (CO), high oleic (HO), and high linoleic (HL) salchichon samples – following high pressure treatment and subsequent chilled storage, contributing thereby to the growing body of knowledge on this new food preservation technology, which produces microbiologically safe food products with long shelf lives, whilst retaining high nutritional and sensory qualities.

Effect of High-Pressure Treatment on the Survival of Listeria monocytogenes Scott A in Sliced Vacuum-Packaged Iberian and Serrano Cured Hams

High-pressure treatment is useful for increasing the microbiological safety of ready-to-eat foods. With dry-cured hams, this treatment can be applied to the finished product after slicing and vacuum packaging. The effect of high-pressure treatment on the survival of inoculated Listeria monocytogenes Scott A and on the sensory characteristics of two Spanish dry-cured hams, Iberian and Serrano, was investigated. Ham slices were inoculated with L. monocytogenes at 6 × 106 CFU/g and held at 4°C for 20 h before high-pressure treatment. During this holding period, the population of the pathogen declined by 0.44 and 0.51 log CFU/g in Iberian and Serrano hams, respectively. Treatment at 450 MPa for 10 min at 12°C reduced L. monocytogenes populations by 1.50 and 1.16 log CFU/g in Iberian and Serrano hams, respectively. During the first week of storage at4or 8°C, L. monocytogenes populations declined by an average 0.89 log CFU/g in pressurized Iberian ham and 2.09 log CFU/g in pressurized Serrano ham. After 60 days at 4 or 8°C, the respective populations in pressurized and control hams were 3.24 and 4.70 log CFU/g for Iberian ham and 2.73 and 5.07 log CFU/g for Serrano ham. The color parameters L* and a* were not influenced by high-pressure treatment, and parameter b* was increased only in Iberian ham. Sensory characteristics of hams were not affected by high-pressure treatment. Treatment of Iberian and Serrano hams at 450 MPa for 10 min significantly reduced the population of L. monocytogenes Scott A without a detrimental effect on the sensory characteristics of the hams.

Effect of High-Pressure Treatment and a Bacteriocin-Producing Lactic Culture on the Proteolysis, Texture, and Taste of Hispánico Cheese

The effects of high-pressure treatment, by itself or in combination with a bacteriocin-producing culture added to milk, on the proteolysis, texture, and taste of Hispánico cheese were investigated. Two vats of cheese were manufactured from a mixture of cow and ewe milk. Milk in one vat was inoculated with 0.5% Lactococcus lactis ssp. lactis INIA 415, a nisin Z and lacticin 481 producer; 0.5% L. lactis ssp. lactis INIA 415-2, a bacteriocin-nonproducing mutant; and 2% of a commercial Streptococcus thermophilus culture. Milk in the other vat was inoculated with 1% L. lactis ssp. lactis INIA 415-2 and 2% S. thermophilus culture. After ripening for 15 d at 12°C, half of the cheeses from each vat were treated at 400MPa for 5min at 10°C. Ripening of high-pressure-treated and untreated cheeses continued at 12°C until d 50. High-pressure treatment of cheese made from milk without the bacteriocin producer accelerated casein degradation and increased the free AA content, but it did not significantly influence the taste quality or taste intensity of the cheese. Addition of the bacteriocin producer to milk lowered the ratio of hydrophobic peptides to hydrophilic peptides, increased the free AA content, and enhanced the taste intensity. The combination of milk inoculation with the bacteriocin producer and high-pressure treatment of the cheese resulted in higher levels of both hydrophobic and hydrophilic peptides but had no significant effect on the free AA content, taste quality, or taste intensity.

Effect of Cheese Water Activity and Carbohydrate Content on the Barotolerance of Listeria monocytogenes Scott A

High-pressure processing is an appropriate technique for improving the microbiological safety of packaged ready-to-eat foods. The effect of high-pressure treatment on Listeria monocytogenes Scott A inoculated into fresh Hispánico-type cheese and ripe Mahón cheese was investigated. A 3.8-log reduction in the counts of L. monocytogenes Scott A in fresh cheese was recorded after 3 min at 400 MPa and 12°C, whereas 18 min under the same conditions was required to obtain a 1-log reduction in ripe cheese. Dry matter values were 48.96% for fresh cheese and 58.79% for ripe cheese, and water activity (aw) values were 0.983 and 0.922, respectively. In dehydrated fresh cheese (58.20% dry matter) in which 5% NaCl was added to achieve a 0.904 aw value, L. monocytogenes Scott A counts were lowered by only 0.4 log after treatment for 10 min at 400 MPa. On the other hand, in a 60:40 mixture of ripe cheese:distilled water with a 0.976 aw value, the reduction under the same conditions was 3.9 log. Within the aw range of 0.945 to 0.965, L. monocytogenes Scott A barotolerance was significantly higher in fresh cheese than in ripe cheese for equivalent aw values. Carbohydrate content was higher in fresh cheese than in ripe cheese. The addition of lactose at a concentration of 5 mg/g to an 85:15 mixture of ripe cheese:distilled water did not influence L. monocytogenes Scott A barotolerance during treatment for 10 min at 400 MPa. Galactose at a concentration of 5 mg/g had a protective effect during high-pressure treatment, and glucose at a concentration of 5 mg/g favored L. monocytogenes Scott A survival during refrigerated storage of pressurized samples at 8°C for 5 days.

WITHDRAWN: Effect of high-pressure treatment on processing quality of tilapia meat fillets

WITHDRAWN: Effect of high-pressure treatment on processing quality of tilapia meat fillets

Changes in vitamin C content and antioxidant capacity of raw and germinated cowpea ( Vigna sinensis var. carilla) seeds induced by high pressure treatment

The effect of high pressure treatment on the vitamin C content and antioxidant capacity of raw and germinated cowpea seeds ( Vigna sinensis var. carilla) at 300, 400 and 500 MPa for 15 min at room temperature has been investigated. A considerable amount of vitamin C was detected in germinated cowpeas, but the vitamin was not detected in raw seeds. An increase on the antioxidant capacity (TEAC) in cowpea sprouts was also observed (58–67%). High pressure treatment (HP) slightly modified vitamin C content and TEAC and, after pressurization at 500 MPa, the decrease was more pronounced, although the germinated seeds submitted to this HP treatment still provided a high amount of vitamin C (15–17 mg/100 g d.m.) and the antioxidant capacity was 26–59% higher than that of the raw cowpeas. The HP process can provide minimally processed fresh-like sprouts of high quality.

High-pressure treatment of cloudy apple juice

A factorial design with four factors (pressure, holding time, temperature and waiting period between crushing of apple and high-pressure (HP) treatment) was built up to study the effect of HP treatment on pectin methylesterase activity (PME, EC 3.1.1.11) in cloudy apple juice. PME activity was measured by the methanol release during the storage of samples at 4 °C for 1 month. Only the holding time of the treatment and three interactions between factors (holding time×temperature, pressure×waiting and holding time×waiting) had significant effects on the PME level. Increasing the pressure or the holding time at moderate temperatures (15–40 °C) increased the activity. PME purified from apple was pressure stable in the range 100–600 MPa at 25 °C. The soluble pectin content was not changed after HP treatment. The particles size increased with the temperature reached during the treatment, in agreement with a diffusion-limited-aggregation model but were independent of pressure and holding time. In a separate experiment we found a positive correlation between the PME activity and the residual content of the catechins suggesting that polyphenoloxidase (PPO, EC 1.14.18.1) and oxidized polyphenols play a role in the PME activity level after HP treatment.

Effects of high pressure treatment on indigenous enzymes in bovine milk: Reaction kinetics, inactivation and potential application

Abstract High pressure-induced inactivation of the indigenous milk enzymes alkaline phosphatase (ALP), γ -glutamyltransferase (GGT) and phosphohexoseisomerase (PHI) was studied in the pressure range 400–800 MPa at temperatures between 5 and 40 °C. With respect to pressure stability the following ranking was observed: ALP>GGT>PHI. PHI was inactivated after pressure treatment at 500 MPa and 20 °C for 10 min. In terms of reaction kinetics, inactivation of GGT followed first-order reaction kinetics in the range of 400–800 MPa whereas a reaction order of 1.5 was found for ALP. Reactivation of pressure-treated ALP was observed at low enzyme activity resulting from severe pressure treatment and 2 h storage at 35 °C. The influence of process temperature on the pressure-induced inactivation of GGT and ALP was limited in the range 5–40 °C.

Pressurisation of raw skim milk and of a dispersion of phosphocaseinate at 9 °C or 20 °C: effects on the distribution of minerals and proteins between colloidal and soluble phases

The effects of high pressure treatments (100-300 MPa; 15 min; 9 degrees C or 20 degrees C) on the distribution of minerals and proteins of raw skim milk (RSM) and of a dispersion of industrial phosphocaseinate (PC) were studied after separation of the micellar and soluble phases by ultracentrifugation (UCF). Whatever the temperature of high pressure treatments, the pressure-induced dissociation of the casein micelles was accompanied by calcium (Ca), phosphorus (P) and casein release from the micelles. The released Ca and P were or became bound to soluble proteins since progressive increases in Ca and P concentrations were observed in the UCF supernatants of RSM and of the PC dispersion but not in the ultrafiltrates from these UCF supernatants (free of soluble proteins). Simultaneously, alpha(S1-), alpha(S2-), beta- and kappa-caseins were progressively released from the micelles, as seen by electrophoretic analysis. The pressure-induced solubilisation of alpha(S1-) and alpha(S2-)caseins, essentially located in the core of the micelles, suggests that high pressure de-stabilized micelles including their internal structure.

高圧極限環境を利用した食品加工における新展開 高圧処理による食品タンパク質のアレルゲン性低減化

This paper describes general methods to eliminate or decrease the allergenicity of food protein, and also describes high pressure-induced elimination of the allergenicity of food protein, especially meat protein.The effect of high pressure treatment on the elimination of bovine serum albumin (BSA, the major beef allergen) allergenicity was evaluated on the basis of histamine release from human basophilic KU812F cells sensitized with sera from allergic patients, and the structural changes of BSA responsible for reducing allergenicity was estimated. BSA pressurized at pressures ranging from 300 to 600 MPa reduced histamine release from the cells sensitized with A5 serum with significance. The reducing effect of high-pressure treatment gradually increased with the increase of pressure applied to BSA. The pressure-induced structural changes of BSA were estimated by fluorescence spectra, circular dichroism (CD) spectra (the content of secondary structure), the amount of surface sulfhydryl (SH) group, and the surface aromatic hydrophobicity. The blue shift and decrease of the fluorescence of BSA gradually progressed with the increase of pressure applied. But no significant effect of pressure on CD spectra was observed. Pressure-treated BSA showed the maximum increase in the amount of SH group by pressure treatment at 100 MPa, and the aromatic hydrophobicity gradually decreased with the increase of high pressure applied. These results indicated that high pressure treatment induced the tertiary structural changes of BSA, but no effect on the secondary structure. We concluded that the pressure-induced elimination of BSA allergenicity seemed to be related to the tertiary structural change of BSA.

高圧処理を利用した食品加工の研究

Until recently, the factor that has played a predominant role in food processing was not “pressure” but “heat”, although both factors are independently responsible for transforming the state of a substance. In food processing, high-pressure treatment produces no aberrant matter that puts the safety of food at risk because the food processing can be achieved without any cleavage of covalent bond contained in the ingredients of food. Moreover, high-pressure treatment is considered to be very promising for food processing of the future. This is because decomposition of nutrients and production of stench can be minimized more effectively and energy consumption can be reduced more efficiently when compared with heat treatment. Further, when a food product in a container is subjected to high-pressure treatment, uniform processing throughout the food can be guaranteed. It has been confirmed that pressure treatment exhibits the following effects, which are useful to improve the quality of food to create new added value. 1) Removal of air bubbles 2) Impregnation of a sold substance. 3) Control of enzyme reaction and destruction of cell wall and cell membrane. 4) Denaturation of starch. 5) Bactericidal effect of high pressure treatment.

Effect of High-Pressure Treatment and a Bacteriocin-Producing Lactic Culture on the Odor and Aroma of Hispánico Cheese: Correlation of Volatile Compounds and Sensory Analysis

The effect on the volatile compounds and on the odor and aroma of Hispánico cheese of a high-pressure (HP) treatment (400 MPa for 5 min at 10 degrees C, applied to 15-day-old cheeses), by itself or combined with the addition of a bacteriocin-producing (BP) culture to milk, was investigated. HP-treated cheeses showed higher levels of hexanal, 3-hydroxy-2-pentanone, 2-hydroxy-3-pentanone, and hexane and lower levels of ethanal, ethanol, 1-propanol, ethyl acetate, ethyl butanoate, ethyl hexanoate, 2-pentanone, and butanoic acid than untreated cheeses. HP cheeses received higher "milky" odor descriptor scores and lower scores for odor quality and intensity and for "buttery", "yogurt-like", and "caramel" odor descriptors. Addition of the BP culture enhanced the formation of three aldehydes, three alcohols, three ethyl esters, and three ketones but decreased the levels of seven ketones and butanoic acid. BP cheeses received higher scores for aroma intensity and for "yogurt-like" and "cheesy" aroma descriptors. Principal component analysis showed the correlation between diketones and aroma descriptors "caramel", "buttery", and "milky" and between 3-methylbutanal and the odor and aroma intensity scores and aroma descriptors "sheepy" and "meat broth".