Combined High Pressure Processing Research Articles

Use of high pressure processing in combination with acidic electrolyzed water depuration for the shelf-life extension of blood clam (Tegillarca granosa)

Use of high pressure processing in combination with acidic electrolyzed water depuration for the shelf-life extension of blood clam (Tegillarca granosa)

Role of pectin characteristics in orange juice stabilization: Effect of high-pressure processing in combination with centrifugation pretreatments

“High-pressure processing (HPP) plus” combined technologies are applied to overcome the limitation of single HPP and to produce juices with more stable quality during storage. This research explored the potential of HPP in combination with centrifugation to produce cloud stable orange juice during refrigerated storage. The results indicated that HPP combined processing technology significantly improved the cloud stability of orange juice, which was related to removed large particles, reduced viscosity, decreased protein contents, and inactivated pectin methylesterase activity induced by centrifugation (P < 0.05). Besides, chelator solubilized pectin (CSP) decreased but water solubilized pectin (WSP) maintained in the juice after centrifugation. During storage, the conversion of pectin fraction from WSP to CSP, resulting in sedimentation appeared in centrifugation treated orange juice when stored for 28 days. In general, pectin characteristics changes and pectin fractions conversion were the main driving forces affecting cloud stability of orange juice pasteurized by HPP in combination with centrifugation and during chilled storage.

High pressure processing for raw meat in combination with other treatments: A review

High pressure processing (HPP) is a well-known technology for nonthermal pasteurization of food materials. High pressures above 100 MPa is proven to cause microbial destruction in food. It has been employed in the treatment of meat and meat products in several commercial industries. When considering raw meat preservation, increasing the pressure beyond 400 MPa results in significant quality degradation including color and textural changes. HPP in combination with other technologies help in achieving a reduction in pathogens below 1 log CFU/g of meat. This review analyzes the effect of HPP with salt, mild heat treatment, plant extracts, essential oils, and antimicrobials on the microbial safety of raw meat with a major focus on microbes such as Escherichia coli O157:H7, Listeria monocytogenes, Salmonella, and Lactic Acid Bacteria. Quality changes (texture, color, and lipid oxidation) in the raw meat while achieving the required pathogen reduction using these methods are also discussed. The review helps in understanding how HPP in combination with other hurdle technologies can be used to provide microbiologically safe raw meat for different end-users. Novelty impact statement High pressure processing is a successful nonthermal processing technology that is employed in meat processing industries. Use of combination technologies with HPP had synergistic effect on reducing microbial load in raw meat. Investigation on applying multiple hurdles with HPP in a cost-effective way could help in the successful application of the technology for meat preservation.

Control of Listeria monocytogenes in sliced dry-cured Iberian ham by high pressure processing in combination with an eco-friendly packaging based on chitosan, nisin and phytochemicals from rice bran

In the last few years, severaloutbreaks caused by Listeria monocytogenes from meat products have been reported, implying potential health problems that can be very serious for the population at risk. This work aimed to evaluate the effect of high hydrostatic pressure processing (HPP) combined with chitosan-based films on the reduction of L. monocytogenes inoculated onto the surface of sliced dry-cured Iberian ham. Chitosan-based films used in this study contained nisin and/or a rice bran extract as antimicrobial agents. A process of 600 MPa for 8 min was established as optimum in this product, although this treatment alone was not effective enough and therefore must be combined with other technologies following a multiple hurdle approach. The combination of HPP with nisin or oryzanol chitosan based-films was the best treatments tested, reducing the population of L. monocytogenes by 6 log cfu/g.

Yüksek basınç işleminin ringa marinatında Photobacterium phosphoreum gelişimi ve biyojen amin üretimi üzerine etkisi

The effects of high-pressure processing (HPP) on Photobacterium phosphoreum growth and biogenic amine formation were evaluated in marinated herring (prepared with 2% acetic acid+8% NaCl; or 4% acetic acid+8% NaCl solutions). Marinated fish fillets were inoculated with P. phosphoreum, vaccum packaged and treated with HPP in different pressure levels (100, 300, and 500 MPa) and pressure holding times (5 and 10 min). Control was left as untreated for both marination group. All batches were stored at 4±1oC up to 3 months. The results showed that combined effect of HPP and 4% acetic acid had much more inhibitory effect on the growth of P. phosphoreum, especially pressure levels 300 and 500 MPa. During the storage period, H2S-producing bacteria growth was not observed in the groups subjected to 500 MPa pressure. Total psychrophilic bacteria did not grow in 500 MPa pressure treated group and 300 MPa 10 min pressure treated group prepared with 2% acetic acid during the storage period. Histamine was detected insignificant levels in the fillets marinated with 4% acetic acid and treated with HPP. Except for the control group tyramine formation was not found in the samples prepared with 4% acetic acid. Similarly, putrescine was not found in the samples prepared with 2% acetic acid and subjected to HPP treatment at the beginning of the storage. Cadaverine levels were found insignificant amount and 300 and 500 MPa pressure treatments suppressed the formation in 4% acetic acid treated groups compared with 2% acetic acid treated groups. The results of this study revealed that HPP in combination with 4% acetic acid had inhibitory effect on P. phosphoreum growth and suppressed the formation of histamine, tyramine, putrescine and cadaverine.

Inhibitory effects of high pressure treatment on microbial growth and biogenic amine formation in marinated herring (Clupea harengus) inoculated with Morganella psychrotolerans

Inhibitory effects of high pressure processing (HPP) on the biogenic amine formation (histamine, tyramine, putrescine and cadaverine) in marinated herring fillets (2% acetic acid+8% NaCl; or 4% acetic acid+8% NaCl solutions) were investigated. Marinated fillets were inoculated with M. psychrotolerans followed by vacuum-packaging and HPP treatment at 100, 300 and 500 MPa for 5 and 10 min. One batch was left untreated for each marination group and the batches were stored at 4 °C for 3 months. HPP in combination with 4% acetic acid had a strong inhibitory effect on the growth of M. psychrotolerans, since there was no growth in samples treated with 300 MPa for 10 min and 500 MPa for 5, 10 min. Psychrophilic bacteria growth was not detected in samples marinated with 4% acetic acid and treated with 500 MPa H2S-producing bacteria were not observed in marinated herring during the storage period. Histamine and cadaverine formation were not observed in the samples marinated with 4% acetic acid along the storage. Taken together, the findings of this research might be helpful to enhance the safety of consumption of marinated herring.

Using High Pressure Processing for Bioconversion of Hazelnut Shells to Generate Fermentable Sugars

Development of cost-effective process technologies to produce biofuels and enzymes from lignocellulosic materials has gained importance. However, few studies have considered high pressure processing (HPP) as an emerging technology for the bioconversion of lignocellulosic biomass. This study aimed to determine and optimize the effect of HPP combined with dilute acid and enzymatic saccharification on the production of fermentable sugars from hazelnut shells. Optimization via response surface methodology was carried out for acid concentration of 1 to 3% (w/v) for a pretreatment time of 10 to 30 min at a pressure range of 200 to 500 MPa. The combined HPP processes were evaluated in terms of the production of total reducing sugars. The optimized total reducing sugar production was estimated at 473.4 mg/g, with production of 88.4% fermentable sugars under 2.9% H2SO4 for 10 min at 350 MPa. The results implied a 2.4 fold increase in fermentable sugar production under the optimized conditions using combined HPP. The combined HPP process appeared to significantly lower costs due to the decreases in pressure requirement, liquid consumption, and pretreatment time.

High Pressure Processing Effects on All Beef Summer Sausage Quality

ObjectivesSummer sausages are currently fermented to a lower pH (≤ 4.6) and mildly heat treated to temperatures of ≥ 54.4°C to meet USDA FSIS performance standards for E. coli O157:H7. Alternatives such as high pressure processing (HPP) may allow for processing with greater pH and lower temperatures while still meeting performance standards, however, the effect of HPP and different processing parameters on sausage quality is not known. The objective of this project was to evaluate HPP in combination with greater pH and minimal heat treatment for their effects on sausage quality.Materials and MethodsThree replicates of all-beef summer sausage products (11% fat) were produced following: (i) pH 4.6, 54.4°C with a traditional smoke house and cooler chill (T); (ii) pH 5.0, 54.4°C T; (iii) pH 5.0, 54.4°C with ice bath chilling (RC); (iv) pH 5.0, 48.9°C RC; and (v) pH 5.0, 43.3°C RC. After chilling, sausages were sliced (3.1 mm), vacuum packaged, transported to a commercial HPP processor, and subjected to HPP at 586 MPa for 0, 1, 150, or 300 s. Post HPP sausages were evaluated for proximate analysis (n = 9), lipid oxidation (n = 9), objective color (n = 9), texture profile analysis (n = 15; hardness, springiness, cohesiveness, gumminess, and chewiness), and sensory characteristics (n = 9) including firmness, cohesion, springiness, and gumminess using trained panelists. Data were analyzed using Proc Mixed (SAS v9.4; SAS Inst. Inc., Cary, NC), as a completely randomized split plot design. The raw sausage chubs were considered the whole plot to which cooking treatments were applied, and the cooked chubs were the split plot, to which HPP times were applied.ResultsThe fat content of the sausages was similar (P = 0.17) among all treatments. There was no difference for moisture:protein attributed to final pH/cooking endpoint or HPP time (P > 0.63), nor was there a difference for lipid oxidation due to pH/cooking endpoint (P = 0.45) or HPP (P = 0.69). Objective color measurements showed that fermentation of summer sausage to pH 4.6, heated to 54.4°C, and traditionally chilled was lighter in color (greater L*; P < 0.01) than all other pH/cooking endpoint combinations which were similar (P > 0.17). Additionally, treatment (i) was less red (lower a*; P < 0.01) than all other treatments while (iv) and (v) exhibited the greatest redness (P < 0.01). Samples became less red and had more fading as HPP time increased (P < 0.05), however, the differences were small in magnitude. Texture profile and sensory characteristic analysis were in agreement and showed that as cooking intensity increased so did the hardness of the sausage (P < 0.01). Similar trends were noted between sensory characteristics and texture profile analysis, with a positive correlation between cooking intensity and the springiness, cohesiveness, and gumminess of the sausage products. High pressure processing also had an effect on springiness and gumminess (P < 0.05), however sensory panelists were unable to detect differences (P > 0.46) for these same attributes.ConclusionHigh pressure processing at 586 MPa for up to 300 s can be used as an alternate method for manufacturing beef summer sausages with marginal impacts on final product quality. Further research needs to be conducted to evaluate the efficacy of the process in reducing E. coli O157:H7 and other STEC population using this alternate summer sausage manufacturing process.

High pressure processing and retrogradation of potato starch: Influence on functional properties and gastro-small intestinal digestion in vitro

A combined approach of high pressure processing (HHP) along with retrogradation was used to treat potato starch samples in order to influence their functional properties and kinetics of glucose release during gastro-small intestinal digestion in vitro. Native potato starch was treated at two levels of high hydrostatic pressure (400 MPa and 600 Mpa) and number of cycles (3 and 6) for 10 min and then subjected to retrogradation at 4 °C for 7 days. The granular starch samples treated at 400 MPa for 6 cycles showed higher peak and breakdown viscosities whereas peak time and final viscosity for the same samples treated for 3 cycles followed by retrogradation were higher than the native control sample. HHP in combination with retrogradation promoted an increase in the relative crystallinity whereas reduction in To and Tp was observed with an increase in the number of cycles at 400 MPa. The use of 3 cycles of 600 MPa led to significant changes in morphology of the granules, causing light eruptions on the surface of most granules, abrasions and major disruptions in some granules. After applying 6 cycles at 400 Mpa, a significant reduction was observed in starch hydrolysis (during gastro-small intestinal digestion in vitro) of the HHP-retrograded sample throughout the small intestinal phase, with a final reduction of 10–15% compared to the native and pressure-treated only sample.

Contribution of high pressure and thyme extract to control Listeria monocytogenes in fresh cheese - A hurdle approach

Abstract Capability of thyme natural antimicrobials (NAs) to reduce the intensity of high pressure processing (HPP) and enhance the inactivation of Listeria monocytogenes in fresh cheese was investigated. Thyme extracts were obtained by supercritical fluid extraction at 30 MPa and 40 MPa and their concentration was estimated in units of carvacrol (190.44–609.57 μg/mL). The acceptable sensorial threshold of thyme extract in cheese was 0.2% (v/w), a value lower than the MIC for L. monocytogenes. Detailed kinetic studies of L. monocytogenes inactivation in cheese were performed following HPP (200–300 MPa) treatments. A maximum 1.68-log10 CFU/g supplementary reduction was achieved for L. monocytogenes in cheese with HPP & NAs than without NAs. The kinetic parameter zp indicated an accelerated inactivation of L. monocytogenes when HPP was combined with thyme NAs, as hurdle applied to fresh cheese (55.99 MPa for HPP and 33.29 MPa for HPP with thyme NAs). Industrial relevance Applied as a post-processing treatment high pressure processing (HPP) is considered an effective listericidal tool that produces limited quality changes in foods compared to other preservative methods. In order to overcome the main drawback related to HPP effect on cheese structure, a combination of pressure with natural antimicrobials (NAs) is proposed for reducing the intensity of processing while improving microbiological safety of food. The efficacy of L. monocytogenes inactivation in cheese by HPP and HPP with NAs from thyme was kinetically evaluated and modeled in the present work. The current results provide support for the industrial development of more effective combined HPP with NAs treatment, able to minimize the risk of Listeria presence in cheese.

Modeling the inactivation of psychrotrophic Bacillus cereus spores in beef slurry by 600 MPa HPP combined with 38–70 °C: Comparing with thermal processing and estimating the energy requirements

The growth of psychrotolerant Bacillus cereus in pre-prepared cooked chilled foods and refrigerated processed foods of extended durability (REPFED) is a concern. High pressure processing (HPP) is an established food processing technology that retains the flavor and nutrients in the processed food. In this study, the efficacy of 600MPa HPP in combination with 70°C for the inactivation of B. cereus ICMP 12442 spores in beef slurry was investigated and compared with 70°C thermal processing alone. The HPP-70°C process enhanced the B. cereus spore thermal inactivation in beef slurry, resulting in 4.9log reductions after 20min vs. 0.5log for thermal processing. Then, the effect of temperature at 600MPa on the spore inactivation up to 40min was studied, and the log survivors vs. time were modeled. Weibull model was appropriate to characterize the inactivation. Increasing the HPP temperature from 38 to 70°C, increased the spore inactivation in beef slurry up to 3log. Lastly, the thermal inactivation of the spores was investigated. The spore thermal inactivation was linear and first order kinetic parameters were determined. The results of this study confirm the advantage of HPP technology for the inactivation of B. cereus spores in beef slurry at moderate temperatures.

The application of high pressure–mild temperature processing for prolonging the shelf-life of strawberry purée

ABSTRACTThe aim of this study was to monitor the shelf-life and quality of strawberry purée preserved using combined high pressure processing (HPP)–mild temperature processing at 300 and 600 MPa for 15 min during cold storage (6°C). Increasing the pressure resulted in a prolonged shelf-life of from 4 to 28 weeks for HPP-preserved purée at 300 and 600 MPa, respectively. The highest inactivation of peroxidases, pectinesterases and polygalacturonases was noted when a higher pressure was used, whereas a lower pressure was more efficient for polyphenoloxidases. The degradation of vitamin C and anthocyanins was 20% and 5% higher at 600 MPa than at 300 MPa, respectively. Significantly fewer changes in the colour coefficient, expressed as ΔE, and the browning index, were observed in purée preserved at 600 MPa. Oxidative and hydrolytic enzymes are highly pressure-resistant, which suggests other inhibitors should be used to increase the shelf-life of good-quality fruit products.

Effect of high pressure processing in combination with Weissella viridescens as a protective culture against Listeria monocytogenes in ready-to-eat salads of different pH

This study explored the effect of HPP (400 MPa/1 min) and a Weissella viridescens protective culture, alone or in conjunction, against Listeria monocytogenes in ready-to-eat (RTE) salads with different pH values (4.32 and 5.59) during storage at 4 and 12 °C. HPP was able to reduce the counts of the pathogen after treatment achieving approximately a 4.0 and 1.5 log CFU/g reduction in the low and higher pH RTE salad, respectively. However, L. monocytogenes was able to recover and grow during subsequent storage. W. viridescens grew in both RTE salads at both storage temperatures, with HPP resulting in only a small immediate reduction of W. viridescens ranging from 0.50 to 1.2 log CFU/g depending on the pH of the RTE salad. For the lower pH RTE salad, the protective culture was able to gradually reduce the L. monocytogenes counts during storage whereas for the higher pH RTE salad in some cases it delayed growth significantly or exerted a bacteriostatic effect. exerted a bacteriostatic effect. The results revealed that the increased storage temperature led to an increase in the inactivation/inhibition of L. monocytogenes in the presence of W. viridescens. The combination of HPP and W. viridescens is a promising strategy to control L. monocytogenes and can increase safety even when a break in the chill chain occurs.

Influence of high pressure processing and alkaline treatment on sugarcane bagasse hydrolysis

High pressure processing (HPP) is an emerging technology for food preservation, however its application in pretreatment of lignocellulosic biomass has not been studied; therefore, the objective of this work was to evaluate the effect of HPP in combination with sodium hydroxide on the enzymatic hydrolysis of sugarcane raw and prehydrolyzed bagasse. The results indicated that high pressure treatments alone or combined with sodium hydroxide had a little effect on the lignocellulosic fraction of sugarcane bagasse, however in prehydrolyzed bagasse, removal of the major hemicellulose was observed. Also, changes in the microstructure and crystallinity of sugarcane bagasse were observed at 450 MPa as the modification of the cellulose fiber improved the porosity, increasing the susceptibility of bagasse to cellulases, obtaining a glucose concentration of 25.91 g/L with NaOH (6% treatment). These results are important because the application of HPP on lignocellulosic materials could be used to get fermentable sugars for production of food additives.

Effect of high pressure processing and vacuum packaging on the preservation of fresh-cut peaches

Nowadays consumers demand fresh-cut fruits free from additives and with appealing appearance. High pressure processing (HPP) could be a suitable alternative to preserve fresh-cut fruit, since it is less aggressive than thermal treatments. This work was accomplished to study the effect of HPP in combination with vacuum packaging (VP) on the preservation of fresh-cut peaches. Cubes of peaches were treated with a solution of ascorbic acid and citric acid to inhibit enzymatic browning and then subjected to: A) VP + HPP (500 MPa-5 min), B) only VP and C) Control. Immediately after processing, after 15 and 21 days, different evaluations were carried out over the samples: chromatic parameters (CIE L∗C∗h°), polyphenoloxidase (PPO) activity, Textural Profile Analysis, and ethanol content. During the period evaluated, L∗ and C∗ were significantly lower in vacuum-packed and pressurized samples than in the control. At day 21, the pressurized samples showed the best textural properties. Peaches subjected to HPP + VP also had significantly lower content of ethanol and PPO activity than the other treatments, which evidences that fermentation and browning were successfully inhibited by this combination. It can be concluded that HPP + VP could preserve fresh-cut peaches for at least 21 days at 10 °C, with only a slight translucency caused by VP.

High-Pressure Processing of Manuka Honey: Improvement of Antioxidant Activity, Preservation of Colour and Flow Behaviour

Manuka honey in New Zealand is known for its superior antimicrobial and antioxidant properties. However, these valuable properties are known to be compromised when raw honey goes through conventional thermal processing, thus reducing its final quality. As such, this present work is undertaken to assess the effect of high-pressure processing on quality of honey, namely, the antioxidant activity, colour and viscosity. The honey was subjected to different pressures (200–600 MPa) at ambient temperatures (25 to 33 °C) and combined with moderate temperatures (53 to 74 °C) for holding times (10 to 30 min). Thermal processing (49 to 70 °C) was also carried out for comparison purpose. In the absence of heat, the antioxidant activity of high-pressure processing (HPP)-treated samples (600 MPa, 10 min) was found to increase by about 30 % with no colour changes detected. The shear-thinning behaviour of the honey was also retained after HPP at ambient temperature, whereas for combined HPP–thermal treatment, no added benefit in antioxidant activity was observed particularly at higher temperature. Colour was significantly degraded when processed for ≥15 min at 70 °C and the flow behaviour was brought about from shear thinning to Newtonian. Thus, it can be concluded that the quality of honey can be enhanced by using high-pressure processing at ambient temperature.

Effect of Packaging Systems and Pressure Fluids on Inactivation of Clostridium botulinum Spores by Combined High Pressure and Thermal Processing

Several studies have been published on the inactivation of bacterial spores by using high pressure processing in combination with heat. None of the studies investigated the effect of the packaging system or the pressurizing fluid on spore inactivation. The objective of this study was to select and validate an appropriate packaging system and pressure transfer fluid for inactivation of Clostridium botulinum spores by using high pressure processing in combination with thermal processing. Inactivation of spores packaged in three packaging systems (plastic pouches, cryovials, and transfer pipettes) was measured in two pressure test systems (laboratory-scale and pilot-scale) at 700 MPa and >105°C. Total destruction (>6.6-log reduction) of the spores packaged in the graduated tube part of transfer pipettes was obtained after processing for up to 10 min at 118°C and 700 MPa in both pressure test systems, compared with the spores packaged either in plastic pouches or cryovials. Reduction of spores packaged in plastic pouches was lowest (<4.8 log) for both pressure test systems when processed at the same conditions (i.e., 700 MPa and 118°C). Within the pilot-scale pressure system, increasing the process temperature from 118 to 121°C at 700 MPa for 10 min resulted in only a small increase in spore reduction (<5.1 log) for spores packaged in plastic pouches, whereas there were no recoverable spores for either of the other two packaging systems. Use of plastic pouches for packaging spores in inactivation kinetic studies could lead to erroneous conclusions about the effect of high pressure in combination with heat. BioGlycol is the pressure-heat transfer fluid of choice, as compared with Duratherm oil, to maximize the temperature response rate during pressurization within the laboratory-scale pressure test system.