Effect of High Hydrostatic Pressure (HHP) Treatment on Physicochemical Properties of Horse Mackerel (Trachurus trachurus)

The basic objective of this study was to determine the effect of high hydrostatic pressure (HHP; 220, 250 and 330 MPa), holding time (5 and 10 min) and temperature (7, 15 and 25 °C) on some quality parameters of horse mackerel such as colour changes, thiobarbituric acid (TBA-i) and trimethylamine nitrogen (TMA-N), free amino acid content. HHP increased L ^* values of horse mackerel. The a ^* and b ^* of treated horse mackerel did not change significantly after HHP applications. After, HHP, TBA-i and TMA values of all HHP-treated horse mackerel samples remained unchanged than those of untreated samples. The results obtained from this study showed that the quality of high pressure treated horse mackerel is best preserved at 250 MPa, 7–15 °C for 5 min, 220 MPa, 15–25 °C for 5 min, 250 MPa, 15 °C for 10 min and 330 MPa, 25 °C for 10 min.     

A preliminary study about the influence of high hydrostatic pressure processing on the physicochemical and sensorial properties of a cloudy wheat beer

High hydrostatic pressure (HHP) (400 MPa/15 min, 500 MPa/10 min, 600 MPa/5 min at 20 °C) and heat (60 °C/15 min) processing of wheat beers were evaluated by examining their impacts on microorganisms, colloidal haze, flavour, foam stability and shelf‐life prediction during 84 days of storage at 20 °C. The results obtained showed that the microbiological stability of HHP beers was comparable with heat‐treated samples, and the development of both aerobic bacteria and lactic acid bacteria was inhibited for 84 days of storage. The main parameters of the wheat beer, such as ethanol content, original extract, pH, bitterness and viscosity, were scarcely affected by either treatment compared with the control samples; however, heat pasteurization increased the colour value. Heat‐pasteurized beer resulted in an increase in the phenethyl alcohol concentration and a decrease in isoamyl acetate and ethyl acetate levels compared with the HHP samples. These treatments did not affect the amount of 4‐vinylguaiacol and 4‐vinylphenol in the beer. The HHP‐treated beers had higher colloidal haze and foam stability values than the heat‐pasteurized beers. Dynamic light scattering analysis showed that HHP treatments at 500 MPa/10 min resulted in smaller and more uniform particle sizes, which had a positive effect on beer haze stability during storage. Copyright © 2016 The Institute of Brewing & Distilling     

Effect of high pressure (HP) on the quality and shelf life of red mullet (Mullus surmelutus)

The effect of different temperature/time/pressure high hydrostatic pressure (HP) treatment on the quality and shelf life of red mullet were studied. Different high pressure treatments (at 3, 7, 15 and 25 °C, 5 to 10 min and 220, 250 and 330 MPa) were tested to establish the best processing conditions for the quality of red mullet. The effect of the process on the quality of the sample was examined by colour, Trimethylamine nitrogen (TMA-N) and Thiobarbituric acid number (TBA) analysis. Based on the results of the parameters, the best combinations of HP treatments were determined as 220 MPa/5 min/25 °C and 330 MPa/5 min/3 °C for red mullet. The effects of this combination treatment on sensory, chemical and microbiological properties of red mullet stored at 4 °C were studied. The results obtained from this study showed that the shelf life of untreated and HP treated stored at 4 °C, as determined by overall acceptability of sensory and microbiological data, are 12 days for untreated red mullet and 14 days for treated red mullet at 220 MPa for 5 min at 25 °C and 15 days for treated red mullet at 330 MPa for 5 min at 3 °C.Industrial relevanceFresh fish have short shelf life. HP treatment has shown to be an effective method to control pathogen and spoilage microorganisms in fish and fish products. However, high pressure treatment can promote colour and oxidation changes that could modify their sensory characteristics. The main objective of the first part of this study was to detect the best combination among the applied pressure (220, 250 and 330 MPa), temperature (3, 7, 15 and 25 °C) and time (5 and 10 min) combinations. The treatment ranges were chosen according to the unchanging colour, lower TBA value and TMA stability by HP and considering the economical aspects of HP processing. In the second part of the study, HP was applied on the selected samples and a shelf-life study was performed by measuring the changes in the quality parameters, of the samples throughout their storage. The storage conditions were set so as to achieve refrigeration handling (4 °C). Shelf-life estimation was performed according to the data obtained. HP (at 220 MPa for 5 min at 25 °C and at 330 MPa for 5 min at 3 °C) treatment is the most effective treatment for shelf-life extension as compared to non-treated red mullet.     

Preservation of iced refrigerated sea bream (Sparus aurata) by irradiation: microbiological, chemical and sensory attributes

Quality and shelf life of non-irradiated and irradiated (2.5 and 5 kGy) sea bream in ice conditions and stored at +4 °C were investigated by measurement of microbiological, chemical and sensory analysis. Microbial counts for non-irradiated sea bream samples were higher than respective irradiated fish. Total volatile base nitrogen (TVB-N) values increased value of 38.64 mg/100 g for non-irradiated, sea bream during iced storage whereas for irradiated fish lower values of 13.48 and 12.06 mg/100 g were recorded at 2.5 and 5 kGy, respectively (day 19). Trimethylamine (TMA-N) values and thiobarbituric acid (TBA) values for irradiated samples were lower than non-irradiated samples. Acceptability scores for odour, taste and texture of cooked decreased with storage time. The sensory scores of sea bream stored in control and 2.5–5 kGy at +4 °C were 13 and 15 days, respectively. The results obtained from this study showed that the shelf life of sea bream stored in ice, as determined by overall acceptability all data, is 13 days for non-irradiated sea bream and 15 days for 2.5 kGy irradiated and 17 days for 5 kGy irradiated sea bream.     

Effects of high pressure treatment on physicochemical characteristics of fresh sea bass (Dicentrarchus labrax)

The effects of high pressure (HP) treatment (pressure: 220–250–330 MPA; holding time: 5 and 10 min; temperature: 3, 7, 15 and 25°C) on physicochemical characteristics (colour, thiobarbituric acid, trimethylamine nitrogen values) of fresh sea bass fillets were investigated. HP-treated sea bass fillets had higher lightness (Hunter L*) values than untreated sea bass fillets; the magnitude of changes increased with treatment pressure. HP-induced changes in colour generally imparted a cooked sample. The TBA value of HP treated sea bass samples (except 220–330 MPa, 3°C for 5 min) were found to be insignificant (P > 0.05) or significantly (P < 0.05) lower than the untreated samples. TMA-N content of HP treated at 220–250–330 MPa, 3–7–25°C for 10 min sea bass samples were found to insignificant according to the untreated samples. The results obtained from this study showed that the quality of high pressure treated sea bass is best preserved at 220 MPa, 25°C for 5 min.     

Influence of high hydrostatic pressure processing on physicochemical characteristics of a fermented pomegranate (Punica granatum L.) beverage

The effect of high hydrostatic pressure at 500 MPa/10 min (HHP1), 550 MPa/10 min (HHP2) and 600 MPa/5 min (HHP3) on the microbiological, physicochemical, antioxidant and sensory characteristics of a fermented pomegranate (FP) beverage, stored for 42 days (4 ± 1 °C), was evaluated. The FP beverage was also pasteurized at 63 °C/30 min (VAT) and 72 °C/15 s (HTST). The high hydrostatic pressure (HHP) and VAT pasteurized beverages did not show microbial growth (<10 CFU/mL) throughout 42 days of storage. The physicochemical characteristics were not affected (p > 0.05) by HHP or pasteurization. Color of the samples showed significant differences (p ≤ 0.05) in all HHP processed and pasteurized beverages. Antioxidant activity, total phenolic compounds, flavonoids and anthocyanins increased slightly after HHP processing. Antioxidants decreased throughout the storage in all treatments. Both HHP processed and pasteurized beverages were well accepted by average consumers when evaluated using a 9-points hedonic scale.Industrial relevanceThe high hydrostatic pressure (HHP) improves the microbiological, antioxidant and sensorial stability of fermented pomegranate beverages during storage. The HHP is more common for processing fruit juices than for fermented beverages; therefore, it can be expanded to the fermented beverages industry, which could modify the today usual thermal processing methods and, or the addition of preservatives, that are not natural, for delivering high quality and healthier pomegranate fermented beverages to consumers.     

Effect of high hydrostatic pressure on the quality of four edible flowers: Viola × wittrockiana,Centaurea cyanus,Borago officinalis and Camellia japonica

The aim of the study was to evaluate the effect of high hydrostatic pressure (HHP) on the appearance, bioactivity and microbial content of four edible flowers along storage. Several treatments at 75–450 MPa and holding times (1, 5 and 10 min) were applied. Borage and camellia were unacceptable after all treatments, while centaurea showed good appearance at 100/5 MPa min^?1; however, the shelf life did not increase. Pansies treated at 75/5 and 75/10 MPa min^?1 also retained the appearance of fresh flowers. Furthermore, pansies submitted at 75/5 MPa min^?1 maintained good appearance over 20 days of storage at 4 °C, while the untreated remained satisfactory only until 6 days. Even though no significant differences on microbial load were observed between untreated and HHP‐treated pansies in day 0, HHP induced the production of bioactive compounds, increasing the shelf life of pansies. So, the HHP treatment is a promising technology for Viola × wittrockiana.     

Effects of high pressure treatment on physicochemical characteristics of fresh sea bass (Dicentrarchus labrax)

The effects of high pressure (HP) treatment (pressure: 220–250–330 MPA; holding time: 5 and 10 min; temperature: 3, 7, 15 and 25°C) on physicochemical characteristics (colour, thiobarbituric acid, trimethylamine nitrogen values) of fresh sea bass fillets were investigated. HP-treated sea bass fillets had higher lightness (Hunter L*) values than untreated sea bass fillets; the magnitude of changes increased with treatment pressure. HP-induced changes in colour generally imparted a cooked sample. The TBA value of HP treated sea bass samples (except 220–330 MPa, 3°C for 5 min) were found to be insignificant (P > 0.05) or significantly (P < 0.05) lower than the untreated samples. TMA-N content of HP treated at 220–250–330 MPa, 3–7–25°C for 10 min sea bass samples were found to insignificant according to the untreated samples. The results obtained from this study showed that the quality of high pressure treated sea bass is best preserved at 220 MPa, 25°C for 5 min.     

Effects of high hydrostatic pressure on the quality and shelf-life of jujube (Ziziphus jujuba Mill.) pulp

This study evaluated the effects of high hydrostatic pressure (HHP) on the microbial counts, physicochemical properties, bioactive compounds, and antioxidant capacity of jujube pulp. Additionally, this study compared the shelf life of jujube pulp following HHP (600 MPa/20 min) and thermal treatment (100 °C/10 min) during 40 days of storage at 4 °C and 15 °C. The microbial count of HHP-treated jujube pulp (≥ 400 MPa/20 min) was below the detection limit. Total soluble solids and total sugars were not significantly affected by HHP processing, and > 90% ascorbic acid was retained in HHP-treated samples. HHP slightly reduced pH and browning degree and increased total phenolic content, flavonoid content, and antioxidant capacity. HHP can be used as an alternative to thermal pasteurization of freshly squeezed jujube pulp.Industrial relevanceEffects of high hydrostatic pressure (HHP) processing and thermal treatment (TT) on microbiological quality, physicochemical properties, bioactive compounds and antioxidant activity in jujube pulp were investigated. Greater inhibition of microorganisms and better retention of ascorbic acid, total phenolics, flavonoid and antioxidant capacity were observed after HHP-treatment. The available data could be used to design the HHP parameters for high quality jujube juice. Further, this research would provide a useful method for preservation of jujube products and potential technical support for jujube commercial production.     

High hydrostatic pressure treatment and storage of carrot and tomato juices: Antioxidant activity and microbial safety

The application of high hydrostatic pressure (HHP) (250 MPa, 35 °C for 15 min) and thermal treatment (80 °C for 1 min) reduced the microbial load of carrot and tomato juices to undetectable levels. Different combinations of HHP did not cause a significant change in the ascorbic acid content of either juice (P > 0.05). Both heat treatments (60 °C for 5–15 min and 80 °C for 1 min) resulted in a significant loss (P < 0.05) in the free‐radical scavenging activity as compared to untreated samples. HHP‐treated juices showed a small loss of antioxidants (below 10%) during storage. The ascorbic acid content of pressurized tomato and carrot juices remained over 70 and 45% after 30 days of storage, respectively. However, heat treatment caused a rapid decrease to 16–20%. Colour changes were minor (ΔE = 10) for pressurised juices but for heat‐pasteurised samples it was more intense and higher as a result of insufficient antioxidant activity. HHP treatment (250 MPa, 35 °C for 15 min) led to a better product with regard to anti‐radical scavenging capacity, ascorbic acid content and sensory properties (colour, pH) of the tomato and carrot juices compared to conventional pasteurisation. Therefore, HHP can be recommended not only for industrial production but also for safe storage of fresh juices, such as tomato and carrot, even at elevated storage temperatures (25 °C). Copyright © 2007 Society of Chemical Industry     

Effects of high hydrostatic pressure on shelf life of lager beer

Filtered bright lager beer samples were either treated with high hydrostatic pressure (HHP, 350 MPa for 3 and 5 min at 20 °C) or conventional heat pasteurization (60 °C for 15 min). A storage period of 56 days showed that HHP and heat pasteurization had similar results in terms of pH and color (p<0.05). However HHP-treated samples had lower bitterness and protein sensitivity and higher chill haze values than the heat pasteurized samples at the end of the storage period. The microbiological stability of HHP-treated beers was the same as that of heat-treated beers, and the development of both lactic and acetic acid bacteria was inhibited for 56 days of storage. Although more studies should be carried out to investigate the effects of HHP treatment on different types of lagers and ales, our results revealed that HHP could be successfully used to increase the shelf life of beer even at temperatures well below those required for heat pasteurization.     

Effect of combined treatments of ultrasound and high hydrostatic pressure processing on the physicochemical properties,microbial quality and shelf-life of cold brew tea

Effects of ultrasound combined with high hydrostatic pressure (HHP) on physicochemical properties,microorganisms and storage attributes of cold brew tea were investigated. HHP at 400 MPa/5 min/25 °C inactivated the total aerobic bacteria, yeast and mould in cold brewed tea prepared by static brewing (SB-tea) at 13 h/4 °C, ultrasonic bath (UB-tea) at 150 W/120 min/0 °C and ultrasonic pulveriser (UP-tea) at 600 W/40 min/0 °C, ensuring their microbiological safety. The results showed that there was no significant difference in the concentration of tea polyphenols between hot brewed tea prepared by 7 min/100 °C and cold brewed tea under different preparation conditions, while the caffeine in cold brewed tea was significantly lower (P < 0.05) than that in hot brewed tea. During the storage period of 8 days, compared with the untreated group, the cold brewed tea after HHP treatment had better microbiological safety. In addition, HHP treatment constantly maintained the tea polyphenols, pH, colour, antioxidant capacity and turbidity in cold brewed tea. The untreated and HHP-treated cold brew tea were evaluated by 20 trained volunteers. Results showed that UB-tea was more close to SB-tea than UP-tea in sensory profile, while HHP seem to maintain a good sensory profile as well. Therefore, this particular combined technology of ultrasonic bath and HHP displayed considerable potential for application in the cold brew tea manufacturing industry.     

Inactivation of peroxidase and lipoxygenase in carrots, green beans, and green peas by combination of high hydrostatic pressure and mild heat treatment

The efficiency of high hydrostatic pressure (HHP) with the combination of mild heat treatment on peroxidase (POD) and lipoxygenase (LOX) inactivation in carrots, green beans, and green peas was investigated. In the first part of the study, the samples were pressurized under 250–450 MPa at 20–50 °C for 15–60 min. In the second part, two steps treatments were performed as water blanching at 40–70 °C for 15 and 30 min after pressurization at 250 MPa and 20 °C for 15–60 min. Carrot POD was decreased to 16% residual activity within the first 30 min at a treatment condition of 350 MPa and 20 °C and then it decreased to 9% at 60 min. When the carrots were water blanched at 50 °C for 30 min after HHP treatment of 250 MPa at 20 °C for 15 min, 13% residual POD activity was obtained. For green beans, the most effective results were obtained by two steps treatment and approximately 25% residual POD activity was obtained by water blanching at 50 °C for 15 min after pressurization at 250 MPa and 20 °C for 60 min. An effective inactivation of POD in green peas was not obtained. For carrots, LOX activity could not be measured due to very low LOX activity or the presence of strong antioxidants such as carotenoids. After pressurization at 250 MPa and 20 °C for 15 or 30 min, water blanching at 60 °C for 30 min provided 2–3% residual LOX activity in green beans. The treatment of 250 MPa for 30 min and then water blanching at 50 °C for 30 min provided 70% LOX inactivation in green peas.     

Effect of high hydrostatic pressure on quality parameters of lager beer

Unpasteurized lager beer samples from a commercial brewery were treated either by high hydrostatic pressure (HHP; 200, 250, 300, 350 MPa for 3 and 5 min at 20 °C) or by conventional heat pasteurization (60 °C for 15 min). The main attributes of the beer, such as ethanol content, extract and pH, were not affected by either treatment; however HHP and heat pasteurization affected colour, chill haze, protein sensitivity and bitterness. Change in bitterness was higher in conventional heat pasteurization, but pressures up to 300 MPa had no significant affect on bitterness. Although more studies should be carried out to investigate the effects of HHP treatment on different types of lagers and ales, our results revealed that HHP could be successfully used to process beer, even at temperatures well below those required for heat pasteurization, without affecting some of the quality attributes. Copyright © 2005 Society of Chemical Industry     

Effect of High-Pressure Processing on Physical, Biochemical, and Microbiological Characteristics of Black Tiger Shrimp (Penaeus monodon)

The effect of high-pressure processing on quality and shelf life of black tiger shrimp was studied. Shrimp was high-pressure processed at selected pressure levels of 100, 270, and 435 MPa for 5 min at room temperature (25?±?2 °C). Changes in physical, biochemical, and microbiological characteristics after processing and during subsequent chilled storage were examined for 35 days. After processing significant (P?<?0.05) increase in moisture content and parallel reduction in protein content was observed. No significant changes were observed in TVB-N and TMA-N levels of shrimp after processing; however, these significantly increased with storage. Whiteness index increased with pressure intensity imparting brighter and mildly cooked appearance. Pressure-induced hardening effect was observed, which showed decreasing trend during storage. The treated samples maintained lower viable counts throughout the storage, thus having better microbial quality than untreated sample. Shelf life was extended to 15 days in shrimp treated at 435 MPa compared with 5 days in untreated sample. Pressure treatment of 435 MPa was found to be most effective in preserving the quality and extending the shelf life of black tiger shrimp.     

Influence of packaging strategy on microbiological and biochemical changes in high‐pressure‐treated oysters (Crassostrea gigas)

BACKGROUND: High‐pressure (HP) treatment is being increasingly employed for commercial processing of oysters, but there is relatively limited information on the microbiological quality and enzymatic activity of HP‐treated in‐shell oysters. The objective of this research was to study the influence of packaging strategy on microbiological and biochemical changes in oysters HP treated at 260 MPa for 3 min or 400 MPa for 5 min at 20 °C and stored at 0 °C either aerobically on ice, in vacuum packaging (VP) or under modified atmosphere packaging (MAP; 40% CO₂, 60% N₂), compared with changes in untreated oysters. RESULTS: Both HP treatments reduced the microbiological load to below the detection limit (<100 colony‐forming units g^?1). MAP and VP also delayed subsequent microbial growth compared with aerobically stored samples. After 21 days of storage, total volatile base levels remained lower than the proposed acceptability limits for all samples; however, after 28 days, only oysters HP treated at 400 MPa, irrespective of the packaging system used, did not exceed this limit. HP increased the thiobarbituric acid‐reactive substance (TBARS) values of oysters, indicating increased lipid oxidation. During storage, TBARS values of all MAP and VP oysters remained lower than those of aerobically stored oysters. CONCLUSION: HP treatment, in combination with adequate chilled storage and MAP, can extend the shelf‐life and safety of oysters. Copyright © 2008 Society of Chemical Industry     

Quality Attributes and Shelf Life of High-Pressure Preserved Beef as Affected by Pre-treatment Conditions

This study analyzed the effects of high hydrostatic pressure (HHP) and composition of the pre-treatment immersion step, on quality attributes (color and lipid oxidation) and shelf life based on microbial counts of a beef product, during cold storage at 0 °C. Meat slices were immersed in a preservative solution containing sodium nitrite, ascorbic acid, and two different concentrations of NaCl (30 and 60 g/L); HHP of 400 and 600 MPa were applied. Results were compared with those of an untreated beef control. Color parameters of the HHP-treated beef were visually acceptable (a* > 14) in all tested cases, although they were affected by NaCl concentration and the applied pressure. HHP increased TBARS index, observing higher values at 600 than at 400 MPa; samples immersed in the solution containing 30 g/L NaCl presented higher TBARS values. However, in all cases, they remained below the detection limit of rancid meat products (<1 mg MDA/kg). Beef samples immersed in the solution with the highest concentration of NaCl (60 g/L) and subjected to 400 or 600 MPa maintained their microbial stability over 5 and 6 weeks, respectively, at 0 °C; these shelf life values were higher than those observed in the samples treated with 30 g/L NaCl.     

Effects of High Hydrostatic Pressure on the Physical,Microbial, and Chemical Attributes of Oysters (Crassostrea virginica)

The change in the quality attributes (physical, microbial, and chemical) of oysters (Crassostrea virginica) after high hydrostatic pressure (HHP) treatment at 300 MPa at room temperature (RT, 25 °C) 300, 450, and 500 MPa at 0 °C for 2 min and control oysters without treatment were evaluated over 3 wk. The texture and tissue yield percentages of oysters HHP treated at 300 MPa, RT increased significantly (P < 0.05) compared to control. Aerobic and psychrotrophic bacteria in control oysters reached the spoilage point of 7 log CFU/g after 15 d. Coliform counts (log MPN/g) were low during storage with total and fecal coliforms less than 3.5 and 1.0. High pressure treated oysters at 500 MPa at 0 °C were significantly higher (P < 0.05) than oysters HHP treated at 300 MPa at 0 °C in lipid oxidation values. The highest pressure (500 MPa) treatment in this study, significantly (P < 0.05) decreased unsaturated fatty acid percentage compared to control. The glycogen content of control oysters at 3 wk was significantly higher (P < 0.05) when compared to HHP treated oysters [300 MPa, (RT); 450 MPa (0 °C); and 500 MPa (0 °C)]. HHP treatments of oysters were not significantly different in pH, percent salt extractable protein (SEP), and total lipid values compared to control. Based on our results, HHP prolongs the physical, microbial, and chemical quality of oysters.     

Effect of innovative food processing technologies on microbiological quality,colour and texture of fresh-cut potato during storage

The objective of this work was to find the optimal conditions that extend the shelf life of fresh-cut potatoes using innovative food processing technologies. Potato cultivar, Longshu No. 10, was treated with high hydrostatic pressure (HHP) with 200 MPa (HHP 200) for 2, 6 and 10 min, and HHP with 400 MPa (HHP 400) for 1, 2 and 6 min; electrolysed water with pH 5.2 (EW 5.2) for 2, 5 and 10 min of soaking; and ultrasonic (US) with 200 W (US 200) for 5 and 10 min, and US with 500 W (US 500) for 5, 10 and 15 min. Microbiological quality, colour and textural changes and polyphenol oxidase (PPO) activity were determined during 12 days of storage at 4 °C. Processing technologies showed an effect on reducing the microbial load of fresh-cut potatoes with respect to control. EW (5 min) and US (500 W for 15 min) were the best treatments in terms of colour, and these treatments did not modify the texture of the fresh-cut potato, which make them promising for extending the shelf life of fresh-cut potatoes. Also, the US treatment showed the lowest PPO activity.     

The effects of high hydrostatic pressure at subzero temperature on the quality of ready-to-eat cured beef carpaccio

We compared the application of high hydrostatic pressure (HHP) on unfrozen carpaccio (HHP at 20 °C) and on previously-frozen carpaccio (HHP at − 30 °C). HHP at 20 °C changed the color. The pressure increase from 400 to 650 MPa and the time increment from 1 to 5 min at 400 MPa increased L* and b*. a* decreased only with 650 MPa for 5 min at 20 °C. The prior freezing of the carpaccio and the HHP at − 30 °C minimized the effect of the HHP on the color and did not change the shear force, but increased expressible moisture as compared to the untreated carpaccio. HHP at 20 °C was more effective in reducing the counts of microorganisms (aerobic total count at 30 °C, Enterobacteriaceae, psychrotrophs viable at 6.5 °C and lactic acid bacteria) than HHP at − 30 º C. With HHP at 20 °C, we observed a significant effect of pressure and time on the reduction of the counts.