Enrichment of free amino acid content and reduction of astringent taste compounds in soybean by high hydrostatic pressure

ABSTRACT

We investigated the effect of high hydrostatic pressure (HHP) on the distribution of free amino acids and isoflavones in soybean immediately after pressure treatment (100–600?MPa, 10–60?min). HHP-treatment at 200 and 300?MPa resulted in high accumulation of free amino acids. Additionally, Gly, Val, and Pro levels increased even after HHP of 400?MPa. The application of HHP-treatment to soybean decreased sources of an astringent taste such as genistein-, daizein-, and glycitein-type molecules under all pressure conditions over 200?MPa. High accumulation of free amino acids with specific pressure–time conditions would be caused by the acceleration of proteolysis and specific amino acid metabolism. We concluded that HHP alone with no subsequent storage enabled the enrichment of specific amino acids such as GABA, Glu, Lys, and Pro in soybean. Soybean with enrichment of these amino acids and improved taste should be an innovative component of functional foods.     

The variability of times to detect growth from individual Clostridium botulinum type E endospores is differentially affected by high pressure treatments

High pressure thermal (HPT) processing is a candidate technology for the production of safe and stable food. However, little is known about the effect of HPT or high hydrostatic pressure (HHP) treatments at ambient temperature on the variability of times to detect growth from individual spores. We investigated this effect by treating Clostridium botulinum type E spores with HHP (200–600?MPa, 20°C) and HPT (600?MPa, 80°C and 800?MPa, 60°C). Our results indicate that the mean detection times increase and the frequency distribution shifts toward longer times when HHP treatment intensity is increased. HPT treatments result in a highly scattered distribution. In contrast, pressure levels ≤300?MPa decrease detection times and heterogeneity of their distribution, which could lead to an increase in the potential risk originating from C. botulinum type E spores. Data provided here could help to refine risk assessment regarding this important food intoxicator.     

Effect of high hydrostatic pressure processing and squeezing pressure on some quality properties of pomegranate juice against thermal treatment

The aim of this study was to investigate the effect of high hydrostatic pressure (HHP) treatment (200, 300, 400?MPa; 5°C, 15°C and 25°C; 5 and 10 min) on some quality properties of pomegranate juice. Juice samples are obtained under industrial conditions at two different squeezing pressure levels (100 and 150?psi – 0.689 and 1.033?MPa, respectively). Results are compared against conventional thermal treatment (85°C/10 min) and raw sample. For all three processing temperature, HHP combinations at 400?MPa for 10 min were sufficient to decrease the microbial load around 4.0 log cycles for both squeeze levels. All HHP treatments showed no significant decrease at antioxidant activity, total phenolic content and monomeric anthocyanin pigment concentrations, while there was a significant decrease (p?≤?.05) in thermal-treated samples. Being the highest sugar alcohol in pomegranate juice, mannitol content must be considered for determining the authenticity, and mannitol content increased with squeezing pressure and thermal treatment.     

Effects of high hydrostatic pressure on β-glucan content,swelling power,starch damage,and pasting properties of high-β-glucan barley flour

ABSTRACT

The effects of high hydrostatic pressure (HHP) on the physicochemical properties of high-β-glucan barley flour were investigated in the present study. Dough samples were made from two types of barley flour with low and high β-glucan content, respectively, and treated with HHP (200–600?MPa) for 10?min. Although the elevation of pasting properties for the samples treated at 600?MPa was reduced to the same extent as that in wheat flour at normal atmospheric pressure, β-glucan content was maintained regardless of the pressure applied. The significant increase in starch damage of the dough samples at 550 and 600?MPa was confirmed by the results of microscopic observation, which revealed that elliptical starch granules were cracked and damaged in samples with low β-glucan at 600?MPa, and in samples with high β-glucan content at 400?MPa or more. X-ray diffraction patterns of the samples treated at 600?MPa indicated the formation of amylose-lipid complexes that were considered to inhibit the elevation of viscosity.     

Effect of high pressure on growth and bacteriocin production of Pediococcus acidilactici HA-6111-2

This study was aimed to investigate the effect of high pressure processing (HPP, 200–600?MPa) on the (i) survival of Listeria innocua and Pediococcus acidilactici HA-6111-2; (ii) production of bacteriocin bacHA-6111-2 and (iii) activity of bacteriocin against untreated and pressure-treated L. innocua cells. Inactivation of P. acidilactici was observed for pressures of >300?MPa. However, at this pressure level, L. innocua was more sensitive. Bacteriocin crude extract was pressure stable, with a decrease for pressures of ≥400 MPa. Pressures of ≤200?MPa did not affect bacteriocin production when compared with non-pressure-treated cells, whereas higher pressures caused a 2- to 4-fold decrease on the maximum level of bacteriocin production. Growth curves of P. acidilactici were fitted with the modified Gompertz model. The lag phase period depended on the magnitude of the pressure applied: there was a delay in the exponential phase as pressure increased and, as a consequence, in the beginning of bacteriocin production. Since P. acidilactici HA-6111-2 and its bacteriocin have shown resistance to pressures up to 300–400 MPa, they could be used in combination with HPP in order to improve food safety.     

Optimization of high pressure processing parameters of Indian white prawn (Fenneropenaeus indicus)

The effect of pressure (150, 250 and 350?MPa), ramp rate (200, 400 and 600?MPa/min) and holding time (3, 6 and 9?min) on the quality indices (dependent variable) of Indian white prawn (Fenneropenaeus indicus) was optimized using response surface methodology. Box–Behnken response surface design was used with 15 runs. Second-order response surface model was fitted to the experimental data and the model adequacy was measured by R² value. The linear and quadratic effect of pressure, ramp rate and holding time was significant for tri-methylamine, total volatile base nitrogen and total plate count. Based on the ridge analysis and response surface plots, the optimum combination obtained was 250?MPa pressure, 400?MPa/min ramp rate and 6?min holding time for high pressure (HP) processing of Indian white prawn. Validation of the experiment indicated that the developed model was appropriate to predict quality indices in Indian white prawn processed by HP processing.     

Effect of high hydrostatic pressure and reducing sodium chloride and phosphate on physicochemical properties of beef gels

ABSTRACT

The effect of high hydrostatic pressure (HHP) treatment (100–200?MPa, 10?min, 20°C) combined with sodium chloride and sodium phosphate on the physicochemical properties of beef gels was investigated. The water content, cooking losses, color, protein composition by SDS-PAGE analysis and texture parameters of beef gels were determined. The beef gels treated with high pressure at 150?MPa showed a synergistic effect in the increased water content and the decreased cooking losses compared with the unpressurized gels. The L*, a* and b* color values of beef gels were slightly decreased under HHP treatment at 100–200?MPa. In the SDS-PAGE analysis, the staining intensity of the α-actinin protein band was decreased in pressurized samples. The cohesiveness, adhesiveness, gel strength and modulus of elasticity were improved after HHP treatment. Application of high pressure treatment (150–200?MPa) before heat treatment would be beneficial for the manufacturing of low salt and/or low phosphate meat products for a healthy diet.     

Effects of high hydrostatic pressure on secondary structure and emulsifying behavior of sweet potato protein

In this study, secondary structures of sweet potato protein (SPP) after high hydrostatic pressure (HHP) treatment (200–600?MPa) were evaluated and emulsifying properties of emulsions with HHP-treated SPP solutions in different pH values (3, 6, and 9) were investigated. Circular dichroism analysis confirmed the modification of the SPP secondary structure. Surface hydrophobicity increased at pH 3 and decreased at 6 and 9. Emulsifying activity index at pH 6 increased with an increase in pressure, whereas emulsifying stability index increased at pH 6 and 9. Oil droplet sizes decreased, while volume frequency distribution of the smaller droplets increased at pH 3 and 6 with the HHP treatment. Emulsion viscosity increased at pH 6 and 9 and pseudo-plastic flow behaviors were not altered for all emulsions produced with HHP-treated SPP. These results suggested that HHP could modify the SPP structure for better emulsifying properties, which could increase the use of SPP emulsion in the food industry.     

Effects of High Pressure Treatment on the Microbiological Quality,Texture and Colour of Vacuum Packed Pork Meat Products

The aim of the study was to define usefulness of high pressure treatment for inactivation of microorganisms and prolongation of shelf life of two types of cooked pork ham and raw smoked pork loin. The samples of ham and loin in the presentation of standard 200 g pieces were vacuum packed in polylayer polyethylene bags and exposed to high pressure treatment in the range of 300-600 MPa and time of exposure of 10-30 minutes. Results indicate that 300 MPa and 400 MPa pressure applied for 10 minutes was insufficient for prolongation of storage period of ham. Pressure of 500 MPa, applied for 10 minutes caused significant decrease of microbiological parameters studied such as: total bacterial count, psychrophylic bacteria, acidophylic bacteria and enterococci in investigated samples, stored in refrigarator conditions for 4 weeks. Pressure of 600 MPa applied for 10 minutes reduced the number of all investigated microorganisms by 10 5 -10 6 fold. Application of this pressure prolonged storage period of traditionally produced ham to 6-8 weeks. Physico-chemical characteristics of ham, measured 24 h after high pressure treatment and after 4, 6 and 8 weeks of storage, did not change when compared to the initial samples. High pressure treatment caused increase in the colour lightness parameters only in pork smoked loin.     

高压与加热协同处理对牛肌肉中蛋白酶活性的影响

在不同温度(20～60℃)和压力(0.1～600 MPa)下处理20 min,对牛肌肉中蛋白酶活性的影响进行了研究.结果显示:室温下,随着处理压力的增加,酶的活力显著下降,而压力达400 MPa及以上时,酶的活力则没有明显变化,同时在pH值为3和7.5时酶的活性几乎完全丧失.200 MPa以下的压力处理使肌肉中游离氨基...     

Effect of high pressure treatment on liquid whole egg

In our tests, we artificially infected liquid whole egg samples with Salmonella enteritidis, Listeria monocytogenes, and Staphylococcus aureus bacteria, and then treated the samples in “Food Lab900” high hydrostatic pressure (HHP) instrument for 3–17 min at 200–400 MPa. Subsequently, the change of the viable cell count of the specific bacteria has been tested. In addition to the samples infected with various bacteria, non-infected samples were also treated in each test and the change in viable cell count, colour and viscosity of the samples upon the effect of the treatment. In summary, it can be concluded that in each test of our investigations, the viable cell count of S. enteritidis critical for egg products is reduced significantly, while the reduction of the total viable cell count was around two magnitudes. Additionally, based on our results, microbial destruction, reduction of enthalpy (denaturation of egg white) caused by the treatment at HPP, and colour change are primarily affected by the pressure level, while the changes in rheological properties are also significantly affected by the duration of high pressure treatment (p<0.05).     

Preparation of black soybean (Glycine max L) extract with enhanced levels of phenolic compound and estrogenic activity using high hydrostatic pressure and pre-germination

We investigated the influence of high hydrostatic pressure (HHP) treatment on the estrogenic properties and conversion of the phenolic compounds in germinated black soybean. The black soybean was germinated for two- or four-days, and then subjected to HHP at 0.1, 50, 100, or 150?MPa for 12 or 24?h. The highest total polyphenol content (3.9?mg GAE/g), flavonoid content (0.8?mg?CE/g), phenolic acid content (940?±?18.96?μg/g), and isoflavonone content (2600?μg/g) were observed after germination for four days and HHP treatment at 100?MPa for 24?h. In terms of isoflavone composition, the malonyl, acetyl and β-glycoside contents decreased, while the aglycone content increased with HHP. The highest proliferative effect (150%) is observed at four days germination and HHP treatment at 100?MPa. These results suggest that application of HHP may provide useful information regarding the utility of black soybean as alternative hormone replacement therapy.     

Listeria monocytogenes cells injured by high hydrostatic pressure and their recovery in nutrient-rich or -free medium during cold storage

ABSTRACT

Cells of Listeria monocytogenes suspended in phosphate-buffered saline (PBS) were treated by high hydrostatic pressure (HHP; 500?MPa, 25°C, 10?min), diluted by ten folds using trypticase soy broth (TSB) or PBS, and stored at cold temperatures of 0–15°C. Viable cell count in TSB increased logarithmically close to the initial count at each storage temperature, while that in PBS increased temporarily and subsequently decreased to almost nondetectable level except the case at 15°C, where it showed logarithmic increase thereafter. Based on proliferation experiments where their healthy cells were inoculated to TSB or to PBS containing their heat-killed dead cells, it was suggested that increase in the viable count of HHP-treated cells in TSB and PBS could be ascribed to the recovery of colony forming ability and/or proliferation depending on the cold storage temperature.     

High hydrostatic pressure pasteurization of a draft sake brewed using a Niigata-sake yeast

ABSTRACT

Draft (non-pasteurized) sake typically has a fresh flavor, but usually has to be consumed as soon as possible because of its short shelf life due to the potential for over-fermentation by residual yeast. In contrast, thermally pasteurized sake has a long shelf life, but the fresh flavor is lost during heat sterilization. High hydrostatic pressure (HHP) treatment can be used as a non-thermal pasteurization process while maintaining the characteristics of a draft sake. We evaluated the HHP inactivation behavior of sake yeast for the application of HHP pasteurization as an alternative to thermal pasteurization. The results showed complete pasteurization of sake yeast in the draft sake by HHP treatment at 400?MPa for 10?min. The viable cell count in HHP-pasteurized sake was below the detection limit during storage at 10°C for 3 months. Thus, we have established a HHP pasteurization technology to prevent over-fermentation and succeeded in producing a prototype of HHP-sparkling-cloudy sake, which we have designated AWANAMA.     

Effect of high pressure processing on textural and microbiological quality of pink perch (Nemipterus japonicus) sausage during chilled storage

The non-thermal high pressure (HP) processing was studied on fish sausage to enhance the quality during chilled storage. Pink perch (Nemipterus japonicus) sausages, packed in poly amide casing under vacuum were subjected to 400, 500 and 600?MPa pressures (dwell time: 10?min and ramp rate: 300?MPa/min) and compared with heat-set samples for physico-chemical and microbial quality parameters. Pressurized samples formed softer and glossier gels with a slight reduction in water-holding capacity. HP made the texture of sausage softer, cohesive and less chewy and gummier than heat-treated ones. Folding test seen higher acceptance values in samples treated at 500 and 600?MPa, during storage. Maximum log reduction in microbial count was observed in 600?MPa immediately, and significant difference in cooked and pressurized sausages was seen only up to 7th day. This revealed the potential application of HP in replacing conventional heat treatment for sausages preparation with enhanced shelf-life.     

Effect of high hydrostatic pressure on the profile of proteins extracted from Betula pendula pollens

High hydrostatic pressure (HHP) has high success potential in pollen protein extraction, but its effect on pollen protein profiles has not been studied yet. The aim of this study is to put forward whether HHP processing causes a change in the protein profiles extracted from pollens or not. In this study, proteins extracted from Betula pendula pollens were studied at 100, 200 and 300?MPa at room temperature for 5?min. In addition, the efficiency of three different extraction solvents, namely phosphate buffer saline (PBS) buffer pH 7.5, trichloroacetic acid–acetone and Tris–HCl buffer pH 8.8, was also observed, and the results were compared with the conventional pollen protein extraction procedure. As a result, it is concluded that 200?MPa for 5?min has extracted similar amounts of protein compared with the conventional extraction method which lasted for 24?h, which lasted for 24 h. On the other hand, the application time for 200 MPa for 5 min is extremely shorter when it is compared to the conventional extraction method.     

Impacts of sonication and high hydrostatic pressure on the structural and physicochemical properties of quinoa protein isolate dispersions at acidic,neutral and alkaline pHs

Herein, 1 wt% quinoa protein isolate (QPI) was exposed to sonication using a 20 kHz ultrasonicator equipped with a 6 mm horn (14.4 W, 10 mL, up to 15 min) or high hydrostatic pressure (HHP, up to 600 MPa, 15 min) treatments at pH 5, pH 7, and pH 9. The changes to physicochemical properties were probed by SDS-PAGE, FTIR, free sulfhydryl group (SH), surface hydrophobicity (H₀), particle size and solubility. As revealed by SDS-PAGE, substantial amounts of 11S globulin participated in the formations of aggregates via SS bond under HHP, particularly at pH 7 and pH 9. However, protein profiles of QPI were not significantly affected by the sonication. Free SH groups and surface hydrophobicity were increased after the sonication treatment indicating protein unfolding and exposure of the embedded SH and/or hydrophobic groups. An opposite trend was observed in HHP treated samples, implying aggregation and reassociation of structures under HHP. HHP and sonication treatments induced a decrease in ordered secondary structures (random coil and β-turn) accompanied with an increase in disordered secondary structures (α-helix and β-sheet) as probed by FTIR. Finally, the sonication treatment induced a significant improvement in the solubility (up to ∼3 folds at pH 7 and ∼2.6 folds at pH 9) and a reduction in particle sizes (up to ∼3 folds at pH 7 and ∼4.4 folds at pH 9). However, HHP treatment (600 MPa) only slightly increased the solubility (∼1.6 folds at pH 7 and ∼1.2 folds at pH 9) and decreased the particle size (∼1.3 folds at pH 7 and ∼1.2 folds at pH 9). This study provides a direct comparison of the impacts of sonication and HHP treatment on QPI, which will enable to choose the appropriate processing methods to achieve tailored properties of QPI.     

Use of pulsed-high hydrostatic pressure treatment to decrease patulin in apple juice

This study was aimed at reducing patulin content of apple juice using a non-thermal method, namely pulsed-high hydrostatic pressure (p-HHP). Commercially available clear apple juice was contaminated artificially with different concentrations of patulin (5, 50 and 100?ppb). Then, the samples were processed 5?min at different pressure treatments (300–500?MPa) in combination with different temperatures (30–50°C) and pulses (6 pulses?×?50?s and 2 pulses?×?150?s). To compare the impact of pulses, single pulse of high hydrostatic pressure (HHP) treatment was also applied with the same pressure/temperature combinations and holding time. Results indicated that pressure treatment in combination with mild heat and pulses reduced the levels of patulin in clear apple juice up to 62.11%. However, reduction rates did not follow a regular pattern. p-HHP was found to be more effective in low patulin concentrations, whereas HHP was more effective for high patulin concentrations. To the best of our knowledge, this is the first study using p-HHP to investigate the reduction of patulin content in apple juice.     

Size reduction of “reformed casein micelles” by high-power ultrasound and high hydrostatic pressure

We investigated the effect of ultrasound (US) and high hydrostatic pressure (HHP) on the size of reformed casein micelles (RMCs) obtained by titrating calcium and phosphorous solution into sodium caseinate solutions. Both US and HHP reduced the size of the RMCs. A decrease in size from ~200 nm to ~170 nm when US (20 kHz, 0.46 W/mL) was applied for 30 min; and down to ~85 nm when HHP was applied 500 MPa for 15 min. Electron microscopic analysis showed that the RMCs before and after US are similar to milk native casein micelles, and that HHP extensively disintegrated the RMCs. Small angle X-ray scattering and SDS-PAGE showed that the internal structure of the RMCs as well as the casein molecules are not affected by the US and HHP treatments.     

Combined of ultrasound irradiation with high hydrostatic pressure (US/HHP) as a new method to improve immobilization of dextranase onto alginate gel

In this research work, dextranase was immobilized onto calcium alginate beads by the combination of ultrasonic irradiation and high hydrostatic pressure (US/HHP) treatments. Effects of US/HHP treatments on loading efficiency and immobilization yield of dextranase enzyme onto calcium alginate beads were investigated. Furthermore, the activities of immobilized enzymes prepared with and without US/HHP treatments and that prepared with ultrasonic irradiation (US) and high hydrostatic pressure (HHP), as a function of pH, temperature, recyclability and enzyme kinetic parameters, were compared with that for free enzyme. The maximum loading efficiency and the immobilization yield were observed when the immobilized dextranase was prepared with US (40 W at 25 kHz for 15 min) combined with HHP (400 MPa for 15 min), under which the loading efficiency and the immobilization yield increased by 88.92% and 80.86%, respectively, compared to immobilized enzymes prepared without US/HHP treatment. On the other hand, immobilized enzyme prepared with US/HHP treatment showed V_max, K_M, catalytic and specificity constants values higher than that for the immobilized enzyme prepared with HHP treatment, indicated that, this new US/HHP method improved the catalytic kinetics activity of immobilized dextranase at all the reaction conditions studied. Compared to immobilized enzyme prepared either with US or HHP, the immobilized enzymes prepared with US/HHP method exhibited a higher: pH optimum, optimal reaction temperature, thermal stability and recyclability, and lower activation energy, which, illustrating the effectiveness of the US/HHP method. These results indicated that, the combination of US and HHP treatments could be an effective method for improving the immobilization of enzymes in polymers.