Effect Of Ultra-high Pressure Research Articles

Spinodal decomposition, ordering, and precipitation transformation in CoCrFeNiAl HEAs under GPa pressure

Pressure is a critical component of preparation processes regardless of its magnitude, whether it is a few megapascals, such as in metal squeeze casting, or thousands of megapascals, such as in the experimental preparation of amorphous materials, quasicrystals and nanocrystals. Spinodal decomposition and ordering are two common forms of unstable phase transformation in solid solutions. Reasonable regulation of these two transformations can effectively control microstructures and improve properties. Therefore, the study of solid solution instability under the effect of ultrahigh pressure is of great significance for regulating the properties of high-entropy alloys (HEAs). From this perspective, CoCrFeNiAl HEAs were prepared under pressures of ambient pressure, 4 GPa and 7 GPa. Both solid spinodal decomposition and ordering of the BCC structure were detected when CoCrFeNiAl HEAs are solidified at ambient pressure. Nevertheless, after high-pressure solidification, liquid‒liquid phase spinodal decomposition occurred. One phase was rich in (Fe, Cr), and the other phase was rich in (Ni, Al). Both phases experienced solid spinodal decomposition during cooling. Discontinuous precipitates were generated in the (Ni, Al)-rich solid phase, each with a size of approximately 1.4 μm. Furthermore, a graphic thermodynamic model was established to reveal the solidification behavior. After solidification at 7 GPa, the corrosion rate of the alloy decreased by 98.3 %; that is, the high pressure greatly improved the corrosion resistance of the alloy. This improvement was attributed to the influences of high pressures on the dynamics of spinodal decomposition processes.

Effect of ultra-high pressure on the relationship between endogenous proteases and protein degradation of Yesso scallop (Mizuhopecten yessoensis) adductor muscle during iced storage.

This study aimed to explore the effect of ultra-high pressure (UHP) treatment (100-500MPa, 5min, 15±1℃) on the relationship between endogenous proteases and protein degradation of Yesso scallop (Mizuhopecten yessoensis) adductor muscle during iced storage for 28days. Our findings showed that the UHP treatment kept the water holding capacity stable, increased the hardness and decreased the springiness of scallop adductor muscle during iced storage. 400 and 500MPa UHP treatments caused protein denaturation and oxidation significantly, decreased protein degradation rate and inhibited the activities of endogenous proteases. According to the correlation analysis, the activities of cathepsin B, D, H, L, calpain and serine protease were positively correlated with TCA-soluble peptides. The activities of endogenous proteases were significantly correlated with protein degradation. Therefore, the effect of UHP on endogenous protease caused the protein degradation rate to slow down and prevented the texture deterioration in scallops.

Effect of ultra-high pressure treatment on the characteristics of a tea polysaccharide conjugate aqueous solution

Previous studies have shown that ultra-high pressure (UHP) processing technology to extract, prepare, and sterilize tea beverages (tea infusion) significantly increases the extraction rate of tea polyphenols (catechins), free amino acids, caffeine, and other small molecules in green tea, besides sterilizing and inactivating residual oxidases, such as polyphenol oxidase and peroxidase. UHP avoids the deterioration of color and aroma, as high-quality green tea infusions were obtained with nutritional value and flavor quality close to the original tea. However, the effect of UHP on polysaccharides in green tea infusions is unclear. The water-extracted tea polysaccharide conjugates (TPC-W) and alkali-extracted tea polysaccharide conjugates (TPC-A) from low-grade green tea were subjected to a UHP treatment of 100, 300, and 500 MPa for 5, 12, and 25 min. The circular dichroism (CD) spectra results showed that UHP transformed the secondary structure of the TPC-W and TPC-A from compact and ordered α-helices and β-sheets to disordered β-turns and random coils; one component of TPC-A was dissociated into two components. The absolute values of the zeta potential of TPC-W treated with 100, 300, and 500 MPa increased by 2.4–5.6, 5.3–8.0, and 5.5–9.1 mV, while those of TPC-A increased by 0.5–2.8, 3.5–5.5, and 4.8–6.9 mV, respectively. The stability of TPC-W and TPC-A aqueous solutions treated with 300 and 500 MPa was enhanced during storage at 5°C. These findings will contribute to applying UHP for tea beverage processing and in-depth investigations on the physiochemical properties of TPC, particularly the protein moiety.

Effect of ultrahigh pressure on structural and physicochemical properties of rice and corn starch in complexes with apple polyphenols.

Ultrahigh-pressure (UHP) treatment, a non-thermal processing technology, exerts a bactericidal effect and affects food texture. How UHP treatments influence starch-polyphenol complexes has not yet been reported. Here, we studied the effects of UHP treatment on the structure of common rice starch (CRS)-apple polyphenol (AP) and common corn starch (CCS)-AP mixtures. Overall, UHP treatment decreased the particle size of the CRS-AP and CCS-AP composites. Furthermore, the ΔH values of the CRS-AP and CCS-AP mixtures decreased, and the heating stability was improved after UHP treatment. X-ray diffraction indicated that the relative crystallinity of the mixtures was unaffected by UHP treatment. Fourier-transform infrared spectroscopy proved that no new absorption peaks were observed in the infrared spectra, and the order of starch-AP was decreased after UHP treatment. These results indicated that UHP treatment inhibited the retrogradation of the starch-AP mixture. Our analyses of the microstructures of CRS-AP and CCS-AP mixtures showed increased folding and more pronounced network structures under high-pressure. These results provide a theoretical basis for further exploring the properties of starch-AP mixtures following UHP treatment and provide insights regarding the use of UHP treatments for food production. © 2020 Society of Chemical Industry.

Ultra-High Pressure Chilled Meat Processing: A Promising Storage Method

The positive effect of ultra-high pressure on the shelf life of chilled meat during refrigerated storage has been established. It has been proven that 6 minutes meat processing at the 800 MPa pressure provides high organoleptic characteristics (color, smell, texture), microbiological safety, so KMAFAnM, yeast and other studied parameters do not exceed the requirements of the technical regulation of the Customs Union “On Food Safety” (TR TS 021/2011), prevents the breakdown of protein and does not result into oxidative damage. At that time, samples of chilled meat not processed by pressure, after 60 days of refrigerated storage, corresponded to stale meat according to organoleptic, physiochemical and microbiological indicators. Therefore, the processing of meat, packed in vacuum packaging, helps to increase its storage time. We have calculated the design of equipment for processing meat with high pressure, by comprehensive compression of the working fluid in a special working chamber.

Effect of ultra-high pressure on quality characteristics of parboiled rice

Quality characteristics of parboiled rice pre-treated by ultra-high pressures (UHP, 100–600 MPa) were investigated in this study. The LF-NMR results and morphologies of parboiled rice grain showed that UHP treatment promoted uniform distribution of water in rice grain and effectively eliminated “white-core” grain. The total colour difference (ΔE*) increased with increasing treatment pressures. DSC results showed that onset gelatinization temperature (To) of rice flour was increased after soaking but decreased after UHP treatment. And the degree of starch gelatinization (DSG) presented an increase at 100 and 200 MPa, but opposite trends were found at 200–600 MPa. Scanning electron microscopic images showed that the morphology of starch in rice changed a little after UHP treatment but lost polygonal shape after steaming. RVA results showed that the viscosity of rice flour increased after soaking and whether rice flour or parboiled rice flour's viscosity decreased with increasing pressures.

Effect of ultra-high pressure on the structure and gelling properties of low salt golden threadfin bream (Nemipterus virgatus) myosin

The effects of ultra-high pressure (UHP) treatment (150–600 MPa for 5 min) on the conformation and related gelation properties of golden threadfin bream (Nemipterus virgatus) myosin with two different NaCl concentrations (0.3 moL/L and 0.6 moL/L) were investigated. Upon increases in pressure (0.1–600 MPa), myosin unfolded from α-helical to a β-sheets, and buried hydrophobic and sulfhydryl groups became exposed. Therefore, the surface hydrophobicity and the reactive sulfhydryl content increased for both NaCl concentrations. The rheological modulus of groups in a low NaCl concentration (0.3 moL/L) reached a maximum value of 150 MPa, but decreased upon further increases in pressure (300–600 MPa); a similar tendency was also observed in the 0.6 moL/L NaCl groups. Low-field pulsed nuclear magnetic resonance and scanning electron microscopy results with the low NaCl groups indicated that moderate UHP treatment (≤300 MPa) strengthened the water retention and structure properties of the myosin gel, while stronger UHP treatment (≥450 MPa) weakened them. This undesirable effect of excess UHP treatment was somewhat mitigated in the 0.6 moL/L concentration groups. These findings show the potential use of UHP treatment in improving the gelling properties of myosin at low salt concentrations.

The effect of ultra-high pressure and heat on the allergenicity and structural properties of bovine serum albumin

The objective of this study is to investigate the impact of Ultra-High Pressure (UHP) combined with moderate heat treatment on the allergenic properties of Bovine Serum Albumin (BSA). The effects of high pressure treatment at 100-500 MPa on allergenicity and structural properties of BSA were investigated. This study was performed using Competitive Indirect-Enzyme Linked Immunosorbent Analysis (CI-ELISA) to get the allergenicity change of BSA and the spectroscopy technology to get the structural properties change. At 500 MPa and 55°C, the inhibition of IgE decreased and reached a maximum of 17.5% relative to untreated BSA. At 100-500 MPa and 25-40°C, the free Sulfhydryl (SH) content, relative surface hydrophobicity (H0) and the fluorescence intensity of BSA significantly (P<0.05) increased at first and then decreased with increasing pressure. A pressure of 100 MPa gave the maximum increase, but using 55°C resulted in a significantly decrease in SH, H0 and fluorescence intensity. This might be due to protein refolding and subsequent aggregation or association. A significant change in the secondary structure was also detected at higher temperatures. UHP combined with higher temperature treatments resulted in a significant decrease in the number of α-helices and a significant increase in β-sheets, β-turns and random coils. These interactions and the secondary results provide direct explanation for the UHP- and heat-induced modification of BSA. This could alter the allergenicity of BSA and enhance the security of beef, milk and beef products.

Effect of ultra-high pressure on small animals, tardigrades and Artemia

AbstractThis research shows that small animals, tardigrades (Milnesium tardigradum) in tun (dehydrated) state and Artemia salina cists (dried eggs) can tolerate the very high hydrostatic pressure of 7.5 GPa. It was really surprising that living organisms can survive after exposure to such a high pressure. We extended these studies to the extremely high pressure of 20 GPa by using a Kawai-type octahedral anvil press. After exposure to this pressure for 30 min, the tardigrades were soaked in pure water and investigated under a microscope. Their bodies regained metabolic state and no serious injury could be seen. But they were not alive. A few of Artemia eggs went part of the way to hatching after soaked in sea water, but they never grew any further. Comparing with the case of blue-green alga, these animals are weaker under ultra-high pressure.

Improving the Yields of Carotene from Red Yeast by Using Ultra High Pressure and its Mutagenic Mechanism

The R. glutinis NR98 of high-producing β-carotene was treated by ultra high pressure (UHP) of 100~500 MPa for 10~30 min. The survival curve of NR98 treated for 10 min was saddle, which shows that the effect of UHP on this strain maybe was the cumulation of many biology effects. The rate of β-carotene production from mutant G39 (obtained at 300 MPa for 10 min) was increased by 59.87% compared with the initial strain NR98, and its genetic quality was proved to be stable by experiments. The result of restriction fragment length polymorphism analysis suggested that mutant strain G39 was likely to change in nucleic acid level.

Effect of ultra-high pressure on gel properties of fish (Nemipterus virgatus) sausage

Changes of the gel strength, springness and chromatic value of fish (Nemipterus virgatus) sausage at different pressure and time were analyzed at 25℃, and the effect of ultra-high pressure (UHP) on them also was investigated. The results showed that the gel strength increased slightly with increasing pressure below 15min. When the processing time was 15min or 20min, the gel strength increased firstly and then decreased with increasing pressure and reached a maximum value at 300MPa. The springness increased firstly and then decreased with increasing pressure and time, and reached a maximum value at 400MPa when the time at 15min. L* and whiteness increased significantly with increasing pressure and dwell time, but increased slowly in 400500MPa, on the contrary, both a* and b* reduced gradually. Dyeing observation of hematoxylin-eosin (HE) staining showed that porosity of network structure of the gel declined with increasing pressure and its roundness increased. Uniformity and compactness of network structure reached the highest value in 300MPa. When the pressure continued to increase, the pore of network structure increased even ruptured.

An Experimental Method of LY12 Duralumin Alloy Affected by the Ultrahigh Pressure

Design an experimental method which can test the strength change of materials under the ultrahigh pressure, and a set of experimental data about the LY12 duralumin alloys materials yield strength and tensile strength are gained under the different ultrahigh pressure environment. The analysis result shows the strength of LY12 duralumin alloys will enhance. Because of effect of ultrahigh pressure, both yield strength and tensile strength increment of materials will approximately increase linearly. Beyond this, the method that can effectively build ultrahigh pressure environment has guidance significance for a real project.

Effect of Ultra-High Pressure on the Characterization of Ursolic Acid/β-Cyclodextrin Inclusion Complex

To study the characterization of ursolic acid (UA) and β- cyclodextrin(β-CD) inclusion complex which prepared by ultra-high pressure method. Inclusion complex of UA /β-CD was prepared at 100MPa and 500MPa. The inclusion complex was characterized by IR spectra, X-ray diffraction, Differential scanning calorimetry and Scanning electron microscope. It was testified that the inclusion complex was formed between β-CD and UA at ultra-high pressure conditions.

The Effect of Ultra-High Pressure on the Functional Property and Conformation of Whey Protein Isolated

The whey protein has a highly nutritional value but poor functional properties. Ultra-high pressure (UHP) is a new technology for food processing. It dose not cause environmental pollution and could maintain food nutrition as much as possible. The effects of applied pressure and treatment time on functional properties and conformation changes of whey protein isolated (WPI) treated by UHP were studied in present paper. The results indicated that WPI treated by UHP showed reduced solubility, foaming and emulsifying property with the increasing of applied pressure and prolonging of treatment time. For WPI treated at 400MPa for 15min, the 1-anilinonaphthalene-8-sulphonate (ANS) studies showed the increasing fluorescence regions when the applied pressure increased. The most fluorescence regions were exposed to aqueous solution for WPI treated at 400MPa for 5min, and degree of exposure reduced when treatment time was prolonged. With the increasing of applied pressure and prolonging of treatment time, the amino acid residues having ultraviolet absorbance showed the same change as hydrophobic group.

Ultra high pressure extraction (UHPE) of ginsenosides from Korean Panax ginseng powder

To elucidate the potential of ultra high pressure (UHP) processing on ginseng, effect of UHP on extraction yield, crude saponin content, and ginsenoside contents of ginseng powder was investigated. Ginseng slurries (70, 80, and 90% moisture content) were put into a retortable pouch then hermetically sealed. These mixtures were pressurized at room temperature up to 600 MPa for 5–15 min. UHP ginseng showed relatively higher extraction yield (312.2–387.1 mg) and amounts of crude saponins (19.3–32.6 mg/g ginseng) than control ginseng (189.9 and 17.5 mg/g ginseng, respectively). Correlation coefficient between extraction yield and crude saponin content was relatively low (R2=0.2908). In high performance liquid chromatography (HPLC) analysis, amounts of measured total ginsenosides (Rb1, Rb2, Rc, Rd, Re, and Rg1) increased with UHP processing but pressure level and pressing time did not proportionally influence the ginsenosides content. This work shows a potential of UHP processing on extraction of ginseng powder and provides basic information on UHP extraction of ginseng powder.

EFFECT OF ULTRA-HIGH PRESSURE ON THE QUALITY AND SAFETY OF FRESH-CUT LONGAN FRUIT

Peeling and cutting increased the area of injured tissue available for microbial proliferation and biochemical deterioration reduced the shelf-life as compared to intact longan fruits. Thereby, it is necessary to develop a suitable technology to extend the shelf life for the commercial use of fresh-cut longan fruit. In this paper, the effects of ultra-high pressure (UHP) on the quality of fresh-cut longan fruits were studied. The slices of fresh-cut longan fruit were treated with different pressure for 10 min and then were stored at 4°C for 9 days. The effect of UHP on micro-organisms, sensory characteristics, total soluble solids, titratable acidity and ascorbic acid of fresh-cut longan fruit were determined during storage. UHP of 400 MPa was able to reduce the number of bacteria on fresh-cut longan fruit by 4.47 log 10 cfu/g and no bacteria was assayed on fresh-cut longan fruit treated with 600 Mpa before storage. After 9 days of storage, the total bacteria counts on fresh-cut longan fruit treated with 400 and 600 MPa were 1.55 log 10 cfu/g and 0 log 10 cfu/g, respectively. The UHP treatment of 600 MPa significantly blocked the browning of fruit slices and microorganisms growth and maintained the quality of fresh-cut longan fruit. The UHP treatment could result in microbial destruction and product stabilization without affecting the sensory characteristics. So, UHP was an alternative potential nonthermal preservation method for pasteurization of fresh-cut longan fruit.

Water Dynamics and Retrogradation of Ultrahigh Pressurized Wheat Starch

The water dynamics and retrogradation kinetics behavior of gelatinized wheat starch by either ultrahigh pressure (UHP) processing or heat are investigated. Wheat starch completely gelatinized in the condition of 90, 000 psi at 25 degrees C for 30 min (pressurized gel) or 100 degrees C for 30 min (heated gel). The physical properties of the wheat starches were characterized in terms of proton relaxation times (T2 times) measured using time-domain nuclear magnetic resonance spectroscopy and evaluated using commercially available continuous distribution modeling software. Different T2 distributions in both micro- and millisecond ranges between pressurized and heated wheat starch gels suggest distinctively different water dynamics between pressurized and heated wheat starch gels. Smaller water self-diffusion coefficients were observed for pressurized wheat starch gels and are indicative of more restricted translational proton mobility than is observed with heated wheat starch gels. The physical characteristics associated with changes taking place during retrogradation were evaluated using melting curves obtained with differential scanning calorimetry. Less retrogradation was observed in pressurized wheat starch, and it may be related to a smaller quantity of freezable water in pressurized wheat starch. Starches comprise a major constituent of many foods proposed for commercial potential using UHP, and the present results furnish insight into the effect of UHP on starch gelatinization and the mechanism of retrogradation during storage.

Lifetime of the ruby R1 line under ultrahigh pressure

The effect of ultrahigh pressure on the lifetime τ of 2E→ 4A 2 (the R1 line) of ruby was considered. Rapid increase of τ with increase of pressure (up to 1200 kbar) is theoretically predicted. The increase of τ was explained with the help of a procedure used earlier to model the lifetime increase with low pressure (up to 120 kbar), and also with a precisely determined spectral shift of the R1 line and of the refractive index n. Good agreement was found between the predicted and measured τ.

超高圧圧縮の黒鉛の酸化性への影響

超高圧圧縮の黒鉛の酸化性への影響

超高圧圧縮の窒化ホウ素への影響

超高圧圧縮の窒化ホウ素への影響