•The increase of HPP pressure at 70°C enhanced the B. cereus spores’ inactivation in milk.•HPP–thermal temperatures from 38 to 70°C tripled B. cereus log reductions in milk.•HPP technology allowed ...20°C lower temperatures for B. cereus spore inactivation.•Weibull modeled the 600MPa HPP–thermal inactivation of B. cereus in milk.
Bacillus cereus is a pathogen that can grow in foods and beverages with low acidity. The main objective of this work was to model the inactivation of psychrotrophic B. cereus spores in reconstituted milk treated by high pressure (HPP) combined with a thermal process, and to compare it with thermal inactivation kinetics. First, the effect of HPP pressure (200, 400 and 600MPa) for up to 40min at 70°C on B. cereus spores was investigated. A pressure increment from 200 to 600MPa slightly reduced the spore numbers in the reconstituted milk. Then the influence of temperature at 600MPa on spore inactivation for up to 40min was studied. Increasing the HPP temperature from 38 to 70°C increased the spore inactivation in milk by 3.5log. The 600MPa combined with heat enhanced the spore inactivation in milk, requiring a temperature 20°C lower to achieve the same spore inactivation. However, for a 5log spore inactivation, the pressure–thermal process required a higher specific energy than the thermal processing. The resistance of two psychrotrophic strains of B. cereus spores in milk was also investigated and showed similar results. The Weibull model described spore inactivation by pressure–heat, whereas the first order kinetics was more appropriate for the thermal inactivation alone. The results of this study confirmed the advantage of HPP technology to further increase the thermal inactivation of B. cereus spores in milk.
This study examines the pressure-temperature (P-T) behavior of reactive mixtures composed of lactalbumin and water under subcritical and isochoric conditions. The impact of density on the P-T ...behavior was investigated for an initial lactalbumin composition of 5%, covering a density range of 0.7597 g/mL to 0.85620 g/mL. Additionally, the effect of varying lactalbumin concentrations, ranging from 3% to 15% (w/w), at a constant initial density of 0.831 g/mL, was also studied. Isochoric lines and density values of the reactive mixtures were compared to those of pure water under identical pressure and temperature conditions in all experiments. Furthermore, the total soluble solids (TSS) content was analyzed after each experiment, along with the thermal stability of amino acids subjected to prolonged reaction periods and high temperatures.
•Density and composition significantly influence P-T behavior of studied mixtures.•Linear P-T relationship observed, with steeper isochores at higher density.•Mixtures density can be assumed equal to pure water at same T and P conditions.•Mixtures pressure can significantly differ than that of pure water at same T and ρ.•Phenylalanine showed high thermal stability below 240 °C.
The aim of this study was to evaluate the effect of enzyme-assisted extraction (EAE) and high hydrostatic pressure (HHP) on the recovery of phenolic compounds from grape pomace (GP). For this, GP was ...subjected to four conditions: (E1) EAE without HHP, (E2) EAE with the enzyme previously submitted to HHP, (E3) EAE simultaneously with HHP, (H4) HHP (without adding enzymes) at different pressures (50, 100 and 200 MPa) and times (0–30 min). HHP increased by up to 16 times the activity of the enzymes used in the extraction. Treatments with HHP were more efficient than the enzyme-assisted extraction, and the treatments E3 and E1 showed high inhibitory α-amylase activity. Results suggest that the application of HHP can be efficient and economical in the phenolic compounds recovery from GP when compared to other more complex processes that require longer processing time, adding value to a low-value industrial waste.
•Grape pomace phenolics were extracted using enzymes and high hydrostatic pressure.•High hydrostatic pressure (HHP) increased the activity of some enzymes.•Treatments using HHP were more efficient in relation to enzyme-assisted extraction.•The combination of both technologies resulted in higher phenolic recovery.•Phenolic compounds were successfully recovered by sustainable and clean methods.
The effects of high hydrostatic pressure (HHP) combined with pH-shifting treatment, on the structural and emulsifying properties of soy protein isolate (SPI) were investigated. SPI was subject to ...different pH solutions (pH 7, pH 3, and pH 11) with pressure levels ranging from 0.1 MPa to 400 MPa before being neutralized to pH 7. The combination of HHP and the pH-shifting process increased the protein solubility and the surface charge of the protein molecule, and induced the formation of smaller re-aggregated protein particles. Structural changes were characterized by free sulfhydryl groups, surface hydrophobicity, ultraviolet–visible spectroscopy, and circular dichroism spectra. Emulsions fabricated with SPI treated by the combined treatment were characterized by mean droplet size, zeta potential, emulsifying activity, emulsifying stability, and fluorescence microstructure. The results suggested that the increasing pressure enhanced the effect of pH shifting, and the protein structure could be significantly unfolded by the synergistic effect of HHP and pH-shifting, further improving the emulsifying performance of SPI.
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•Structural changes of soy protein isolate were induced by high pressure and pH shifting.•Enhanced unfolding in pH shifted SPI were observed after pressurization.•High pressure aided pH shifting improved the emulsifying properties of SPI.
The development of natural inhibitors of polyphenol oxidase (PPO) is crucial in the prevention of enzymatic browning in fresh foods. However, few studies have focused on the effect of subsequent ...sterilization on their inhibition efficiency. This study investigated the influence and mechanism of high hydrostatic pressure (HHP) on the inhibition of PPO by epigallocatechin gallate (EGCG), cyanidin-3-O-glucoside (C3G), and ferulic acid. Results showed that under the conditions of 550 MPa/30 min, the activity of EGCG-PPO decreased to 55.92%, C3G-PPO decreased to 81.80%, whereas the activity of FA-PPO remained stable. Spectroscopic experiments displayed that HHP intensified the secondary structure transformation and fluorescence quenching of PPO. Molecular dynamics simulations revealed that at 550 MPa, the surface interaction between PPO with EGCG or C3G increased, potentially leading to a reduction in their activity. In contrast, FA-PPO demonstrated conformational stability. This study can provide a reference for the future industrial application of natural inhibitors.
•HHP treatment improved the inhibitory efficiency of PPO by EGCG or C3G•The activity of FA-PPO remained stable even at 550 MPa/30 min•TEM observed that HHP promoted the aggregation of PPO in the presence of EGCG•MD simulations showed an increase in interaction between PPO and inhibitors under HHP•FA was embedded inside the PPO to form a complex that exhibited pressure stability
•A novel silk fibroin-Ti3C2TX hybrid nanofiller was synthesized.•Silk fibroin improved the interfacial compatibility between Ti3C2TX nanosheets and epoxy resin.•SF-Ti3C2TX composite coating exhibited ...outstanding protection ability.•SF-Ti3C2TX nanosheets could prevent further cracks propagation under high hydrostatic pressure.
The complex and harsh deep sea environment is the main reason for the failure of the protective coating of marine equipment. However, excellent protective coating is the key to prolong the service life of the equipment under deep sea environment. Ti3C2TX, with high aspect ratio, abundant surface functional groups and excellent mechanical properties, is the suitable candidate nanofiller for coating reinforcement. Herein, we synthesized a novel silk fibroin-Ti3C2TX (SF-Ti3C2TX) hybrid nanofiller as reinforced-additives for improving the anti-corrosion ability of waterborne epoxy coating. Due to the rough surface of SF-Ti3C2TX nanosheets, they have excellent compatibility with the resin matrix and could fill the inherent defects of the coating. The anticorrosion behaviors of as-prepared composite coatings under both of atmospheric pressure and simulated deep sea environment were investigated in detail. Particularly, the composite coating with 0.5 wt% SF-Ti3C2TX sheets showed outstanding corrosion protection (impedance value remained 1.31 × 108 Ω⋅cm2, four orders of magnitude higher than pure EP) after 240 h immersion under 20 MPa hydrostatic pressure. In addition, the interface of coating/steel was not damaged and the coating remained the favorable adhesion strength (3.16 MPa, but that of pure EP only 0.88 MPa) even in the harsh high hydrostatic pressure. Based on the experiment data, we discussed and analyzed the failure process of coatings and explained the corrosion protection mechanism of SF-Ti3C2TX hybrid under simulated deep sea environment.
Natural deep eutectic solvents (NADESs) choline chloride with citric acid (DES-CA), lactic acid (DES-LA), maltose (DES-MA) and glycerol (DES-GLY) and an addition of 20% v/v water in the NADES ...solutions combined with homogenate – (HAE), microwave – (MAE), ultrasound – (UAE) or high hydrostatic pressure – (HHPAE) assisted extractions were first successfully applied to phenolic compounds recovery from olive pomace. DES-CA and DES-LA showed the best extraction efficiency in terms of the total phenolic content and the antioxidant activity of the extracts obtained by HAE and UAE and by MAE and HHPAE, respectively. HAE proved to be the best method with extraction efficiency superior to MAE, UAE and HHPAE. HPLC analysis revealed that almost all NADESs obtained extracts were more enriched in phenolic compounds than those with conventional solvents. The results confirmed that the proposed combined methods could provide an excellent alternative for sustainable and green extraction of phenolic compounds from plant sources leading to novel industrial applications.
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•Phenolic compounds from olive pomace were first extracted with eutectic solvents.•Eutectic solvents combined with extraction-assisted methods were successfully applied.•The eutectic solvents enhanced the polyphenols extraction compared to water/ethanol.•Homogenization was the best assisted extraction method used.•Green and efficient extraction of olive pomace polyphenols was proposed.
In this study, high hydrostatic pressure extraction (HHPE) and ultrasound-assisted extraction (UAE) were used for the improvement of pectin and polyphenol recovery from tomato peel waste.
HHPE ...enhanced pectin recovery by 15% after 45 min of recycling, in comparison with the conventional extraction (CE) for 180 min. Similar mass fractions of anhydrouronic acid, total sugars and total phenols were obtained by using both methods. FTIR and 1H NMR data confirmed that chemical composition of pectin obtained by HHPE and CE is identical, therefore it was concluded that the faster HHPE method can be used for its further isolation.
Although depectinized residues subjected to UAE in 70% ethanol for 15 min contained two times lower values of total phenols (1625.7 mg/100 g) than pectinized samples (3643.9 mg/100 g), their quantities are not negligible, considering the fact that they are generated after HHPE. At the end of UAE, the residues were exploited as a source of fatty acids, among which lauric, palmitic and stearic acids are dominant.
In conclusion, by shortening the extraction time using HHPE and UAE, it is possible to efficiently produce two valuable functional ingredients, pectin and polyphenols, and at the same time to reduce peel waste from tomato canning industry, which presents an environmental problem.
Utilizing HHPE and UAE as novel and emerging technologies, and combining them with traditional ones (Soxhlet) is given the solution for sequential isolation of pectin, polyphenols and fatty acids from tomato peel waste, generated by canning factory.
Shortening of extraction time using HHPE and UAE, it is possible to replace the conventional techniques, and achieve efficient production of pectin and polyphenols.
Overall, the extraction methodology proposed in this work could provide two valuable benefits, i.e. the producers could find mode for decreasing of disposal costs of waste and consumer would take opportunity that isolated compounds could be reintroduced into food.
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•Tomato peel waste is utilized for sequential extraction of pectin and polyphenols.•Shortening of time using HHPE and UAE is achieved their efficient production.•HHPE enhanced pectin recovery by 15% after 45 min of recycling.•UAE of depectinized samples for 15 min yielded high quantities of phenols.•At the end of sonication, the residues are utilized as a source of fatty acids.
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•HHP caused OVA fragmentation and unfolding.•HHP induced the secondary and tertiary structural changes of OVA.•The allergenicity of OVA decreased by 24.13 % at 600 MPa.•HHP induced ...potential epitope alterations of OVA.
Egg proteins, notably ovalbumin (OVA), contribute to a prevalent form of food allergy, particularly in children. This study aims to investigate the impact of high hydrostatic pressure (HHP) treatment at varying levels (300, 400, 500, and 600 MPa) on the molecular structure and allergenicity of OVA. The structure of HHP-treated OVA was assessed through fluorescence spectroscopy, circular dichroism spectroscopy, and molecular dynamics (MD) simulation. HHP treatment (600 MPa) altered OVA structures, such as α-helix content decreased from 28.07 % to 19.47 %, and exogenous fluorescence intensity increased by 8.8 times compared to that of the native OVA. The free sulfhydryl groups and zeta potential value were also increased with HHP treatment (600 MPa). ELISA analysis and MD simulation unveiled a noteworthy reduction in the allergenicity of OVA when subjected to 600 MPa for 10 min. Overall, this study suggests that the conformational changes in HHP-treated OVA contribute to its altered allergenicity.
The present study evaluated the effect of high isostatic pressure (HIP) on the activity of peroxidase (POD) and polyphenol oxidase (PPO) from açaí. Açaí pulp was submitted to several combinations of ...pressure (400, 500, 600MPa), temperature (25 and 65°C) for 5 and 15min. The combined effect of HIP technology and high temperatures (690MPa by 2 and 5min at 80°C) was also investigated and compared to the conventional thermal treatment (85°C/1min). POD and PPO enzyme activity and instrumental color were examined after processing and after 24h of refrigerated storage. Results showed stability of POD for all pressures at 25°C, which proved to be heat-resistant and baro-resistant at 65°C. For PPO, the inactivation at 65°C was 71.7% for 600MPa after 15min. In general, the increase in temperature from 25°C to 65°C reduced the PPO relative activity with no changes in color. Although the thermal treatment and the HIP (690MPa) along with high temperature (80°C) reduced the PPO relative activity, and relevant darkening was observed in the processed samples. Thus, it can be concluded that POD is more baro-resistant than PPO in açaí pulp subjected to the same HIP processing conditions and processing at 600MPa/65°C for 5min may be an effective alternative for thermal pasteurization treatments.
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•POD is more baro-resistant than PPO in açaí subjected to the HIP processing at 65°C.•600MPa/65°C for 5min may be an effective alternative for thermal pasteurization.•The color of açaí pulp changed after the thermal process (85°C/1min).•HIP processing did not perceptibly affect the color of the açaí pulp.•PPO inactivation by HIP is partially reversible after 24h of refrigerated storage.
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