Is the persistence of Listeria monocytogenes in food processing facilities and its resistance to pathogen intervention linked to its phylogeny?

The foodborne pathogen Listeria monocytogenes is differentiated into four distinct lineages which differ in their virulence. It remains unknown, however, whether the four lineages also differ with respect to their ability to persist in food processing facilities, their resistance to high pressure, a preservation method that is used commercially for Listeria control on ready-to-eat meats, and their ability to form biofilms. This study aimed to determine differences in the pressure resistance and biofilm formation of 59 isolates of L. monocytogenes representing lineages I and II. Furthermore, the genetic similarity of 9 isolates of L. monocytogenes that were obtained from a meat processing facility over a period of 1 year and of 20 isolates of L. monocytogenes from food processing facilities was analyzed to assess whether the ability of the lineages of L. monocytogenes to persist in these facilities differs. Analysis of 386 genomes with respect to the source of isolation revealed that genomes of lineage II are over-represented in meat isolates when compared with clinical isolates. Of the 38 strains of Lm. monocytogenes that persisted in food processing facilities (this study or published studies), 31 were assigned to lineage II. Isolates of lineage I were more resistant to treatments at 400 to 600 MPa. The thickness of biofilms did not differ between lineages. In conclusion, strains of lineage II are more likely to persist in food processing facilities while strains of lineage I are more resistant to high pressure.IMPORTANCEListeria monocytogenes substantially contributes to the mortality of foodborne disease in developed countries. The virulence of strains of four lineages of L. monocytogenes differs, indicating that risks associated with the presence of L. monocytogenes are lineage specific. Our study extends the current knowledge by documentation that the lineage-level phylogeny of L. monocytogenes plays a role in the source of isolation, in the persistence in food processing facilities, and in the resistance to pathogen intervention technologies. In short, the control of risks associated with the presence of L. monocytogenes in food is also lineage specific. Understanding the route of contamination L. monocytogenes is an important factor to consider when designing improved control measures.

Stabilization of galactose oxidase by high hydrostatic pressure: Insights on the role of cavities size.

High hydrostatic pressure stabilized galactose oxidase (GaOx) at 70.0-80.0°C against thermal inactivation. The pseudo-first-order rate constant of inactivation kinact decreased by a factor of 8 at 80°C and by a factor of 44 at 72.5°C. The most pronounced effect of pressure was at the lowest studied temperature of 70.0°C with an activation volume of inactivation ΔV‡ of 78.8 cm3 mol-1. The optimal pressure against thermal inactivation was between 200 and 300 MPa. Unlike other enzymes, as temperature increased the ΔV‡ of inactivation decreased, and as pressure increased the activation energy of inactivation Eai increased. Combining the results for GaOx with earlier research on the pressure-induced stabilization of other enzymes suggests that ΔV‡ of inactivation correlates with the total molar volume of cavities larger than ~100 Å3 in enzyme monomers for enzymes near the optimal pH and whose thermal unfolding is not accompanied by oligomer dissociation.

Effect of Novel Processing Techniques on the Carotenoid Release during the Production of Red Guava Juice.

Red guava, distinguished by its elevated lycopene content, emerges as a promising natural source of carotenoids. This study systematically evaluates the impact of diverse processing techniques on the efficient release of carotenoids. The primary objective is to facilitate the transfer of carotenoids into the juice fraction, yielding carotenoid-enriched juice seamlessly integrable into aqueous-based food matrices. The untreated guava puree exhibited a modest release of carotenoids, with only 66.26% of ß-carotene and 57.08% of lycopene reaching the juice. Contrastly, both high-pressure homogenization (HPH) at 25 MPa and enzyme (EM) treatment significantly enhanced carotenoid release efficiency (p < 0.05), while high hydrostatic pressure (HHP) at 400 MPa and pulsed electric field (PEF) of 4 kV/cm did not (p > 0.05). Notably, HPH demonstrated the most substantial release effect, with ß-carotene and lycopene reaching 90.78% and 73.85%, respectively. However, the stability of EM-treated samples was relatively poor, evident in a zeta-potential value of -6.51 mV observed in the juice. Correlation analysis highlighted the interactions between pectin and carotenoids likely a key factor influencing the stable dissolution or dispersion of carotenoids in the aqueous phase. The findings underscore HPH as a potent tool for obtaining carotenoid-enriched guava juice, positioning it as a desirable ingredient for clean-label foods.

Quality changes in high hydrostatic pressure treated enriched tomato sauce.

BACKGROUND: Use of high hydrostatic pressure (HHP) with reduced processing times is gaining traction in the food industry as an alternative to conventional thermal treatment. In order to enhance functional benefits while minimizing processing losses, functionalized products are being developed with such novel techniques. In this study, changes in quality parameters for HHP treated enriched tomato sauce were evaluated, with the aim to assess its viability as an alternative to conventional thermal treatment methods. RESULTS: HHP treatments at 500 MPa, 30 °C/50 °C significantly increased the total phenolic and lycopene content of the sauce samples, achieving 6.7% and 7.5% improvements over conventionally treated samples. The antioxidant capacity of the HHP-treated samples was also found to match or be better than conventionally treated samples. Furthermore, a T2 relaxation time study revealed that pressure-temperature processing treatments were effective in maintaining the structural integrity of water molecules. Microbiological analyses revealed that 500 MPa/50 °C 5 min treatment can offer 8 logs reduction colony formation, matching the results of conventional thermal treatment. CONCLUSION: Combined pressure-temperature treatments improve results, reduce time consumption. 500 MPa/50 °C treatments provided retention of quality parameters and significant reduction in microbial activity. © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Effects of high hydrostatic pressure on peelability and quality of crayfish(Procambarus clarkii).

BACKGROUND: Peeling of crayfish is a very important process in production. Crayfish peeling by machine can increase production efficiency and enhance safety in the production process. The tight muscle-shell attachment causes difficulty in peeling freshly caught crayfish. However, few studies have explored the changes in crayfish quality under favorable shell-loosening treatments. RESULTS: In this study, the shell-loosening properties of crayfish and changes in crayfish quality, microstructure and protein fluorescent features were investigated after high hydrostatic pressure (HHP) treatment. New methods were established to measure the peeling performance of crayfish, which are peelability and meat yield rate (MYR). The normalization of peelability and MYR were verified by different weights of crayfish tails and different treatments. The peeling effect of HHP-treated crayfish was evaluated by a new quantitative measurement method, and MYR was calculated. The results showed that all the HHP treatments reduced crayfish peeling work and increased MYR. The HHP treatment provided better crayfish quality in terms of texture and color and enlarged the shell-loosening gap. Among all HHP treatments, 200 MPa treatment exhibited lower peeling work, higher MYR and an expansion of the shell-loosening gap, reaching up to 573.8 µm. At the same time, 200 MPa treatment could maintain crayfish quality. CONCLUSION: The findings outlined above suggest that high pressure is a promising method for loosening crayfish shells. 200 MPa is an optimal HHP treatment condition for crayfish peeling, exhibiting a promising application in industrial processing. © 2023 Society of Chemical Industry.

Strategy for the Adaptation to Stressful Conditions of the Novel Isolated Conditional Piezophilic Strain Halomonas titanicae ANRCS81.

Microorganisms have successfully predominated deep-sea ecosystems, while we know little about their adaptation strategy to multiple environmental stresses therein, including high hydrostatic pressure (HHP). Here, we focused on the genus Halomonas, one of the most widely distributed halophilic bacterial genera in marine ecosystems and isolated a piezophilic strain Halomonas titanicae ANRCS81 from Antarctic deep-sea sediment. The strain grew under a broad range of temperatures (2 to 45°C), pressures (0.1 to 55 MPa), salinities (NaCl, 0.5 to 17.5%, wt/vol), and chaotropic agent (Mg2+, 0 to 0.9 M) with either oxygen or nitrate as an electron acceptor. Genome annotation revealed that strain ANRCS81 expressed potential antioxidant genes/proteins and possessed versatile energy generation pathways. Based on the transcriptomic analysis, when the strain was incubated at 40 MPa, genes related to antioxidant defenses, anaerobic respiration, and fermentation were upregulated, indicating that HHP induced intracellular oxidative stress. Under HHP, superoxide dismutase (SOD) activity increased, glucose consumption increased with less CO2 generation, and nitrate/nitrite consumption increased with more ammonium generation. The cellular response to HHP represents the common adaptation developed by Halomonas to inhabit and drive geochemical cycling in deep-sea environments. IMPORTANCE Microbial growth and metabolic responses to environmental changes are core aspects of adaptation strategies developed during evolution. In particular, high hydrostatic pressure (HHP) is the most common but least examined environmental factor driving microbial adaptation in the deep sea. According to recent studies, microorganisms developed a common adaptation strategy to multiple stresses, including HHP, with antioxidant defenses and energy regulation as key components, but experimental data are lacking. Meanwhile, cellular SOD activity is elevated under HHP. The significance of this research lies in identifying the HHP adaptation strategy of a Halomonas strain at the genomic, transcriptomic, and metabolic activity levels, which will allow researchers to bridge environmental factors with the ecological function of marine microorganisms.

Effect of high hydrostatic pressure on the edible quality, health and safety attributes of plant-based foods represented by cereals and legumes: a review.

Consumers today are increasingly willing to reduce their meat consumption and adopt plant-based alternatives in their diet. As a main source of plant-based foods, cereals and legumes (CLs) together could make up for all the essential nutrients that humans consume daily. However, the consumption of CLs and their derivatives is facing many challenges, such as the poor palatability of coarse grains and vegetarian meat, the presence of anti-nutritional factors, and allergenic proteins in CLs, and the vulnerability of plant-based foods to microbial contamination. Recently, high hydrostatic pressure (HHP) technology has been used to tailor the techno-functionality of plant proteins and induce cold gelatinization of starch in CLs to improve the edible quality of plant-based products. The nutritional value (e.g., the bioavailability of vitamins and minerals, reduction of anti-nutritional factors of legume proteins) and bio-functional properties (e.g., production of bioactive peptides, increasing the content of γ-aminobutyric acid) of CLs were significantly improved as affected by HHP. Moreover, the food safety of plant-based products could be significantly improved as well. HHP lowered the risk of microbial contamination through the inactivation of numerous microorganisms, spores, and enzymes in CLs and alleviated the allergy symptoms from consumption of plant-based foods.

Non-thermal emerging technologies as alternatives to chemical additives to improve the quality of wheat flour for breadmaking: a review.

Wheat flour is the main ingredient used in the preparation of bread. Factors such as low gluten content and the addition of nontraditional ingredients in baking affect the quality of wheat flour and may limit its use in baking. With the increasing trend of "clean label" products, it may be interesting to develop and use physical processes to improve the quality of wheat flour and avoid the use of chemical additives. High hydrostatic pressure, non-thermal plasma, ultrasound, ozonation, ultraviolet light, and pulsed light treatments are non-thermal emerging technologies (NTETs) that have been studied for this purpose. They were originally developed to inactivate microorganisms and enzymes in foods. Additionally, these technologies can be used at low temperatures to modify the most important component of wheat flour, i.e., gluten and its fractions, which are responsible for the rheological properties of wheat flour dough. Thus, this review focuses on the effects of these NTETs by considering the following factors: (1) the technological properties of gluten, (2) gluten-starch interactions, (3) possible effects of NTETs on minor components of flours, and (4) the quality of wheat flour and the resulting final products.

Recent developments in the use of cold plasma, high hydrostatic pressure, and pulsed electric fields on microorganisms and viruses in seafood.

Non-thermal processing methods, such as cold plasma (CP), high pressure processing (HPP) and pulsed electric fields (PEF), have been proposed for natural and fresh-like foods to inactivate microorganisms at nearly-ambient or moderate temperature. Since natural, safe, and healthy foods with longer shelf-life are increasingly demanded, these requests are challenging to fulfill by using current thermal processing technologies. Thus, novel preservation technologies based on non-thermal processing methods are required. The aim of this article is to provide recent developments in maintaining seafood safety via CP, HHP, and PEF technologies, as well as their mechanisms of action regarding contamination with food-borne microorganisms. Their application to control parasites, spores and the possibility to eradicate the hazard of SARS-CoV-2 transmission through seafood products are also discussed. CP, HHP, and PEF have been applied to inactivate food-borne microorganisms in the seafood industry. However, the drawbacks for each emerging technology have also been reported. To ensure safety and maintain quality of seafood products, the combination of these processing techniques with natural antimicrobial agents or existing thermal methods may be more applicable in the case of the seafood industry. Further studies are required to examine the effects of these methods on viruses, parasites, and SARS-CoV-2 in seafood.

Combining high pressure and electric fields towards Nannochloropsis oculata eicosapentaenoic acid-rich extracts.

Nannochloropsis oculata is naturally rich in eicosapentaenoic acid (EPA). To turn this microalga into an economically viable source for commercial applications, extraction efficiency must be achieved. Pursuing this goal, emerging technologies such as high hydrostatic pressure (HHP) and moderate electric fields (MEF) were tested, aiming to increase EPA accessibility and subsequent extraction yields. The innovative approach used in this study combined these technologies and associated tailored, less hazardous different solvent mixtures (SM) with distinct polarity indexes. Although the classical Folch SM with chloroform: methanol (PI 4.4) provided the highest yield concerning total lipids (166.4 mglipid/gbiomass), diethyl ether: ethanol (PI 3.6) presented statistically higher values in terms of EPA per biomass, corresponding to 1.3-fold increase. When SM were used in HHP and MEF, neither technology independently improved EPA extraction yields, although the sequential combination of technologies did result in 62% increment in EPA extraction. Overall, the SM and extraction methodologies tested (HHP-200 MPa, 21 °C, 15 min, followed by MEF processing at 40 °C, 15 min) enabled increased EPA extraction yields from wet N. oculata biomass. These findings are of high relevance for the food and pharmaceutical industries, providing viable alternatives to the "classical" extraction methodologies and solvents, with increased yields and lower environmental impact. KEY POINTS: • Et2O: EtOH is a less toxic and more efficient alternative to Folch solvent mixture • HHP or MEF per se was not able to significantly increase EPA extraction yield • Combinations of HHP and MEF technologies increased both lipids and EPA yields.

High pressure processing to control Salmonella in raw pet food without compromising the freshness appearance: The impact of acidulation and frozen storage.

The trend of feeding dogs and cats with raw pet food claiming health benefits poses health concerns due to the occurrence of pathogenic bacteria. High pressure processing (HPP) allows the non-thermal inactivation of microorganisms, preserving the nutritional characteristics with minimal impact on organoleptic traits of food. The present study aimed to evaluate and model the effect of HPP application (450-750 MPa for 0-7 min) on the inactivation of Salmonella, endogenous microbiota and colour of raw pet food formulated with different concentrations of lactic acid (0-7.2 g/kg) as natural antimicrobial. Additionally, the effect of a subsequent frozen storage of pressurized product was assessed. Salmonella inactivation ranged between 1 and 9 log, depending on the combination of conditions. According to the polynomial model obtained, the effect of pressure was linear, while a quadratic term was also included for holding time (depicting the occurrence of a resistant tail at ca. 4-6 min). The effect of lactic acid was dependent on the pressure level, being most relevant for treatments below 600 MPa. Frozen storage after HPP prevented the pathogen recovery and caused a further Salmonella inactivation enhanced by lactic acid in most of the treatments. Endogenous microbial groups were significantly reduced by HPP to below the detection level in several conditions. In general, little effect of HPP on the instrumental colour parameters was observed, except for a slight increase in lightness, which was hardly appreciable from visual observation. High pressure processing emerges as a relevant technology for the control of Salmonella spp. and to manage the microbiological safety of raw pet food. The mathematical model can be used as decision support tool to design safer raw pet food, while keeping the desired freshness appearance of the products.

Effect of high hydrostatic pressure treatment on the inactivation and sublethal injury of foodborne pathogens and quality of apple puree at different pH.

The objectives of this study were to evaluate the survival of high hydrostatic pressure (HHP)-treated Salmonella Typhimurium, Escherichia coli O157:H7, and Listeria monocytogenes in apple puree, as well as to determine the levels of HHP-induced cell injury according to the pressure level, holding time, and pH of apple puree. Apple puree was inoculated with three foodborne pathogens and treated at pressures of 300-600 MPa for up to 7 min at 22 °C using HHP equipment. Increasing the pressure level and lowering the pH of apple puree led to larger microbial reductions, and E. coli O157:H7 showed higher resistance compared to S. Typhimurium and L. monocytogenes. Besides, approximately 5-log injured cells of E. coli O157:H7 were induced in apple puree at pH 3.5 and 3.8. HHP treatment at 500 MPa for 2 min effectively achieved complete inactivation of the three pathogens in apple puree at pH 3.5. For apple puree at pH 3.8, more than 2 min treatment of HHP at 600 MPa is seemingly needed to achieve complete inactivation of the three pathogens. Transmission electron microscopy analysis was conducted to identify ultrastructural changes in the injured or dead cells after HHP treatment. Plasmolysis and uneven cavities in the cytoplasm were observed in injured cells, and additional deformations, such as distorted and rough cell envelopes, and cell disruption occurred in dead cells. No changes in solid soluble content (SSC) and color of apple puree were observed after HHP treatment, and no differences were detected between control and HHP-treated samples during 10 d of storage at 5 °C. The results of this study could be useful in determining the acidity of apple purees or the treatment time at specific acidity levels when applying the HHP processing.

Effects of Epigenetic Modification and High Hydrostatic Pressure on Polyketide Synthase Genes and Secondary Metabolites of Alternaria alternata Derived from the Mariana Trench Sediments.

The hadal biosphere is the most mysterious ecosystem on the planet, located in a unique and extreme environment on Earth. To adapt to extreme environmental conditions, hadal microorganisms evolve special strategies and metabolisms to survive and reproduce. However, the secondary metabolites of the hadal microorganisms are poorly understood. In this study, we focused on the isolation and characterization of hadal fungi, screening the potential strains with bioactive natural products. The isolates obtained were detected further for the polyketide synthase (PKS) genes. Two isolates of Alternaria alternata were picked up as the representatives, which had the potential to synthesize active natural products. The epigenetic modifiers were used for the two A. alternata isolates to stimulate functional gene expression in hadal fungi under laboratory conditions. The results showed that the chemical epigenetic modifier, 5-Azacytidine (5-Aza), affected the phenotype, PKS gene expression, production of secondary metabolites, and antimicrobial activity of the hadal fungus A. alternata. The influence of epigenetic modification on natural products was strongest when the concentration of 5-Aza was 50 µM. Furthermore, the modification of epigenetic agents on hadal fungi under high hydrostatic pressure (HHP) of 40 MPa displayed significant effects on PKS gene expression, and also activated the production of new compounds. Our study demonstrates the high biosynthetic potential of cultivable hadal fungi, but also provides evidence for the utility of chemical epigenetic modifiers on active natural products from hadal fungi, providing new ideas for the development and exploitation of microbial resources in extreme environments.

Effect of high hydrostatic pressure processing on the rennet coagulation kinetics and physicochemical properties of sheep milk rennet-induced gels.

The effects of high hydrostatic pressure on the constituents and coagulation ability and their effect on cheese production of sheep milk have not been studied in detail. The objective of this work was to evaluate the effect of high hydrostatic pressure processing on the coagulation kinetics and physicochemical properties of sheep milk and to explore how such treatment could improve the cheesemaking process. Five batches of milk were tested: 1 untreated control batch and 4 batches each subjected to a different pressure (150, 300, 450, or 600 MPa) for 5 min at 10°C. As treatment pressure increased, values of electrical conductivity and oxidation-reduction potential were found to decrease. However, no significant reduction in pH was recorded. Treatment pressures >300 MPa produced milk with lower lightness (luminosity) and a more yellow and green hue. Pressures >150 MPa resulted in micellar fragmentation, as well as significant increases in particle size, viscosity, and water-holding capacity as a consequence of the denaturing of soluble proteins. High-pressure treatments increased the solubility of colloidal calcium phosphate, leading to a considerable increase in the concentration of minerals in the serum phase. The highest concentrations of calcium and phosphorus in the rennet whey of milk were reached at 300 MPa. Curd coagulation time was reduced by 28% at pressures >300 MPa, and an increase in the curd firming rate was observed. As treatment pressure increased to 450 MPa, the firmness, elasticity, and the percentage creep recovery of gels increased, whereas values of compliance and fracture strain were reduced. Thus, we can conclude that 300 MPa is the optimum treatment pressure for milk intended for cheesemaking by enzymatic coagulation. This pressure produced milk with optimal coagulation kinetics and water-holding properties with the least loss of fat and protein to the whey.

Effects of high hydrostatic pressure on antimicrobial protein stability and the rheological and shelf-life properties of donkey milk.

The effects of high hydrostatic pressure (HHP) and heat treatments on antimicrobial protein stability and on the physico-chemical, microbiological, rheological and shelf-life properties of donkey milk were investigated. Although heat treatment at 75°C for 2 min resulted in 1.50 log CFU ml-1 microbial inactivation, losses in activities of lysozyme (58%) and lactoferrin (82%) were observed due to whey protein denaturation. By contrast, HHP application at 400 MPa caused lower enzyme activity losses (22 and 37% respectively) whilst maintaining a significant reduction of microbial load (1.80 log CFU ml-1). Color analyses showed that the lightness values of all samples decreased during storage. Higher flow consistency (viscosity) and lower flow behavior indexes were observed in heat-treated samples compared to untreated and HHP-treated ones, which can be explained by advanced protein denaturation during heat-treatment. The results suggest that HHP is a more suitable process than heat treatment for preservation of donkey milk within the conditions studied.

Does a Similar 3D Structure Mean a Similar Folding Pathway? The Presence of a C-Terminal α-Helical Extension in the 3D Structure of MAX60 Drastically Changes the Folding Pathway Described for Other MAX-Effectors from Magnaporthe oryzae.

Does a similar 3D structure mean a similar folding pathway? This question is particularly meaningful when it concerns proteins sharing a similar 3D structure, but low sequence identity or homology. MAX effectors secreted by the phytopathogenic fungus Magnaporthe oryzae present such characteristics. They share a common 3D structure, a ß-sandwich with the same topology for all the family members, but an extremely low sequence identity/homology. In a previous study, we have investigated the folding of two MAX effectors, AVR-Pia and AVR-Pib, using High-Hydrostatic-Pressure NMR and found that they display a similar folding pathway, with a common folding intermediate. In the present work, we used a similar strategy to investigate the folding conformational landscape of another MAX effector, MAX60, and found a very different folding intermediate. Our analysis strongly supports that the presence of a C-terminal α-helical extension in the 3D structure of MAX60 could be responsible for its different folding pathway.

High Hydrostatic Pressure in the Modulation of Enzymatic and Organocatalysis and Life under Pressure: A Review.

The interest in high hydrostatic pressure (HHP) is mostly focused on the inactivation of deleterious enzymes, considering the quality-related issues associated with enzymes in foods. However, more recently, HHP has been increasingly studied for several biotechnological applications, including the possibility of carrying out enzyme-catalyzed reactions under high pressure. This review aims to comprehensively present and discuss the effects of HHP on the kinetic catalytic action of enzymes and the equilibrium of the reaction when enzymatic reactions take place under pressure. Each enzyme can respond differently to high pressure, mainly depending on the pressure range and temperature applied. In some cases, the enzymatic reaction remains significantly active at high pressure and temperature, while at ambient pressure it is already inactivated or possesses minor activity. Furthermore, the effect of temperature and pressure on the enzymatic activity indicated a faster decrease in activity when elevated pressure is applied. For most cases, the product concentration at equilibrium under pressure increased; however, in some cases, hydrolysis was preferred over synthesis when pressure increased. The compiled evidence of the effect of high pressure on enzymatic activity indicates that pressure is an effective reaction parameter and that its application for enzyme catalysis is promising.

Enzymatic Activity and Its Relationships with the Total Phenolic Content and Color Change in the High Hydrostatic Pressure-Assisted Curing of Vanilla Bean (Vanilla planifolia).

Diverse enzymatic reactions taking place after the killing of green vanilla beans are involved in the flavor and color development of the cured beans. The effects of high hydrostatic pressure (HHP) at 50-400 MPa/5 min and blanching as vanilla killing methods were evaluated on the total phenolic content (TPC), polyphenoloxidase (PPO), and peroxidase (POD) activity and the color change at different curing cycles of sweating-drying (C0-C20) of vanilla beans. The rate constants describing the above parameters during the curing cycles were also obtained. The TPC increased from C1 to C6 compared with the untreated green beans after which it started to decrease. The 400 MPa samples showed the highest rate of phenolic increase. Immediately after the killing (C0), the highest increase in PPO activity was observed at 50 MPa (46%), whereas for POD it was at 400 MPa (25%). Both enzymes showed the maximum activity at C1, after which the activity started to decrease. As expected, the L* color parameter decreased during the entire curing for all treatments. An inverse relationship between the rate of TPC decrease and enzymatic activity loss was found, but the relationship with L* was unclear. HHP appears to be an alternative vanilla killing method; nevertheless, more studies are needed to establish its clear advantages over blanching.

Green Synthesis of Aromatic Nitrogen-Containing Heterocycles by Catalytic and Non-Traditional Activation Methods.

Recent advances in the environmentally benign synthesis of aromatic N-heterocycles are reviewed, focusing primarily on the application of catalytic methods and non-traditional activation. This account features two main parts: the preparation of single ring N-heterocycles, and their condensed analogs. Both groups include compounds with one, two and more N-atoms. Due to the large number of protocols, this account focuses on providing representative examples to feature the available methods.

Impacts of soybean protein isolate hydrolysates produced at high hydrostatic pressure on gelling properties, structural characteristics, and molecular forces of myofibrillar protein.

BACKGROUND: Soybean protein isolate hydrolysates (SPIHs) produced at high hydrostatic pressure have higher bioactivity. The aim of the study was to analyze the effects of different SPIH concentrations obtained under various pressures (0.1, 100, 200, and 300 MPa) on gelling properties, structural characteristics, and main forces of myofibrillar protein (MP) in MP-SPIH plural gels. RESULTS: The MP-SPIH plural gel with 3% SPIH produced under 200 MPa had the maximum gel strength (0.42 N) and water holding capacity (53.69%). A decline in thermal stability and a rise in storage modulus (G') of MP-SPIH plural gels were found with increased SPIH pressure and concentration. Additionally, the addition of SPIHs increased the amounts of α-helix and ß-sheet, decreased random coil structural content of MP in MP-SPIH plural gels, and facilitated the generation of a denser and uniform gels network. The molecular forces in MP-SPIH plural gels were mainly hydrophobic interaction and hydrogen bond. CONCLUSION: This study showed that the interaction of MP with 3% SPIH obtained at 200 MPa improved the quality of plural gels. © 2022 Society of Chemical Industry.