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The beneficial antimicrobial effects of high hydrostatic pressures (HHP) treatments on chill-stored seafood are well documented. Less attention has been given to their impact on the metabolic profile of the seafood, which can offer valuable insights into the preservation mechanisms of these treatments. To address this gap, the present work describes the effects of HHP on the metabolome of chill-stored grey mullet using 1H-NMR. Samples were treated with HHP at 0, 400, 500, and 600 MPa for 10 min and stored at 2–4 °C. HHP effectively inactivated Lactobacillus spp., E. coli , Pseudomonas spp., total Coliforms, and sulfite-reducing anaerobic bacteria (AB), and significantly (p < 0.05) reduced the total mesophilic bacteria (TMB). Additionally, the microbiological shelf-life of grey mullet was extended from 9 to 35 days with the application of 600 MPa HHP. Unsupervised hierarchical cluster analysis and robust Principal Component Analysis (rPCA) revealed the overall changes in metabolites' profile caused by HHP. HHP treatment significantly reduced the formation rate of decay-related metabolites, including hypoxanthine, trimethylamine (TMA), and biogenic amines, which significantly (p < 0.05) positively correlated with all considered microorganisms. A metabolic pathway analysis revealed several pathways that may underly the spoilage of grey mullet, including tyrosine metabolism, pyruvate metabolism, lysine metabolism, glycolysis/gluconeogenesis, butanoate metabolism, citrate cycle (TCA cycle), phenylalanine metabolism, and sulfur metabolism. Interestingly, among these pathways, lysine metabolism remained unaffected by the considered HHP treatments. These findings provide a better understanding of the mechanisms underlying the effects of HHP on chilled grey mullet. • HHP at 600 MPa effectively inactivated microorganisms in grey mullet product. • The metabolome responses to HHP were proportional to the pressure levels. • The pressures tested slowed down nearly all grey mullet spoilage pathways. • Metabolomics effectively elucidated HHP's preservation mechanism for grey mullet. [ABSTRACT FROM AUTHOR]

The present study investigates the application of annealing and plasma-activated water (PAW) for starch modification, as alternative methods compared to the chemical one. Native potato starch was subjected to PAW, annealing with distilled water (DW-ANN), and the combination of the two (PAW-ANN) at different incubation times (1, 4, 8, and 12 h). The changes in rheological, pasting, and thermal properties were evaluated. The results showed that all treatments promoted significant modifications of the investigated parameters. In particular, while the pasting properties of the potato starch remained unchanged after the PAW treatment, G' (elastic) and G" (viscous) of the PAW-treated starch were significantly (p < 0.05) higher than those of the native. DW-ANN significantly increased all rheological parameters and reduced peak viscosity, breakdown, and setback and significantly (p < 0.05) incremented pasting temperature, holding strength, and final viscosities of the potato starch may be due to cross-linking reaction. The combination of treatment (PAW-ANN) showed a synergistic effect leading to strong gel formation up to 4 h, while further treatment reduced the possibility of depolymerization. In conclusion, the combined treatment is a promising new green method to modify the properties of starch and improve its stability within a short treatment time. • Plasma-activated water and annealing were combined for potato starch modification. • Effect of incubation time was investigated for the first time. • All treatments increased the starch viscosity. • The thermal stability and the stability against retrogradation were increased. • The treatments showed a synergistic effect, allowing to reduce total processing time. [ABSTRACT FROM AUTHOR]

This study investigated the effect of different CAP exposures on the activity of horseradish peroxidase (HRP) in phosphate buffer and in model systems with different concentrations of monosaccharides (glucose, fructose) and disaccharides (sucrose, trehalose) to evaluate the potential role of sugars in enzyme inactivation. Spectroscopic analyses (fluorescence, circular dichroism, UV–Vis absorption) were conducted to highlight structural modifications possibly responsible for HRP inactivation. In phosphate buffer, the inactivation of HRP by CAP resulted dependent on both the treatment time (up to 70% after 30 min) and ozone concentration in the chamber. HRP residual activity was fitted with a very good approximation by the Weibull model. Sugars reduced the CAP efficacy, and this effect was concentration-dependent and much higher for disaccharides than monosaccharides. UV and fluorescence spectra showed that sugars differently preserved HRP tertiary structure, hindering heme degradation and quenching of aromatic amino acids. Likewise, sugars differently affected the loss of secondary structures. These findings only partially explained the diverse protective effects of sugars on HRP. Other factors, such as the different sugars' abilities to quench plasma reactive species, reduce the system mobility, and stabilize proteins by preserving their hydration shell, were retained to play a role in the reduction of HRP inactivation. This study deepened the knowledge of the effect of CAP on peroxidase activity and demonstrated that the presence of mono and disaccharides, naturally found in fruits and vegetables and widely employed in food and beverage industries, can mitigate the inactivation and structural alterations induced by CAP on peroxidase enzymes. • Cold atmospheric plasma (CAP) can reduce the activity of horseradish peroxidase (HRP). • The inactivation efficiency depends on plasma exposure time and ozone concentration. • Cold atmospheric plasma affected the HRP tertiary and secondary structures. • Sugars reduced the CAP efficacy with a concentration-dependent effect. • Disaccharides protect more than monosaccharides the HRP activity and conformation. [ABSTRACT FROM AUTHOR]