No abstract

Abstract:The article focuses on investigation of the effects of usage of acidic electrolyzed water (AEW) with different sodium chloride concentration (0.001%, 0.01%, and 0.1%) for the preparation of carrageenan and gelatine hydrosols and hydrogels. To determine physiochemical properties of hydrosols, the pH, oxidation-reduction potential (ORP), available chloride concentration (ACC) and rheological parameters such us gelation and flow temperatures were measured. The samples were also characterized using Fourier transform infrared spectroscopy (FT IR) and texture profile analysis (TPA). Additionally, the article contains an analysis of antibacterial activity of carrageenan and gelatine hydrosols incorporated with acidic electrolyzed water, against Staphylococcus aureus and Escherichia coli. The FT IR spectra demonstrated that the structure of gelatine and carrageenan are not significantly affected by electrolyzed NaCl solution components. Furthermore, TPA analysis showed that the use of AEW did not cause undesirable changes in hydrogels layer. The microbiological analysis confirmed inhibition of bacterial growth by hydrosols to about 2.10 log reduction. The results showed that the range of reduction of microorganisms depends on the type AEW used. This might be explained by the fact that the lowest pH and the highest ACC values of hydrosols were obtained for samples with the longest period of exposure to electrolysis (10 min) and the highest amount of NaCl (0.1% w/v). These results suggest that hydrogels and hydrosols incorporated with AEW may be used for food preservation.

Abstract:The aim of the study was to investigate the effect of using direct electric current (DC) of 400 mA for five minutes on the physiochemical properties of gelatine (2%, 4%, and 8%), carrageenan (1.5%, 2%, and 2.5%) and sodium alginate (0.75%, 1%, and 1.25%) hydrosols with different sodium chloride concentration. The pH, oxidation-reduction potential (ORP), electrical conductivity (EC), available chlorine concentration (ACC) and rheological parameters were measured. Moreover, Fourier transform infrared spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM) analysis were carried out. The results have shown that pH, ORP, EC and ACC values are changed upon applying DC and the magnitude of change depends on the concentration of the polymer and the addition of sodium chloride. After seven days of storage, the ACC of the samples exposed to DC decreased by 88%-96%. The FT-IR spectra demonstrated that the structure of gelatine, carrageenan and sodium alginate are not significantly affected by DC. Furthermore, the use of DC did not affect the flow and gelation temperature of the hydrosols. These results suggest that the use of DC did not cause undesirable changes in hydrosols layer and these innovative materials can be used, e.g., for food preservation.

Summary The study analysed the effect of low‐concentrated acidic electrolysed water (LCAEW) treatment on meat. Microbiological analysis and colour and sensory quality testing during storage were performed on Longissimus thoracis. FT‐IR and FT‐Raman spectroscopy were used to detect eventual changes in the structure of meat after treatment. Meat samples were sprayed for 120 s with LCAEW (0.001%, 0.01% or 0.1% NaCl solution were electrolysed for 0, 5 or 10 min). The highest reduction in total number of micro‐organisms (3.25 log reduction), yeast and moulds (2.68 log reduction) and psychrotrophs (3.10 log reduction) was observed after spraying the meat samples with 0.1% NaCl electrolysed for 10 min. LCAEW caused a decrease in deoxymyoglobin and metmyoglobin concentration in unstored meat samples. The preliminary sensory studies proved that colour changes are not significant for consumers. The IR and Raman spectra indicate that the structure of compounds of meat tissues are not affected by chlorine and chlorine compounds (LCAEW components). LCAEW has no influence on denaturation of meat protein.

In this work, the gold nanoparticles (AuNPs) were synthesized using pulse-modulated radio-frequency atmospheric pressure glow discharge (pm-rf-APGD). By tailoring selected operating parameters of the pm-rf-APGD reaction-discharge system, the experimental conditions for the synthesis of raw-AuNPs with controlled optical and structural properties were found. The colloidal suspension of the size-controlled raw-AuNPs was mixed with an aqueous solution of gelatine and turmeric oil to produce an oil-in-water (O/W) nanoemulsion. AuNPs loaded into the nanoemulsion were characterized using ultraviolet-visible absorption spectrophotometry, dynamic light scattering, scanning electron microscopy supported by energy dispersive X-ray spectroscopy, and transmission electron microscopy equipped with selected area X-ray diffraction. Additionally, attenuated total reflectance Fourier-transform infrared spectroscopy was used to confirm the efficient functionalization of the AuNPs by nanoemulsion component. It was revealed that AuNPs were mostly spherical with an average size of 4.6 ± 1.0 nm and a face-centered cubic crystal system. The developed O/W nanoemulsion carrying AuNPs was applied towards the human breast cancer cell lines MCF7 and MDA-MB-231. It was found that it exhibited the cytotoxicity towards the breast cancer cells while were non-cytotoxic towards the non-tumour breast cells MCF10A. Moreover, it also inhibited the migration of the invasive cancer breast cells (line MDA-MB-231) and hence, could prevent the breast cancer metastasis. Keywords Cold atmospheric pressure plasma • Pulse-modulated radio-frequency atmospheric pressure glow discharge • Nanomaterials • Cytotoxicity Abbreviations ATR FT-IR Attenuated total reflectance Fourier-transform infrared spectroscopy AuNPs Gold nanoparticles CAPP Cold atmospheric pressure plasma * Anna Dzimitrowicz