Protozoan parasites can survive under ambient and refrigerated storage conditions when associated with a range of substrates. Consequently, various treatments have been used to inactivate protozoan parasites (Giardia, Cryptosporidium, and Cyclospora) in food, water, and environmental systems. Physical treatments that affect survival or removal of protozoan parasites include freezing, heating, filtration, sedimentation, UV light, irradiation, high pressure, and ultrasound. Ozone is a more effective chemical disinfectant than chlorine or chlorine dioxide for inactivation of protozoan parasites in water systems. However, sequential inactivation treatments can optimize existing treatments through synergistic effects. Careful selection of methods to evaluate inactivation treatments is needed because many studies that have employed vital dye stains and in vitro excystation have produced underestimations of the effectiveness of these treatments.

This study was carried out to evaluate the effects of power ultrasound (US) on the molecular weight and rheological properties of a food polysaccharide, konjac glucomannan (KGM). Upon the exposure of KGM solution (1% w/v in water) to US at a relatively high power intensity (50 W/cm2), the apparent viscosity decreased rapidly from about 50 Pa s to a negligible level within 10–20 min. The intrinsic viscosity ([η]) of KGM solution decreased gradually during the US exposure with a time course closely fitted to the first-order polymer degradation kinetics (random chain scission). The US treatment also caused a significant reduction of particle size (Zavg) of KGM aggregates and changes in the rheological properties including the decrease of storage modulus (G′) and loss modulus (G″), and the increase in phase angle (tan δ = G″/G′). Nevertheless, no change in primary structure was detected by Fourier transformation infrared (FT-IR) analysis. The results suggested that high intensity US was an effective means for KGM degradation without significant structural destruction.

The synthesis of new chitin derivatives through ultrasound-assisted treatment of the chitin with 1-azido-3-chloropropan-2-ol under Green Chemistry conditions is described. This is the first example of ultrasound-assisted polymer analogues transformation of chitin unaccompanied by noticeable backbone degradation or deacetylation. The obtained water-soluble azido chitin derivatives are characterized by high antibacterial activity, which is comparable with that of commercial antibiotics ampicillin and gentamicin. At the same time, they were demonstrated almost identical in vitro toxicity as unmodified chitin and chitosan. The antibacterial activity of the obtained polymers is mainly provided by azido moiety in their macromolecules. The conjugation of azido moiety to chitin backbone strongly diminishes the toxicity of the azido pharmacophore, but preserves its antibacterial properties. The most potent chitin derivative was used for the film coating of Ricotta cheese samples. This food coating proved to be efficient for the prolongation of shelf life of Ricotta cheese.

Preconcentration of aluminum Al³⁺ was carried out by a novel deep eutectic solvent based ultrasound-assisted liquid phase microextraction (DES-UALPME) method. The deep eutectic solvents (DESs), a green solvent was first time used for enrichment and quantification of very low concentration of Al³⁺ in water and food samples, prior to analysed by electrothermal atomic absorption spectrometry (ETAAS). In present method it was observed that % recovery of Al-8-hydroxyquinoline chelates efficiently extracted by DES solvent. Pre-enrichment factor and limit of detection were observed to be 50, and 0.032μgL⁻¹, respectively. Developed procedure was validated with the CRM (SLRS-5 river water) of Al and a good agreement was observed in results of measured value to the certified value. The RSD was calculated as 3.3%. The presented procedure was successfully carried out to different water and food samples.

The valorisation and management of agri‐food waste are currently hot investigation topics which probe the recovery of valuable compounds, such as polyphenols. In this study, high‐pressure/high‐temperature extraction (HPTE) and ultrasound‐assisted extraction (UAE) have been used to study the recovery of phenolic compounds from grape marc and olive pomace in hydroalcoholic solutions. The main phenolic compounds in both extracts were identified by HPLC‐DAD. Besides extraction yield (total polyphenol and flavonoid content) and the antiradical power, polyphenol degradation under HPTE and UAE has also been studied. HPTE with ethanol 75% gave higher phenolic extraction yields: 73.8 ± 1.4 mg of gallic acid equivalents per gram of dried matter and 60.0 mg of caffeic acid equivalents per gram of dried matter for grape marc and olive pomace, respectively. In this study, the efficient combination of ethanol/water mixture with HPTE or UAE has been used to enhance the recovery of phenolic compounds from grape marc and olive pomace. HPLC‐DAD showed that UAE prevents phenolic species degradation damage because of its milder operative conditions.

An environmentally friendly, sensitive, easy and fast ultrasound-assisted ionic liquid-based dispersive liquid-liquid microextraction technique (UA-IL-DLLME) was developed to preconcentrate trace quantities of nickel Ni(II) ion in water, food and tobacco samples prior to detection by FAAS. The proposed technique based on utilisationthe of ionic liquid (IL) (1-hexyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate [HMIM][FAP]) as an extraction solvent for Ni(II) ions after the complexation with quinalizarin (Quinz) at pH 6.0. The impact of different analytical parameters on the microextraction efficiency was investigated. In the range of 2.0–300 µg L⁻¹, the calibration graph was linear. Limit of detection and preconcentration factor were 0.6 µg L⁻¹ and 100. Relative standard deviation (RSD%) as precision at 50 and 100 µg L⁻¹ of Ni(II) were 2.4% and 3.6%, respectively (n = 10). The validation of the proposed procedure was verified by a test of two certified reference materials (TMDA-51.3 fortified water, TMDA-53.3 fortified water and SRM spinach leaves 1570A) applying the standard addition method. Finally, the proposed UA-IL-DLLME method was developed and applied to preconcentrate and determine of trace quantities of Ni(II) in real water, food and tobacco samples with satisfactory results.

In this study, the effect of high‐intensity ultrasound (HIUS) (200 and 400 W for 0, 5, 10 and 15 min respectively) on conformational changes, physicochemical, rheological and emulsifying properties of scallop (Patinopecten yessoensis) myofibrillar protein (SMP) was investigated. HIUS‐treated SMP had lower α‐helix content and higher β‐sheet content compared with the native SMP. HIUS treatment induced the unfolding of SMP and increased the surface hydrophobicity. The particle size of SMP decreased and the absolute zeta‐potential increased after ultrasonication, which in turn increased the solubility of SMP. The conformational changes and the improvement of physicochemical properties of SMP increased the ability for SMP to lower the interfacial tension at the oil–water interface and increased the percentage of adsorbed protein. As a result, the emulsifying properties, rheological properties of SMP and storage stability of emulsions were also improved. In conclusion, HIUS treatment has future potential for improving the emulsifying properties of SMP.

Direct determination of arsenic species in real samples is challenging due to their trace concentration and spectral interferences by coexisting ions. Herein, we proposed an ultrasound-assisted dispersive solid phase microextraction (DSPME) procedure for the analyses of the trace inorganic arsenic. The hydrothermally synthesized cadmium sulfide nanoparticles (CdS NPs) completely adsorbed both arsenic species within 20 s at the initial arsenic concentration of 100 µg L⁻¹. The detection limit (3 S/m) of the proposed method was found to be 0.5 ± 0.2 and 0.8 ± 0.2 ng L⁻¹ for As(III) and As(V), respectively. The accuracy of the method against the systematic and constant errors was confirmed by the analysis of the Standard Reference Material (SRM) (>95% recovery with <5% RSD). The Student’s t-test values were found to be less than the critical Student’s t value at a 95% confidence level. The method was successfully employed for the determination of arsenic in food samples.

This study reports a simple, rapid and greener method based on ultrasound assisted-cloud point extraction coupled with inductively coupled plasma-optical emission spectroscopy (ICP-OES) for preconcentration and determination of antimony (Sb), tin (Sn) and thallium (Tl) in food and water samples. Factors affecting the preconcentration procedure were optimized using fractional factorial design and response surface methodology based on Box-Behnken design. Under optimum conditions, the calibration graphs were linear over the concentration range of 0.023–700 μg L−1 with correlation coefficients up to 0.9994, the limits of detection ranged from 0.007–0.010 μg L−1, the limits of quantification were from 0.023 to 0.033 μg L−1 and the relative standard deviations (n = 15) were between 1.3% and 4.1%. In addition, the preconcentration factors were found to be 150, 145 and 160 for Sb, Sn and Tl, respectively. Finally, the developed method was successfully applied in various food and water samples as well as certified reference materials for rapid determination of Sb, Sn and Tl.

A novel ultrasound-assisted liquid phase microextraction (UALPME) based on environmental friendly extractants, deep eutectic solvent (DES) was first time presented for speciation of selenium. In present study, five DES solvents of different composition was prepared and used as efficient extractive medium for hydrophobic chelate of Se(IV) with 3,3′-Diaminobenzidine (DAB). The total inorganic Se species were determined after pre-reduction of Se(VI) to Se(IV), prior to applying developed method. The concentration of Se(VI) was calculated by the difference of Se(IV) values and total selenium contents. The concentration of Se in DES rich phase was measured with electrothermal atomic absorption spectrometer (ETAAS). The effects of different parameters on extraction efficiency of study analyte, including pH, ligand concentration, type and volume of DES, sonication time, volumes tetrahydrofuran and aqueous samples were examined. At the optimum conditions, limit of detection and quantification, preconcentration factor, and relative standard deviation (RSD %) were determined as 4.61ngL⁻¹, 15.4ngL⁻¹, 50% and 4.1%, respectively. The accuracy of the presented method was confirmed by analysis of certified reference material and standard addition method for different water and ice tea samples. The developed method was effectively applied to real water and food samples.