A review on plasma-activated water and its application in the meat industry.

Meat is a nutritious food with a short shelf life, making it challenging to ensure safety, quality, and nutritional value. Foodborne pathogens and oxidation are the main concerns that lead to health risks and economic losses. Conventional approaches like hot water, steam pasteurization, and chemical washes for meat decontamination improve safety but cause nutritional and quality issues. Plasma-activated water (PAW) is a potential alternative to thermal treatment that can reduce oxidation and microbial growth, an essential factor in ensuring safety, quality, and nutritional value. This review explores the different types of PAW and their physiochemical properties. It also outlines the reaction pathways involved in the generation of short-lived and long-lived reactive nitrogen and oxygen species (RONS) in PAW, which contribute to its antimicrobial abilities. The review also highlights current studies on PAW inactivation against various planktonic bacteria, as well as critical processing parameters that can improve PAW inactivation efficacy. Promising applications of PAW for meat curing, thawing, and decontamination are discussed, with emphasis on the need to understand how RONS in PAW affect meat quality. Recent reports on combining PAW with ultrasound, mild heating, and non-thermal plasma to improve inactivation efficacy are also presented. Finally, the need to develop energy-efficient systems for the production and scalability of PAW is discussed for its use as a potential meat disinfectant without compromising meat quality.

Influence of Molecular Weight Distribution on the Thermoresponsive Transition of Poly(N-isopropylacrylamide).

A series of poly(N-isopropylacrylamide) (PNIPAm) homopolymers with narrow molecular weight distributions (MWDs) is prepared via photoinduced electron/energy transfer-reversible addition-fragmentation chain transfer (PET-RAFT) polymerization. The thermal transition temperature of these polymer samples is analyzed via turbidity measurements in water/N,N'-dimethylformamide mixtures, which show that the cloud point temperatures are inversely proportional to the weight average molecular weight (Mw ). Binary mixtures of the narrowly distributed PNIPAm samples are also prepared and the statistical parameters for the MWDs of these blends are determined. Very interestingly, for binary blends of the PNIPAm samples, the thermoresponsive transition is not only dependent on the Mw , which has been shown previously, but also on higher order statistical parameters of the MWDs. Specifically, at very high values of skewness and kurtosis, the polymer blends deviate from a single sharp thermoresponsive transition toward a broader thermal response, and eventually to a regime of two more distinct transitions. This work highlights the importance of in-depth characterization of polymer MWDs for thermoresponsive polymers.

Microwave pre-treatment of canola seeds and flaked seeds for increased hot expeller oil yield.

Microwave (MW) pre-treatment of canola seeds or flaked seeds was found to be a superior alternative to the conventional thermal pre-treatment (steam). Flaked seeds were "cooked" (heat-treated) with steam or using microwave treatments in the temperature range of 62-130 °C prior to expeller pressing. Microwave cooking at 100 °C resulted in the highest increase in the pressed oil yield, which is an increase of 3.7% (w/w) on a pressed oil basis or 9.0% (oil in seed basis) compared with steam cooking. Whole canola seeds conditioning was conducted with microwaves or steam, in the temperature range of 40-75 °C, followed by microwave or steam cooking at 100 °C to evaluate the effect of MW treatment during conditioning on the expeller oil yield. The use of a continuous microwave process for combined conditioning of whole seeds at 55 °C and subsequent cooking of flaked seeds at 100 °C resulted in a 4.0% increase in expeller oil yield, compared with steam conditioning and cooking. The influence of dry basis (db %) moisture contents of 5%, 11.5%, and 16.5% on oil yield after steam or MW treatments of seeds and flaked seeds was also studied. The moisture content of 11.5% (db %) yielded the highest net oil yield for both MW and steam at best conditioning and cooking temperatures of 55 °C and 100 °C, respectively. No significant impact of MW cooking was seen on oil quality compared with conventional steam cooking.

A Spanish-language patient safety questionnaire to measure medical and nursing students' attitudes and knowledge.

OBJECTIVE: To design and validate a questionnaire for assessing attitudes and knowledge about patient safety using a sample of medical and nursing students undergoing clinical training in Spain and four countries in Latin America. METHODS: In this cross-sectional study, a literature review was carried out and total of 786 medical and nursing students were surveyed at eight universities from five countries (Chile, Colombia, El Salvador, Guatemala, and Spain) to develop and refine a Spanish-language questionnaire on knowledge and attitudes about patient safety. The scope of the questionnaire was based on five dimensions (factors) presented in studies related to patient safety culture found in PubMed and Scopus. Based on the five factors, 25 reactive items were developed. Composite reliability indexes and Cronbach's alpha statistics were estimated for each factor, and confirmatory factor analysis was conducted to assess validity. After a pilot test, the questionnaire was refined using confirmatory models, maximum-likelihood estimation, and the variance-covariance matrix (as input). Multiple linear regression models were used to confirm external validity, considering variables related to patient safety culture as dependent variables and the five factors as independent variables. RESULTS: The final instrument was a structured five-point Likert self-administered survey (the "Latino Student Patient Safety Questionnaire") consisting of 21 items grouped into five factors. Compound reliability indexes (Cronbach's alpha statistic) calculated for the five factors were about 0.7 or higher. The results of the multiple linear regression analyses indicated good model fit (goodness-of-fit index: 0.9). Item-total correlations were higher than 0.3 in all cases. The convergent-discriminant validity was adequate. CONCLUSIONS: The questionnaire designed and validated in this study assesses nursing and medical students' attitudes and knowledge about patient safety. This instrument could be used to indirectly evaluate whether or not students in health disciplines are acquiring and thus likely to put into practice the professional skills currently considered most appropriate for patient safety.

Microencapsulation technology for delivery of enzymes in ruminant feed.

The ruminant digestive system is uniquely designed to make efficient use of high-fibre feed, including forages. Between 40 to 100% of the ruminant diet consists of forages which are high in fibre and up to 70% of this may remain undigested in the ruminant gut, with substantial impact on feed utilisation rate and productivity and the economic and environmental sustainability of livestock production systems. In ruminants, feed costs can make up to 70% of the overall cost of producing an animal product. Increasing feed utilisation efficiency, i.e., more production with less feed lowers feeding costs and improves livestock economic viability. Strategies for improving nutrient utilisation in animal feed has been investigated over the years. Incorporation of fibre digesting enzymes in the feed to facilitate the digestion of the residual fibre in hind gut is one of the proposed strategies. However, delivering such enzymes to the hind gut in active state is challenging due to the unfavourable biochemical environment (pH, microbial proteases) of ruminant's gastrointestinal tract. This review discusses the potential application of microencapsulation for protected and targeted delivery of enzymes into the hind gut of ruminants.

Coffee brewing sonoreactor for reducing the time of cold brew from several hours to minutes while maintaining sensory attributes.

This research designed and developed an ultrasonic reactor for a fast and on demand production of cold brew coffee, remarkably reducing the brewing time from 24 h to less than 3 min. The technology was engineered by utilizing resonance to induce ultrasonic waves around the walls of the brewing basket of an espresso machine. The sound transmission system comprised a transducer, a horn and a brewing basket. This arrangement transformed the coffee basket into an effective sonoreactor that injected sound waves at multiple points through its walls, thereby generating multiple regions for acoustic cavitation within the reactor. Furthermore, acoustic streaming induced greater mixing and enhanced mass transfer during brewing. The design was accomplished by modeling the transmission of sound, and acoustic cavitation. Brew characterization and chemical composition analysis was performed, considering factors such as pH, acidity, color, and the composition of caffeine, fatty acids, and volatiles. The efficiency of the extraction increased by decreasing the basket loading percentage (BLP). For instance, sonicating at 100 W doubled the extraction yield and caffeine concentration, from 15.05 % to 33.44 % at BLP = 33 %, and from 0.91 mg/mL to 1.84 mg/mL at BLP = 67 %, respectively. The total fatty acids increased from 1.16 mg/mL to 9.20 mg/mL, representing an eightfold increase, at BLP = 33 %. Finally, a sensory analysis was conducted to evaluate appearance, aroma, texture, flavor, and aftertaste, which demonstrated that coffee brewed for 1 and 3 min in the sonoreactor exhibited almost undistinguishable properties compared to a standard 24 h brewing without ultrasound.

The antimicrobial effects of mist spraying and immersion on beef samples with plasma-activated water.

The use of plasma-activated water (PAW) as an antimicrobial agent to inactivate Salmonella Typhimurium on chilled beef during meat washing was evaluated. Two meat washing methods, spraying and immersion, were evaluated at contact times of 15, 30 and 60 s and meat storage times of 0, 1 and 7 days. The temperature of PAW was elevated to 55 °C for washing as it increased the microbial inactivation compared to ambient temperature. At the contact time of 60 s and meat storage time of 7 days, PAW spraying and immersion achieved 0.737-log10 and 0.710-log10 reductions against Salmonella Typhimurium, respectively; there were no significant differences between both washing methods, with spraying being preferred for commercial implementation. Compared to untreated and water-treated samples, meat washing with PAW alone improved the S. Typhimurium inactivation and did not cause negative impacts on the lightness and hue angle values, TBARS value, water holding capacity and pH. However, PAW reduced the redness, yellowness and chroma values with the decreased oxymyoglobin values of 44.1% at the storage time of 1 day. PAW spraying at 55 °C followed by additional water washing at 25 °C for 60 s achieved 0.696-log10 reduction and mitigated a reduction in (i) the redness value, from 11.3 to 18.2, (ii) the yellowness value, from 9.19 to 11.1, and (iii) the chroma value, from 14.5 to 21.3, without displaying colour differences (∆E), as detected by human eyes, compared to water-treated samples. Moreover, the content of myoglobin forms was maintained by additional water washing.

A Response Surface Methodology (RSM) Approach for Optimizing the Attenuation of Human IgE-Reactivity to ß-Lactoglobulin (ß-Lg) by Hydrostatic High Pressure Processing.

The response surface methodology (RSM) and central composite design (CCD) technique were used to optimize the three key process parameters (i.e., pressure, temperature and holding time) of the high-hydrostatic-pressure (HHP) processing either standalone or combined with moderate thermal processing to modulate molecular structures of ß-lactoglobulin (ß-Lg) and α-lactalbumin (α-La) with reduced human IgE-reactivity. The RSM model derived for HHP-induced molecular changes of ß-Lg determined immunochemically showed that temperature (temp), pressure (p2) and the interaction between temperature and time (t) had statistically significant effects (p < 0.05). The optimal condition defined as minimum (ß-Lg specific) IgG-binding derived from the model was 505 MPa at 56 °C with a holding time of 102 min (R2 of 0.81 and p-value of 0.01). The validation carried at the optimal condition and its surrounding region showed that the model to be underestimating the ß-Lg structure modification. The molecular change of ß-Lg was directly correlated with HHP-induced dimerization in this study, which followed a quadratic equation. The ß-Lg dimers also resulted in the undetectable human IgE-binding.

Brewing coffee? - Ultra-sonication has clear beneficial effects on the extraction of key volatile aroma components and triglycerides.

Ultrasound has been investigated as a new technique for brewing coffee. A two-level factorial experimental design was conducted to identify the effects of ultra-sonication on the extraction of coffee components during ultrasonically-assisted coffee brewing. Different brews were produced by aqueous extraction from roasted ground coffee beans with sonication, and without it as a control, by varying coffee concentration (5% and 10% w/w), temperature (25 and 50 °C) and sonication time (1 and 5 min). These brews were tested for antioxidant capacity (using the ABTS assay), caffeine and triglycerides (using quantitative NMR spectroscopy) and specific aroma/flavour volatiles (using headspace SPME-GC-MS). Additional observations of colour, foaming, body and flavour were also reported. Ultrasound was found to significantly increase the extraction of caffeine, triglycerides and several of the key volatile compounds from coffee, although it did appear to decrease the concentration of antioxidants over the controls, especially with longer time and higher temperature. Furthermore, all the sonicated samples exhibited a lighter caramel colour and lower foam formation which were attributed to their higher triglyceride content. The increased concentration of triglycerides and volatiles were by far the most outstanding responses.

Numerical and experimental investigation of pulse bubble aeration with high packing density hollow-fibre MBRs.

A three-dimensional Computational Fluid Dynamics (CFD) model was developed to study shear stress induced by spherical cap bubbles in hollow fibre (HF) membrane modules configured with a packing density of 38 m2/m3, to predict the shear profile in a commercial hollow fibre membrane module of 265 m2/m3. The CFD model's computational effort was minimised by simulating the formation of bubble structures and their rising velocities in modules with packing densities of 1.8 and 38 m2/m3 and validated with experimental calibration of shear profiles via electro-diffusion methods (EDM). Pulse bubbles (300 mL) generated from a single sparger at 0.5 Hz produced more satellite bubbles in the wake zone of the leading bubble in high packing density (38 m2/m3) than in low packing density modules (1.8 m2/m3). The bubble rise velocity was approximately 8% lower in the 38 m2/m3 than in the 1.8 m2/m3 module. Increasing packing density reduced the shear profile from a single sparger and the dispersion of the satellite bubbles in the horizontal plane, especially in the upper part of the membrane module. For systems with multiple spargers, the interaction between pulses generated more shear than the pulses from a single sparger, and produced a more uniform shear profile in the module through asynchronous bubble release from adjacent spargers than synchronous release. A 33% increase in the "Zone of Influence", the flow region where the upward velocity >0.2 m/s, was achieved by moving from a synchronous to an asynchronous form of aeration.

Inactivation kinetics of Escherichia coli in cranberry juice during multistage treatment by electric fields.

The inactivation of Escherichia coli inoculated in cranberry juice by processing with radio frequency electric fields was studied. E. coli ATCC 35218 was chosen among three non-pathogenic strains based on its ability to survive in low pH cranberry juice. Studies were conducted by measuring the survival population when changing the electric field strength between 2.2 and 13.2 kV cm-1, number of treatment stages from 1 to 6 and flow rates between 13 and 25 L h-1 at moderate temperatures of 20, 30 and 40 °C. A minimum inactivation of 5-log reduction, as requested by the Food and Drug Administration (FDA), can be achieved by increasing the number of treatment stages, temperature or both. At 40 °C and 6 treatment stages, 6.57 ±â€¯0.02 log CFU ml-1 reduction in the initial population of E. coli (ATCC 35218) was obtained. At a constant electric field, increasing the temperature produced higher microbial inactivation, consuming lower radio frequency energy input, than increasing the number of treatment stages. Furthermore, a primary model that accounts for the combined effect of time and electric field is proposed. The model represented the sigmoidal curve composed of shoulder, log-linear and tailing sections as observed when changing electric fields. A secondary model that accounts for the effect of temperature and flow rate on the primary model constants is also proposed. The combined primary and secondary models were found to fit the data well with a high coefficient of determination (R2 = 0.965). The proposed model can be extended to kinetic models for pulsed electric fields.

A new pressure formulation for gas-compressibility dampening in bubble dynamics models.

We formulated a pressure equation for bubbles performing nonlinear radial oscillations under ultrasonic high pressure amplitudes. The proposed equation corrects the gas pressure at the gas-liquid interface on inertial bubbles. This pressure formulation, expressed in terms of gas-Mach number, accounts for dampening due to gas compressibility during the violent collapse of cavitation bubbles and during subsequent rebounds. We refer to this as inhomogeneous pressure, where the gas pressure at the gas-liquid interface can differ to the pressure at the centre of the bubble, in contrast to homogenous pressure formulations that consider that pressure inside the bubble is spatially uniform from the wall to the centre. The pressure correction was applied to two bubble dynamic models: the incompressible Rayleigh-Plesset equation and the compressible Keller and Miksis equation. This improved the predictions of the nonlinear radial motion of the bubble vs time obtained with both models. Those simulations were also compared with other bubble dynamics models that account for liquid and gas compressibility effects. It was found that our corrected models are in closer agreement with experimental data than alternative models. It was concluded that the Rayleigh-Plesset family of equations improve accuracy by using our proposed pressure correction.

Separation of suspensions and emulsions via ultrasonic standing waves - a review.

Ultrasonic standing waves (USW) separation is an established technology for micro scale applications due to the excellent control to manipulate particles acoustically achieved when combining high frequency ultrasound with laminar flow in microchannels, allowing the development of numerous applications. Larger scale systems (pilot to industrial) are emerging; however, scaling up such processes are technologically very challenging. This paper reviews the physical principles that govern acoustic particle/droplet separation and the mathematical modeling techniques developed to understand, predict, and design acoustic separation processes. A further focus in this review is on acoustic streaming, which represents one of the major challenges in scaling up USW separation processes. The manuscript concludes by providing a brief overview of the state of the art of the technology applied in large scale systems with potential applications in the dairy and oil industries.

Multiphysics modelling of the separation of suspended particles via frequency ramping of ultrasonic standing waves.

A model was developed to determine the local changes of concentration of particles and the formations of bands induced by a standing acoustic wave field subjected to a sawtooth frequency ramping pattern. The mass transport equation was modified to incorporate the effect of acoustic forces on the concentration of particles. This was achieved by balancing the forces acting on particles. The frequency ramping was implemented as a parametric sweep for the time harmonic frequency response in time steps of 0.1s. The physics phenomena of piezoelectricity, acoustic fields and diffusion of particles were coupled and solved in COMSOL Multiphysics™ (COMSOL AB, Stockholm, Sweden) following a three step approach. The first step solves the governing partial differential equations describing the acoustic field by assuming that the pressure field achieves a pseudo steady state. In the second step, the acoustic radiation force is calculated from the pressure field. The final step allows calculating the locally changing concentration of particles as a function of time by solving the modified equation of particle transport. The diffusivity was calculated as function of concentration following the Garg and Ruthven equation which describes the steep increase of diffusivity when the concentration approaches saturation. However, it was found that this steep increase creates numerical instabilities at high voltages (in the piezoelectricity equations) and high initial particle concentration. The model was simplified to a pseudo one-dimensional case due to computation power limitations. The predicted particle distribution calculated with the model is in good agreement with the experimental data as it follows accurately the movement of the bands in the centre of the chamber.

A Spanish-language patient safety questionnaire to measure medical and nursing students' attitudes and knowledge / Un cuestionario en espanol sobre seguridad del paciente para medir las actitudes y los conocimientos de los estudiantes de medicina y enfermería

OBJECTIVE: To design and validate a questionnaire for assessing attitudes and knowledge about patient safety using a sample of medical and nursing students undergoing clinical training in Spain and four countries in Latin America. METHODS: In this cross-sectional study, a literature review was carried out and total of 786 medical and nursing students were surveyed at eight universities from five countries (Chile, Colombia, El Salvador, Guatemala, and Spain) to develop and refine a Spanish-language questionnaire on knowledge and attitudes about patient safety. The scope of the questionnaire was based on five dimensions (factors) presented in studies related to patient safety culture found in PubMed and Scopus. Based on the five factors, 25 reactive items were developed. Composite reliability indexes and Cronbach's alpha statistics were estimatedfor each factor, and confirmatory factor analysis was conducted to assess validity. After a pilot test, the questionnaire was refined using confirmatory models, maximum-likelihood estimation, and the variance-covariance matrix (as input). Multiple linear regression models were used to confirm external validity, considering variables related to patient safety culture as dependent variables and the five factors as independent variables. RESULTS: The final instrument was a structured five-point Likert self-administered survey (the "Latino Student Patient Safety Questionnaire") consisting of 21 items grouped into five factors. Compound reliability indexes (Cronbach's alpha statistic) calculated for the five factors were about 0.7 or higher. The results of the multiple linear regression analyses indicated good model fit (goodness-of-fit index: 0.9). Item-total correlations were higher than 0.3 in all cases. The convergent-discriminant validity was adequate. CONCLUSIONS: The questionnaire designed and validated in this study assesses nursing and medical students' attitudes and knowledge about patient safety. This instrument could be used to indirectly evaluate whether or not students in health disciplines are acquiring and thus likely to put into practice the professional skills currently considered most appropriate for patient safety.

OBJETIVO: Diseñar y validar un cuestionario de evaluación de las actitudes y los conocimientos en materia de seguridad del paciente con una muestra de estudiantes de medicina y enfermería que reciben formación médica en Espana y en cuatro países de América Latina. MÉTODOS: En este estudio transversal se llevó a cabo una revisión bibliográfica y se encuestó a un total de 786 estudiantes de medicina y enfermería de ocho universidades de cinco países (Chile, Colombia, El Salvador, Espana y Guatemala) con objeto de elaborar y corregir un cuestionario en espanol sobre conocimientos y actitudes en materia de seguridad del paciente. El ámbito del cuestionario se basó en cinco dimensiones (factores) presentadas en estudios relacionados con la cultura de la seguridad del paciente encontrados en PubMed y Scopus. Con base en los cinco factores, se elaboraron 25 ítems reactivos. Se calcularon los índices de fiabilidad compuesta y alfa de Cronbach para cada factor, y se realizó un análisis factorial confirmatorio para evaluar la validez. Tras una prueba piloto se corrigió el cuestionario mediante modelos confirmatorios, el cálculo de la máxima probabilidad y la matriz de variancia-covariancia (como insumo). Se utilizaron modelos de regresión lineal múltiple para confirmar la validez externa, considerando las variables relacionadas con la cultura de seguridad del paciente como variables dependientes y los cinco factores como variables independientes. RESULTADOS: El instrumento final fue una encuesta autoadministrada mediante escala de Likert estructurada en cinco puntos ("Cuestionario de Seguridad del Paciente para Estudiantes Latinos"), que consta de 21 ítems agrupados en cinco factores. Los índices de fiabilidad compuesta (prueba estadística de alfa de Cronbach) calculados para los cinco factores fueron aproximadamente de 0,7 o superiores. Los resultados de los análisis de regresión lineal múltiple indicaron un buen ajuste del modelo (índice de bondad de ajuste: 0,9). Las correlaciones ítem-total fueron superiores a 0,3 en todos los casos. La validez convergente y discriminatoria fue adecuada. CONCLUSIONES: El cuestionario disenado y validado en este estudio evalúa las actitudes y los conocimientos de los estudiantes de enfermería y medicina en materia de seguridad del paciente. Este instrumento podría utilizarse para evaluar indirectamente si los estudiantes de disciplinas de la salud están adquiriendo, y por lo tanto, es probable que pongan en práctica, las habilidades profesionales consideradas actualmente como más apropiadas para la seguridad del paciente.