Comparison of the viscosity of camel milk with model milk systems in relation to their atomization properties

To correlate the viscosity of camel milk with its atomization properties, first, the viscosity profiles of camel milk are compared with model milk systems (reconstituted skimmed cow milk powder). Then, atomization experiment was conducted using model milk systems and finally, the findings of the atomization experiments were coincided with the viscosity profiles. The effect of total solids of whole (10% to 40%) and skimmed (7.5% to 30%) camel milks on its viscosity was investigated. At 30% total solids level and a temperature of 20 °C, skimmed camel milk exhibited a viscosity of 7.68 mPa.s whereas whole camel milk 8.96 mPa.s. This value is small compared to suspension of reconstituted skimmed cow milk powder, which reached up to 18.55 mPa.s and to that of suspension of whey protein concentrate (28.15 mPa.s). By raising the total solid from 20% to 30%, it was shown that, the average spray droplet size would be changed from 18.77 to 29.40 µm and the span from 1.76 to 1.55. Based on their viscosity profiles, these values would be obtained for camel milk at total solid values of 35% for whole and 38% for skimmed milks. This would allow camel milk to be concentrated to higher total solid levels than bovine milk

Investigation of Oil Droplet Breakup during Atomization of Emulsions: Comparison of Pressure Swirl and Twin-Fluid Atomizers

This article belongs to the Special Issue Trends in Spray Atomizatio

Production of starch aerogel in form of monoliths and microparticles

Pea and amylomaize starches were used to produce aerogel in form of monoliths and microparticles. The formation of starch gel was investigated, and we showed that each starch needed a different pasting temperature for its complete dissolution. The gelation kinetics was investigated with oscillatory rheometry for both systems as a function of the starch concentration. The gelation and retrogradation temperature of the starch gel were varied and its impact on the final aerogel evaluated. The emulsion gelation was carried out batch wise in a stirred vessel with different impeller geometries, concentrations of surfactant (Span80 and PGPR) and stirring rates. A particle size prediction approach based on idealized flow (Couette, 2D hyperbolic and turbulent) during the emulsification was proposed. A semi-continuous set-up for the emulsion gelation was developed in which the emulsification occurs in a single pass through a colloid mill and the gelation is triggered in-line with a counter-current heat exchanger

Breakup and Coalescence of Oil Droplets in Protein-Stabilized Emulsions During the Atomization and the Drying Step of a Spray Drying Process

The goal of this study was to investigate the changes in oil droplet size in whey protein–stabilized emulsions during the atomization and the subsequent drying step of a spray drying process. For this purpose, experiments were performed in an atomization rig and a pilot spray dryer with two commercial pressure swirl atomizers. By comparing the oil droplet size before atomization, after atomization, and after spray drying, the changes in oil droplet size during each process step were quantified. The effect of oil droplet breakup during atomization was isolated by atomizing emulsions with 1 wt.% oil content and a protein to oil concentration ratio of 0.1. At 100 bar, the Sauter mean diameter of oil droplet size was reduced from 3.13 to 0.61 μm. Directly after breakup, coalescence of the oil droplets was observed for emulsions with a high oil content of 30 wt.%, leading to a droplet size after atomization of 1.15 μm. Increasing the protein to oil concentration ratio to 0.2 reduced coalescence during atomization and oil droplets with a mean diameter of 0.92 μm were obtained. Further coalescence was observed during the drying step: for an oil content of 30 wt.% and a protein to oil concentration ratio of 0.1 the mean droplet size increased to 1.77 μm. Powders produced at high oil contents showed a strong tendency to clump. Comparable effects were observed for a spray drying process with a different nozzle at 250 bar. The results confirm that droplet breakup and coalescence during atomization and coalescence during drying have to be taken into consideration when targeting specific oil droplet sizes in the product. This is relevant for product design in spray drying applications, in which the oil droplet size in the powder or after its redispersion determines product quality and stability

Oil droplet breakup during pressure swirl atomization of food emulsions: Influence of atomization pressure and initial oil droplet size

Atomization of emulsions with pressure swirl atomizers is a common task in food process engineering. Especially in spray drying processes for food materials like dairy products, it is the technology of choice. During atomization, emulsions are subjected to high stresses, which can lead to deformation and breakup of the dispersed droplets. In this study, the influence of atomization pressure (5–20 MPa) and initial oil droplet size (0.26, 3.1, and 20.8 μm) on the oil droplet breakup during atomization of food based oil‐in‐water emulsions with pressure swirl atomizers was investigated. It was shown that a significant oil droplet breakup takes place upon atomization. The size of oil droplets with an initial value of 3.1 and 20 μm was reduced up to 0.36 μm. No breakup of oil droplets with an initial value of 0.26 μm was observed. The breakup was highly dependent on the atomization pressure. The results were analyzed based on existing knowledge on droplet breakup in laminar flow. A concept to estimate capillary numbers during atomization was developed based on common models from different applications. The results of this study can be used to control the resulting oil droplet size after atomization with pressure swirl atomizers. Practical application: Spray drying of emulsions is a widely used process in the food industry to produce products with encapsulated oily components. Product examples include infant formula, milk powder, and the encapsulation of aroma and coloring compounds. Breakup of the oil droplets during the atomization step of spray drying can change a previously adjusted and desired oil droplet size. As the oil droplet size in the final product can be responsible for several properties like sensorial aspects and stability, a control of oil droplet breakup is essential. Pressure swirl atomizers are widely used in industrial applications as atomization devices. In this study, oil droplet breakup during atomization with these atomizers was investigated. The findings in this study allow a better control of the oil droplet size during atomization in practical applications

Influence of Nozzle Geometry and Scale-Up on Oil Droplet Breakup in the Atomization Step during Spray Drying of Emulsions

Spray drying of oil-in-water emulsions is a widespread encapsulation technique. The oil droplet size (ODS) significantly impacts encapsulation efficiency and other powder properties. The ODS is commonly set to a specific value during homogenization, assuming that it remains unchanged throughout the process, which is often inaccurate. This study investigated the impact of atomizer geometry and nozzle dimensions on oil droplet breakup during atomization using pressure-swirl atomizers. Subject of the investigation were nozzles that differ in the way the liquid is set in motion, as well as different inlet port and outlet orifice dimensions. The results indicate that nozzle inlet port area may have a significant impact on oil droplet breakup, with x90,3 values of the oil droplet size distribution decreasing from 5.29 to 2.30 µm with a decrease of the inlet area from 2.0 to 0.6 mm. Good scalability of the findings from pilot to industrial-scale was shown using larger nozzles. A simplified theoretical model, aiming to predict the ODS as a function of calculated shear rates, showed reasonable agreement to the experimental data for different atomization pressures with coefficients of determination of up to 0.99. However, it was not able to predict the impact of different nozzle dimensions, most likely due to changes in flow characteristics. These results suggest that the stress history of the oil droplets might have a larger influence than expected. Further studies will need to consider other zones of high stress in addition to the outlet orifice

Estrategias de fidelización para colaboradores impulsadas por el área de recursos humanos en empresas del rubro automotriz

El presente proyecto tiene como objetivo abordar el desafío de la falta de reconocimiento y recompensas en el entorno laboral. A través de una consultora especializada, buscamos promover un cambio positivo en las organizaciones, brindando soluciones que fortalezcan el desarrollo personal y profesional de los colaboradores, generen mayor integración en los equipos de trabajo y mejoren el clima laboral. Nuestro enfoque se basa en la implementación de estrategias innovadoras y personalizadas, que permitan a las empresas impulsar la motivación, el compromiso y el rendimiento de sus colaboradores. Para lograrlo, ofrecemos servicios como la definición de objetivos corporativos, el fortalecimiento del liderazgo y habilidades, la capacitación constante y la creación de programas de reconocimiento y recompensas. Durante el proceso de investigación, identificado la necesidad de contar con un equipo especializado que brinde acompañamiento y asesoramiento a las organizaciones, adaptándose a sus necesidades y desafíos específicos. Asimismo, hemos recogido la retroalimentación de diferentes actores involucrados, quienes han mostrado interés y apoyo a nuestro enfoque y propuesta de valor. Nuestras recomendaciones se centran en la implementación de un plan estratégico que incluya la creación de alianzas estratégicas, la promoción de canales de comunicación efectivos y la medición constante de los resultados obtenidos. En resumen, este proyecto se presenta como una solución integral para las organizaciones que buscan mejorar el reconocimiento y las recompensas hacia sus colaboradores. Nuestra consultora, respaldada por un equipo altamente capacitado y comprometido, está preparada para acompañar a las empresas en su camino hacia un entorno laboral más satisfactorio

Spray drying of emulsions: Influence of the emulsifier system on changes in oil droplet size during the drying step

The goal of this study was to investigate the influence of the emulsifier system on the changes in oil droplet size occurring during the drying step of spray drying of emulsions. Atomization and spray drying experiments were performed with emulsions stabilized with whey protein isolate (WPI) alone or in combination with low molecular weight emulsifiers (lecithin, mono- and diglycerides (MoDi), and citrem). Oil droplet coalescence was observed for the systems WPI/Citrem and WPI/MoDi, as the d$_{90,0}$ increased from 0.86 ± 0.16 and 1.67 ± 0.35 µm after atomization to 1.83 ± 0.24 and 1.90 ± 0.17 µm after drying, respectively. Oil droplets stabilized with WPI or WPI/Lecithin remained stable during drying. Measurements of dilatational rheology of the interfacial film showed that phase angle values increase in the order WPI/Lecithin < WPI < WPI/Citrem = WPI/MoDi. Therefore, in the studied system oil droplet coalescence during drying increases when the elastic behavior of the interfacial film decreases