Milk powder agglomerate growth and properties in fluidized bed agglomeration

[EN] Fluidized bed agglomeration is used to produce large and porous dry agglomerates with improved instant properties. Water (or binder solution) is sprayed in the fluidized bed of particles to render their surface sticky. The agglomerate growth results from the repetition of different steps (wetting of the particle surface, particles collision and bridging, and drying) and depends on the processing conditions and product properties. In this work, skim and whole milk powders were fluidized in hot air and agglomerated by spraying water in a bench-scale batch fluidized bed. The aim was to study the impact of the sprayed water flow rate (0 5.5 g.min−1), particle load (300 400 g), initial particle size (200 350 ìm), and composition (skim whole milk) on the growth mechanisms and on the properties of the agglomerates obtained. Powder samples were regularly taken in the fluidized bed during agglomeration and characterized for the size, size distribution, and water content. Whatever the conditions tested, the size increase and the evolution of the particle size distribution during agglomeration were found to mainly depend on the relative amount of water sprayed in the particle bed. Agglomeration occurred in two stages, with first the rapid association of initial particles into intermediate structures, and second, the progressive growth of porous agglomerates. In any case, agglomeration allowed improving instant properties of the milk powder.Barkouti, A.; Turchiuli, C.; Carcel Carrión, JA.; Dumoulin, E. (2013). Milk powder agglomerate growth and properties in fluidized bed agglomeration. Dairy Science and Technology. 93(4-5):523-535. doi:10.1007/s13594-013-0132-7S523535934-5Banjac M, Stakic M, Voronjec D (1998) Kinetics of agglomeration of milk powder in a vibro-fluidized bed. Proc. 11th International Drying Symposium (IDS'98), B: 998–1005.Banjac M, Stamenić M, Lečić M, Stakić M (2009) Size distribution of agglomerates of milk powder in wet granulation process in a vibro-fluidized bed. Brazilian J Chem Eng 26:515–525Dewettinck K, Deroo L, Messens W, Huyghebaert A (1998) Agglomeration tendency during top-spray fluidized bed coating with gums. Lebensm Wiss Technol 31:576–584Forny L, Marabi A, Palzer S (2011) Wetting, disintegration and dissolution of agglomerated water soluble powders. Powder Technol 206:72–78Fries L, Dosta M, Antonyuk S, Heinrich S, Palzer S (2010) Moisture distribution in fluidized beds with liquid injection. Proc. 17th International Drying Symposium (IDS 2010), Magdeburg, Germany.Heinrich S, Blumschein J, Henneberg M, Ihlow M, Mörl L (2003) Study of dynamic multidimensional temperature and concentration distributions in liquid-sprayed fluidized beds. Chem Eng Sci 58:5135–5160Jimenez T (2007) Agglomération de particules par voie humide en lit fluidisé [Wet fluidized bed agglomeration of particles]. PhD, ENSIA, Massy, France.Jimenez T, Turchiuli C, Dumoulin E (2006) Particles agglomeration in a conical fluidized bed in relation with air temperature profiles. Chem Eng Sci 61:5954–5961Kim EH-J, Dong Chen X, Pearce D (2009) Surface composition of industrial spray-dried milk powder. J Food Eng 94:169–181Koga S, Kobayashi T, Inoue I (1989) Drying and agglomeration of skim milk powder by a vibro-fluidized bed, heat transfer. Japan Res 18:1–8Maronga SJ, Wnukowski P (1997) Establishing temperature and humidity profiles in fluidized bed particulate coating. Powder Technol 94:181–185Maronga SJ, Wnukowski P (1998) The use of humidity and temperature profiles in optimizing the size of fluidized bed in a coating process. Chem Eng Sci 37:423–432Murrieta-Pazos I, Gaiani C, Galet L, Cuq B, Desobry S, Scher J (2011) Comparative study of particle structure evolution during water sorption: skim and whole milk powders. Coll and Surf B Biointerfaces 87:1–10Neff E, Morris HAL (1968) Agglomeration of milk powder and its influence on reconstitution properties. J Dairy Sci 51:330–338Niskanen T, Yliruusi J, Niskanen M, Kontro O (1990) Granulation of potassium chloride in instrumented fluidized bed granulator—part I: effect of flow rate. Acta Pharm Fenn 99:13–22Palzer S (2011) Agglomeration of pharmaceutical, detergent, chemical and food powders—similarities and differences of materials and processes. Powder Technol 206:2–17Saad MM, Barkouti A, Rondet E, Ruiz T, Cuq B (2011) Study of agglomeration mechanisms of food powders: application to durum wheat semolina. Powder Technol 208:399–408Turchiuli C, Smail R, Dumoulin E (2012) Fluidized bed agglomeration of skim milk powder: analysis of sampling for the follow-up of agglomerate growth. Powder Technol 238:161–168Vuataz G (2002) The phase diagram of milk: a new tool for optimizing the drying process. Lait 82:485–500Waldie B, Wilkinson D, Zachra L (1987) Kinetics and mechanisms of growth in batch and continuous fluidized bed granulation. Chem Eng Sci 42:653–66

Influence of ultrasound application on both the osmotic pretreatment and subsequent convective drying of pineapple (Ananas comosus)

[EN] Ultrasound application represents an alternative means of improving heat and mass transfer. This study explored the combined application of ultrasound (US) during both the osmotic dehydration (OD) pretreatment and the convective drying of pineapple. For that purpose, fresh and pretreated samples (20 or 40 min, with (55.5 kW/m3, 40 kHz) and without ultrasound application) in an osmotic solution of sucrose (40% w/w) were dried (40 °C and 70 °C) with (21.8 kHz, 31 kW/m3) and without ultrasound application. A diffusion model permitted to quantify the influence of the factors studied (time of pretreatment, ultrasound application during pretreatment, drying temperature and ultrasound application during drying) in drying kinetics. The increase in drying temperature and the application of ultrasound during drying significantly accelerated the drying process by reducing both the internal and the external mass transport resistance. On the contrary, the osmotic pretreatments reduced the drying rate by increasing the external resistance.The authors would like to thank the Generalitat Valenciana, Spain, (PROMETEOII/2014/005), INIA (RTA2015-00060-C04-02) and CAPES (BEX 9496/11-4), CNPq (309346/2015-0) and FAPEMIG (CAG - APQ-01426-15), from Brazil, for the financial support to perform this study.Correa, J.; Rasía, M.; Mulet Pons, A.; Cárcel Carrión, JA. (2017). Influence of ultrasound application on both the osmotic pretreatment and subsequent convective drying of pineapple (Ananas comosus). Innovative Food Science & Emerging Technologies. 41:284-291. https://doi.org/10.1016/j.ifset.2017.04.002S2842914

On the investigation into the kinetics of the ultrasound-assisted atmospheric freeze drying of eggplant

[EN] Atmospheric freeze drying is a highly attractive process for the dehydration of thermosensitive products, like food, due to the fact that water is removed at low temperature by sublimation. Unfortunately, drying times can be very long because of the internal resistance of the product to vapor diffusion: power ultrasound can be an effective means of accelerating the process, thus reducing the operating cost. The aim of this study was to assess the effect of air temperature and velocity, ultrasound power and sample size on the drying kinetics of eggplant (Solanum melongena L.) samples and, afterward, to analyze in silico an industrial process. Experiments were performed under various conditions regarding air temperature (¿5, ¿7.5, ¿10°C), velocity (2 and 5¿m¿s¿1), power ultrasound (0, 10.3, 20.5¿kW¿m¿3, 21.9¿kHz), and sample size. Drying rate was measured experimentally. The air velocity showed no relevant effects on the drying kinetics, and the effect of air temperature was slight when compared to the marked reduction in the drying time obtained when ultrasound was applied. The uniformly retreating interface model was modified to account for the cubic shape of the samples and used to establish the kinetic parameters, in particular to evaluate water diffusivity in the dried product, searching for the best fit between measured and calculated moisture content. The model was finally used to optimize the process in silico, considering an industrial unit as test case. In this case, it appeared that power ultrasound can increase the productivity of a tunnel dryer up to four or five times, and it allows the operational and fixed costs of the plant to be reduced significantly.The authors acknowledge the financial support from Generalitat Valenciana (PROMETEOII/2014/005) and INIA (RTA2015-00060-C04-02).Colucci, D.; Fissore, D.; Mulet Pons, A.; Cárcel Carrión, JA. (2017). On the investigation into the kinetics of the ultrasound-assisted atmospheric freeze drying of eggplant. Drying Technology. 35(15):1818-1831. https://doi.org/10.1080/07373937.2016.1277738S18181831351

Antioxidant potential of atmospheric freeze-dried apples as affected by ultrasound application and sample surface

[EN] Atmospheric freeze drying (AFD) yields products of a similar quality to the conventional vacuum freeze-drying technique, but reduces the operating cost. However, it involves very low drying rates. The sample surface/mass ratio is one of the process variables that can be taken into account to reduce drying time. Moreover, power ultrasound (US) can also be used to intensify this process because of its effects on external and internal mass transfer resistance. However, both factors may affect not only the drying time but also the final product quality. Therefore, the aim of this study was to address the influence of both ultrasound application and the sample surface/mass ratio on the drying process and the antioxidant potential of atmospheric freeze-dried apple. For that purpose, two sample geometries with different surface/mass ratio were considered: slabs (30 � 30 � 10 mm3) and cylinders (diameter: 9 mm and height: 30 mm). The samples were freeze dried (􀀀 10°C) with ultrasound application (21.7 kHz) at different power levels (0, 10.3, 20.5, and 30.8 kW/m3). The total phenolic content (TPC), antioxidant capacity (AC), and ascorbic acid content (AA) were measured in the dried apple. The drying time was significantly shorter for cylindrical samples than for slabs, probably due to their higher surface/mass ratio. The application of US increased the drying rate, this increase being greater for the slab than for the cylindrical particles used in this study. In general, AFD reduced the TPC, AC, and AA, the final content being significantly greater for slabs than for cylinders. This fact can also be related to the lower surface/ mass ratio in the case of slabs. US application further reduced TPC, AC, and AA content, probably due to some cellular damage produced by the acoustic waves and to the oxygen transfer improvement. Nevertheless, the bigger particles (slabs) dried with ultrasound needed a 10% of drying time than the smaller ones (cylinders) dried without ultrasound. Moreover both kind of samples presented similar antioxidant potential.The authors acknowledge the financial support of the Generalitat Valenciana (PROMETEOII/2014/005).Moreno, C.; Brines, C.; Mulet Pons, A.; Rosselló, C.; Carcel Carrión, JA. (2017). Antioxidant potential of atmospheric freeze-dried apples as affected by ultrasound application and sample surface. Drying Technology. 35(8):957-968. doi:10.1080/07373937.2016.1256890S95796835

Influence of air velocity and temperature on ultrasonically assisted low temperature drying of eggplant

[EN] The aim of this work was to evaluate the feasibility of power ultrasound (US) application during the low temperature drying (LTD) of eggplant, analyzing the influence of the process variables linked to the air flow (velocity and temperature) on the drying kinetics and different quality aspects of the dehydrated product. For that purpose, eggplant (Solanum melongena var. Black Enorma) cubes (8.6 mm side) were dried at different air velocities (1, 2, 4 and 6 m/s) and temperatures (10, 0 and −10 ◦C) without (AIR) and with (AIR + US) US application. The rise in the air velocity and temperature led to an increase in the drying rate in AIR experiments. US application accelerated the drying process under every experimental condition tested, shortening the drying time by up to 87%. As for the quality parameters, no remarkable influence of the process variables (US application, air velocity and temperature) on the rehydration, reconstitution in olive oil or hardness of the rehydrated product was observed.The authors acknowledge the financial support of the Spanish Ministerio de Economia y Competitividad (MINECO) and the European Regional Development Fund (ERDF) through project DPI2012-37466-CO3-03 and the FPI fellowship (BES-2010-033460) granted to J.V. Santacatalina and the Generalitat Valenciana through the project PROMETE0II/2014/005.Santacatalina, JV.; Soriano, J.; Cárcel Carrión, JA.; García Pérez, JV. (2016). Influence of air velocity and temperature on ultrasonically assisted low temperature drying of eggplant. Food and Bioproducts Processing. 100:282-291. https://doi.org/10.1016/j.fbp.2016.07.010S28229110

Ultrasonically assisted low-temperature drying of desalted codfish

[EN] Low-temperature drying (LTD) constitutes an interesting means of dehydrating foodstuffs, thus preserving the quality of the product. Power ultrasound (US) generates several mechanical effects that could help to shorten the long drying times associated with LTD. In this work, the feasibility of using US in LTD of desalted cod was assessed. For this purpose, desalted cod slices (50 30 5 mm) were dried (2 m/s) at different temperatures (10, 0 and 10 C) without (AIR) and with (AIR þ US, 20.5 kW/m3) US application. Afterwards, the dried samples were rehydrated in distilled water (25 C). A diffusion model was used to describe both drying and rehydration kinetics. The color and hardness of both dried and rehydrated cod samples were also measured. The application of US increased the drying rate at every temperature tested, shortening the drying time by 16% at 0 C and up to 60% at 10 C. The ultrasonically assisted dried samples presented a rehydration rate which was slightly lower than that of those that had been conventionally dried, but they were harder and whiter, which is more suited to consumer preferences. Therefore, power ultrasound could be considered an affordable technology with which to accelerate LTD of desalted cod, providing high quality dried products.The authors acknowledge the financial support of the Spanish Ministerio de Economia y Competitividad (MINECO) - European Regional Development Fund (ERDF) from the project DPI2012-37466-CO3-03 and the FPI fellowship (BES-2010-033460) granted to J.V. Santacatalina. They also wish to acknowledge Carmen Cambra S.L. for their technical support with the selection of the raw material.Santacatalina Bonet, JV.; Guerrero, M.; García Pérez, JV.; Mulet Pons, A.; Cárcel Carrión, JA. (2016). Ultrasonically assisted low-temperature drying of desalted codfish. Food Science and Technology Research. 65:444-450. https://doi.org/10.1016/j.lwt.2015.08.023S4444506

Food Process Innovation Through New Technologies: Use of Ultrasound

[EN] The use of new or non-conventional technologies widens the food processing innovation possibilities. Among technologies with a potential application, high intensity ultrasonics has emerged. Ultrasound is a mechanical wave that can affect transport phenomena. Accordingly, the effect associated to ultrasonic application will be dependent on the medium where ultrasound is travelling and on the material to be affected. In this work, ultrasonic applications in different media, such as liquid, gas and supercritical fluid, are addressed as innovative alternatives to enhance transport phenomena and highlight the main factors affecting the processThe authors acknowledge the financial support of the Ministerio de Ciencia e Innovacion (DPI2009-14549-C04-04), Ministerio de Ciencia e Innovacion (Fondos FEDER) Ref.: PSE-060000-2009-003 and Generalitat Valenciana, Programa PROMETEO/2010/062.Cárcel Carrión, JA.; García Pérez, JV.; Benedito Fort, JJ.; Mulet Pons, A. (2012). Food Process Innovation Through New Technologies: Use of Ultrasound. Journal of Food Engineering. 110(2):200-207. https://doi.org/10.1016/j.jfoodeng.2011.05.038200207110

Modeling and optimization of the E-beam treatment of chicken steaks and hamburgers, considering food safety, shelf-life, and sensory quality

[EN] The present work was carried out to model the effect of E-beam treatment on the safety,shelf-life and sensory attributes of two poultry products, steaks and hamburgers, and tooptimize the radiation treatment. The inactivation of Salmonella spp. by means of differ-ent irradiation doses was modeled using a first order kinetics. The shelf-life was studiedby periodically counting the bacterial number in samples. For the modeling of experimen-tal data, only the exponential phase of growth was taken into account. The effect of theirradiation dose on the sensory attributes (appearance, odor and flavor) and instrumen-tal color (L*, a* and b* parameters) was modeled using the Gompertz function and theActivation Inactivation or linear models. The optimization of the irradiation dose was car-ried out by maximizing the sensory scores of samples and minimizing the instrumentalcolor changes. The safety and the shelf-life of samples were ensured by introducing con-straints into the optimization problem. In the case of hamburgers, the optimum calculateddose was 2.04 kGy, which guarantees the safety of the product and provides the best combi-nation of sensory and instrumental attributes. As regards the steaks, the optimum assesseddose was 1.11 kGy, significantly lower than for hamburgersThe authors acknowledge the financial support from the Project CSD2007-00016 (CONSOLIDER-INGENIO 2010) and AGL 2010-19158, both funded by the Spanish Ministry of Economy and Competitiveness.Cárcel Carrión, JA.; Benedito Fort, JJ.; Cambero, M.; M. C. CABEZA; Ordóñez, J. (2015). Modeling and optimization of the E-beam treatment of chicken steaks and hamburgers, considering food safety, shelf-life, and sensory quality. Food and Bioproducts Processing. 96:133-144. https://doi.org/10.1016/j.fbp.2015.07.006S1331449

Intensification of low-temperature drying by using ultrasound

[EN] The main aim of this work was to test the feasibility of power ultrasound to intensify low-temperature drying processes. For this purpose, the convective drying kinetics of carrot, eggplant, and apple cubes (side 10 mm) were carried out at atmospheric pressure, 2 m/s, 14 C, and 7% relative humidity with (acoustic power 19.5 kW/m3) and without ultrasound application. Under the same experimental conditions, kinetics studies of ethanol removal from a solid matrix were also performed. Diffusion models were used to describe drying curves and identify kinetic parameters in order to evaluate and quantify the process intensification attained by ultrasound application. The effect of ultrasound application was similar for all products tested; that is, the drying time was shortened between 65 and 70%. In the case of ethanol removal, the time reduction achieved by ultrasound application was 55%. The mass transfer coefficient and effective moisture diffusivity increased by 96 to 170% and by 407 to 428%, respectively, when ultrasound was appliedThe authors acknowledge financial support from the Ministry of Economy and Finance of Spain under Projects DPI2009-14549-C04-01 and DPI2009-14549-C04-04. Moreover, the authors acknowledge the contribution of Eng. Ramon Pena, Cesar Ozuna, and Juan V. Santacalina in the experimental work and development of the new drying device.García Pérez, JV.; Carcel Carrión, JA.; Riera, E.; Rossello Matas, C.; Mulet Pons, A. (2012). Intensification of low-temperature drying by using ultrasound. Drying Technology. 30(11-12):1199-1208. doi:10.1080/07373937.2012.675533S119912083011-1

Influence of Temperature, Air Velocity, and Ultrasound Application on Drying Kinetics of Grape Seeds

The objective of this work was to determine the influence of temperature, air velocity, and ultrasound application on the drying kinetics of grape seeds. The drying kinetics were determined at 1.0, 1.5, 2.0, and 3.0 m/s and at 40, 50, 60, and 70 C. At 1.0 and 1.5 m/s, the experiments were carried out with and without ultrasound application. To establish the influence of the variables on the drying kinetics, the results were modeled by means of both the Peleg and a diffusion model. The activation energy was determined (Arrhenius equation). For an air velocity of over 1.5 m/s, it was determined that the external resistance to mass transfer was negligible. No influence of ultrasound application was observed, probably due to the fact that grape seeds are very hard and have a low level of porosity.The authors of this article acknowledge financial support from the Valencian Government ("Generalitat Valenciana,'' Valencia, Spain, PROMETEO/2010/062).Clemente Polo, G.; Sanjuán Pellicer, MN.; Cárcel Carrión, JA.; Mulet Pons, A. (2014). Influence of Temperature, Air Velocity, and Ultrasound Application on Drying Kinetics of Grape Seeds. Drying Technology. 32(1):68-76. https://doi.org/10.1080/07373937.2013.811592S687632