Détermination des isothermes de sorption de l eau des abricots et raisins

[EN] Sorption isotherms determination of apricots and raisins. Sorption isotherms are an important information source in order to establish the stability of food products and their storage conditions. This work addresses the sorption isotherms determination of apricots and raisins. In the case of apricots, the influence of the maturity index (acidity index) on isotherms has been analysed. GAB parameters have been determined from the experimental equilibrium isotherm data, showing a good correlation between experimental and predicted values. The isotherms obtained for the two maturity index studied are very similar. On the other hand, the isotherms of intermediate maturity apricots and raisins are almost superposable[FR] Les isothermes de sorption constituent une source d'information importante pour établir la stabilité des produits alimentaires et ses conditions de conservation. Le but de ce travail est la détermination des isothermes de sorption des abricots et du raisin au cours de l'opération de séchage. Dans le cas des abricots, on a aussi analysé l'influence sur les isothermes de leur stade de maturité. À partir des données expérimentales des isothermes d'équilibre on a calculé les paramètres du modèle GAB, montrant une bonne concordance. Les isothermes obtenues pour les deux degrés de maturité d'abricot étudiés sont très similaires. D'autre part, les isothermes obtenues pour les abricots d'indice de maturité moyenne et les raisins sont pratiquement superposées.Mulet Pons, A. (2011). Détermination des isothermes de sorption de l eau des abricots et raisins. e-Revue de Génie Industriel. 6:33-40. http://hdl.handle.net/10251/78983S3340

Fruita deshidratada i envasada: influència del procés i de les condicions de conservació sobre la seua vida útil = Dried fruit and packaged: influence of process and storage conditions on the shelf life

El present treball tracta de l'evolució de fruites deshidratades durant la seua conservació sotmeses a distints procediments de conservació.Una de les causes de la degradació d'aquestos aliments deshidratats sol ser el procés d'enfosquiment, a causa de reaccions enzimàtiques o no enzimàtiques. La degradació dels aliments durant l'emmagatzemament pot reduir-se en gran mesura mitjançant una adequada elecció del material i de l'atmosfera d'envasament. Com a envasos, es van utilitzar safates de polipropilè termosegellades amb materials polimèrics i flascons de vidre; com a atmosferes, es van emprar nitrogen i aire. S'ha modelitzat l'evolució de la humitat durant la conservació considerant els intercanvis amb l'ambient i la producció d'aigua atribuïda a reaccions de Maillard i s'obté una bona correlació. S'ha comprovat també que l'evolució del contingut en SO2 i en humitat es poden simular mitjançant un model cinètic de primer ordre. Quant a la textura, per a les mostres envasades en films, el seu valor va creixent a mesura que augmenta la temperatura, en disminuir la humitat. El fet que a temperatures de 35 i 40 ºC la humitat de les mostres en vidre augmente i, no obstant açò, els valors de textura fins i tot sofrisquen un lleuger increment pot atribuir-se a l'aparició de canvis en l'estructura del producte entre 25 i 35 ºC.This study addresses the evolution of dehydrated fruits during its storage, submitted to different preservation procedures. One of the causes of dried fruit degradation is usually linked to browning processes, both due to enzymatic and non-enzymatic reactions. Food deterioration during storage could be greatly minimized by means of a proper choice of the packaging material and atmosphere. Packages based on polypropylene trays thermosealed with polymeric material and glass flasks and nitrogen and air as inside atmospheres were used. The evolution of themoisture content during the storage has been modeled considering the exchanges with the environment and the production of water due to Maillard reactions, obtaining a good correlation. The SO2 content andmoisture can be depicted by means of a first order kinetics.With regard to the texture, for the samples packaged in films, the value of maximum force increases with the temperature, along with amoisture decrease. The fact that at temperatures of 35 and 40 ºC the moisture of the samples in glass increases and however the texture suffers a slight increment, could be explained by the appearance of changes in the structure of the product between 25 and 35 ºC

Influence of temperature and ultrasound on drying kinetics and antioxidant properties of red pepper

This is an Author's Accepted Manuscript of J. A. Cárcel, D. Castillo, S. Simal & A. Mulet (2019) Influence of temperature and ultrasound on drying kinetics and antioxidant properties of red pepper, Drying Technology, 37:4, 486-493, DOI: 10.1080/07373937.2018.1473417 [copyright Taylor & Francis], available online at: http://www.tandfonline.com/10.1080/07373937.2018.1473417[EN] Red pepper samples (1 m/s) were dried at different temperatures (30, 50, 70 degrees C) without and with (20.5 kW/m(3); 21.7 kHz) ultrasound application. The antioxidant capacity (AC), the total phenolic content (TPC), and the ascorbic acid (AA) content of fresh and dried red pepper samples were used as indicators of the quality of the dried products. Ultrasound application significantly improved the kinetics in every case, influencing not only the effective diffusivity but also the mass transport coefficient thus implying a reduction in energy needs. Drying significantly reduced AC, TPC, and AA, this reduction being significantly smaller at 70 degrees C due to the shorter drying time. Compared with conventional drying, ultrasound application reduced the loss of antioxidant properties at 50 degrees C but produced greater degradation at 70 degrees C, which points toward an optimal drying temperature when using ultrasound.The authors acknowledge the financial support from Generalitat Valenciana [PROMETEOII/2014/005] and INIA [RTA2015-00060-C04-02 and RTA2015-00060-C04-03].Carcel, JA.; Castillo, D.; Simal, S.; Mulet Pons, A. (2019). Influence of temperature and ultrasound on drying kinetics and antioxidant properties of red pepper. Drying Technology. 37(4):486-493. https://doi.org/10.1080/07373937.2018.1473417S486493374Di Scala, K., & Crapiste, G. (2008). Drying kinetics and quality changes during drying of red pepper. LWT - Food Science and Technology, 41(5), 789-795. doi:10.1016/j.lwt.2007.06.007Doymaz, İ., & Pala, M. (2002). Hot-air drying characteristics of red pepper. Journal of Food Engineering, 55(4), 331-335. doi:10.1016/s0260-8774(02)00110-3Cárcel, J. A., García-Pérez, J. V., Riera, E., Rosselló, C., & Mulet, A. (2017). Ultrasonically Assisted Drying. Ultrasound in Food Processing, 371-391. doi:10.1002/9781118964156.ch14Kowalski, S. J., & Pawłowski, A. (2015). Intensification of apple drying due to ultrasound enhancement. Journal of Food Engineering, 156, 1-9. doi:10.1016/j.jfoodeng.2015.01.023Soria, A. C., & Villamiel, M. (2010). Effect of ultrasound on the technological properties and bioactivity of food: a review. Trends in Food Science & Technology, 21(7), 323-331. doi:10.1016/j.tifs.2010.04.003Do Nascimento, E. M. G. C., Mulet, A., Ascheri, J. L. R., de Carvalho, C. W. P., & Cárcel, J. A. (2016). Effects of high-intensity ultrasound on drying kinetics and antioxidant properties of passion fruit peel. Journal of Food Engineering, 170, 108-118. doi:10.1016/j.jfoodeng.2015.09.015Fan, K., Zhang, M., & Mujumdar, A. S. (2017). Application of airborne ultrasound in the convective drying of fruits and vegetables: A review. Ultrasonics Sonochemistry, 39, 47-57. doi:10.1016/j.ultsonch.2017.04.001Riera, E., Vicente García-Pérez, J., Cárcel, J. A., Acosta, V. M., & Gallego-Juárez, J. A. (2011). Computational Study of Ultrasound-Assisted Drying of Food Materials. Innovative Food Processing Technologies: Advances in Multiphysics Simulation, 265-301. doi:10.1002/9780470959435.ch13Pulido, R., Bravo, L., & Saura-Calixto, F. (2000). Antioxidant Activity of Dietary Polyphenols As Determined by a Modified Ferric Reducing/Antioxidant Power Assay. Journal of Agricultural and Food Chemistry, 48(8), 3396-3402. doi:10.1021/jf9913458Gao, X., Bj�rk, L., Trajkovski, V., & Uggla, M. (2000). Evaluation of antioxidant activities of rosehip ethanol extracts in different test systems. Journal of the Science of Food and Agriculture, 80(14), 2021-2027. doi:10.1002/1097-0010(200011)80:143.0.co;2-2Jagota, S. K., & Dani, H. M. (1982). A new colorimetric technique for the estimation of vitamin C using Folin phenol reagent. Analytical Biochemistry, 127(1), 178-182. doi:10.1016/0003-2697(82)90162-2García-Pérez, J. V., Rosselló, C., Cárcel, J. A., De la Fuente, S., & Mulet, A. (2006). Effect of Air Temperature on Convective Drying Assisted by High Power Ultrasound. Defect and Diffusion Forum, 258-260, 563-574. doi:10.4028/www.scientific.net/ddf.258-260.563Gallego-Juárez, J. A., Riera, E., de la Fuente Blanco, S., Rodríguez-Corral, G., Acosta-Aparicio, V. M., & Blanco, A. (2007). Application of High-Power Ultrasound for Dehydration of Vegetables: Processes and Devices. Drying Technology, 25(11), 1893-1901. doi:10.1080/07373930701677371Kim, S., Lee, K. W., Park, J., Lee, H. J., & Hwang, I. K. (2006). Effect of drying in antioxidant activity and changes of ascorbic acid and colour by different drying and storage in Korean red pepper (Capsicum annuum, L.). International Journal of Food Science and Technology, 41(s1), 90-95. doi:10.1111/j.1365-2621.2006.01349.xCarrillo Montes, J. P., Cruz y Victoria, M. T., Anaya Sosa, I., & Santiago Pineda, T. (2010). Quality assessment of dehydrated red bell pepper using tempering drying cycles. International Journal of Food Science & Technology, 45(6), 1270-1276. doi:10.1111/j.1365-2621.2010.02273.xMoreno, C., Brines, C., Mulet, A., Rosselló, C., & Cárcel, J. A. (2017). Antioxidant potential of atmospheric freeze-dried apples as affected by ultrasound application and sample surface. Drying Technology, 35(8), 957-968. doi:10.1080/07373937.2016.1256890Wang, J., Fang, X.-M., Mujumdar, A. S., Qian, J.-Y., Zhang, Q., Yang, X.-H., … Xiao, H.-W. (2017). Effect of high-humidity hot air impingement blanching (HHAIB) on drying and quality of red pepper (Capsicum annuum L.). Food Chemistry, 220, 145-152. doi:10.1016/j.foodchem.2016.09.200Garau, M. C., Simal, S., Rosselló, C., & Femenia, A. (2007). Effect of air-drying temperature on physico-chemical properties of dietary fibre and antioxidant capacity of orange (Citrus aurantium v. Canoneta) by-products. Food Chemistry, 104(3), 1014-1024. doi:10.1016/j.foodchem.2007.01.009Ahmad-Qasem, M. H., Barrajón-Catalán, E., Micol, V., Mulet, A., & García-Pérez, J. V. (2013). Influence of freezing and dehydration of olive leaves (var. Serrana) on extract composition and antioxidant potential. Food Research International, 50(1), 189-196. doi:10.1016/j.foodres.2012.10.028López, J., Uribe, E., Vega-Gálvez, A., Miranda, M., Vergara, J., Gonzalez, E., & Di Scala, K. (2010). Effect of Air Temperature on Drying Kinetics, Vitamin C, Antioxidant Activity, Total Phenolic Content, Non-enzymatic Browning and Firmness of Blueberries Variety O´Neil. Food and Bioprocess Technology, 3(5), 772-777. doi:10.1007/s11947-009-0306-8Rodríguez, Ó., Santacatalina, J. V., Simal, S., Garcia-Perez, J. V., Femenia, A., & Rosselló, C. (2014). Influence of power ultrasound application on drying kinetics of apple and its antioxidant and microstructural properties. Journal of Food Engineering, 129, 21-29. doi:10.1016/j.jfoodeng.2014.01.001Vega-Gálvez, A., Lemus-Mondaca, R., Bilbao-Sáinz, C., Fito, P., & Andrés, A. (2008). Effect of air drying temperature on the quality of rehydrated dried red bell pepper (var. Lamuyo). Journal of Food Engineering, 85(1), 42-50. doi:10.1016/j.jfoodeng.2007.06.03

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

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

Management of Surface Drying Temperature to Increase Antioxidant Capacity of Thyme Leaf Extracts (Thymus vulgaris L.)

[EN] Thyme leaves are an important source of essential oils with antioxidant activity; these compounds are located in trichomes on the leaf surface. The drying conditions affect not only the drying time but also the antioxidant activity. In the literature, a drying temperature of 70 ºC appears to be the best for drying thyme leaves according to their antioxidant capacity. Considering drying periods at different temperature also could be quality beneficial. From these considerations, the goal of this work was to establish a drying strategy with which to manage a drying temperature on the leaf surface which will enable the drying time to be shortened and improve the antioxidant capacity (AC) of the extract of dried thyme leaves. The drying strategy consisted of two consecutive drying periods in order to manage the drying temperature on the leaf surface. The first drying period was carried out at 80°C (Ta1) until the sample surface reached a temperature of 70 ºC, which then immediately being set to 70, 60, 50 and 40 °C (second drying period (Ta2)), at a different air velocity (v) (1 and 2 m s-1). Compared with constant drying conditions, two consecutive drying periods were found to improve the drying kinetics, the AC increased from 10.5% to 27.4 % while reducing the drying time by 14.5% to 39.2 %. The use of this drying strategy was found to be an interesting means of intensifying the convective drying of thyme leaves and its application should be considered when drying similar materials with bioactive compounds on the surface.The authors of this work acknowledge financial support from the "Ministerio de Educacion y Ciencia" in Spain, Consolider Ingenio 2010 (CSD2007-00016) and PROMETEO/2010/062.Rodríguez Cortina, J.; Melo, E.; Mulet Pons, A.; Bon Corbín, J. (2014). Management of Surface Drying Temperature to Increase Antioxidant Capacity of Thyme Leaf Extracts (Thymus vulgaris L.). Drying Technology. 32(16):1931-1941. https://doi.org/10.1080/07373937.2014.917094S19311941321

Influence of high-intensity ultrasound application on the kinetics of sugar release from acid suspensions of artichoke (Cynara scolymus) biomass

[EN] The study of sugar release kinetics is an essential step prior to developing new technologies for applying in the bioethanol industry. To this end, the kinetics of reducing and total sugar release (extraction/hydrolysis) from artichoke waste were obtained in different conditions to evaluate the solubility of free sugars from raw matter and the hydrolysis of larger chain molecules separately. Thus, experiments of extraction with water (WE), hydrolysis (HY) in acid solutions and a conventional industrial hydrolysis (IHY), which combines dissolution and hydrolysis effects, were carried out. All of the treatments were studied with ultrasound application (US) or with conventional agitation (AG). Compared to AG experiments, US application accelerated the sugar dissolution reducing 50% the time to reach the equilibrium. The decrease in the biomass concentration in the suspensions increased the US effects in HY experiments. In IHY experiments, US was also able to enhance the final yield of sugars achieving relative reducing sugar and total sugar amounts 213% and 175%, significantly higher than AG experiments. The Theological changes in the suspensions during treatments can explain the different magnitude of ultrasound effects. The acoustic field characterization and the measurement of viscosity in the acid suspensions agreed with these results.The authors acknowledge the INIA-ERDF (RTA2015-00060-004-02) from Spain, the Sao Paulo Research Foundation - FAPESP (Grant 2017/06518-2) and the Coordination for the Improvement of Higher Level Personnel - CAPES (Grant 88881.132626/2016-01) from Brazil for the financial support.Carregari-Polachini, T.; Mulet Pons, A.; Telis Romero, J.; Carcel, JA. (2019). Influence of high-intensity ultrasound application on the kinetics of sugar release from acid suspensions of artichoke (Cynara scolymus) biomass. Chemical Engineering and Processing Process Intensification. 145:1-9. https://doi.org/10.1016/j.cep.2019.107681S1914

Rheology of acid suspensions containing cassava bagasse: Effect of biomass loading, acid content and temperature

[EN] Understanding the characterization and rheological behavior of acid suspensions of cassava bagasse provides essential information for the design of conversion processes. Samples with different cassava bagasse concentrations (0-10% w.w-1), phosphoric acid (0-10% w.w(-1)) at temperatures between 278.13 and 318.13 K were submitted to steady-state flow over a wide range of shear rates (1-265 s(-1)). The biomass particles had considerable residual starch (similar to 50% db), low lignin content and adequate particle size (<200 mu m) for the conversion process. Flow curves were well-fitted to the Herschel-Bulkley model, presenting a Newtonian domain at low solids and acid content and a non-Newtonian behavior with noticeable yield stress and shear-thinning characteristic (n < 1) at above 6% of cassava bagasse. Resistance to flow increased as the solids loading and acid content increased. Temperature dependence could be expressed as a function of an Arrhenius-type equation with good accuracy of fit. (C) 2019 Elsevier B.V. All rights reserved.The authors would like to thank Prof. Rosiane Lopes Cunha and Prof. Ana Carla Kawazoe Sato from University of Campinas (UNICAMP) for their support with particle size analyses. The authors also acknowledge the Sao Paulo Research Foundation - FAPESP (Grant number 2017/06518-2) and the Coordination for the Improvement of Higher Education Personnel -CAPES (Grant number 88881.132626/2016-01) for their financial support.Carregari-Polachini, T.; Mulet Pons, A.; Carcel, JA.; Telis Romero, J. (2019). Rheology of acid suspensions containing cassava bagasse: Effect of biomass loading, acid content and temperature. Powder Technology. 354:271-280. https://doi.org/10.1016/j.powtec.2019.05.086S27128035

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 &#65533; 30 &#65533; 10 mm3) and cylinders (diameter: 9 mm and height: 30 mm). The samples were freeze dried (&#1048576; 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

Mechanistic modelling to address process analysis: Kibbles of carob (Ceratonia siliqua, L.) pod extraction

[EN] The daily challenge involved in operating a process is the attainment of the objectives. Process management requires the use of tools adapted to the system s complexity. In order to obtain real time results, simplified mechanistic modeling offers a way to deal with this. To this end, carob pod (Ceratonia siliqua, L.) kibbles extraction is addressed in this work. They are a source of different, valuable components and have a complex structure and a highly variable concentration of components. The components considered are sugars and soluble polyphenols. Obtaining the extracts with an optimal composition of a particular component, while avoiding or limiting other components in the extract, is a challenge to be addressed. Two steps can be considered: solubilization and diffusion, modeled by means of a first order reaction and by considering slab geometry. The optimal processing time and temperature are obtained by taking a particular kibble size and composition into accountThe support from Generalitat Valenciana PROMETEO/2014/005 is acknowledged.Mulet Pons, A.; Fernández-Salguero, J.; García Pérez, JV.; Bon Corbín, J. (2016). Mechanistic modelling to address process analysis: Kibbles of carob (Ceratonia siliqua, L.) pod extraction. Journal of Food Engineering. 176:71-76. https://doi.org/10.1016/j.jfoodeng.2015.06.011S717617