Combined Drying Technologies for High-Quality Kiwifruit Powder Production

Freeze-drying is a dehydration technique which, from a sensory, nutritional and functional point of view, provides high-quality powder products. Nevertheless, both long processing times and high economic costs are required. In this study, pre-drying the samples using hot air or microwave has been considered in order to reduce the initial product's water content thereby shortening the freeze-drying time so as to obtain high value products at a reduced cost. The effect of dehydration pre-treatments on the kinetics, antioxidant activity and solubility of freeze-dried kiwifruit products was evaluated. Nine different thin-layer semi-theoretical models were used to fit the drying data. According to the obtained results, the pre-treated samples exhibited higher drying rates than the fresh sample. In turn, the dehydration pre-treatments used did not affect the solubility or the antioxidant activity of the samples.The authors thank the Ministerio de Educacion y Ciencia and the Generalitat Valenciana for the financial support given throughout the Projects AGL 2010-22176 and ACOMP/2012/161, respectively.Benlloch Tinoco, M.; Moraga Ballesteros, G.; Camacho Vidal, MM.; Martínez Navarrete, N. (2013). Combined Drying Technologies for High-Quality Kiwifruit Powder Production. Food and Bioprocess Technology. 6(12):3544-3553. https://doi.org/10.1007/s11947-012-1030-3S35443553612Agnieszka, C., & Andrzej, L. (2010). Rehydration and sorption properties of osmotically pretreated freeze-dried strawberries. Journal of Food Engineering, 97, 267–274.Akpinar, E. K. (2006). Determination of suitable thin layer drying curve model for some vegetables and fruits. Journal of Food Engineering, 73, 75–84.Antunes, M. D. C., Dandlen, S., Cavaco, A. M., & Miguel, G. (2010). Effects of postharvest application of 1-mcp and postcutting dip treatment on the quality and nutritional properties of fresh-cut kiwifruit. Journal of Agricultural and Food Chemistry, 58, 6173–6181.Beekwilder, J., Jonker, H., Meesters, P., Hall, R. D., Van der Meer, I. M., & Vos, C. H. R. (2005). Antioxidants in raspberry: on-line analysis links antioxidant activity to a diversity of individual metabolites. Journal of Agricultural and Food Chemistry, 53, 3313–3320.Cano, P. (1991). HPLC separation of chlorophyll and carotenoid pigments of four kiwi fruit cultivars. Journal of Agricultural and Food Chemistry, 39, 1786–1791.Clary, C. D., Mejia-Meza, E., Wang, S., & Petrucci, V. E. (2007). Improving grape quality using microwave vacuum drying associated with temperature control. Journal of Food Science, 72(1), 23–28.Contreras, C., Martín-Esparza, M. E., Chiralt, A., & Martínez-Navarrete, N. (2008). Influence of microwave application on convective drying: effects on drying kinetics, and optical and mechanical properties of apple and strawberry. Journal of Food Engineering, 88, 55–64.Contreras, C., Martín-Esparza, M. E., Martínez-Navarrete, N., & Chiralt, A. (2007). Influence of osmotic pre-treatment and microwave application on properties of air dried strawberry related to structural changes. European Food Research and Technology, 224, 499–504.Cozic, C., Picton, L., Garda, M., Marlhoux, F., & Le Cerf, D. (2009). Analysis of arabic gum: study of degradation and water desorption processes. Food Hydrocolloids, 23, 1930–1934.Cubero, N., Monferrer, A., & Villalta, J. (2002). Aditivos alimentarios. Madrid: A. Madrid Vicente.Daoussi, R., Vessot, S., Andrieu, J., & Monnier, O. (2009). Sublimation kinetics and sublimation end-point times during freeze-drying of pharmaceutical active principle with organic co-solvent formulations. Chemical Engineering Research and Design, 87, 899–907.De Ancos, B., Cano, M. P., Hernández, A., & Monreal, M. (1999). Effects of microwave heating on pigment composition and color of fruit purees. Journal of the Science of Food and Agriculture, 79, 663–670.Dewanto, V., Wu, X., Adom, K., & Liu, R. (2002). Thermal processing enhances the nutritional value of tomatoes by increasing total antioxidant activity. Journal of Agricultural and Food Chemistry, 50, 3010–3014.Doymaz, I. (2004). Effect of pre-treatments using potassium metabisulphide and alkaline ethyl oleate in the drying kinetics of apricots. Biosystems Engineering, 89(3), 281–287.Doymaz, I. (2006). Drying kinetics of black grapes treated with different solutions. Journal of Food Engineering, 76, 212–217.Doymaz, I., & Pala, M. (2003). The thin-layer drying characteristics of corn. Journal of Food Engineering, 60, 125–130.Du, G., Li, M., Ma, F., & Liang, D. (2009). Antioxidant capacity and the relationship with polyphenol and vitamin C in Actinidia fruits. Food Chemistry, 113, 557–562.Fabra, M. J., Talens, P., Moraga, G., & Martínez-Navarrete, N. (2009). Sorption isotherm and state diagram of grapefruit as a tool to improve product processing and stability. Journal of Food Engineering, 93, 52–58.Fahloul, D., Lahbari, M., Benmoussa, H., & Mezdour, S. (2009). Effect of osmotic dehydration on the freeze drying kinetics of apricots. Journal of Food, Agriculture and Environment, 7, 117–121.Fúster, C., Préstamo, G., & Cano, M. P. (1994). Drip loss, peroxidase and sensory changes in kiwi fruit slices during frozen storage. Journal of the Science of Food and Agriculture, 64, 23–29.Fyfe, K. N., Kravchuk, O., Le, T., Deeth, H. C., Nguyen, A. V., & Bhandari, B. (2011). Storage induced changes to high protein powders: influence on surface properties and solubility. Journal of Food Science and Agriculture, 91, 2566–2575.Gabas, A. L., Telis, V. R. N., Sobral, P. J. A., & Telis-Romero, J. (2007). Effect of maltodextrin and arabic gum in water vapor sorption thermodynamic properties of vacuum dried pineapple pulp powder. Journal of Food Engineering, 82, 246–252.Ghosal, S., Indira, T. N., & Bhattacharya, S. (2010). Agglomeration of a model food powder: effect of maltodextrin and gum Arabic dispersions on flow behavior and compacted mass. Journal of Food Engineering, 96, 222–228.Huang, L., Zhang, W., Mujumdar, A. S., & Lim, R. (2011). Comparison of four drying methods for re-structured mixed potato with apple chips. Journal of Food Engineering, 103, 279–284.Igual, M., García-Martínez, E., Camacho, M. M., & Martínez-Navarrete, N. (2010). Effect of thermal treatment and storage on the stability of organic acids and the functional value of grapefruit juice. Food Chemistry, 118, 291–299.Igual, M., García-Martínez, E., Martín-Esparza, M. E., & Martínez-Navarrete, N. (2012). Effect of processing on the drying kinetics and the functional value of dried apricot. Food Research International, 47, 284–290.Jaya, S., & Das, H. (2009). Glass transition and sticky point temperatures and stability/mobility diagram of fruit powders. Food Bioprocess Technology, 2, 89–95.Karathanos, V. T., & Belessiotis, V. G. (1999). Application of thin-layer equation to drying data of fresh and semi-dried fruits. Journal of Agricultural Engineering Research, 74, 355–361.Lu, X., Wang, J., Al-Qadiri, M., Ross, C. F., Powers, J. R., Tang, J., & Rasco, B. A. (2011). Determination of total phenolic content and antioxidant capacity of onion (Allium cepa) and shallot (Allium oschaninii) using infrared spectroscopy. Food Chemistry, 129, 637–644.Marques, L. G., Prado, M. M., & Freire, J. T. (2009). Rehydration characteristics of freeze-dried tropical fruits. LWT—Food Science and Technology, 42, 1232–1237.Maskan, M. (2001). Drying, shrinkage and rehydration characteristics of kiwifruits during hot air and microwave drying. Journal of Food Engineering, 48, 177–182.Maskan, M., & Gögus, F. (1998). Sorption isotherms and drying characteristics of mulberry (Morus alba). Journal of Food Engineering, 37, 437–449.Menlik, T., Özdemir, M. B., & Kirmaci, V. (2010). Determination of freeze-drying behaviours of apples by artificial neural network. Expert Systems with Applications, 37, 7669–7677.Mimouni, A., Deeth, H. C., Whittaker, A. K., Gidley, M. J., & Bhandari, B. R. (2009). Rehydration process of milk protein concentrate powder monitored by static light scattering. Food Hydrocolloids, 23, 1958–1965.Mosquera, L. H., Moraga, G., & Martínez-Navarrete, N. (2010). Effect of maltodextrin on the stability of freeze-dried borojó (Borojoa patinoi Cuatrec.) powder. Journal of Food Engineering, 97, 72–78.Mosquera, L. H., Moraga, G., & Martínez-Navarrete, N. (2012). Critical water activity and critical water content of freeze-dried strawberry powder as affected by maltodextrin and arabic gum. Food Research International, 47, 201–206.Panchariya, P. C., Popovic, D., & Sharma, A. L. (2002). Thin-layer modeling of black tea drying process. Journal of Food Engineering, 52, 349–357.Pardo, J. M., & Leiva, D. A. (2010). Effects of different pre-treatments on energy consumption during freeze drying of pineapple pieces. Interciencia, 35(12), 934–938.Pina-Pérez, M. C., Rodrigo-Aliaga, D., Saucedo-Reyes, D., & Martínez-López, A. (2007). Pressure inactivation kinetics of Enterobacter sakazakii in infant formula milk. Journal of Food Protection, 70(10), 2281–2289.Prabhanjan, D. G., Ramaswamy, H. S., & Raghavan, G. S. V. (1995). Microwave-assisted convective air drying of thin layer carrots. Journal of Food Engineering, 25, 283–293.Schokker, E. P., Church, J. S., Mata, J. P., Gilbert, E. P., Puvanenthiran, A., & Udabage, P. (2011). Reconstitution properties of micellar casein powder: effects of composition and storage. International Dairy Journal, 21, 877–886.Simal, S., Femenia, A., Garau, M. C., & Roselló, C. (2005). Use of exponential, Page’s and diffusional models to simúlate the drying kinetics of kiwi fruit. Journal of Food Engineering, 66, 323–328.Therdthai, N., & Zhou, W. (2009). Characterization of microwave vacuum drying and hot air drying of meant leaves (Mentha cordifolia Opiz ex Fresen). Journal of Food Engineering, 91, 482–489.Togrul, I. T., & Pehlivan, D. (2003). Modelling of drying kinetics of single apricot. Journal of Food Engineering, 58, 23–32.Troygot, O., Saguy, I. S., & Wallach, R. (2011). Determination of characteristic curve from water sorption isotherms. Journal of Food Engineering, 105, 408–415.Turkmen, N., Sari, F., & Velioglu, S. (2005). The effect of cooking methods on total phenolics and antioxidant activity of selected green vegetables. Food Chemistry, 93, 713–718.Vadivambal, R., & Jayas, D. S. (2007). Changes in quality of microwave treated agricultural products. Biosystems Engineering, 98, 1–16.Xiang, J., Hey, J. M., Liedtke, V., & Wang, D. Q. (2004). Investigation of freeze-drying sublimation rates using a freeze-drying microbalance technique. International Journal of Pharmaceutics, 279, 95–105.Zhai, S., Taylor, R., Sanches, R., & Slater, N. K. H. (2003). Measurement of lyophilisation primary drying rates by freeze-drying microscopy. Chemical Engineering Science, 58, 2313–2323.Zhang, M., Tang, J., Mujumdarc, A. S., & Wang, S. (2006). Trends in microwave related drying of fruits and vegetables. Trends in Food Science and Technology, 17, 524–534.Zolfaghari, M., Sahari, A., Barzegar, M., & Samadloiy, H. (2010). Physicochemical and enzymatic properties of five kiwifruit cultivars during cold storage. Food Bioprocess Technology, 3, 239–246

Extensional Properties of Hydroxypropyl Ether Guar Gum Solutions

The extensional properties of 2-hydroxypropyl ether guar gum solutions were investigated using a capillary breakup extensional rheometer (CaBER). Optimization of the geometric parameters of this device allowed for the measurement of the characteristic relaxation times and the apparent extensional viscosities of a series of dilute to semidilute guar gum solutions. The measured relaxation times were compared with predicted Zimm relaxation times, assuming that the hydrophobically modified guar was in a good solvent. Good agreement was found at low concentrations (0.01 wt % ≈ 0.17c*, where c* is the polymer overlap concentration), and this technique allowed for relaxation times on the order of 1 ms to be measured for solutions with shear viscosities of 2 mPa·s. Both the shear and (apparent) steady-state extensional viscosities of this set of industrially relevant fluids exhibited two regions of dependency on polymer concentration: linear up to concentrations of 0.2 wt % (c/c* ≈ 3) and power law thereafter, where interchain interactions became significant. The extracted relaxation times followed the same trend (i.e., having a near linear dependency on concentration up to 0.2 wt % and a power-law dependency on concentration up to 9c*). The results indicate that the transition from dilute to semidilute behavior occurs at a nominal concentration of 3c* instead of c*. The results presented suggest that interchain interactions for this modified guar are weak overall, and the solutions investigated are absent of entanglements over the whole range of frequencies and concentrations explored ((0.17−9)c*)