Roasted coffee oil (RCO) is rich in volatile organic compounds (VOCs), but the VOCs’ volatility and the presence of unsaturated fatty acids make RCO unstable. The microencapsulation process can extend RCO properties by transforming the liquid RCO into stable powders for further application in coffee brews to better result in-cup. In this work, a central composite rotational design was used to study the effect of the emulsification process and discuss the effect of added microcapsules to instant coffees on the time-resolved release of VOCs upon reconstitutions. Capsules were produced by complex coacervation loaded with RCO, and ultrasound-assisted (US) emulsification was used to obtain stable coffee oil–loaded emulsions. VOC release was monitored by proton-transfer reaction time-of-flight mass spectrometry (PTR-ToF–MS). High encapsulation efficiency (EE) (> 80%) was obtained even at a high load (100%) of RCO. EE was only affected by US power while particle mean size (D43) was strongly affected by US power and the RCO concentration. The presence of microcapsules affected the VOC release from the moment of reconstitution. The microcapsules accelerated the VOC release in soluble coffee, while in instant cappuccino, an opposite effect was observed. A zero-order model described well the mechanism of VOC release during the first 300 s. The diffusional exponent values of the Korsmeyer–Peppas equation explained a zero-order transport during the first seconds of release (burst effect) and a non-Fickian release mechanism when the release slowed down. Such findings shed new light on the development of instant coffees in order to improve their sensorial properties.
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Alvim, I. D., & Grosso, C. R. F. (2010). Microparticles obtained by complex coacervation: Influence of the type of reticulation and the drying process on the release of the core material. Ciência e Tecnologia De Alimentos, 30(4), 1069–1076. https://doi.org/10.1590/S0101-20612010000400036
Böger, B. R., Mori, A. L. B., Viegas, M. C., & Benassi, M. T. (2021). Quality attributes of roasted Arabica coffee oil extracted by pressing: Composition, antioxidant activity, sun protection factor and other physical and chemical parameters. Grasas y Aceites, 72(1), e394. https://doi.org/10.3989/gya.1144192
Buffo, R. A., & Cardelli-Freire, C. (2004). Coffee flavour: An overview. Flavour and Fragrance Journal, 19(2), 99–104. https://doi.org/10.1002/ffj.1325
Cano-Chauca, M., Stringheta, P. C., Ramos, A. M., & Cal-Vidal, J. (2005). Effect of the carriers on the microstructure of mango powder obtained by spray drying and its functional characterization. Innovative Food Science and Emerging Technologies, 6(4), 420–428. https://doi.org/10.1016/j.ifset.2005.05.003
Carmo, C. S., Pais, R., Simplício, A. L., Mateus, M., & Duarte, C. M. M. (2017). Improvement of aroma and shelf-life on non-alcoholic beverages through cyclodextrins-limonene inclusion complexes. Food and Bioprocess Technology, 10, 1297–1309. https://doi.org/10.1007/s11947-017-1897-0
Carneiro, H. C. F., Tonon, R. V., Grosso, C. R. F., & Hubinger, M. D. (2013). Encapsulation efficiency and oxidative stability of flaxseed oil microencapsulated by spray drying using different combinations of wall materials. Journal of Food Engineering, 115(4), 443–451. https://doi.org/10.1016/j.jfoodeng.2012.03.033
Charles, M., Romano, A., Yener, S., Barnabà, M., Navarini, L., Märk, T. D., Biasioli, F., & Gasperi, F. (2015). Understanding flavour perception of espresso coffee by the combination of a dynamic sensory method and in-vivo nosespace analysis. Food Research International, 69, 9–20. https://doi.org/10.1016/j.foodres.2014.11.036
Comunian, T. A., Thomazini, M., Alves, A. J. G., Junior, F. E. M., Balieiro, J. C. C., & Favaro-Trindade, C. S. (2013). Microencapsulation of ascorbic acid by complex coacervation: Protection and controlled release. Food Research International, 52(1), 373–379. https://doi.org/10.1016/j.foodres.2013.03.028
Dong, Z., Ma, Y., Hayat, K., Jia, C., Xia, S., & Zhang, X. (2011). Morphology and release profile of microcapsules encapsulating peppermint oil by complex coacervation. Journal of Food Engineering, 104(3), 455–460. https://doi.org/10.1016/j.jfoodeng.2011.01.011
Eghbal, N., & Choudhary, R. (2018). Complex coacervation: Encapsulation and controlled release of active agents in food systems. LWT - Food Science and Technology, 90, 254–264. https://doi.org/10.1016/j.lwt.2017.12.036
Esfahani, R., Jafari, S. M., Jafarpour, A., & Dehnad, D. (2019). Loading of fish oil into nanocarriers prepared through gelatin-gum Arabic complexation. Food Hydrocolloids, 90, 291–298. https://doi.org/10.1016/j.foodhyd.2018.12.044
Frascareli, E. C., Silva, V. M., Tonon, R. V., & Hubinger, M. D. (2012). Effect of process conditions on the microencapsulation of coffee oil by spray drying. Food and Bioproducts Processing, 90(3), 413–424. https://doi.org/10.1016/j.fbp.2011.12.002
Gallardo, G., Guida, L., Martinez, V., López, M. C., Bernhardt, D., Blasco, R., Pedroza-Islas, R., & Hermida, L. G. (2013). Microencapsulation of linseed oil by spray drying for functional food application. Food Research International, 52(2), 473–482. https://doi.org/10.1016/j.foodres.2013.01.020
Hosseini, S. F., Zandi, M., Rezaei, M., & Farahmandghavi, F. (2013). Two-step method for encapsulation of oregano essential oil in chitosan nanoparticles: Preparation, characterization and in vitro release study. Carbohydrate Polymers, 95(1), 50–56. https://doi.org/10.1016/j.carbpol.2013.02.031
Jafari, S. M., Assadpoor, E., He, Y., & Bhandari, B. (2008). Re-coalescence of emulsion droplets during high-energy emulsification. Food Hydrocolloids, 22(7), 1191–1202. https://doi.org/10.1016/j.foodhyd.2007.09.006
Jain, A., Thakur, D., Ghoshal, G., Katare, O. P., & Shivhare, U. S. (2015). Microencapsulation by complex coacervation using whey protein isolates and gum acacia: An approach to preserve the functionality and controlled release of β-carotene. Food and Bioprocess Technology, 8, 1635–1644. https://doi.org/10.1007/s11947-015-1521-0
Kaltsa, O., Gatsi, I., Yanniotis, S., Mandala, I. (2014). Influence of ultrasonication parameters on physical characteristics of olive oil model emulsions containing xantan. Food and Bioprocess Technology, 7, 2038–2049. https://doi.org/10.1007/s11947-014-1266-1
López, J. A. S., Wellinger, M., Gloess, A. N., Zimmermann, R., & Yeretzian, C. (2016). Extraction kinetics of coffee aroma compounds using a semi-automatic machine: On-line analysis by PTR-ToF-MS. International Journal of Mass Spectrometry, 401, 22–30. https://doi.org/10.1016/j.ijms.2016.02.015
Lubes, G., & Goodarzi, M. (2017). Analysis of volatile compounds by advanced analytical techniques and multivariate chemometrics. Chemical Reviews. https://doi.org/10.1021/acs.chemrev.6b00698
Lv, Y., Zhang, X., Abbas, S., Karangwa, E., Lemetter, C. Y. G., & Zuidam, F. M. (2012). Simplified optimization for microcapsule preparation by complex coacervation based on the correlation between coacervates and the corresponding microcapsule. Journal of Food Engineering, 111(2), 225–233. https://doi.org/10.1016/j.jfoodeng.2012.02.030
Maderuelo, C., Zarzuelo, A., & Lanao, J. M. (2011). Critical factors in the release of drugs from sustained release hydrophilic matrices. Journal of Controlled Release, 154(1), 2–19. https://doi.org/10.1016/j.jconrel.2011.04.002
McClements, D. J. (2016). Emulsion stability. In D. J. McClements (Ed.), Food emulsions: Principle, practices, and techniques (3rd ed., pp. 289–382). CRC Press LLC.
Müller, M., Mikoviny, T., Jud, W., D’Anna, B., & Wisthaler, A. (2013). A new software tool for the analysis of high resolution PTR-TOF mass spectra. Chemometrics and Intelligent Laboratory Systems, 127, 158–165. https://doi.org/10.1016/j.chemolab.2013.06.011
Nazarzadeh, E., & Sajjadi, S. (2013). Thermal effects in nanoemulsification by ultrasound. Industrial and Engineering Chemistry Research, 52(28), 9683–9689. https://doi.org/10.1021/ie4003014
Peppas, N. A., & Narasimhan, B. (2014). Mathematical models in drug delivery: How modeling has shaped the way we design new drug delivery systems. Journal of Controlled Release, 190, 75–81. https://doi.org/10.1016/j.jconrel.2014.06.041
Ribeiro, A. M., Estevinho, B. N., & Rocha, F. (2019). Spray drying encapsulation of eldeberry extract and evaluating the release and stability of phenolic compounds in encapsulated powders. Food and Bioprocess Technology, 12, 1381–1394. https://doi.org/10.1007/s11947-019-02304-z
Roberts, D. D., Pollien, P., Antille, N., Lindinger, C., & Yeretzian, C. (2003). Comparison of nosespace, headspace, and sensory intensity ratings for the evaluation of flavor absorption by fat. Journal of Agricultural and Food Chemistry, 51, 3636–3642.
Rocha-Selmi, G. A., Favaro-Trindade, C. S., & Grosso, C. R. F. (2013). Morphology, stability, and application of lycopene microcapsules produced by complex coacervation. Journal of Chemistry, 2013, 1–7. https://doi.org/10.1155/2013/982603
Saifullah, M., Shishir, M. R. I., Ferdowsi, R., Tanver Rahman, M. R., & Van Vuong, Q. (2019). Micro and nano encapsulation, retention and controlled release of flavor and aroma compounds: A critical review. Trends in Food Science and Technology, 86, 230–251. https://doi.org/10.1016/j.tifs.2019.02.030
Sanchez-Reinoso, Z., & Gutiérrez, L. F. (2017). Effects of the emulsion composition on the physical properties and oxidative stability of sacha inchi (Plukenetia volubilis L.) oil microcapsules produced by spray drying. Food Bioprocess Technology, 10, 1354–1366. https://doi.org/10.1007/s11947-017-1906-3
Siepmann, J., & Peppas, N. A. (2001). Modeling of drug release from delivery systems based on hydroxypropyl methylcellulose (HPMC). Advanced Drug Delivery Reviews, 48(2–3), 139–157. https://doi.org/10.1016/S0169-409X(01)00112-0
Silva, E. K., Gomes, M. T. M. S., Hubinger, M. D., Cunha, R. L., & Meireles, M. A. A. (2015). Ultrasound-assisted formation of annatto seed oil emulsions stabilized by biopolymers. Food Hydrocolloids, 47, 1–13. https://doi.org/10.1016/j.foodhyd.2015.01.001
Soares, B. S., Carvalho, C. W. P., & Garcia-Rojas, E. E. (2021). Microencapsulation of sacha inchi oil by complex coacervates using ovalbumin-tannic acid and pectin as wall materials. Food Bioprocess Technology, 14, 817–830. https://doi.org/10.1007/s11947-021-02594-2
Soukoulis, C., Cappellin, L., Aprea, E., Costa, F., Viola, R., Märk, T. D., Gasperi, F., & Biasioli, F. (2013). PTR-ToF-MS, a novel, rapid, high sensitivity and non-invasive tool to monitor volatile compound release during fruit post-harvest storage: The case study of apple ripening. Food and Bioprocess Technology, 6, 2831–2843. https://doi.org/10.1007/s11947-012-0930-6
Soukoulis, C., Biasioli, F., Aprea, E., Schuhfried, E., Cappellin, L., Märk, T. D., & Gasperi, F. (2012). PTR-ToF-MS analysis for influence of milk base supplementation on texture and headspace concentration of endogenous volatile compounds in yogurt. Food and Bioprocess Technology, 5(6), 2085–2097. https://doi.org/10.1007/s11947-010-0487-1
Sunarharum, W. B., Williams, D. J., & Smyth, H. E. (2014). Complexity of coffee flavor: A compositional and sensory perspective. Food Research International, 62, 315–325. https://doi.org/10.1016/j.foodres.2014.02.030
Timilsena, Y. P., Akanbi, T. O., Khalid, N., Adhikari, B., & Barrow, C. J. (2019). Complex coacervation: Principles, mechanisms and applications in microencapsulation. International Journal of Biological Macromolecules, 121, 1276–1286. https://doi.org/10.1016/j.ijbiomac.2018.10.144
Walton, D. E., & Mumford, C. J. (1999). Spray dried products-Characterization of particle morphology. Institution of Chemical Engineers, 77, 21–38.
Zanin, R. C., Smrke, S., Kurozawa, L. E., Yamashita, F., & Yeretzian, C. (2020). Novel experimental approach to study aroma release upon reconstitution of instant coffee products. Food Chemistry, 317, 126455. https://doi.org/10.1016/j.foodchem.2020.126455
Zanin, R. C., Viegas, M. C., Smrke, S., Yeretzian, C., Kurozawa, L. E., & Yamashita, F. (2021a). The role of ultrasound-assisted emulsification of roasted coffee oil on aroma profile in spray-dried microparticles and its dynamic release by PTR-ToF–MS. European Food Research and Technology. https://doi.org/10.1007/s00217-020-03670-1
Zanin, R. C., Smrke, S., Kurozawa, L. E., Yamashita, F., & Yeretzian, C. (2021b). Modulation of aroma release of instant coffees through microparticles of roasted coffee oil. Food Chemistry, 341, 128193. https://doi.org/10.1016/j.foodchem.2020.128193
The authors thank Café Iguaçu, Gelita, and Nexira for providing the samples.
The authors were financially supported by the Zürich University of Applied Sciences and the Brazilian government (CAPES).
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Zanin, R.C., Smrke, S., Yeretzian, C. et al. Ultrasound-Assisted Emulsification of Roasted Coffee Oil in Complex Coacervates and Real-time Coffee Aroma Release by PTR-ToF–MS. Food Bioprocess Technol 14, 1857–1871 (2021). https://doi.org/10.1007/s11947-021-02683-2
- Soluble coffee
- Instant cappuccino
- Real-time online analysis
- Central composite rotational design
- Kinetic release