CHEMICAL ENGINEERING TRANSACTIONS VOL. 75, 2019 A publication of The Italian Association of Chemical Engineering Online at www.cetjournal.it Guest Editors: Sauro Pierucci, Laura Piazza Copyright © 2019, AIDIC Servizi S.r.l. I SBN 978-88-95608-72-3; I SSN 2283-9216 Mathematical Modeling of Convective Drying Acerola (Malpighia emarginata) Residue in Different Thicknesses Jefferson D. O. Silva a , Débora E. L. Santos b , Ana Karla S. Abud b,* , Antonio M. Oliveira Junior a,b a Postgraduate Program of Chemical Engineering, Federal University of Sergipe, São Cristóvão, Sergipe, Brazil b Food Technology Department, Federal University of Sergipe, São Cristóvão, Sergipe, Brazil ana.abud@gmail.com The increasing demand and processing capacity of the fruit processing industries generates a huge amount of waste. Brazil stands out as a producer and exporter of acerola (Malpighia emarginata). One of the alternatives to add value to this by-product and contribute to minimizing environmental impacts from its disposal is drying. The drying was carried out with forced air circulation at a speed of 2,20 m s -1 and a temperature of 75 ºC, in thicknesses of 3, 4, 5 and 6 mm. The adjustment of the models to the experimental data was performed with Software Statistica 10.0. The effective diffusion coefficient, in the order of 10 -10 m 2 s -1 , is adequate and did not present a significant difference, among the three major thicknesses. Drying parameters of design and operation were analyzed by mathematical models of Page, Lewis and Midilli, using performance indicators as accuracy (A f ) and noise factors (B f ), mean square error (RMSE) and standard error of prediction (% SEP), associated with each model. All the models present a good adjustment. Despite the greater accuracy of the Midilli model, the Page model is considered more appropriate for process purposes, since it is necessary to adjust only two parameters. 1. Introduction Brazil stands out as one of the largest producers in the agribusiness sector, with acerola being one of the fruits of growing importance and progressive expansion of the cultivation area, leading the country to the top of the world production ranking (Malegori et al., 2017). Acerola (Malpighia emarginata), also known as Antillean cherry, West-Indian cherry or Barbados cherry, is a fruit native to Central America, Northern South America and the Antilles (Rezende et al., 2017). The economic interest in its culture is mainly due to its high amount of vitamin (695 a 4827 mg 0.01 g -1 ), also presenting high levels of other antioxidants, such as carotenoids, bioflavonoids, anthocyanins and phenolics compounds (Mezadri et al., 2008; Rezende et al., 2018). The fruits of the acerola are industrially processed into juices and pulps, food supplements and pharmaceutical products (Almeida et al., 2014), serving multiple markets, which adds even more value to acerola's fruit growing, increasing its demand. In this context, with the increase of production due to the improvement of industrial processing techniques, an enormous amount of organic waste is generated in concomitantly, approximately 40% of the volume of fruit used (Duzionni et al., 2013), composed basically of bagasse, kernels and seeds, which are generally rejected because they are considered of no commercial value and can generate a series of environmental problems when they are improperly discarded (Nóbrega et al., 2015). The acerola residue still presents high concentrations of bioactive compounds, as well as fruit pulp (Rezende et al., 2017) and their non-reuse represents a loss of raw material and energy, since they present enormous potential for applications such as food supplements (Sancho et al., 2015).They may also contain more than 80% of water (Silva et al., 2016), which allows the occurrence of undesirable biochemical reactions that cause the degradation of the material, limiting their shelf life, besides allowing microbiological contamination. Aiming at a better possible alternative for the reuse of these wastes, it is necessary to subject them to a dehydration process (Sanmartin et al., 2017). DOI: 10.3303/CET1975094 Paper Received: 25 July 2018; Revised: 9 November 2018; Accepted: 25 February 2019 Please cite this article as: Oliveira Da Silva J.D., Lima Santos D.E., Abud A.K.D.S., Oliveira Junior A.M., 2019, Mathematical Modeling of Convective Drying Acerola (malpighia Emarginata) Residue in Different Thicknesses, Chemical Engineering Transactions, 75, 559-564 DOI:10.3303/CET1975094 559