Osmotic dehydration of physalis (Physalis peruviana L.): Evaluation of water loss and sucrose incorporation and the quantification of carotenoids Cl  audia Leites Luchese a, * , Poliana Deyse Gurak b , Ligia Damasceno Ferreira Marczak a a Chemical Engineering Program, Federal University of Rio Grande do Sul (UFRGS), RS, Brazil b Department of Nutrition, Federal University of Health Sciences of Porto Alegre (UFCSPA), RS, Brazil article info Article history: Received 19 November 2014 Received in revised form 16 April 2015 Accepted 26 April 2015 Available online xxx Keywords: Effective mass diffusivity Scanning electron microscopy Bioactive compounds Water activity Colorimetric analysis abstract The rapid growth in demand for physalis production is associated with its nutraceutical and medicinal characteristics. However, one aspect that hampers its commercialization is the high perishability. In present work it is proposed to submit Physalis peruviana L. for osmotic dehydration, to evaluate the effects of temperature (40e70  C) and osmotic sucrose solution concentration (40e70 g 100 g 1 so- lution). Moisture content and total sugar content analysis were performed along the osmotic dehy- dration process and the total content of carotenoids was analyzed for the fresh fruit and after 10 h of processing. Water mass diffusivity ranging between 1.4e2.9  10 10 m 2 s 1 and the effective mass diffusivity of sucrose ranged from 0.7 to 1.1  10 10 m 2 s 1 . Among all conditions studied in the experimental design, the osmotic dehydration was more efficient when performed at a temperature of 70  C and an osmotic solution concentration of 70 g 100 g 1 of solution. In these conditions, there was the highest water loss and a statistically significant reduction in the water activity of this fruit. However, the greatest loss of total carotenoids (approximately 50%) was observed. Under this experimental condition, the tissue matrix of physalis suffered structural changes, as proven through scanning electron microscopy analysis. © 2015 Elsevier Ltd. All rights reserved. 1. Introduction The physalis genus includes approximately 100 species, and the main species are Physalis angulata Linnaeus, Physalis pubescens L., Physalis alkekengi L. and Physalis peruviana L.; the last species is the most well-known and studied. Physalis peruviana L. originates from the region of the South American Andes and belongs to the family Solanaceae; it grows in different soil types and has low re- quirements for fertilization (Cede~ no & Montenegro, 2004; Puente, Pinto-Mu~ noz, Castro, & Cort es, 2011; Ramadan, 2011). The physalis fruit is characterized as a spherical berry, with a diameter between 1.25 and 2.50 cm and a mass between 4 and 10 g. The physalis is protected by the calyx, which completely covers the fruit during its development and ripening (Mayorga, Knapp, Winterhalter, & Duque, 2001; Tapia & Fries, 2007). Physalis peruviana L. has been known for centuries, but its potential for intensive cultivation has only recently begun to be explored, mainly due to the presence of bioactive compounds, such as ascorbic acid, phenolic compounds, phytosterols and carotenoids. Other compounds are also present in physalis, and its medicinally active components have been studied, including withanolides (Chandrasekaran, Dayakar, Veronica, Sundar, & Maurya, 2013; Fang, Liu, & Li, 2012), withaesteroides (P erez-Castorena, Luna, Martínez, & Maldonado, 2012) and phys- alins (Hsu et al., 2012; Soares et al., 2006). These compounds pre- sented important pharmacological properties, including antimicrobial, antibacterial, antitumor, antinflammatory, hep- atoprotective, immunomodulatory and immunosuppressive prop- erties e in addition to demonstrating effectiveness for the inhibition of unwanted responses in autoimmune diseases and al- lergies as well as the transplantation of organs. Colombia is the world's leading producer of the fruit of physalis. However, since 2009, Brazil and Chile have appeared as active competitors, mainly due to promising results regarding the * Corresponding author. E-mail addresses: claudialuchese@yahoo.com.br (C.L. Luchese), poligurak@ hotmail.com (P.D. Gurak), ligia@enq.ufrgs.br (L.D.F. Marczak). Contents lists available at ScienceDirect LWT - Food Science and Technology journal homepage: www.elsevier.com/locate/lwt http://dx.doi.org/10.1016/j.lwt.2015.04.060 0023-6438/© 2015 Elsevier Ltd. All rights reserved. LWT - Food Science and Technology xxx (2015) 1e9 Please cite this article in press as: Luchese, C. L., et al., Osmotic dehydration of physalis (Physalis peruviana L.): Evaluation of water loss and sucrose incorporation and the quantification of carotenoids, LWT - Food Science and Technology (2015), http://dx.doi.org/10.1016/ j.lwt.2015.04.060