Effect of thermal and high hydrostatic pressure treatments on mango bars shelf-life under refrigeration Florina Danalache a, b , Claudia Y. Carvalho b , Luisa Brito b , Paulina Mata a , Margarida Mold ~ ao-Martins b , Vitor D. Alves b, * a LAQV, REQUIMTE, Departamento de Química, Faculdade de Ci^ encias e Tecnologia, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal b LEAF e Linking Environment Agriculture and Food, Instituto Superior de Agronomia, Universidade de Lisboa, Tapada da Ajuda,1349-017, Portugal article info Article history: Received 19 August 2016 Received in revised form 8 April 2017 Accepted 9 May 2017 Available online xxx Keywords: Mango bars Thermal treatment High hydrostatic pressure Volatiles Microbial quality and safety Sensory quality abstract Ready-to-eat mango bars, previously developed, were packaged using a heat-sealable multilayer material (PET/PE aluminium film). They were then subjected to two types of preservation treatments: thermal treatments (TT) (80 and 90  C for 120 and 300 s) and high hydrostatic pressure (HHP) (500 MPa for 120 and 240 s), in order to compare their impact on flavour release and microbial stability of the mango bars. A similar effect of both thermal and non-thermal treatments on the referred bars characteristics was observed. As such, TT at 80  C for 120 s was selected as ideal for bars treatment, as it is the one carried out at lower temperature and lower period of time. For bars treated with this TT, parameters such as, hardness, cohesiveness, springiness, total colour difference, browning index, sensory quality, microbial growth (aerobic colonies and yeasts and moulds) and microbiological safety (detection of Listeria monocytogenes) of the bars were monitored under refrigerated conditions (5  C). Results indicated the TT of 80  C, for 120 s, as the more adequate to extend the shelf-life of the mango bars. The bars presented good stability during refrigerated storage, as the monitored parameters did not change significantly. The shelf-life of the untreated mango bars was estimated to be nine days, while the thermal treatment of the bars extended their shelf-life to 18 days at 5  C. © 2017 Elsevier Ltd. All rights reserved. 1. Introduction An active promotion of fruit as a basic component of a healthy diet resulted in an increased consumer’s interest for fruit products. This became an area of interest of the food industry with the development of a wide range of ready-to-eat (RTE) fresh fruit products. In fact, consumption of fruits and their products is asso- ciated with a decreased risk of degenerative diseases such as cancer and coronary heart disease, due to health promoting phytochemi- cals such as carotenoids, flavonoids, phenolic compounds and vi- tamins (Hansen et al., 2003). From a quality point of view, it is desirable to preserve the characteristics of fruits and vegetables while being processed, namely into RTE products. The consumers consider their fresh-like appearance, taste and flavour, in addition to their convenience, the most appealing attributes for these products. Microbial spoilage, discoloration or browning, textural changes and development of off-flavour or off-odour are the major factors affecting the shelf-life of the processed fruit products (Van Boxstael et al., 2014). Food industry needs to ensure the food products safety while maintaining their quality. The loss of compounds responsible for aroma during food processing operations is one of the major drawbacks in food industry (Daelman et al., 2013). Furthermore, the control of microbial contamination and growth in food products is essential to ensure consumers’ health and well-being and to minimise loss of food through spoilage (Hussein et al., 2015; Smigic et al., 2016). Thermal treatment (TT) is the preferred technology to inactivate microorganisms and enzymes that causes spoilage, mainly because is less expensive and more accessible than the other processing treatments. However, several studies on thermally treated fruit products such as guava puree (Yen and Lin, 1996), apples (Yamada et al., 2004), tomato and carrot purees (Patras et al., 2009), melon juice (Chen et al., 2009), fruit smoothies (Keenan et al., 2010) and tamarillo fruit (Mertz et al., 2010) reported loss of nutritional quality, in consequence, reducing the beneficial health effects. * Corresponding author. E-mail address: vitoralves@isa.ulisboa.pt (V.D. Alves). Contents lists available at ScienceDirect Journal of Food Engineering journal homepage: www.elsevier.com/locate/jfoodeng http://dx.doi.org/10.1016/j.jfoodeng.2017.05.009 0260-8774/© 2017 Elsevier Ltd. All rights reserved. Journal of Food Engineering xxx (2017) 1e8 Please cite this article in press as: Danalache, F., et al., Effect of thermal and high hydrostatic pressure treatments on mango bars shelf-life under refrigeration, Journal of Food Engineering (2017), http://dx.doi.org/10.1016/j.jfoodeng.2017.05.009