food and bioproducts processing 9 0 ( 2 0 1 2 ) 442–448 Contents lists available at SciVerse ScienceDirect Food and Bioproducts Processing j ourna l ho me p age: www.elsevier.com/locate/fbp The effect of pulsed electric fields, ultraviolet light or high intensity light pulses in combination with manothermosonication on selected physico-chemical and sensory attributes of an orange and carrot juice blend Irene M. Caminiti, Francesco Noci, Desmond J. Morgan, Denis A. Cronin, James G. Lyng * UCD Institute of Food and Health, School of Agriculture, Food Science and Veterinary Medicine, College of Life Sciences, University College Dublin, Belfield, Dublin 4, Ireland a b s t r a c t A blend of orange and carrot juice was processed by three selected treatments combining pulsed electric fields (PEF) (24 kV/cm, 18 Hz, 93 s), ultraviolet light (UV) (10.6 J/cm 2 ) or high intensity light pulses (HILP) (3.3 J/cm 2 ), in each case, with manothermosonication (MTS) technology (400 kPa, 35 ◦ C, 1000 W, 20 kHz). Treatment effects on selected physico- chemical and sensory properties of the juice were evaluated. No significant changes were found in non-enzymatic browning (NEBI) or antioxidant activity compared to an untreated control. However, the treatments increased all the Hunter Lab colour values, while total phenolics were significantly decreased. Each combination achieved on average 78% inactivation of pectin methyl esterase (PME). Sensory analysis showed that the colour of the product processed by hurdle combinations was preferred to that of a pasteurised sample (72 ◦ C, 26 s), while the flavour was adversely affected by all of the non-thermal treatments. Panellists did not perceive differences in the odour, sweetness or acidity of the product. Results indicate that, under the current experimental conditions, the application of the selected combinations of non-thermal technologies resulted in a product in which certain quality attributes were somewhat inferior to those of a lightly pasteurised control juice. © 2011 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved. Keywords: Non-thermal hurdle processing; Sensory evaluation; Ultraviolet light (UV); High intensity light pulses (HILP); Pulsed electric field (PEF); Manothermosonication (MTS) 1. Introduction During the last decade, research interest has been increasingly focused on non-thermal technologies as beverage preser- vation methods because of their potential in inactivating microorganisms and enzymes, while maintaining the quality of the product (Senorans et al., 2003). Due to the relatively high temperatures generally needed to inactivate food-poisoning and spoilage microorganisms, conventional pasteurisation can adversely affect the quality of food products, by reduc- ing their nutritional value or altering sensory attributes, such as colour and flavour. Alternative novel technologies are based on physical methods to slow or prevent the growth ∗ Corresponding author. Tel.: +353 01 7167710; fax: +353 01 7161147. E-mail address: james.lyng@ucd.ie (J.G. Lyng). Received 25 January 2011; Received in revised form 28 October 2011; Accepted 10 November 2011 of microorganisms, providing a less-intensive heating and milder processing conditions. They include the application of pulsed electric fields (PEF), high hydrostatic pressure, ultra- sound (US) and continuous or pulsed ultraviolet (UV) light (Barbosa-Canovas and Bermúdez-Aguirre, 2008; Leadley and Williams, 2005). Short wave UV light (UV-C 200–280 nm) can be absorbed by the DNA of microorganisms, inducing some chemical mod- ifications in its structure and, consequently, damaging the vital processes of the cell. The peak of absorption corre- sponds to approximately 260 nm and, for this reason, the light sources employed are low-pressure mercury lamps (main emission wavelength at 254 nm) (Lopez-Malo and Palou, 2004). 0960-3085/$ – see front matter © 2011 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved. doi:10.1016/j.fbp.2011.11.006