Evaluation of fresh-cut apple slices enriched with probiotic bacteria Christian Rößle a, ⁎, Mark A.E. Auty b , Nigel Brunton a , Ronan T. Gormley a , Francis Butler c a Ashtown Food Research Centre (Teagasc), Ashtown, Dublin 15, Ireland b Moorepark Food Research Centre (Teagasc), Fermoy, Co. Cork, Ireland c Biosystems Engineering, School of Agriculture, Food Science and Veterinary Medicine, University College Dublin, Dublin 4, Ireland abstract article info Article history: Received 20 May 2009 Accepted 28 August 2009 Editor Proof Receive Date 10 September 2009 Keywords: Probiotic Lactobacillus LGG Fresh-cut Apple Non-dairy The aim of this study was to apply a probiotic microorganism (Lactobacillus rhamnosus GG; LGG) to fresh-cut apple wedges (cultivar Braeburn) and measure entrapment and stability of the microorganism. Instrumental eating quality parameters (Colour Lab, texture, soluble solids, titratable acidity and pH) and sensory acceptability were also monitored to investigate if application of the probiotic significantly influenced eating quality. Apple samples were cut into skin-on wedges and were dipped in an edible buffer solution containing approximately 10 10 cfu/ml of LGG. LGG were enumerated on each test day (0, 2, 4, 6, 8 and 10) on whole wedges, on wedges flushed with a buffer solution (2% tri-sodium citrate), and on the flush-off liquid itself. All three samples sets contained ca. 10 8 cfu/g over the test period, which is sufficient for a probiotic effect, and is comparable to counts of probiotic bacteria in commercially available dairy products. This included the sample set of wedges which had been flushed with buffer solution indicating good adherence of the bacteria over the test period. Physicochemical properties of the apple wedges containing LGG compared to the control remained stable over the 10 day period. Cryo scanning electron microscopy and confocal scanning laser microscopy demonstrated good adherence of LGG to the surface of apple wedges. Industrial relevance: Probiotic dairy foods, e.g. yoghurts, are well recognised by most consumers and command a significant market share. However, many people are allergic or intolerant to dairy products and an alternative option is desirable. Minimally processed freshly prepared fruits are a popular item and are perceived as healthy by consumers. They are therefore an ideal vehicle for incorporation of other functional components such as probiotics. Therefore, a probiotic bacterium was applied to fresh-cut apple wedges. This will provide an alternative probiotic food choice for consumers and could be particularly appealing to children. The process for making this product is relatively simple and the product would retail from the conventional chill counters of supermarket stores. It is likely that its price would be competitive with existing probiotic dairy products. © 2009 Elsevier Ltd. All rights reserved. 1. Introduction In the early years bacteria were generally regarded as undesirable and the cause of many diseases. More recently scientific research has done much to reduce their negative image. In particular, much research has been aimed at searching for healthy bacteria and components which can beneficially affect health conferring bacteria. Probiotics belong to the former category and are classically defined as ‘live microbial feed supplements which beneficially affect the host animal by improving its intestinal microbial balance’ (Fuller, 1989). Several scientific studies have shown that microbial cells have a beneficial effect on the health and well-being of the human host (Salminen et al., 1998a,b) if directed in the right amounts (Dave and Shah,1997; Kailasapathy & Rybka,1997; Brown & Valiere, 2004; Prado, Parada, Pandey & Soccol, 2008). Some studies have indicated that regular consumption of viable probiotics can confer a number of health benefits such as a reduction of cholesterol (Anderson & Gilliland, 1999; Nguyen, Kang & Lee, 2007), control of gastrointestinal infections (McFarland et al., 1995; Saavedra, Bauman, Oung, Perman & Yolken, 1994), improvement of lactose tolerance (Hove, Norgaard & Mortensen, 1999; Kim & Gilliland, 1983; Shah, 2007), improvement in inflammatory bowel disease (Lammers et al., 2003) , inhibition of some cancers (Aso et al., 1995; Cross, 2002), anti-diabetic properties (Matsuzaki, Yamazaki, Hashimoto & Yokokura, 1997; Yadav, Jain & Sinha, 2007), anti-diarrhoeal effects (Nomoto, 2005), and immune system stimulation (De Moreno de LeBlanc et al., 2008; Cross, 2002). Over the last years the minimally processed foods market has been extended especially due to an increase of the fresh-cut fruits market (Buckley, Cowan & McCarthy, 2007; Gorny, 2003). Development of health promoting foods is one of the key drivers for the food industry due to an increasing demand for foods enriched with physiologically active components such as probiotics (Mark-Herbert, 2004). Probiotic Innovative Food Science and Emerging Technologies 11 (2010) 203–209 ⁎ Corresponding author. Tel.: +353 1 8059529; fax: +353 1 8059550. E-mail address: christian.roessle@teagasc.ie (C. Rößle). 1466-8564/$ – see front matter © 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.ifset.2009.08.016 Contents lists available at ScienceDirect Innovative Food Science and Emerging Technologies journal homepage: www.elsevier.com/locate/ifset