Lebensm.-Wiss. u.-Technol. 38 (2005) 81–87 Research note Effect of short- and long-term frozen storage with MAP on the quality of freeze-chilled lasagne G.A. Redmond a , T.R. Gormley a, *, F. Butler b a Teagasc, The National Food Centre, Ashtown, Dunsinea, Castle, Dublin 15, Ireland b Biosystems Engineering, University College, Dublin, Ireland Received 13 January 2004; accepted 10 March 2004 Abstract The effect of long- and short-term frozen storage prior to thawing, on the quality of freeze-chilled, commercially made lasagnes was examined as was the effect of modified atmosphere packaging (MAP). In the short-term trial, four process treatments were used; fresh, chilled, freeze-chilled and frozen. In the long-term trial, the lasagnes were frozen for 3, 6, 9 or 12 months, thawed and tested, or were thawed and then chilled at 4  C for 6 days (freeze-chilled). In the MAP trial, the lasagnes were subjected to either the freeze- chill treatment or freeze treatment, and before freezing were packed in either (i) air, (ii) 40% CO 2 /60% N 2 or (iii) 40% CO 2 /30% N 2 / 30% O 2 . In the short-term trial frozen and freeze-chilled lasagne had significantly higher drip loss than fresh or chilled before reheating, but this was not evident after heating. Similarly, freeze-chilled lasagne had a brighter colour (L/b) than chilled before heating, but again this was not evident after heating. No difference was found in firmness or sensory acceptability of lasagne from the different treatments. Freeze-chilled and frozen lasagne had higher total viable counts (TVC) than chilled or fresh. Packing in CO 2 /N 2 /O 2 (40:30:30) led to a darker unheated lasagne than packing in CO 2 /N 2 (40:60) or air, but this was not evident for heated lasagne. Packing in CO 2 /N 2 (40:60) led to a firmer product than packing in air for the frozen lasagne but not for freeze-chilled lasagne. Atmosphere had no effect on TVC or drip loss values. Lasagnes stored frozen for 12 months were firmer than those stored for 3, 6, or 9 months. Storing frozen for 9 or 12 months also led to higher drip loss values than storing for 3 months for unheated lasagnes but when heated, the opposite effect was seen. Lasagnes stored for 3 months had the highest L/b (white/yellow ratio) values while those stored for 12 months had the lowest. Length of time in frozen storage had no influence on TVC values. r 2004 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved. Keywords: Lasagne; Freeze-chilling; MAP 1. Introduction The ready-meals market has grown significantly in Europe over the past decade with the chilled sector experiencing the most dynamic growth (Mintel, 1997). It is expected to grow by 20% from current values to exceed &6.8 billion by 2005; the growth potential is particularly strong in southern European countries (Sands, 2002). Chilled ready-meals have a relatively short shelf-life and are perceived to be of better quality than frozen meals (Stringer, 1990). However, frozen ready-meals are bought more often due to their long shelf-life (Mahon, Cowan, & Bogue, 2000); they also offer better manufacturing and distribution flexibility, food safety and extended storage time (Kobs, 1997). Lasagne is an increasingly popular ready-meal with average consumption per capita in Ireland at 0.32 kg annually, compared to 0.2 kg in the UK and 1.0 kg in Belgium (Anon, 2001a). Freeze-chilling involves freezing and frozen storage followed by thawing and chilled retail display (Red- mond and Gormley, 2003; Gormley, Redmond, & Fagan, 2003). It has an advantage over chilling as it allows bulk preparation of frozen products followed by controlled batch release of thawed product into the chill chain. It has a logistic advantage of enabling ‘chilled’ products to reach foreign markets more easily. Freeze- chilling can also reduce the level of product recalls as it enables routine microbiological tests to be completed before the product is released from the factory. ARTICLE IN PRESS *Corresponding author. Tel: +353-1-8059500, fax: +353-1- 8059550. E-mail address: rgormley@nfc.teagasc.ie (T.R. Gormley). 0023-6438/$30.00 r 2004 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.lwt.2004.03.012