Quality and storage life of par-baked frozen breads

During storage of frozen par-baked breads for a prolonged period of time, bread quality may undergo changes such as increased firmness, moisture and flavour losses resulting in product deterioration. Four categories of par-baked breads namely-variety, white, multi-grain and rye were stored at -18degreesC for 9 months to evaluate the effects of storage period on product quality, and to develop prediction models that describe kinetics of deterioration of selected quality parameters. The quality was evaluated based on sensory, chemical and physical attributes and properties. Storage life was determined based on the changes in bread quality below certain level. The principal component analysis indicated that approximately 90% of the total variability of 19 quality parameters can be explained with only two principal components. The zero-order kinetic reaction showed good agreement (R-2 > 80%) with quality changes observed by the sensory panel over the storage period. A prediction model, based on the bread quality at zero time and the quality at the time when the bread was rejected by the sensory panel, was developed. The proposed prediction model would provide a useful means of estimating storage life of par-baked breads made with similar formulations. (C) 2003 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.