Assessing the effect of product variability on the management of the quality of mushrooms (Agaricus bisporus)

To study the shelf-life of mushrooms, over 25 batches were subjected to three storage temperatures (T) (5, 15 and 25 degrees C) and three storage relative humidity (RH) levels (70, 80 and 90%). The effect of T and the RH on the kinetics of quality attributes of the batches was studied by measuring water activity, turgor, colour (L, a* and b* in the Hunter Scale) and weight loss of three different tissues (cap, gills and stipe) of the mushroom. Linear mixed effect models, comprising polynomial models to describe quality kinetics and allowing for batch-to-batch and inside-batch nested variability structure, were built. The resulting models described changes in the six quality factors with time, their kinetic dependence on temperature and relative humidity and estimated the variability components in a typical retailer situation. Significant quadratic effects, pointing to optimal storage conditions were found for the temperature (L and a values, b value, water activity, turgor and weight) and for the relative humidity (L and a values, b value, water activity and total weight). Optimal storage conditions point to a practice of low temperature and high relative humidity to preserve product weight, although other properties can be optimally preserved using higher storage temperatures and therefore pointing to possible cost savings in storage. Significant batch-to-batch and inside-batch variability components were identified, giving an estimate of the variability expected on the management of different quality attributes of such a biological product in an agricultural retail scenario. (C) 2008 Elsevier B.V. All rights reserved.