The objectives of this work were to determine the influence of the application of two different coatings (galactomannan and chitosan) and of storage temperature on the gas exchange rate of "Regional" cheese; subsequently, the coating that showed the greatest influence on the cheese gas exchange and simultaneously decreased the O(2) consumption (R(O2)) and the CO(2) production (R(CO2)) rates was applied on cheese, being the shelf-life parameters monitorized through the performance of chemical and microbiological analyses. Both coatings caused a reduction of R(O2) and R(CO2) of the cheese (between 0.19- and 1.30-fold for R(O2) and between 0.19- and 1.50-fold for R(CO2), depending on the temperatures). The cheese coated with the galactomannan coating was the one with the lower values of R(O2) (between 0.195 and 0.635 mL kg(-1) h(-1)) and R(CO2) (between 0.125 and 0.900 mL kg(-1) h(-1)). Temperature was also found to have an important effect on R(O2) and R(CO2), its influence being well described by an Arrhenius equation with coefficients of determination, R(2), of 0.85 and above. The chemical and microbiological analyses showed that the application of the coating in cheese samples can be used to decrease the water loss and the colour changes during the storage time. The presence of the coating decreased the moisture loss of the cheese in 2.5% and 1.9%, and the weight loss in 3.8% and 3.1% at 4 degrees C and 20 degrees C, respectively. Also, the hardness of the cheese can be decreased as a result of the interaction of the presence of the coating with changes in the storing temperature. In the studied range (4-20 degrees C) temperature has a statistically significant effect in moisture loss, colour change, hardness and total mesophilic bacterial growth.
Overall, galactomannan coating can be used to improve "Regional" cheese shelf-life as it decreases R(O2) and R(CO2), improves its weight and appearance and can be used to incorporate natural preservatives to reduce post contamination. (C) 2009 Elsevier Ltd. All rights reserved.