Study of the stability of dried tomato halves during shelf-life to minimise oxidative damage

Optimal operating conditions for storage of dried tomato halves were invest igated to obtain decreased oxidative damage, evaluated in terms of colour v ariation, combined with microbial stability of the product, ie inhibition o f growth of eumycetes. Experiments were planned using a saturated factorial design. Variables studied were the moisture content of dried tomato halves in the range 10-60%, temperature in the range 5-30 degreesC and storage ti me in the range 1-38 days. Eighteen storage experiments were carried out in the dark under vacuum at the storage conditions indicated by the experimen tal design. At the end of each experiment, surface colour was measured by a tristimulus colorimeter, and growth of eumycetes was evidenced by olfactor y and visual perception, followed by qualitative microbial analysis. Eumyce tes were present in all stored products, except that at 10% moisture, and, generally speaking, storage conditions did not allow micro-organisms to gro w. From isoresponse curves the optimal region for storage to minimise oxida tive damage was extrapolated, which was represented by residual moisture va lues between 20 and 40% and less than or equal to 18 degreesC storage tempe rature, with a minimum point of colour variation at approximately 30% moist ure content and 10 degreesC. (C) 2000 Society of Chemical Industry.