Influence of a test preservative on sponge cakes under different storage conditions.

A study was performed on 240 samples, divided into four batches, of sponge cakes baked following their industrial recipe to which different concentrations of a test preservative, mainly lactic acid and propylene glycol, were added. Each batch was submitted to three different temperature and relative humidity conditions. The counts of mesophilic aerobic bacteria, enterobacteria, enterococci, staphylococci, clostridia, lactic acid bacteria, and yeasts were less than 1 log CFU/g in all the batches studied and throughout the 120 days of study. Depending on batches and conditions, the mold counts were between less than 1 and 6.40 log CFU/g. Aspergillus, Eurotium, Penicillium, and Wallemia were detected and were potentially toxigenic in two cases. The test preservative added at 18 g/kg produced the greatest preserving effect, prolonging the product's shelf life by more than 4 months and showing itself to be effective at the other concentrations, especially at 15 degrees C and at 80 and 51% relative humidity.