The combined effects of carbon dioxide and ethanol vapours on the preservation of sliced bread stored at low oxygen partial pressure

The experimental design proposed in this work aims at statistically estimating the simultaneous effects of carbon dioxide and ethanol vapours on storage of sliced bread; in particular, it is important to find the best combination of variables assuring to sliced bread a longer shelf-life than the present one (10 days). In our experiments, the bread was inoculated with a spore suspension of Aspergillus niger and pouched with different combinations of carbon dioxide and ethanol vapours; the ethanol was released by an ethanol emitter obtained with ethanol-saturated silical gel. Results show that Aspergillus niger grew in presence of high levels of carbon dioxide, even if oxygen was present at low concentration; moreover, ethanol alone was not sufficient to inhibit mould grow.