Microbiological and chemical characterisations of organic and conventional date pastes (Phoenix dactylifera L.) from Tunisia

Chemical and microbiological properties of organic and conventional date pastes produced from the Deglet Nour cultivar were investigated. Significant differences were observed in water content, sugar profiles, and pH among the date pastes. The low moisture and the high acidity of organic date paste were two important positive attributes for its storage and potential manufacturing uses. Before pasteurisation, moulds CPU's of the organic paste was significantly (P < 0.01) lower than those of the conventional one but no significant differences were observed for yeasts, coliforms and the total aerobic flora among the two date pastes. Considerable interest has developed on the preservation of conventional date paste by the use of natural additives such as Juniperus phoenicea and olive oil (conditioned paste). At a given mixture of Juniperus and olive oil and after pasteurisation, mould CFU's were reduced by 95% (P < 0.01) whereas the reduction was only 84% for the yeast populations, after 45 days at 25 °C.