Characterisation of the dry salted process for the production of the msayer, a traditional lemon aromatising condiment

Msayer is a dry salted lemon used as an aromatising condiment in many North-African food recipes. This preparation is obtained by adding coarse salt (10 g/100 g fresh lemons) to fresh cut lemons in containers kept under dark conditions away from air for around a month and a half. A survey of 52 days showed low initial uptake of citric acid and sugars from the formed liquid phase. Nevertheless, there were still sugars detected even at the end of the survey attesting for the low microbial activity as also shown by carbon dioxide production and microbial viable counts. Indeed, the microbial counts showed a steady decrease reaching 2 log units at the 52nd day of curing. Moulds were detected only at the beginning but at low numbers. No viable counts of lactic acid bacteria were observed on MRS medium despite detection of lactic acid (8 g/l). In contrast, yeasts seem to dominate in the msayer preparation. They count for almost all the microbial population especially after the first week. Six of these acid and halotolerant yeast isolates were identified, by sequence analysis of the amplified 5.8S rRNA and the two internal transcribed spacer regions, as Candida parapsislosis (2 isolates) and unclassified Saccharomycetales (4 isolates).