The survival of Listeria monocytogenes in two foods of Arabic origin, namely labneh and houmos, was studied. Counts of L. monocytogenes in excess of 10 000 cfu g(-1) from labneh (pH 3.8) were reduced to zero within 72 h at 4 and 10 degrees C, but increased survival was noted at pH 4.5, especially in unsalted labneh; at 30 degrees C, no organisms could be detected 24 h after inoculation. From a starting count of 27 000 cfu g(-1), L. monocytogenes was able to survive on houmos throughout the anticipated shelf life (3 days); when houmos was stored at 4 and 10 degrees C under olive oil, the numbers of Listeria declined slowly over 3 days. It was concluded that care should be taken to avoid the contamination of houmos with Listeria during preparation in the kitchen. (C) 1996 Academic Press Limited