Microbiological and chemical profiles of retail falafel sandwich in Jordan

Abstract

Microbiological contamination of food poses a significant risk to public health, as a popular ready-to-eat food in the Middle-East, falafel sandwiches require no processing. When ingested, their microbiological integrity is extremely important to the population’s health. The aim of the present research was to evaluate the microbial load of falafel sandwich and its basic components, which is an important indicator of hygiene and safety; to that effect, we tested 120 samples from different restaurants in Amman, Jordan (30 falafel sandwiches, 30 tahini salad, 30 hummus, and 30 falafel). The collected samples were transferred to the laboratory in the ice box and tested for microbiological and chemical analysis (pH and titratable acidity). Appropriate media were used in the enumeration: Plate Count Agar, De Man, Rogosa, and Sharpe agar (MRS), Violet Red Bile Lactose Agar, and Baird-Parker Agar for mesophilic aerobes, lactic acid bacteria, coliforms, and Staphylococcus aureus, respectively. In all samples, the average pH was ≥ 5 and the average titratable acidity (as citric acid) was ≥ 0.55%, thus permitting the growth of many microorganisms. The samples were assessed for aerobic plate count (APC) and the counts of coliforms (CC), lactic acid bacteria (LABC), yeasts and molds (YMC), Staphylococcus aureus count (S. aureus), as well as for the presence of Salmonella enterica (S. enterica) and Listeria monocytogenes (L. monocytogenes). Average APC of ‘falafel’ sandwich, ‘tahini’ salad, ‘hummus’, and falafel were 6.4, 6.3, 5.8, and 2.9 log10 CFU/g respectively; average CC was 2.3, 2.8,1.9, and 0.6 log10 CFU/g, respectively; average LABC was 5.6, 5.5, 5.3, and 2.4 log10 CFU/g, respectively; average YMC was 4.2, 3.8, 3, and 0.7 log10 CFU/g, respectively; average S. aureus was 2.09,1.68,0, and 0.3 log10 CFU/g, respectively. S. enterica and L. monocytogenes were not isolated from any sample. This might be due of the exposure to high temperatures during the frying process, ‘falafel’ samples had the lowest microbial load. The study revealed through these microbial counts, that hummus and tahini salad are most likely to introduce microorganisms to falafel sandwich. Key words: falafel sandwich, tahini salad, hummus, coliforms, lactic acid bacteria