Multi-criteria Decision-making Technique Approach to Assess the Microbial Quality and Safety of Fresh-cut Salads Sold at Retail in Istanbul, Turkey

Abstract

The goal of this study was to investigate the microbial quality and safety of fresh-cut salads sold in restaurants that were located at Esenler, Fatih, Besiktas, Uskudar, Kadikoy and Umraniye in Istanbul, Turkey. In total, 180 samples were assayed for microbiological analysis including enumeration of total aerobic mesophilic (TMAB), aerobic psychotropic (AP) bacteria, yeast and mold (YM), fecal coliforms bacteria, Escherichia coli, Staphylococcus aureus, isolation of Salmonella spp. and Listeria monocytogenes. Meanwhile, a coagulase test was conducted out for S. aureus. Technique for order preference by similarity to ideal solution (TOPSIS)-based multi-criteria decision-making technique (MCDM) approach was used to rank six districts in terms of microbial count. The enumeration of TMAB in Esenler, Fatih and Besiktas ranged from 4.34 to >7.48 log CFU g-1, 3.69 to >7.48 log CFU g-1 and 4.05 to >7.48 log CFU g-1, respectively. However, the enumeration of TMAB in Uskudar, Kadikoy and Umraniye ranged from 2.57 to >7.48 log CFU g-1, 4.01 to >7.48 log CFU g-1 and 4.24 to >7.48 log CFU g-1, respectively. The enumeration of AP, YM and S. aureus ranged from 2.00 to >7.48 log CFU g-1, 2.00 to >7.48 and 2.00 to 6.13 log CFU g-1, respectively. Coagulase-positive staphylococci were found in 43 samples. When total coliforms counts were calculated for the samples, Esenler had the highest count (3588.1 MPN/g). The highest and lowest count of fecal coliform was found in Esenler and Fatih, respectively. E. coli was isolated 7.22% in samples. Salmonella spp. and L. monocytogenes were not found in any of the samples. According to TOPSIS, Esenler had very bad values of TMAB and AP, S. aureus, coliform and fecal coliform. As for YM, Fatih had the worst scores. Uskudar was found as the best district considering the count of all microbial groups. On the other hand, it has been discovered that the microbial safety of fresh-cut salads sold in Istanbul is adequate for consumption.