Microbial contamination and levels of heavy metals in packaged and loose varieties of some herbs sold in the markets

ABSTRACT

Sixty samples of six different herbs were collected from several markets in Cairo. They were subjected to microbiological analysis. It revealed that most of the loose varieties have worse microbiological quality than packaged except in case of coliform count in chamomile where both varieties revealed similar values [1500 MPN/g]. And in case of Aerobic Mesophilic Count of peppermint, packaged varieties revealed non significantly higher count [l.0xl0[5] compared to 3.9xl0[4] CFU/g in loose peppermint]. Among the thirty loose herbs samples, only a caraway sample was complying with Egyptian Standards regarding Aerobic Mesophilic Count; while seventeen out of the thirty packaged samples [56.6%] were complying with the standard. Despite contamination of all loose herbs varieties with both coliforms and fecal coliforms, the packaged varieties were contaminated only with coliforms and none of them were contaminated with fecal coliforms. Although coagulase positive Staphylococci were detected in all loose herbs varieties none of the packaged varieties were contaminated. All loose herbs varieties were contaminated with mold and yeast, counts were much higher than those encountered in the packaged varieties. Analysis of heavy metals revealed that all loose herbs samples showed significantly higher contamination with arsenic, lead and mercury levels than packaged varieties except in case of mercury in caraway. Heavy metals contents of both packaged and loose peppermint were complying with the Egyptian Standards. Moisture contents of loose herbs were significantly higher than that of the corresponding packaged varieties of the same herb except in case of anise where the difference was not statistically significant, moreover, packaged and loose varieties of cinnamon showed similar mean moisture content [9.0%]. Loose varieties showed significantly higher ash contents than that in the packaged varieties except in tilio. Moreover, packaged and loose chamomile showed more or less similar ash values [9.09 and 9.03%; respectively]. Moisture and ash levels of most samples of both packaged and loose varieties were complying with the Egyptian Standards