Effect of Free‐SH Containing Compounds on Allyl Isothiocyanate Antimicrobial Activity against Escherichia coli O157:H7

Abstract

Escherichia coli O157:H7 contamination is a significant meat safety issue in many countries. Allyl isothiocyanate (AIT) is a natural compound found to limit the survival of E. coli O157:H7 and other pathogens in meat and meat products. In the present study, it was found that glutathione and cysteine naturally present in meat can interfere with AIT antimicrobial activity. Spectroscopy, HPLC, and LC-MS were used to confirm that glutathione was able to react with AIT and formed a conjugate with no or low bactericidal activity against the tested organisms. The same reaction also occurred at pH values of 4.9 and 5.8 at 25 and 4 degrees C, respectively, which broadly represent storage conditions in raw beef (pH 5.8) and during fermented sausage (pH 4.9) manufacture. Reactions observed help to explain reduction in antimicrobial potency of AIT in food (meat) systems.

Characterization of Products from the Reaction of Glucosinolate-Derived Isothiocyanates with Cysteine and Lysine Derivatives Formed in Either Model Systems or Broccoli Sprouts

“…The reactivity of ITCs with egg white proteins has been demonstrated by Kroll et al 7,8 Additionally, Luciano et al revealed that compound 1 reacted with cysteine and glutathione present in meat to form compound 9 correspondingly. 32 However, the reactivity between ITCs and amino acids in Brassica plants was, to our knowledge, not studied before. Cejpek et al investigated the reactions of sulfite with ITCs in mustard paste and observed a decrease in the ITC levels.…”

Antibacterial activity and mode of action of selected glucosinolate hydrolysis products against bacterial pathogens

“…Zsolnai (1966) hypothesized that the antimicrobial activity of ITCs may be linked to intracellular inactivation of sulphydryl-enzymes through oxidative cleavage of disulfide bonds. Other researchers found that ITCs can react with amino acids and microbial proteins forming reactive thiocyanate radicals (Cejpek et al 2000;Delaquis and Mazza 1995;Luciano et al 2008;Verma 2003).…”

Quality Evaluation and Storage Study of Chicken Meat Pickle

“…Mustard oil imparts pleasant pungent flavor to meat (McGorrin, 2011). Also, it contains an active principle, allylisothiocyanate reported as antibacterial compound (Luciano et al, 2008;Dias et al, 2014). The microbial load was lower than 4 log cfu/g suggesting it to be safe for eating.…”