Evaluation of In Vitro Antimicrobial Activity of Bioactive Compounds and the Effect
of Allyl-Isothiocyanate on Chicken Meat Quality under Refrigerated Conditions
Natural antimicrobials are effective against both food-borne pathogens and spoilage
bacteria. The current study aimed to evaluate the in vitro antimicrobial activity
of eight natural bioactive compounds (BACs) and one synthetic compound, butylated
hydroxytoluene (BHT), and to evaluate the effect of one selected BAC (AITC) on the
safety and quality of minced chicken meat. Additionally, physicochemical (pH, color,
water-holding capacity (WHC), chemical forms of myoglobin (deoxymyoglobin-DeoMb, oxymyoglobin-OxyMb,
and metmyoglobin-MetMb), thiobarbituric-acid-reactive substances (TBARs)), and microbiological
properties (in vitro antimicrobial activity and determination of minimum inhibitory
concentration (MIC)) were also evaluated through electronic-nose odor detection. Allyl-isothiocyanate
(AITC), thymol, eugenol, and geraniol showed the broadest spectrum of in vitro antibacterial
activity against one major meat spoilage bacterium and five pathogenic bacteria that
were tested. Subsequently, AITC was selected to be applied to fresh minced chicken
meat at different concentrations (at concentrations of the MIC (MIC-1), two times
the MIC (MIC-2), and four times the MIC (MIC-4)). The chicken meat was then vacuum-packaged
and kept for up to 14 days at 4 degrees C, and its quality properties were checked
during storage. In this study, the addition of low concentrations of AITC (MIC-1)
maintained the lightness (L*) and increased the WHC of the meat. High concentrations
(MIC-2 and MIC-4) caused a significant increase in lightness (L*) and folded yellowness
(b*) value, and they significantly reduced the redness (a*) and TBARS values compared
to the control meat. The amounts of MetMb and DeoMb were reduced and the quantity
of OxyMb was increased as a result of the addition of AITC to the chicken breast.
Throughout storage, particularly at MIC-4, AITC showed the lowest numbers of aerobic
mesophilic cells, as well as a reduction in Listeria monocytogenes cell numbers and
a decrease in Salmonella Typhimurium counts. In addition, the meat containing MIC-4
did not exhibit growth of Pseudomonas lundensis after 10 days. During the storage
period, an electronic-nose assay demonstrated a distinction in the odor buildup of
AITC across the various meat groups, and meat treated with MIC-4 showed a trend that
was clearly opposite to that of untreated meat. These encouraging results demonstrate
the potential of AITC to improve the safety and shelf life of meat and meat products.