Evaluation of In Vitro Antimicrobial Activity of Bioactive Compounds and the Effect of Allyl-Isothiocyanate on Chicken Meat Quality under Refrigerated Conditions

Abstract

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 °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.