P1-04 The Inhibitory Effect of a Sodium-Free Powder Preservative on the Growth of Listeria monocytogenes and Lactic Acid Bacteria in Turkey Ham Applications

Wednesday, 29 March 2017
The Square
Eelco Heintz, Niacet, Tiel, Netherlands
Introduction:  Organic acids are effective antimicrobials against Listeria monocytogenes and Lactic Acid Bacteria (LAB). Current organic acid based preservatives are, mostly, liquids; powdered forms contain sodium. This document compares the antimicrobial efficacy of an organic acid-based, sodium-free powder preservative (Provian®K) to the commonly used liquid preservatives.

Purpose:  This study aimed to evaluate the antimicrobial efficacy of a sodium-free preservative powder in cured and uncured turkey ham applications.

Methods: Deli-style turkey formulations were prepared (75% moisture, 1.9% salt, 6.2-6.4 pH). Analysed treatments: 1.) Control (no antimicrobials); 2.) 2.5% potassium lactate –sodium diacetate 60% solution (PL-SD); and 3.) sodium-free acetate/diacetate powder (Provian®K): 0.25%, 0.5%, and 0.75%. Surfaces were inoculated with approximately three log CFU/g using a cocktail of various serotypes of L. monocytogenes or different species of LAB isolated from meat products. Packages were stored at 4oC and 7°C.

Inoculated samples from each treatment (n=3) were assayed by rinsing and massaging the meat in Butterfield’s phosphate buffer for three minutes. Rinsates were serially diluted and enumerated on appropriate media. Listeria populations were determined by surface plating onto MOX agar (35oC, 48h); LAB plate counts by plating onto APT agar with bromcresol purple (25oC, 48h).

Results: All treatments showed clear growth inhibition of Listeria and LAB. ANOVA with n=3 was used to determine statisitcal significance. At 4°C all treatments show complete inhibition of Listeria growth for 12 weeks. At 7°C, 0.5% Provian®K samples showed comparable inhibition to formulations with 2.5% PL/SD (P>0.05). In uncured meat, 0.25% Provian®K and 2.5% PL/SD performed comparably (P>0.05). Shelf-life extension (LAB inhibition) was most effective in when formulations included Provian®K (P>0.05).

Significance:  This research shows excellent antimicrobial efficacy of a sodium-free powder antimicrobial in improving the safety and shelf-life of processed meats. Besides improvements in handling, shipping, and storage, compared to liquid forms, this powder is sodium-free, making it suitable for sodium reduction programs.