P1-189 Cultures as a Natural Antimicrobial for Food Biopreservation: Example of Leuconostoc mesenteroides Inhibition in Bacon

Monday, August 1, 2016
America's Center - St. Louis
Veronique Zuliani, Chr Hansen, Arpajon, France
Zdenek Cech, Chr Hansen, Milwaukee, WI
Dirk Hoffmann, Chr Hansen, Giessen, Germany
Cees Jan Bakker, Chr Hansen, Giessen, Germany
Introduction: Recent analyze of US bacon from the market has shown that a significant part of the products reaches during their shelf life a high bacterial load (with mainly undefined lactic acid bacteria). Such uncontrolled microflora may negatively impact shelf life and bring significant economic losses.

Purpose: This study focused on application of bioprotective culture on bacon with two main objectives: (i) growth inhibition of Leuconostoc mesenteroides (one of the bacteria mostly involved in the bacon spoilage) to extend shelf life and (ii) clean label, a strong customer trends.

Methods: Six batches of bacon (a control without culture and 5 different starter cultures) were produced using standard US recipe and production process.  Several parameters were measured along the product shelf life: (i) the Leuconostoc mesenteroides concentration through challenge testing and (ii) the sensory features through color and pH measurement, evaluation of slime formation and smell.

Results: Among the tested cultures, a Leuconostoc carnosum strain has shown the best Leuconostoc mesenteroides inhibitory effect. After 80 days of vacuum storage at 41°F, the spoilage growth was limited to 2 log units when the Leuconostoc carnosum strain was added while in the control batch, the spoilage growth potential was close to 6 log unit. No slime formation, nor off smell was detected in the batch with added culture. No difference in color (red intensity) was measured. Finally a slight pH difference (-0.1 pH Unit) was measured at the end of the shelf life between the treated sample and the control. Additional studies have shown that the Leuconostoc carnosum strain used is able to produce a bacteriocin and also to strongly dominate the microflora of meat products. Those two features mainly explain the inhibitory effect of this unique strain.

Significance: These results suggest that the tested Leuconostoc carnosum strain significantly improves bacon microbial quality.