Food additives reduce lactic acid bacterial growth in culture medium and in meat products, increasing product shelf life

Abstract

The uncontrolled growth of lactic acid bacteria (LAB) in meat and meat products leads to product spoilage, and thus shortens product shelf life. Although food additives are known to decrease LAB growth, this effect has not been analyzed in detail. Here, a detailed analysis was performed of the effects of sodium chloride, sodium polyphosphate, sodium lactate, sodium nitrite/nitrate, and garlic on the growth of the Lactobacillus plantarum in culture medium. The results were used to design and test experimental formulations of meat products. Initially, the effect of food additives on L. plantarum was evaluated using a Fractional Factorial Design (FFD), followed by a Central Composite Rotatable Design (CCRD). The Modified Gompertz Model was adjusted to the growth curves to determine the Kinetic parameters of bacterial growth (logarithmic increase in the population, specific growth rate, and lag phase extension). Higher sodium lactate and sodium chloride levels had a negative impact on L. plantarum growth parameters (p≤0.05). Therefore, we designed experimental formulations of mortadella and smoked pork sausages containing 4% sodium lactate (w w-1) and 2.4-3.5% sodium chloride (w w-1), and determined LAB growth from samples of stored products produced according to these formulations, in order to determine product shelf life. There was an increased lag phase of LAB growth for most experimental formulations. Also, the experimental smoked pork sausages had a longer shelf life, which was increased by at least 22 days, suggesting that the proposed formulation, with higher than standard lactate concentration, increased the product's shelf life.