Natural Mold Inhibition in Cheese by Lactic Acid Bacteria

Mold, especially in shredded cheese, continues to be a problem and causes significant shelf-life issues for manufacturers, distributors, and consumers. Alternatives, such as adding mold inhibitory compounds (sodium benzoate or potassium sorbate) to cheese are not approved in all countries and causes acceptance issues with many US customers who demand natural wholesome foods without additives. Forming a unique, safe, natural mold inhibitor during the cheese making process would reduce these concerns and maintain shelf life of cheese. </P>The goal of this project was develop a safe, food-grade, system-compatible biological control agent that inhibits undesirable molds in cheese. Preliminary tests conducted by the researcher indicated that when Cheddar cheese was inoculated with a selected strain of Lactobacillus and challenged with mold, the organism produced a mold inhibiting compound in laboratory media. The current study isolated five strains of Lactobacillus plantarum and one strain of Pediococcus pentasaceus from dairy products, vegetables, and fermented pickles. All six strains demonstrated strong inhibitory activity against Penicillium sp. isolated from the surface of Cheddar cheese. Results show that adding anti-mold lactic acid bacterium to cheese milk (as an adjunct) extends the shelf life 17 days longer than the control cheese.