Heat-and-Eat Meat

Crock pots and roasters across the nation are collecting dust thanks to the increasing prevalence and variety of heat-and-eat meats.

“Meat today needs to be convenient,” says Kim Holman, director of marketing, Wixon Inc., St. Francis, WI. “Consumers want to cut down on the steps it takes to prepare, cook and clean-up dinner and meat, which is usually the main course.”

Keeping pathogens in check

FDA regulates chemical preservatives in Title 21 of the Code of Federal Regulations, Part 172. USDA’s Food Safety and Inspection Service (FSIS) outlines the ingredients permitted in “Safe and Suitable Ingredients Used in the Production of Meat and Poultry Products” (Directive 7120.1). However, today’s heat-and-eat meat designers trend toward avoiding chemical preservatives, opting for “natural” protectants.

The Gram-positive pathogen Listeria monocytogenes, one of the greatest concerns in heat-and-eat meats, is readily found in the environment. FDA has “zero tolerance” for Listeria in foods that support its growth.

FSIS has identified two methods for controlling Listeria in post-process cooked meats: a post-lethality treatment, and the addition of an antimicrobial or process to limit Listeria growth during shelf life.

Nisin, a peptide derived from the controlled fermentation of Lactococcus lactis, can be bacteriocidal to Gram-positive bacteria via addition to a meat brine or marinade, or directly to the tumbler prior to industrial cooking.

“Because of our greater understanding of the antimicrobial nature of food fermentations, we now have the ability to add metabolites produced by food-fermentation microorganisms to normally unfermented foods to provide significant hurdles to the growth of spoilage and pathogenic microorganisms,” says Larry Steenson, principal senior application scientist, food protection, Danisco USA, New Century, KS. “Such metabolites can be purified from specific food-grade cultures for use in food protection, or the metabolites can be added in the form of liquid or powdered concentrates (fermentates) obtained by controlled growth of the producer strain in a food-grade substrate, such as milk or dextrose.”

One antimicrobial fermentate blend specially designed to enhance the safety and quality of refrigerated ready-to-eat (RTE) meals and meat products “is composed of cultured dextrose and is particularly effective against Gram-positive bacteria, as well as Gram-negative bacteria, yeast and mold,” says Steenson. “Because fermentates are unpurified systems, they can contribute to the flavor profile of foods into which they are incorporated, so they must be added judiciously. Normally, fermentates are not added at more than 1.5% by weight of the finished food. Fermentates are also affected by the pH of the food. Typically, fermentates are more active at lower pH, and can be added at decreasing levels to low-pH foods. Since organic acids can play a significant role in the activity of many fermentates, they tend to be most active at, or below, the pKa value of the acids present in the fermentate.”