- Written by Michael Mullan
Commercially, cold-filled acidic pickles, sauces (e.g. salad cream, mayonnaise), and food dressings are preserved, and their microbiological safety and stability are assured, by the use of acetic acid, salt (NaCl), and sugar. This article provides an overview of a preservation model and access to the model to enable the effect of sauce components and pH to be investigated.
Comite´ des Industries des Mayonnaises et Sauces Condimentaires de la Communaute´ Économique Européenne (1992) (CIMSCEE) has provided guidance on a safety value, Σs, for a microbiologically safe product preserved using acetic acid and a stability value, Σ, above which microbial spoilage should not occur.
A safe product has been defined as one which is so formulated that when an inoculum of viable cells of Escherichia coli is added to the product this is reduced by 3 log cycles in less than 72 h. Products exhibiting this level of antibacterial activity have a CIMSCEE safety value (Σs) of greater than 63. Σs is calculated using equation 1. A microbiologically stable product is one that will not support microbial growth at ambient temperature and has a Σ value of greater than 63. Σ is calculated using equation 2.
Equation 1. Σs =15.75 (1 - ɑ) (total acetic acid* %) + 3.08 (salt* %) + (hexose* %) + 0.5 (disaccharide* %) + 40 (4-pH). Note, values with an * must be calculated as water phase values.
Equation 2. Σ =15.75 (1 - ɑ) (total acetic acid* %) + 3.08 (salt* %) + (hexose* %) + 0.5 (disaccharide* %). Note, values with an * must be calculated as water phase values.