Microbial effects of replacing sodium chloride with a magnesium-containing mineral salt in white bread
HELEN MITCHELL1* EVANGELIA KOMITOPOULOU2
*Corresponding author
1. Smart Salt Oy, C/O Visma Services Oy, Promestarinrinne 8B, FI – 00160 Helsinki, Finland
2. Leatherhead Food Research, Randalls Road, Leatherhead, Surrey, K22 7RY, United Kingdom
Abstract
Although desirable from a nutritional point of view, lowering salt (sodium) has the potential to reduce microbial safety in certain products. The aim of this study was to determine the effect of replacing NaCl (regular salt) with a patented mineral salt (Smart Salt® – 40% reduced sodium chloride) on microbiological stability and safety of a non-preserved white bread. The mineral salt, containing potassium and magnesium chloride, was shown to significantly increase process lethality of Bacillus spp after baking compared to regular salt. In addition total aerobic viable counts were significantly reduced at day 6 at both storage temperatures (21°C and 25°C).
INTRODUCTION
For many foods, reducing the sodium content of the product should not create food safety or spoilage concerns. Such foods include; frozen products, products with sufficient thermal processing to kill pathogens (e.g. canned foods), acidic foods (pH<3.8) and foods in which the water activity remains low when sodium is removed (high sugar containing foods (1). For other foods, reducing the sodium content has the potential to increase food spoilage rate and the presence of pathogens.
The antimicrobial activity of salt relates largely to its affect on lowering water activity (aw) but the ability of micro-organisms to tolerate salt stress in otherwise optimal conditions varies widely between species (2).
Bacillus cereus and Bacillus subtilis
Bacillus cereus is a gram positive spore forming organism found in the environment and is commonly isolated from a wide range of foods. It is pathogenic, being responsible for two types of food poisoning, emetic ( ingestion of toxin preformed in foods) and diarrhoeal (release of an enterotoxin in the small intestine). Food poisoning is usually associated with foods t ...
