Rapid method of detection and enumeration of sulfide-producing bacteria in food products

A method of detecting and enumerating sulfide-producing bacteria in a food sample, comprising:

• preparing the food sample as a liquified food sample;
• forming an incubation mixture by combining the liquified food sample with a growth medium comprising iron and sulfur, and wherein an iron precipitate is formed in the incubation mixture when sulfide-producing bacteria act upon the iron and the sulfur in the growth medium;
• incubating the incubation mixture at an incubation temperature for a predetermined incubation period which produces a fluorescence peak when a particular number of sulfide-producing bacteria are present;
• taking a plurality of fluorescence measurements from the incubation mixture during the predetermined incubation period;
• and
• concluding that the food sample has at least the particular number of sulfide-producing bacteria when a fluorescence peak is attained by the end of the predetermined incubation period, and that the food sample does not have the predetermined number of sulfide-producing bacteria when a fluorescence peak is not attained by the end of the predetermined incubation period.

A method of detecting an enumerating sulfide-producing bacteria in a food sample, comprising:

• preparing the food sample as a liquified food sample;
• forming an incubation mixture by combining the liquified food sample with a growth medium having a color and comprising iron and sulfur, and wherein an iron precipitate is formed in the incubation mixture when sulfide-producing bacteria act upon the iron and sulfur in the growth medium;
• incubating the incubation mixture at an incubation temperature;
• determining a time to color change at which time the color of the incubation mixture changes from yellow to gray due to an accumulation of the iron precipitate in the incubation mixture;
• and
• estimating the number of sulfide-producing bacteria in the food sample by comparing the time to color change to a correlation schedule.

A method of detecting and enumerating sulfide-producing bacteria in a food sample, comprising:

• providing a food sample having a normal coloration;
• providing a growth medium comprising iron and sulfur and disposing the food sample into the growth medium forming an incubation mixture, and wherein an iron precipitate is formed on a surface of the food sample in the incubation mixture when sulfide-producing bacteria act upon the iron and sulfur in the growth medium;
• incubating the incubation mixture at an incubation temperature;
• determining a time to color change at which time the normal coloration of the food sample darkens due to accumulation of iron precipitate on the surface of the food sample;
• and
• estimating the number of sulfide-producing bacteria in the food sample by comparing the time to color change to a correlation schedule.