Why would Psychrophilic bacteria be of concern to the food industry?
Why are psychrotrophic bacteria of concern to those in the food-service industry? They can grow at low (refrigerator) temperatures and they tolerate temperature when heated as well so they are capable of causing spoilage in foods. What is the optimum growth temperature for most human pathogens?
What is meant by psychrotrophic bacteria?
Psychrotrophic bacteria are defined as those that grow at 7°C, although their optimal growth temperature is higher. During cold storage after milk collection they dominate the flora, and their extracellular enzymes, mainly proteases and lipases, contribute to the spoilage of dairy products.
What are Psychrotrophic organisms what is their importance?
The psychrotrophic bacteria are commonly associated with spoilage of milk. Species of Bacillus, Micrococcus, Streptococcus, Lactobacillus, and Clostridium are thermophilic bacteria which have been isolated from milk. Their significance is that they may grow during the actual processing of dairy products.
Why are Psychrotrophs a specific problem in raw milk?
Psychrotrophic bacteria affect economic aspects in the dairy industry by limiting the shelf life of raw milk and dairy products via the production of heat-stable extracellular enzymes.
Is Listeria a Psychrotrophic?
L. monocytogenes is a psychrotrophic organism with an optimum growth temperature of 30ºC to 37ºC but has the ability to grow at a wide range of temperatures from 1ºC to 45ºC. Inactivated by exposure to temperatures above 50oC, L. monocytogenes grows optimally at water activity (aw) greater than or equal to 0.97.
How does pH negatively affect the metabolism of microorganisms?
How does pH negatively affect the metabolism of microorganisms? causes proteins and enzymes to denature and causing a loss of enzymantic activity. Urea hydrolysis produces ammonia which would raise pH.
What is the importance of psychrotrophic bacteria to human health?
Psychrotrophic bacteria are defined as able to grow when the temperature is lower than +7°C. Involved in food poisonings and responsible for alterations of the commercial quality of food-stuff, they make it necessary to limit the shelf life of chilled products.
How can psychrotrophic bacteria be controlled?
One attractive method proposed for controlling growth of psychrotrophic bacteria involves applying low levels (10-30mM) of carbon dioxide (CO2 ) to refrigerated milk. Results of preliminary studies (12, 27, 29, 47, 48) indicate CO2 is an effective inhibitor of psychrotrophic bacterial growth in refrigerated raw milk.
Why are psychrotrophs of more concern than psychrophiles?
Differentiate between psychrophile and psychrotroph. Psychorophiles grow best at low temps and psychrotrophs are mesophiles that can grow at low temps. Why are psychrotrophic bacteria of concern to those in the food-service industry? They can spoil food.
Is Listeria a psychrotrophic?
What is the primary pathogen of concern in smoked fish?
Listeria can grow at high salt concentrations, so refrigerated, cured meats and fish can harbor the pathogen. The bug is relatively more prevalent in smoked seafood, seafood salads, luncheon meats and unpasteurized cheese, according to a study reported in the Journal of Food Protection in 2003.
At what temperature would psychrotrophic organisms grow best?
Psychrophiles grow best in the temperature range of 0–15 °C whereas psychrotrophs thrive between 4°C and 25 °C.