30 Questions
What is the optimum temperature range for the growth of bacteria mentioned in the text?
50°C to 70°C
At what temperature does growth of some bacteria occur, as mentioned in the text?
80°C
What type of bacteria are mainly spore formers and are important in the food industry, especially in processed foods?
Bacteria with optimum temperatures above 80°C
What is the term used for the temperature at which a bacterial species grows best?
Optimum growth temperature
Above what temperature do most bacteria stop growing, according to the text?
60°C
What is the recommended core temperature and duration for cooking food to kill bacteria?
75°C for at least 15 seconds
How can poor handling of fresh produce impact its quality?
Poor handling can damage fresh produce, making it susceptible to spoilage and pathogenic microorganisms.
What is one consequence of the presence of cut and damaged surfaces on produce?
It provides opportunities for contamination and growth of microorganisms, leading to spoilage.
Why is washing vegetables important during post-harvest treatment?
Washing removes adhering soil and dirt, reducing the microbiological load of raw fruits and vegetables.
Give examples of microbial contamination through washing.
Contamination of tomatoes with Salmonella javania and parsley with Shigella sonnei.
What is challenging about washing and decontaminating ready-to-eat fruits and vegetables?
Effective washing and decontamination is difficult for all commodities, and not all lend themselves to being washed.
Why is recycling of water used in washing necessary?
Recycling may be necessary to conserve water resources, but purification of the water is difficult due to high organic loading.
Define water activity in the context of food microbiology.
Water activity is defined as the ratio of the vapor pressure of the air in equilibrium with a substance or solution to the vapor pressure of pure water.
What is the impact of lack of free water on the growth of microorganisms?
Microorganisms will not grow if there is a lack of free water.
Explain the concept of osmotic pressure and its effect on microbial growth.
Osmotic pressure depends on the surrounding solute concentration and water availability. Environments with dissolved substances can exert osmotic pressure.
Describe what happens in hyperosmotic environments in terms of cell water loss.
In hyperosmotic environments, cells lose water and undergo plasmolysis (shrinking of the cell).
How does salting and drying affect the water activity of a food product?
Salting and drying reduce the water activity of a food product.
What is the water activity of a saturated salt solution?
A saturated salt solution has a water activity of 0.75.
How can the yolk of an egg be contaminated before it is laid?
If a hen's reproductive organs are infected.
What is an example of contamination in production related to irrigation?
Spraying fields with contaminated water for irrigation.
How can fish in tropical reefs acquire toxins?
From the smaller sea creatures they eat.
What is the first step in processing animals?
Slaughter.
What can happen if contaminated water or ice is used during washing, packing, or chilling of fruits or vegetables?
Contamination can spread to those items.
How can germs from an animal's hide get into the final meat product during the slaughter process?
Germs from the animal's intestines.
What is the potential risk associated with using water from sewage plants for agricultural purposes?
Risk of contaminating the crop
Which countries have implemented the recycling of water for agricultural purposes?
Australia, Germany, Israel, Spain, The Netherlands, US
What is the key factor determining the safety of treated sewage water for agricultural use?
Efficiency and reliability of treatments to inactivate pathogens
What are examples of organic fertilizers commonly used in agriculture?
Sewage, manure, slurry, sludge, compost of human and animal origin
Which pathogens can be found in the intestinal tract of various animals that pose a risk to human health?
Salmonella, Shigella, Yersinia, E.coli, Campylobacter
How can the occurrence of foodborne pathogens on fruits and vegetables be reduced?
Increasing the delay between the application of organic fertilizers and harvest
Test your knowledge on the temperature ranges for bacterial growth, from mesophiles to hyperthermophiles. Learn about the different groups of bacteria based on their optimum growth temperatures and their significance in various industries.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
