Food And Nutrition 3rd Edition - Chapter 9 Testbank

The log phase of the bacterial growth cycle is characterized by rapid growth. During this phase, the bacteria are actively dividing and multiplying at a fast rate. The population size of the bacteria increases exponentially during this phase. This is the period where the bacteria are most metabolically active and are able to utilize nutrients efficiently for growth. As the bacteria continue to divide, the population size increases until it reaches a maximum capacity or is limited by the availability of nutrients or space.

Food-borne micro-organisms pose the greatest health hazard associated with food. These micro-organisms include bacteria, viruses, and parasites that can contaminate food and cause foodborne illnesses. When consumed, these micro-organisms can cause symptoms such as nausea, vomiting, diarrhea, and in severe cases, even death. Contamination can occur during food production, processing, storage, or preparation. It is important to handle and cook food properly to prevent the growth and spread of these micro-organisms.

The HACCP system involves identifying processes in food production where the risk of contamination is high, developing and implementing a plan to control those identified risks, using reliable parameters to monitor the process, and immediately acting to correct identified hazards. All of these steps are crucial components of the HACCP system, making "All of the above" the correct answer.

Soft cheeses should be avoided by pregnant women to reduce the risk of miscarriage or stillbirth arising from Listeria monocytogenes. Listeria monocytogenes is a bacteria that can be found in soft cheeses like brie, camembert, and blue cheese. These cheeses are often made with unpasteurized milk, which can contain harmful bacteria. Listeria infection during pregnancy can lead to serious complications, including miscarriage or stillbirth. Therefore, it is recommended for pregnant women to avoid consuming soft cheeses to protect their health and the health of their unborn baby.

Honey should not be given to infants aged one year because it may cause botulism. Botulism is a rare but serious illness caused by a toxin produced by the bacterium Clostridium botulinum. Infants are more susceptible to botulism because their digestive systems are not fully developed and they do not have enough of the beneficial bacteria in their gut to fight off the bacteria that causes botulism. Honey can sometimes contain spores of Clostridium botulinum, which can multiply and produce the toxin in an infant's immature digestive system, leading to botulism.

Water activity refers to the amount of water in food that is available for microorganisms to grow. It is a measure of the free water in the food, which is necessary for microbial growth. Water activity is important in food preservation and safety, as it can affect the growth and survival of microorganisms. Foods with low water activity are less likely to support microbial growth and have a longer shelf life. Therefore, the correct answer is "Water in food which is available to allow micro-organism growth."

Boiling water rapidly for one minute before drinking is the best advice for people wishing to drink from natural water sources. Boiling water kills harmful bacteria and pathogens that may be present in the water, making it safe to consume. This method is effective in eliminating most waterborne diseases and contaminants, ensuring that the water is safe for drinking.

Campylobacter species is the correct answer because it is one of the leading causes of food poisoning in Australia. These bacteria are commonly found in raw or undercooked poultry, unpasteurized milk, and contaminated water. Consuming contaminated food or water can lead to symptoms such as diarrhea, abdominal pain, fever, and vomiting. It is important to handle and cook food properly to prevent Campylobacter infection.

The most likely micro-organism to have been involved in the food poisoning outbreak is Bacillus cereus. This is because the practice of boiling bulk rice and reheating as required provides an ideal environment for the growth of Bacillus cereus, which is commonly found in rice and other starchy foods. Bacillus cereus produces toxins that can cause vomiting and diarrhea, which are symptoms commonly associated with emetic syndrome.

The correct answer is to discard the rolls if not purchased within four hours of preparation. This is because after four hours, the rolls may no longer be safe to consume due to the potential growth of bacteria. Refrigerating the rolls or toasting them would not address the issue of potential bacterial growth, and discarding them after two hours would be too soon.

Thawing a raw leg of lamb in the microwave would be the microbiologically safest method because the microwave provides a quick and even thawing process, minimizing the time that the lamb is in the temperature danger zone where bacteria can grow. Thawing in cold water or in the refrigerator can take a longer time, increasing the risk of bacterial growth. Thawing on the sink overnight or during the cooking process would not be recommended as they do not provide controlled thawing conditions.

Thorough cooking of foods is not sufficient to prevent food poisoning as some micro-organisms can survive high temperatures. Proper food handling and storage practices are also necessary to prevent food poisoning.