Food Preservation Lecture Notes PDF

Question Answer What is biodegradation? B) The breakdown of simple end products by microorganisms A) The formation of complex materials Explanation: Biodegradation occurs when complex materials are broken down by microorganisms to form...

Question Answer What is biodegradation? B) The breakdown of simple end products by microorganisms A) The formation of complex materials Explanation: Biodegradation occurs when complex materials are broken down by microorganisms to form by microorganisms simple end products, highlighting the role of microorganisms in the decomposition of organic matter. B) The breakdown of simple end products by microorganisms C) The production of host enzymes by microorganisms D) The loss of food quality by intrinsic enzymes E) The undesirable change in the property of a material caused by vital activities of organisms What is biodegradation vs. D) The breakdown of complex materials vs. any undesirable change in the property of a material caused biodeterioration? by vital activities of organisms A) The formation of complex materials Explanation: Biodegradation involves the breakdown of complex materials, while biodeterioration refers to vs. the breakdown of simple end any undesirable change in the property of a material caused by vital activities of organisms, highlighting products the distinction between these two processes. B) The loss of food quality vs. the production of host enzymes C) The undesirable change in the property of a material vs. the breakdown of simple end products D) The breakdown of complex materials vs. any undesirable change in the property of a material caused by vital activities of organisms E) The breakdown of simple end products vs. the undesirable change in the property of a material caused by vital activities of organisms What are the effects of food loss and B) Loss of food quality and safety food spoilage? Explanation: Food loss and food spoilage can lead to the loss of food quality and safety, highlighting the A) Loss of nutritional value and color negative impact of these issues on the overall quality and safety of food products. changes B) Loss of food quality and safety C) Compromised safety and environmental effects D) Economic development and environmental effects E) Loss of nutritional value and organoleptic changes Why is the issue of food losses A) It has an impact on food security for poor people important in the effort to combat hunger? Explanation: The issue of food losses is of high importance in the effort to combat hunger, as it has an impact on food security for poor people, highlighting the direct link between food losses and global A) It has an impact on food security for hunger. poor people B) It raises income and improves food security C) It causes considerable environmental and economic effects D) It has an impact on food quality and safety E) It has an impact on economic development and the environment What are the characteristics of molds? B) Grow as multicellular filaments and reproduce sexually A) Grow as single cells and used in the Explanation: Molds grow as multicellular filaments (hyphae) forming a mycelium and reproduce sexually, production of cheese and soy sauce distinguishing their characteristics and reproductive process. B) Grow as multicellular filaments and reproduce sexually C) Grow on any food source under suitable conditions of moisture, temperature, and oxygen D) Are highly acidic, very salty, and grow best in a neutral or slightly acidic pH environment E) Are aerobic and can survive heating to 90°C for a few minutes What is the role of lysozyme in microbial B) It inhibits microbial growth growth in food? Explanation: Lysozyme, found in eggs, is an inhibitor of microbial growth in food, serving as a protective A) It promotes microbial growth factor against the proliferation of harmful microorganisms. B) It inhibits microbial growth C) It provides nutrients for microbes D) It has no effect on microbes E) It increases water activity in food Question Answer What is the significance of pH in relation D) It affects the hydrogen ion concentrations to microbial growth in food? Explanation: pH, which indicates the hydrogen ion concentrations in a system, plays a crucial role in A) It has no impact on microbial growth microbial growth in food by influencing the environment in which microorganisms can thrive. B) It indicates the availability of water C) It is a measure of the availability of nutrients D) It affects the hydrogen ion concentrations E) It promotes the growth of bacteria What is the function of skins and shells B) They inhibit microbial growth in relation to microbial growth in food? Explanation: Skins and shells act as natural physical barriers that prevent the ingress of moisture and A) They promote microbial growth nutrients, thereby inhibiting microbial growth in the fleshier parts of plants or animals. B) They inhibit microbial growth C) They provide nutrients for microbes D) They increase water activity in food E) They have no effect on microbes What is the impact of water activity on E) It influences the availability of water for biological functions microbial growth in food? Explanation: Water activity in food is a measure of the availability of water for biological functions, and it A) It has no impact on microbial growth directly influences the potential for microbial growth by affecting the water present in the food in free form. B) It indicates the availability of water C) It is a measure of the availability of nutrients D) It affects the hydrogen ion concentrations E) It influences the availability of water for biological functions What is the role of carvacrol in microbial B) It inhibits microbial growth growth in food? Explanation: Carvacrol, found in nutmeg, acts as an antimicrobial agent, inhibiting microbial growth in food A) It promotes microbial growth and contributing to the preservation of food products. B) It inhibits microbial growth C) It provides nutrients for microbes D) It has no effect on microbes E) It increases water activity in food What type of bacteria require a A) Halophiles substantial amount of salt to grow? Explanation: Halophiles are bacteria that are unable to grow in environments with no salt and require a A) Halophiles substantial amount of salt to grow, making them highly dependent on saline conditions for their survival. B) Xerophiles C) Osmophiles D) Aerobic bacteria E) Facultative anaerobes What does the term 'Redox Potential' C) Potential difference in a system generated by a couple reaction measure? Explanation: Redox potential measures the potential difference in a system generated by a couple A) Temperature reaction in which one substance is oxidized and the other is reduced simultaneously, providing insight into B) Osmotic pressure the oxidative and reductive processes within a system. C) Potential difference in a system generated by a couple reaction D) Relative Humidity E) Moisture content What is the redox potential range for C) +100 to -250 mV anaerobic bacteria? Explanation: Anaerobic bacteria have a redox potential of +100 to -250 mV, indicating their ability to thrive A) +500 to +300 mV in low oxygen environments and their distinct redox requirements for growth and metabolism. B) +300 to +100 mV C) +100 to -250 mV D) -250 to -500 mV E) -100 to 0 mV At what temperature do thermophiles C) 55°C grow optimally? Explanation: Thermophiles grow at relatively high temperatures, with an optimal growth temperature of A) 10°C 55°C, showcasing their preference for and adaptation to high-temperature environments. B) 35°C C) 55°C D) -5°C E) 0-5°C What does a high relative humidity A) Formation of molds environment lead to? Explanation: A high relative humidity environment increases moisture content and water activity, leading to A) Formation of molds the formation of molds, which highlights the impact of humidity on microbial growth and food spoilage. B) Inactivation of bacteria C) Protection against microbial infections Question Answer D) Growth of thermophiles E) Reduction in moisture content What is the practice of modifying the C) Modified atmosphere packaging (MAP) composition of the internal atmosphere Explanation: Modified atmosphere packaging (MAP) is the practice of modifying the composition of the of a food package in order to improve internal atmosphere of a food package to improve its shelf life. This technique involves altering the levels the shelf life called? of oxygen, nitrogen, and carbon dioxide to create an environment that slows down the growth of aerobic A) Aerobic packaging organisms and oxidation reactions. B) Anaerobic packaging C) Modified atmosphere packaging (MAP) D) Oxygenated packaging E) Nitrogenated packaging Which mold is associated with the E) Byssochlamys spp. complete breakdown of texture in fruits Explanation: Byssochlamys spp. produce pectic enzymes that cause the complete breakdown of texture and off-flavor development? in fruits and off-flavor development, making them a significant factor in food spoilage, particularly in A) Rhizopus stolonifera canned fruit products. B) Aspergillus C) Penicillium D) Fusarium E) Byssochlamys spp. Which mycotoxin is produced by C) Aflatoxin Aspergillus and has a potent Explanation: Aflatoxin is produced by Aspergillus spp. and has a potent carcinogenic effect. It is a major carcinogenic effect? concern in food safety as it can occur in crops post-harvesting if the moisture levels exceed critical values, A) Patulin and it is also found in various food products such as milk, cheese, and eggs. B) Ochratoxin A C) Aflatoxin D) Zearalenone E) Fumonosins What is the main problem in apple juice E) Toxin contamination production caused by Patulin? Explanation: Patulin, produced by Penicillium, Aspergillus, and Byssochlamys molds, is a main problem in A) Color alteration apple juice production as it can lead to toxin contamination. It is very stable in acid solutions and can B) Flavor enhancement survive pasteurization, posing a significant risk to food safety. C) Shelf life extension D) Bacterial growth E) Toxin contamination What is the group of molds associated C) Penicillium with food spoilage that typically spoil Explanation: Penicillium is a group of molds associated with food spoilage that typically spoil fruits, fruits causing blue and blue-green causing blue and blue-green coloration. Additionally, Penicillium produces mycotoxin, Ochratoxin A, which coloration? further contributes to its impact on food quality and safety. A) Rhizopus stolonifera B) Aspergillus C) Penicillium D) Fusarium E) Byssochlamys spp. Which yeast is implicated in the spoilage A) Rhodotorula of jams, jellies, and candies? Explanation: Rhodotorula is a diverse organism that can grow in high sugar concentrations and is A) Rhodotorula specifically implicated in the spoilage of jams, jellies, and candies, making it a significant factor in food B) Brettanomyces spp. spoilage. C) Debaryomyces D) Saccharomyces bailii E) Zygosaccharomyces Which yeast can cause spoilage in beer, B) Brettanomyces spp. wine, and other fermented products? Explanation: Brettanomyces spp. is known for producing acetic acid from glucose under aerobic A) Rhodotorula conditions and can cause spoilage in beer, wine, and other fermented products, highlighting its impact on B) Brettanomyces spp. the quality of these food items. C) Debaryomyces D) Saccharomyces bailii E) Zygosaccharomyces Which yeast is resistant to benzoate and D) Saccharomyces bailii sorbate preservatives and causes Explanation: Saccharomyces bailii is a spoilage yeast that is resistant to benzoate and sorbate spoilage in mayonnaise, tomato sauce, preservatives, causing spoilage in mayonnaise, tomato sauce, fruit drinks, and wine, making it a fruit drinks, and wine? significant concern in food preservation. A) Rhodotorula B) Brettanomyces spp. C) Debaryomyces D) Saccharomyces bailii E) Zygosaccharomyces Question Answer Which bacteria causes 'sulfide stinker' C) Desulfotomaculum nigrificans spoilage and leads to black discoloration Explanation: Desulfotomaculum nigrificans is a strict anaerobic thermophile that causes 'sulfide stinker' when it reacts with iron in cans? spoilage and leads to black discoloration when it reacts with iron in cans, highlighting its impact on food A) Clostridium thermosaccarolyticum quality and safety. B) Geobacillus stearothermophilus C) Desulfotomaculum nigrificans D) Alicyclobacillus acidoterrestris E) Bacillus coagulans Which spore-forming mesophile A) Bacillus coagulans bacterium has been isolated from Explanation: Bacillus coagulans, a spore-forming mesophile bacterium, has been isolated from canned canned tomato products and causes tomato products and causes reduction in pH of spoilt products, indicating its role in food spoilage and reduction in pH of spoilt products? preservation challenges. A) Bacillus coagulans B) Clostridium butyricum C) Clostridium perfringens D) Clostridium thermosaccarolyticum E) Geobacillus stearothermophilus What type of bacteria is Bacillus cereus? C) Gram-positive, facultative aerobic Explanation: Bacillus cereus is classified as a gram-positive, facultative aerobic, spore-forming A) Gram-negative, facultative anaerobe rod-shaped bacterium, which contributes to its ability to cause diarrheal and vomiting symptoms after B) Gram-positive, obligate anaerobe consumption of certain foods. C) Gram-positive, facultative aerobic D) Gram-negative, obligate anaerobe E) Gram-positive, facultative anaerobe What type of toxin does Clostridium C) Botulinum toxin botulinum produce? Explanation: Clostridium botulinum produces botulinum toxin, which is a heat-resistant spore-forming A) Heat-stable peptide bacterium found in soils and can contaminate vegetables, leading to foodborne illness if not properly B) Protein toxin sterilized or heated. C) Botulinum toxin D) Acidic toxin E) Alkaline toxin Where is Staphylococcus aureus C) In the nasal passages, throats, on the skin, and hair commonly found? Explanation: Staphylococcus aureus is commonly found in the nasal passages, throats, on the skin, and A) In the intestines of mammals hair, with food handlers being the most common source of contamination, making it a significant concern B) In fresh and salt water in food safety. C) In the nasal passages, throats, on the skin, and hair D) In soils E) In animal feces What type of bacteria is Escherichia C) Gram-negative, facultative anaerobe coli? Explanation: Escherichia coli is a gram-negative bacterium found in the intestines of mammals, A) Gram-positive, facultative anaerobe associated with fecal contamination of water by food handlers or unprocessed foods, and is linked to B) Gram-negative, obligate anaerobe foodborne illnesses. C) Gram-negative, facultative anaerobe D) Gram-positive, obligate anaerobe E) Gram-negative, facultative aerobe What is the main characteristic of C) Blue-green pigments production Pseudomonas spp. in food spoilage? Explanation: Pseudomonas spp. is a large group of gram-negative rod-shaped bacteria responsible for A) Acid and gas formation spoilage of refrigerated and proteinaceous products, and it may produce blue-green pigments, B) Heat resistance contributing to its implication in various food spoilage conditions. C) Blue-green pigments production D) Spore formation E) Alkaline production What is food preservation? B) The process of treating food to stop or slow down spoilage caused by microorganisms and intrinsic A) The process of accelerating spoilage enzymes B) The process of treating food to stop Explanation: Food preservation involves treating food to prevent or slow down spoilage caused by or slow down spoilage caused by microorganisms and intrinsic enzymes, which is essential for maintaining food quality and safety. microorganisms and intrinsic enzymes C) The process of increasing water activity in food D) The process of reducing the pH of food E) The process of promoting microbial growth What are some hurdles to microbial B) Water activity, pH, and storage temperature growth in food preservation? Explanation: Hurdles to microbial growth in food preservation include water activity, pH, storage A) Light exposure, high temperature, and temperature, and preservatives, which are critical factors in controlling microbial spoilage and maintaining preservatives food quality. Question Answer B) Water activity, pH, and storage temperature C) Oxygen exposure, low temperature, and vacuum packaging D) Enzymatic activity, chemical reactions, and physical changes E) Mechanical damage, heat treatment, and irradiation What is the purpose of heat treatment in D) To provide the required food safety profiles and enhance the shelf-life of the product food preservation? Explanation: Heat treatment in food preservation aims to provide the necessary food safety profiles and A) To increase water activity extend the shelf-life of the product, although it may result in some loss of organoleptic and nutritional B) To enhance microbial growth properties. C) To reduce the shelf-life of the product D) To provide the required food safety profiles and enhance the shelf-life of the product E) To promote enzymatic browning What is hurdle technology in food C) The combination of two or more food preservation factors at a slightly lower level preservation? Explanation: Hurdle technology in food preservation involves the intelligent combination of different A) The use of a single preservation preservation factors or techniques to achieve multi-target, mild but reliable preservation effects, which is a factor at a high level strategic approach to maintaining food quality and safety. B) The use of a single preservation factor at a low level C) The combination of two or more food preservation factors at a slightly lower level D) The use of a single preservation technique at a high level E) The use of a single preservation technique at a low level What is the benefit of using hurdles to B) Improved product quality microbial growth? Explanation: The use of hurdles to microbial growth is beneficial as it allows for lower intensity hurdles A) Increased microbial growth and results in improved product quality, making it more effective than single targeting. B) Improved product quality C) Reduced product shelf-life D) Lowered product safety E) Decreased effectiveness of preservation What is the basis for the food C) Low pH sterilization principle for low acid and Explanation: The basis for the food sterilization principle for low acid and acid foods is the fact that no acid foods? known spore-forming pathogenic bacteria can grow at pH