Milk Decomposition & Dairy Microbiology Quiz PDF

🙂: Create open-ended questions 🤖 Smallpdf.com: Questions: 1. What happens during the putrefactive period of milk decomposition? 2. What role does lactoferrin play in milk, especially in cases of mastitis? 3. Describe the neutralization period in milk and its effects on microbial activity. 4. W...

🙂: Create open-ended questions 🤖 Smallpdf.com: Questions: 1. What happens during the putrefactive period of milk decomposition? 2. What role does lactoferrin play in milk, especially in cases of mastitis? 3. Describe the neutralization period in milk and its effects on microbial activity. 4. What are the consequences of coliform bacteria in the dairy industry? 5. What is the cause and effect of bitty or broken cream in milk? Answers: 1. During the putrefactive period, the acid in milk disappears due to the activity of fungi, leading to a change in the reaction of milk from acidic to neutral or slightly alkaline. Proteolytic bacteria, which were dormant, become active and dominate, attacking milk proteins, primarily casein. This results in the complete decomposition of milk into a clear fluid that is chemically poisonous and unfit for human consumption. 2. Lactoferrin is an iron-binding protein naturally present in milk and colostrum. It inhibits the growth of most microorganisms by depriving them of iron, which they need for growth. In cases of mastitis, the amount of lactoferrin in milk increases, enhancing its ability to inhibit microbial growth. 3. The neutralization period occurs when considerable quantities of acid inhibit most bacteria from multiplying, allowing yeasts and molds to flourish in the acidic medium. These microorganisms utilize lactic acid as an energy source, producing alkaline by-products that neutralize the acidity of milk, changing its reaction to neutral or slightly alkaline over several days. 4. Coliform bacteria, such as E. coli and Enterobacter aerogenes, can cause significant issues in cheese making by producing large volumes of gas, which results in fermented cheese with a bad taste and holes. Some strains of E. coli can also cause food poisoning in humans and mastitis in dairy animals. 5. Bitty or broken cream occurs when raw or pasteurized milk is shaken, causing the cream layer to break into particles that do not mix homogenously with the milk. This phenomenon is caused by the production of lecithinase, an enzyme that breaks down lecithin in fat globule membranes, allowing fat globules to aggregate into larger particles. 🙂: Generate multiple-choice questions 🤖 Smallpdf.com: Questions: 1. What is the pH range of the fluid produced during the putrefactive period of milk decomposition? A. 4-6 B. 6-8 C. 8-10 D. 10-12 2. Which microorganisms are known to cause serious troubles in cheese making due to gas production? A. Lactobacillus B. Coliforms C. Streptococcus D. Bacillus 3. What is the primary function of lactoferrin in milk? A. To provide flavor B. To bind iron and inhibit microbial growth C. To promote fermentation D. To enhance creaminess 4. What type of fermentation is characterized by the production of lactic acid as the major product? A. Heterofermentative B. Homofermentative C. Proteolytic D. Lipolytic 5. What causes the phenomenon of bitty or broken cream in milk? A. High temperature B. Lecithinase production C. Low pH D. Excessive shaking Answers: 1. C 2. B 3. B 4. B 5. B 🙂: Generate true-or-false questions 🤖 Smallpdf.com: Questions: 1. The putrefactive period of milk is characterized by the activity of fungi and proteolytic bacteria that produce a clear fluid with a pH range of 8-10. True False 2. Coliform bacteria are beneficial in the dairy industry and do not cause any problems in cheese making. True False 3. Lactoferrin levels decrease in milk during cases of mastitis. True False 4. The neutralization period in milk involves the activity of yeasts and molds that reduce acidity and produce alkaline by-products. True False 5. Bitty or broken cream is caused by the production of lecithinase, which breaks down lecithin in fat globule membranes. True False Answers: 1. True 2. False 3. False 4. True 5. True