Food and Industrial Microbiology — Winter 2023

Enlist factors affecting efficacy of heat treatment in foods

Draw a flowchart to indicate the production of citric acid. Enlist its properties and applications.

Describe foodborne infection. Draw diagrams to depict infection caused by serotypes of E. coli.

Explain types of pasteurization methods especially the time and temperature combination.

Draw a diagram to depict infection caused by Vibrio cholerae

Describe the concept and application of Dvalue. Determine the Dvalue for given data obtained by treating a microbial culture at 80Cfor 20 min using an appropriate graph. time cfu/ml

Egg sample was contaminated with 25 cells of Salmonella spp. and 32 cells of S. enterica. Taking into account that the generation time of Salmonella spp. is 30 minutes and its lag phase is 3 h, and that the specific growth rate constant of S. enterica using meat as substrate is 0.17 h-1 and its lag phase lasts 5 h, calculate the number of Salmonella cells that will be present in the meat 10 hours after being prepared

Abacterial cell divides every 30 minutes. The initial no. of cells is exactly 100 bacterial cells. After 3 hours, how many bacteria are present?

The beta galctosidase is genetically regulated by Lac operon. Explain the genetic regulation of operon responsible for production of beta galactosidase in case of 1) only glucose present 2) only lactose present 3) both glucose and lactose present 4) both glucose and lactose absent

Explain the concept of 2dimensional electrophoresis. Justify that 2 Dgel electrophoresis is better than 1D electrophoresis OR1

Draw a well-illustrated schematic diagram to depict the sub parts and probes of a fermenter

Explain how low temperature is effective in reducing microbial load in foods?

Discuss the microbial spoilage of canned products? What is the significance of 12D concept for packaging and processing of canned products?

Draw a flowchart to depict differential centrifugation.

Describe both agar based and broth based methods used to determine antimicrobial resistance.

What is bioethanol? How it is advantageous in comparison to gasoline? Enlist substrate for bioethanol production. Describe the steps by which bioethanol is produced on large scale.

What is meant by indicator organism? Name the indicator organisms for sterilization, pasteurization and fecal contamination

Explain the purification of proteins on the basis of solubility

Draw a flow chart to represent purification and recovery of proteins based on size, polarity, solubility, and binding.

Enlist sources of contamination in milk during milking of cows, transport and storage.

Describe affinity elution chromatography. How does it differ from affinity elution chromatography?

Describe the defects in milk and milk products. Enlist the microorganisms responsible for these defects and their activity responsible for specific defect.

Write a short note on food preservation using chemicals.

Enlist difference between exotoxin and endotoxin

Enlist the microbial causatives of spoilage of fruits and vegetables