Final Exam 2013
THE UNIVERSITY OF NEW SOUTH WALES
SCHOOL OF CHEMICAL ENGINEERING
FOOD2320 Food Microbiology
FOOD2627 Food Microbiology
Final Examination
November 2013
Time allowed: THREE (3) hours
Total number of questions: THREE (3)
Answer all three questions
Total marks: 60
All questions are of equal value (20 marks)
This exam will contribute 40% to the final mark for the subject
This paper may be retained by the candidate
Answers must be written in ink. Except where they are expressly required, pencils may be used only for drawing, sketching or graphical work.
Question 1
Answer two (2) of the following questions.
(a) Describe how microorganisms affect the shelf-life of cook-and-chill pasta with tomato sauce. What factors are likely to determine this shelf-life?
Grow activity in physical, biological effect,texture-pasta become soften, product become sour, different flavor provided, microbial activity
Factor :moisture, temp. ,packaging(vaccum pack or normal pack), pH,sugar content, other ingredient such as spices,salt, initial microbial growth, type of microbial present in food( lactic bacteria –induce facultative bacteria growth)
(b) Your company is the manufacturer of chocolate confectionery products. One of the raw materials used in production is milk powder which is purchased from a supplier company. As part of a purchasing contract, you have been asked to write a microbiological specification for this milk powder. Describe what information you would include in writing this specification. Explain why it is important to have this specification.
(c) Impedance-conductance is one of the modern technologies for measuring microbial populations. With respect to its application to the enumeration of microorganisms in foods, answer the following questions.
(1) Describe the scientific principles underlying the technology and its application. (ELISA)
(2) What are the advantages and limitations of the technology?
(3) Describe the accuracy, precision,
SCHOOL OF CHEMICAL ENGINEERING
FOOD2320 Food Microbiology
FOOD2627 Food Microbiology
Final Examination
November 2013
Time allowed: THREE (3) hours
Total number of questions: THREE (3)
Answer all three questions
Total marks: 60
All questions are of equal value (20 marks)
This exam will contribute 40% to the final mark for the subject
This paper may be retained by the candidate
Answers must be written in ink. Except where they are expressly required, pencils may be used only for drawing, sketching or graphical work.
Question 1
Answer two (2) of the following questions.
(a) Describe how microorganisms affect the shelf-life of cook-and-chill pasta with tomato sauce. What factors are likely to determine this shelf-life?
Grow activity in physical, biological effect,texture-pasta become soften, product become sour, different flavor provided, microbial activity
Factor :moisture, temp. ,packaging(vaccum pack or normal pack), pH,sugar content, other ingredient such as spices,salt, initial microbial growth, type of microbial present in food( lactic bacteria –induce facultative bacteria growth)
(b) Your company is the manufacturer of chocolate confectionery products. One of the raw materials used in production is milk powder which is purchased from a supplier company. As part of a purchasing contract, you have been asked to write a microbiological specification for this milk powder. Describe what information you would include in writing this specification. Explain why it is important to have this specification.
(c) Impedance-conductance is one of the modern technologies for measuring microbial populations. With respect to its application to the enumeration of microorganisms in foods, answer the following questions.
(1) Describe the scientific principles underlying the technology and its application. (ELISA)
(2) What are the advantages and limitations of the technology?
(3) Describe the accuracy, precision,