2- Food technology 2

Question 1

What is meat fermentation?

Answer 1

Method of meat preservation
Lactic acid bacteria converts glucose/fermentable carbs to lactic acid

Question 2

The addition of —– to meat surppresses natural gram -ve flora?

Answer 2

Nitrite/nitrate

Question 3

Addition of nitrite/nitrate promotes the growth of what microorganisms?

Answer 3

Streptococci, Micrococci, Pediococci & lactobacilli

Question 4

0.3-2% of fermentable carb is added to meat at meat fermentation.

What does this cause to be produced?

Answer 4

Lactic acid = Gives pH of 4.8

Question 5

What does the presence of lactic acid in meat cause?

Answer 5

Decreases water binding capacity of meat protein = Assist in the drying process

Question 6

Name 3 common organisms that are used as a starter culture in meat fermentation?

Answer 6

Lactobacillus plantarum
Pediococcus acidilacti
Yeasts
Micrococcus sp. (Only used if nitrate is added/ no nitrite)

Question 7

Define the process of ripening

Answer 7

Breakdown of fats & protein by microbial proteinases = amino acids & others

Produces flavouring compounds

Question 8

Describe the basic steps of meat fermentation

Answer 8

Raw meat (Plus fat)
Mince = ^surface area for microbial activity

Mix with other ingredients: Formulations = Salt, nitrate/nitrite, fermentable carbs

Addition of starter flora
Pack into casings

Ferment = lactic acid bacteria convert glucose/ferm carb to lactic acid

Dry & Ripen = Reduce water content

Question 9

Stability & safety of fermented sausages is due to the combination of what?

Answer 9

Low pH & Reduced water activity

Question 10

Spoilage of canned foods can occur due to:

Answer 10

Underfilling
Quality of can seam
Improper handling
Hygiene/ transport system

Question 11

What is yogurt?

Answer 11

Product of bacterial fermentation of milk

Lactose converted by bacteria into lactic acid

Question 12

In the presence of antibiotics in milk what happens to yogurt production?

Answer 12

Culture won’t multiply
pH will not drop
Yogurt will not set

Question 13

Basic steps of cheese production

Answer 13

Raw milk

Pasteurisation

Starter addition = Lactococuus, lactic ssp

Incubation = Fermentation & lactic acid production

Addition of rennet & coagulation = Milk coagulates

Scalding

Cheddaring = squeeze/stretch curd

Milling/salting = prevents further starter activity, preservation/flavour

Moulding & Pressing

Ripening

Packaging/Storage

Question 14

Microbial problems in cheese

Answer 14

Blowing
Mould growth
Bacteriophages attacking starter

Question 15

What is a sampling plan?

Answer 15

is a detailed outline of which measurements will be taken at what times, on which material, in what manner, and by whom.

Sampling procedure & Decision criteria

Question 16

What does a 3-class plan consist of that a 2-class plan does not?

Answer 16

M = Quantity used to separate marginally acceptable quality from unacceptable quality food

Question 17

What does c stand for in sampling plans?

Answer 17

Max acceptable/allowable number of sample units that may exceed the microbiological criterion

When number is exceeded = Lot is rejected

Question 18

What does m stand for in sampling plans?

Answer 18

Max number/level of relevant bacteria per gram

Values above this are marginally acceptable or unacceptable

Question 19

For count or concentration test which sampling plan do we use?

Answer 19

3-class plan

Question 20

What parameters are used to determine the shelf life of a product?

Answer 20

Flavour, aroma, appearance, texture

Microbial growth - bacterial pathogens, bacterial indicator organism & spoilage organisms

Question 21

What does wood smoke contain

Answer 21

Formaldehyde and higher aldehydes, phenols and methanol- which have antimicrobial activity