Exam paper for first semester National Diploma Food Technolog

De Kock, S., Dr.

Draddy, B., Mr.

Name not available

 
 
 
FACULTY OF SCIENCE 
 
 
 
DEPARTMENT OF FOOD TECHNOLOGY  (DFC) 
 
 
 MODULE: FTN1BF1  
   FOOD TECHNOLOGY I  
   (NATIONAL DIPLOMA FOOD TECHNOLOGY) 
 
 
 
NOVEMBER EXAMINATION 
 
 
 DATE:  1 NOVEMBER 2014 SESSION: 8:30-10:30 
 
 
 
 
 
EXAMINER  Dr S de Kock 
 
 
MODERATOR Mr B Draddy 
 
 
DURATION 2 HOURS MARKS   121 (120=100%) 
 
 
NUMBER OF PAGES:  4 PAGES (PLUS 2 ANNEXURES) 
 
 
INSTRUCTIONS: ANSWER ALL QUESTIONS 
   QUESTIONS MAY BE ANSWERED IN ANY ORDER, BUT SUB-
SECTIONS OF QUESTIONS MUST BE ANSWERED TOGETHER 
   CALCULATORS ARE PERMITTED (ONLY ONE PER STUDENT) 
 
 
REQUIREMENTS:  2 ANSWER SCRIPTS PER STUDENT 
/2... 
 
 
FOOD TECHNOLOGY 1 FTN1BF1  NOVEMBER EXAMINATION 2014 -2- 
____________________________________________________________________ 
 
QUESTION 1 
 
 
Woolworths recently launched a new product: Caramel coffee low fat flavoured milk. 
 
 
 
The following information can be found on the label: 
 
Ingredients: Low-fat milk, sugar, coffee, coffee 
extract, flavouring, stabiliser (plant based) 
 
300ml 
 
Nutritional information 
 
 
 
 
 
 
 
 
The process flow diagram indicating the unit operations during its manufacturing is as follows: 
 
 
Milk     Coffee beans    Sugar cane 
 
Separation    Cleaning    Expression 
 
     Sorting     Filtration 
    
     Roasting    Crystallisation 
 
     Grinding 
  
     Sifting 
 
     Extraction 
 
     Drying 
 
     Mixing 
 
     Pasteurisation 
 
     Homogenisation 
 
     Packaging 
 
 
 Per 100ml 
Protein 2.5g 
Carbohydrate 10g 
Fat 1.5g 
FOOD TECHNOLOGY 1 FTN1BF1  NOVEMBER EXAMINATION 2014 -3- 
____________________________________________________________________ 
 
1.1 A tubular bowl centrifuge can be used to separate the cream from the milk to produce 
low fat milk. Make an illustrated drawing to show the working of this piece of equipment.
           (7) 
 
1.2.1 Describe the contaminants that are removed during the cleaning process.  (5) 
 
1.2.2 Briefly explain four factors that will increase the efficiency of spray washing. (4) 
 
1.3 Explain how the damaged coffee beans can be separated from the good coffee beans 
during sorting (hint: damaged coffee beans have a higher density in water). (3) 
 
1.4 During roasting, the Maillard reaction produces the brown colour of the coffee beans 
and a roasted flavour. Explain the chemistry of the Maillard reaction.  (3) 
 
1.5.1 Grinding is a size reduction unit operation. Why do the coffee beans need to be grinded 
before extraction?         (1) 
 
1.5.2 Suggest an impact mill that can be used to reduce the size of the coffee beans. 
Describe its working and make use of a diagram to illustrate your answer.  (5) 
 
1.5.3 What is the definition of the Reduction Ratio of a grinder? If you want to produce coffee 
with a very small particle size, do you need a grinder with a high or low Reduction Ratio 
and why?          (3) 
 
1.6. A single stage extractor is used to extract the ground coffee beans. Explain its working 
and illustrate your answer with a diagram.      (8) 
 
1.7 Describe the design and operation of a piece of equipment that can be used to express 
sugar from sugar cane. Make a drawing to illustrate your answer.   (9) 
 
1.8.1  Define filtration as a unit operation.       (3) 
 
1.8.2 Do a schematic drawing to show the flow of slurry to filtrate in a vertical shell and leaf 
pressure filter.          (6) 
 
1.9.1 A propeller mixer can be used to mix the final product together. Briefly describe this 
mixer.           (2) 
 
1.9.2 What problems could arise with the use of this mixer? Suggest ways to overcome this 
and make use of drawings to illustrate your answer.     (7) 
 
1.10 A pressure homogeniser is used to create a uniform emulsion in the end product. 
Explain how this machine operates.       (4) 
 
1.11 Suggest a stabiliser (gum) that can be used for this product.   (1) 
 
1.12 The manufacturers found a cheaper caramel flavour than the one that they are 
currently using. They don’t want the flavour of the product to change. They ran a 
triangle test with 7 panellists 3 times. Nine of the responses correctly identified the odd 
one out. What conclusion can you make from this? (5% confidence level).  (4) 
 
1.13.1 How much kJ would you consume if you drank two of these bottles?  (5) 
 
1.13.2 One’s basal metabolic rate (BMR) determines (amongst other things) how many kJ 
you are supposed to consume per day. Discuss the factors affecting the BMR. (6) 
 
FOOD TECHNOLOGY 1 FTN1BF1  NOVEMBER EXAMINATION 2014 -4- 
____________________________________________________________________ 
1.14 Similar products are sold by Pick ‘n Pay, Checkers and OK. Woolworths wanted to 
compare their product with the other three. The results of the ranking test they ran are 
as follows: 
 
Panellist Woolworths 
product 
Pick ‘n Pay 
product 
Checkers  
product 
OK 
product 
1 1 2 3 4 
2 1 3 2 4 
3 2 1 4 3 
4 1 3 2 4 
5 1 2 3 4 
6 2 1 3 4 
 
 1 – most liked 
 4 – least liked 
 
What statistical conclusions can you draw from this?    (5) 
 
1.15 Sugar is one of the ingredients in this product. Name some functional properties of 
sugar in food in general.        (3) 
 
                      [94] 
_________________________________________________________________________ 
 
QUESTION 2 
 
2.1 Explain what reverse osmosis is and make use of a diagram to illustrate your 
answer. (7) 
 
2.2 Give the advantages of using reverse osmosis instead of evaporation (4) 
 
2.3 Mayonnaise is an example of an emulsion.  Suggest an appropriate 
emulsifying agent that can be used in this product and explain how it works. (6) 
  
 [17] 
__________________________________________________________________________ 
 
QUESTION 3 
 
Give one word/term for the following: 
 
3.1 The method used to select and train panellists 
3.2 The vitamin that prevents night blindness 
3.3 The branched component in starch 
3.4 Two sugar units which are linked together 
3.5 An orange pigment in foods 
3.6 Acid in oranges 
3.7 A milk protein 
3.8 The scale used in scoring during sensory evaluation 
3.9 The enzyme that breaks down lipids 
3.10 Glycerol with three fatty acids [10] 
 
________________________________________________________________________ 
  
   
 
FOOD TECHNOLOGY 1 FTN1BF1  NOVEMBER EXAMINATION 2014 -5- 
____________________________________________________________________ 
 
ANNEXURE A 
 
 TRIANGULAR COMPARISON - NUMBER CORRECTLY IDENTIFYING ODD 
 SAMPLE REQUIRED TO INDICATE SIGNIFICANT DIFFERENCE 
 
Total Number of Triangular 
Comparisons 
Number of Correct Selections for Odds: 
 19 : 1 
(5 Per Cent Level) 
99 : 1 
(1 Per Cent Level) 
999 : 1 
(.1 Per Cent Level) 
4    
6 5 6 0 
8 6 7 8 
10 7 8 9 
12 9 9 10 
15 10 11 12 
18 11 12 13 
21 12 14 15 
24 14 15 16 
27 15 16 18 
30 16 18 19 
35 18 20 22 
40 20 22 24 
45 22 24 26 
50 25 26 28 
60 29 30 32 
70 33 35 37 
80 37 39 41 
90 41 43 45 
100 45 47 49 
 
 
ANNEXURE B 
TABLE 91 
 RANK TOTALS REQUIRED FOR SIGNIFICANCE AT THE 5 PER CENT LEVEL (P < 0,05) 
The four-figure blocks represent: Lowest insignificant rank sum, any treatment - Highest insignificant rank sum any treatment.  lowest insignificant rank sum, predetermined treatment - Highest insignificant rank  sum, predetermined 
treatment. 
Number of 
Reps. 
 Number of Treatments, or Samples Ranked 
  3  3  4  5  6  7  8  9  10  11  12 
2 ... 
... 
... 
... 
... 
... 
... 
3-9 
... 
3-11 
... 
3-13 
... 
4-14 
... 
4-16 
... 
4-18 
... 
5-19 
 
5-21 
3 ... 
... 
... 
4-8 
... 
4-11 
4-14 
5-13 
4-17 
6-15 
4-20 
6-18 
4-23 
7-20 
5-25 
8-22 
5-28 
8-25 
5-31 
9-27 
5-34 
10-29 
4 ... 
... 
5-11 
5-11 
5-15 
6-14 
6-18 
7-17 
6-22 
8-20 
7-25 
9-23 
7-29 
10-26 
8-32 
11-29 
8-36 
13-31 
8-39 
14-34 
9-43 
15-37 
5 ... 
6-9 
6-14 
7-13 
7-18 
8-17 
8-22 
10-20 
9-26 
11-24 
9-31 
13-27 
10-35 
14-31 
11-39 
15-35 
12-43 
17-38 
12-48 
18-42 
13-52 
20-45 
6 7-11 
7-11 
8-16 
9-15 
9-21 
11-19 
10-26 
12-24 
11-31 
14-28 
12-36 
16-32 
13-41 
18-36 
14-46 
20-40 
15-51 
21-45 
 17-55 
23-49 
18-60 
25-53 
7 8-13 
8-13 
10-18 
10-18 
11-24 
13-22 
12-30 
15-27 
14-35 
17-32 
15-41 
19-37 
17-46 
22-41 
18-52 
24-41 
19-58 
26-51 
21-63 
28-56 
22-69 
30-61 
8 9-15 
10-14 
11-21 
12-20 
13-27 
15-25 
15-33 
17-31 
17-39 
20-36 
18-46 
23-41 
20-52 
25-47 
22-58 
28-52 
24-64 
31-57 
25-71 
33-63 
27-77 
36-68 
9 11-16 
11-16 
13-23 
14-22 
15-30 
17-28 
17-37 
20-34 
19-44 
23-40 
22-50 
26-46 
24-57 
29-52 
26-64 
32-58 
28-71 
35-64 
30-78 
38-70 
32-86 
41-76 
10 12-18 
12-18 
15-25 
16-24 
17-33 
19-31 
20-40 
23-37 
22-48 
26-44 
25-25 
30-50 
27-63 
34-56 
30-70 
37-63 
32-78 
40-70 
35-85 
44-76 
37-93 
47-83 
11 13-20 
14-19 
16-28 
18-26 
19-36 
21-34 
22-44 
25-41 
25-52 
29-48 
28-60 
33-55 
31-68 
37-62 
34-76 
41-69 
36-85 
45-76 
39-93 
49-83 
42-101 
53-90 
12 15-21 
15-21 
18-30 
19-29 
21-39 
24-36 
25-47 
28-44 
28-56 
32-52 
31-65 
37-59 
34-74 
41-67 
38-82 
45-75 
41-91 
50-82 
44-100 
54-90 
47-109 
58-98 
13 16-23 
17-22 
20-32 
21-31 
24-41 
26-39 
27-51 
31-47 
31-60 
35-66 
35-69 
40-64 
38-79 
45-72 
42-88 
50-80 
45-98 
54-89 
49-107 
59-97 
52-117 
64-105 
14 17-25 
18-24 
22-34 
23-35 
26-44 
28-42 
30-54 
33-51 
34-64 
38-60 
38-74 
44-68 
42-84 
49-77 
46-94 
54-86 
50-104 
59-95 
54-114 
65-103 
57-125 
70-112 
 


Food Technology 1

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