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WorksheetsCL5895 Test 2 Revision
Total questions: 25
Worksheet time: 17mins
What is the most distinguishing element present in proteins?
Nitrogen
Sulfur
Carbon
Hydrogen
What are the general steps in the kjeldahl method?
Distillation - Digestion - Titration
Digestion - Distillation - Titration
Titration - Digestion - Distillation
Titration - Distillation - Digestion
During the distillation process, nitrogen is captured by boric acid in the form of ...
Nitrite
Nitrate
Ammonia
Urea
What is the difference between Dumas method and kjeldahl method?
Dumas method is Time consuming
Dumas methos has affordable equipment
Dumas method use hazard chemicals
Dumas method can analyze many samples
Calculate the conversion factor for milk if the % of protein nitrogen of milk is 15.67%.
6.25
6.28
6.35
6.38
Kjeldahl method will quantitate protein concentration based on ________?
peptide bonds
absorbance
refractive index
nitrogen content
Which of the following is Not an advantage of the Kjeldahl method?
Widely used internationally
High precision
All the nitrogen in food is present as protein
Good reproducibility
What is the order of the steps in Dumas method?
Reduction and Separation, Combustion, Detection
Combustion, Reduction and Separation, Detection
Detection, Reduction and Separation, Combustion
Combustion, Separation, Reduction, Detection,
Why do we measure moisture content?
Legal & Economic requirements
Microbial stability
Food processing operations
None of the options
When measuring samples for moisture content, what are some of the ways
that can be used to minimise moisture gains and losses to the sample?
Minimize exposure to the open atnosphere
Remove the cover so that water can evaporate
Reduce the headspace in the sample storage container
Reduce contaminants for other surfaces
Which of the following is NOT a method used for moisture measurement?
Dumas method
Karl Fischer Titration
Evaporation (loss on drying) methods
Dean and Stark
The following formula is used when calculating dry basis moisture content.
True
False
If the weight of dried sample after oven drying is 1g. The initial weight is 1.5g. What is the moisture content of the sample?
33.33%
66.67%
0.33%
0.67%
Which of the following is NOT an advantage of evaporation method used for measuring moisture content?
Simple to perform
Reasonably accurate
Destructive method
Cost effective: simple instrument
The initial weight of pistachio nuts is 50.01g and after drying in the oven for hours,
the weight of the pistachio nut sample is recorded as 48.64g.
Calculate the moisture content wet basis of the pistachio nuts.
2.47%
2.74%
2.82%
3.74%
Which of the following methods are suitable for measuring water content in low moisture foods?
Dean and Stark
Loss on drying
Karl Fisher Titration
Smoke point is defined as:
Lowest temperature at which a volatile material can vaporize to form an ignitable mixture in air
Temperature at which it will continue to burn for at least 5 seconds after ignition by an open flame
Temperature at which the sample begins to smoke when tested under specified conditions
An application of the cold test is:
Oil doesn’t solidify at certain desired storage condition
Ensures that oils remain clear even when stored at refrigerated temperature.
Marks the beginning of both flavor and nutritional degradation
Name another method that showed milkfat or butterfat analysis in milk
Babcock method
Kjedahl method
Butterfat method
Which of the following are gravimetric solvent extraction
for fat analysis?
Gerber method
Soxhlet extraction
Mojonnier method
Babcock method
Products that are suitable for Gerber method are below except
•Ice cream mix
•Raw milk
•Cottage cheese
•Non dairy products
Which of the following minerals are trace elements?
Copper
Chlorine
Iodine
Sodium
During ash measurement, what is the temperature that the food is ignite overnight in a muffle furnace ?
420—490°C.
450—490°C.
500—550°C.
580—650°C.
The formula is calculate the amount of carbohydrates by difference is:
% Available carbohydrates =
100 - [%Moisture + %Ash + %Fat + %Protein + %Fibre]
% Available carbohydrates =
200 - [%Moisture + %Ash + %Fat + %Protein + %Fibre]
% Available carbohydrates =
100 - [%Moisture + %Ash + %Fat + %Protein ]
% Available carbohydrates =
150 - [%Moisture + %Ash + %Fat + %Protein ]
Tests for reducing sugars include:
Fehling's solution
Benedict's solution
Iodine solution
Sodium bicarbonate
