This set of Food Chemistry Multiple Choice Questions & Answers (MCQs) focuses on “Bound and Free Water and their Implications”.
1. The water that can be frozen at very low temperature i.e. below freezing point of water is called _________
a) Free water
b) Deionized water
c) Ionized water
d) Bound water
View Answer
Explanation: Many food constituents can hold or bind water such that they cannot be easily removed. Such type of water is called as bound water. It can be frozen only at very low temperatures.
2. Which is not a characteristic of bound water?
a) It is not free to act as solvent for salts and sugars
b) It exhibits no vapour pressure
c) Can be easily extracted from food by squeezing
d) Its density is greater than that of free water
View Answer
Explanation: Water that can be easily extracted by squeezing or cutting is free water. The water that cannot be easily removed is bound water.
3. Bound water can act as a solvent.
a) True
b) False
View Answer
Explanation: The water that cannot be easily extracted is termed as bound water. It has more structural bonding than liquid or free water. Hence, bound water unable to act as a solvent.
4. Why is the density of ground water greater than that of free water?
a) The molecules are more closely packed
b) The molecules are loosely packed
c) High boiling point
d) Ice is less dense than water
View Answer
Explanation: As the vapor pressure is negligible the molecules cannot escape as vapor; and the molecules in bound water are more closely packed than in the liquid state. So the density is greater.
5. What is the freezing point of bound water?
a) 100°C
b) 4°C
c) -1°C
d) -20°C
View Answer
Explanation: Bound water is the water that remains unfrozen at temperature 0°C usually -20°C.
6. What is the % of unfreezable water in fruits and vegetables?
a) More than 10%
b) Less than 10%
c) Less than 6%
d) More than 6%
View Answer
Explanation: Most fruits and vegetables contain less than 6% unfreezable water. Egg white, egg yolk, meat and fish all contains approximately 0.4gm of unfreezable water of dry protein.
7. Which type of water can act as a dispersing agent and solvent?
a) Free water
b) Bound water
c) Oxidane
d) Ice
View Answer
Explanation: Most water in food is called as free water. It acts as a dispersing agent and solvent and can be removed by drying foods.
8. In food science which type of water is practically un available for microbiological activity?
a) Free water
b) Bound water
c) Oxidane
d) Ice
View Answer
Explanation: According to food science, bound water is practically un available for microbiological activities. So it will not cause any quality decrease or pathogen increase.
9. What is the proportion of crystalline protein in bound water?
a) 70%
b) 63%
c) 30%
d) 90%
View Answer
Explanation: The crystalline protein high amount of bound water, upto 70% by weight. Removal of this water affects their protein structure.
10. Which type of drying is done to remove bound water?
a) Primary
b) Secondary
c) Tertiary
d) Quaternary
View Answer
Explanation: The purpose of secondary drying is to remove bound water. Due its high absorption energy secondary drying is used.
Sanfoundry Global Education & Learning Series – Food Chemistry.
To practice all areas of Food Chemistry, here is complete set of Multiple Choice Questions and Answers.
If you find a mistake in question / option / answer, kindly take a screenshot and email to [email protected]
