IFS4814_Science of Cooking_Quiz for L4-7

Which of the following is NOT a property of water in food?

• water is essential for bacterial growth.

• Expand in volume when freezes

• polar in nature

• Each molecule contains 1 hydrogen and 2 oxygen atoms

Answer explanation

Correct: it contains 2 hydrogen and 1 oxygen atoms. (H-O-H)

Which of the following food with the highest water activity?

• white bread

• honey

• salted fish

• chocolate

• soy sauce

Answer explanation

Aw of soy sauce is around 0.83-0.89

Water Activity of food items does NOT reflect....

• microbiological spoilage rate

• Product shelf stability

• Water content of the product

Answer explanation

Water activity is the amount of "free water" that can be used by bacteria or react with other substances chemically an physically.

which of the following is a WRONG description of water activity?

• enzymatic activity would be promoted at high water activity

• low water activity would stop all chemical and biological activities

• high water activity would promote bacterial growth

• low water activity would facilitate browning reaction

Answer explanation

Low water content of food will retard the rate of browning reaction during cooking.

What do you know about water characteristics? (more than one correct answers)

• Smaller ice crystals formed during quick freezing helps to improve product quality.

• food can be dehydrated with addition of salt / sugar

• Addition of salt onto ice prolongs its melting process.

Answer explanation

adding salt onto ice BOOSTS ice melting process.

What type of heat transfer is NOT involved in sous vide cooking process?

• conduction in water bath

• convection in water

• conduction in the interior part of the food.

• radiation between the food item and vacuum bag.

Answer explanation

No radiation of heat transfer would happen during sous vide cooling.

What heat transfer methods would happen when resting the steak after searing process? (there are more than one correct answer)

• heat loss to surrounding air by radiation

• carry over cooking

• moisture inside redistribute back through the steak

• heat gain to the container via convection

Answer explanation

The temperature of the steak will eventually match with the temperature of the surrounding temperature.

Why should we be careful to not over mix cookie dough after adding the flour?

• it will make it burn more eaily.

• It will make it fall apart.

• it will make it tough.

• it will make the cookies bland.

Answer explanation

Too much force applied facilitates further gluten network formation and leads to tough and chewy dough texture. (Gluten is the protein in flour to provide extensibility and elasticity of the dough)

what is sodium bicarbonate another name for?

• Yeast

• cream of tartar

• baking powder

• baking soda

Which one of the following ingredients make possible the most physical and chemical changes that add structure and texture to baked goods.

• Yeast

• Sugar

• Liquid

• flour

Answer explanation

Liquid(most likely is water) takes an important role as a medium of chemical and physical reactions.