ALL LECTURE QUIZZES

Question 1

CH11.1 : CHEMISTRY OF FOOD COMPONENTS

Which of the following statements are true about waater in foods? [There can be more than 1 correct statement]

1. Water acts as a solvent for chemical reactions to take place
2. All foods with high moisture content have high water activity.
3. Having a low moisture content will guarantee that no chemical reactions can take place in a food
4. The water activity of a food is reduced significantly when water is entrapped within a polymer gel network
5. None of the above

Answer 1

only 1

4 - Entrapping water within a polymer gel reduces the amount of FREE FLOWING WATER but not its water activity.

Question 2

CH11.1 : CHEMISTRY OF FOOD COMPONENTS

Which of the following statements are true about carbohydrates? There can be more than 1 correct statement.

1. Glucose is a reducing sugar
2. Frustose is a reducing sugar
3. Only reducing sugar can react to form glycosidic bonds
4. The Maillard reaction involves the reaction between reducing sugars and amino groups
5. None of the above

Answer 2

1,4

2 - Fructose is a ketone, cannot oxidise itself further thus it is not a reducing sugar

Question 3

CH11.1 : CHEMISTRY OF FOOD COMPONENTS

Which of the following statements are true about proteins? There can be more than 1 correct answer.

1. Denaturation may cause changes in the primary structure of the protein
2. Denaturation may cause changes in the tetriary structure of the protein
3. The quarternary structure of a protein refers to the structure formed when exactly 4 peptides are bound together
4. The hydrophobic side chain of amino acids are usually folded towards the core of the protein
5. None of the above

Answer 3

2,4

1- Denaturation only causes changes to secondary, tetiary and quaternary structure of a protein

Question 4

CH11.2 : CHEMISTRY OF FOOD COMPONENTS

Which of the following statements are true about lipids? There can be more than 1 correct answer.

1. Lipids in foods refer to any chemical compounds that are soluble in organic solvents but not water.
2. All lipids are triglycerides
3. Saturated fatty acids tend to form triglcerides that are solid at room temperature
4. Trans - fatty acids tend to form triglycerides that are solid at room temperature
5. None of the above.

Answer 4

1,3,4

Question 5

CH11.2 : CHEMISTRY OF FOOD COMPONENTS

Which of the following statements are true about colloids

1. The size of the particles in a colloidal suspension is larger than the particles in a solution
2. Most of the foods we consume are some form of colloids
3. Sucrose dissolved in water is an example of a colloidal suspension
4. A foam is formed when air is dispersed in a protein
5. None of the above

Answer 5

1,2

3 - thougbh sucrose is solid, it is able to dissolve in water to give a solution (homogenous), while sol (colloidal suspension) is heterogenous, particles insoluble and suspended in liquid

Question 6

CH11.2 : CHEMISTRY OF FOOD COMPONENTS

Which of the following are true about chemical reactions in food?

1. Chemical reactions in foods are always catalysed by enzymes
2. Chemical reactions in foods are always undesirable
3. Formation of brown pigments is always due to the Maillard reaction
4. The primary function of food additives is to prevent the growth of microorganisms
5. None of the above

Answer 6

5

4 - Preservatives are the ones that prevent growth of microorganisms and they are a SUBSET of food additives. Food additives perform a wide range of function in food (appearance, structure, taste and aroma)

Question 7

CH11.3 : CHEMISTRY OF FOOD COMPONENTS

Natural additives refer to additives that are derived from food sources. True or False?

Answer 7

True

Question 8

CH12.1 : NUTRITION

Which of the following statements are true? More than 1 option may apply

1. Energy is needed when glycogen is synthesized from glucose
2. During digestion, intestinal cells uptake nutrients from digested food and convert them into ATP to be transported around the body.
3. Digested fat-soluble nutrients and water-soluble nutrients are transported in the same way after absorption by intestinal cells
4. None of the above

Answer 8

1

Option 1 : Synthesizing glycogen from glucose is an anabolic process and all anabolic process consumes energy rather than produce energy.

Option 2 : Macronutrients are uptaken and transported to individual cells. WITHIN the cells, they are then converted to ATP

Option 3 : Recall what was covered about circulatory systems and lymphatic systems

Question 9

CH12.1
Some bodybuilders consume drugs that help them gain muscle mass. Which of the following is most likely the name of the class drugs?

1. Catabolic steroids
2. Anabolic steroids
3. Muscle steroids
4. Energy steroids

Answer 9

2

Question 10

Which of the following factors contribute to higher rates of malnutrition in developing countries than in developed countries? More than one option may apply.

1. Poverty
2. Foodborne infections
3. Parasite infections
4. Genetics
5. None of the above

Answer 10

**3

Question 11

CH12.2 NUTRITION

Which of the following is true about consuming a diet that is lacking in lysine (more than one option may apply)

May hinder growth and development in children.

Is not a problem in adults if they consume sufficient amount of total protein.

Is not a problem in children if they consume sufficient amount of other essential amino acids.

None of the above

Question 11

CH12.2 NUTRITION

Which of the following is true about consuming a diet that is lacking in lysine (more than one option may apply)

1. May hinder growth and development in children.
2. Is not a problem in adults if they consume sufficient amount of total protein.
3. Is not a problem in children if they consume sufficient amount of other essential amino acids.
4. None of the above

Answer 11

1

Question 12

CH12.2 : NUTRITION

Which of the following classes of lipids are essential nutrients that must be obtained from the diet (more than one option may apply)

1. Saturated fatty acids
2. Monounsaturated fatty acids
   3.Polyunsaturated fatty acids
3. Cholesterol
4. None of the above

Answer 12

1 : synthesized from glucose and the carbon skeleton of some amino acids

2 : Monounsaturated fatty acids is made from saturated fatty acids which in turn can be synthesized from glucose and the carbon skeleton of some amino acids

4 : Although cholesterol is essential for normal functioning of the body, humans can synthesize all the cholesterol we need.

Question 13

CH12,2 NUTRITION
Which of the following statements are true? More than one option may apply.

1. Glucose is an essential nutrient that must be obtained from the diet
2. A person’s blood glucose level will increase when he/she is on a ketogenic diet
3. A meal with easily digestible carbohydrates will cause a much faster rise in blood glucose level than a meal that is lacking in carbohydrates
4. A low carbohydrate diet is one that is most beneficial to health
5. None of the above

Answer 13

1 : Glucose can be synthesized from amino acids hence it is not essential

2 : no expln provided

4 : A balanced diet is the most beneficial to health.

Question 14

CH12.2 NUTRITION

Which of the following statements are true? More than one option may apply

1. Soluble fibre can be hydrolysed by enzyme secreted in the small intestines but insoluble fibre cannot
2. There are no adverse effects associated with consuming fibre so we should consume as much dietary fibre as possible.
3. Beta-glucan from oats is an example of an insoluble fibre
4. None of the above

Answer 14

4

No expln provided but

1 : hydrolysed y enzyme –> means digest but dietary fibre cant be digested in the first place !! soluble fibre means can dissolve and get fermented but micrroganisms in large intestine

2 : can lead to malnutrition

Question 15

CH12.3 NUTRITION

Which of the following statements are true? (More than one option may apply)

1. Vitamins may function as cofactors in enzymatic reactions whereas minerals do not.
2. Prosthetic factors are bound tightly to enzymes whereas cosubstrates are only bound transiently to enzymes.
3. Prosthetic factors are not modified by the enzymatic reaction they help catalyzed.
4. Leaching of nutrients into water during blanching can cause losses of minerals in a food but does not affect the vitamins

Answer 15

2 : Cosubstrates bind to the active site of the enzyme and are converted in the process.

Question 16

CH12.3 : NUTRITION

Which of the following processing methods does not cause any losses of vitamins in foods? (More than one option may apply)

1. Pasteurization
2. Commercial sterilization
3. Irradiation
4. Dehydration
5. None of the above

Answer 16

Irradiation produce free radicals which can cause some losses of vitamins

Dehydration usually involves heat which can cause some loss of vitamins

Almost all processing will cause some small losses of vitamins. Even in frozen foods, some small losses may occur if the food is stored for long periods of time.

Question 17

CH12.3 : NUTRITION

Which of the following statements are true? (More than one options may apply)

1. All chemicals components of foods are nutrients
2. All nutrients essential to life provide energy
3. Flavonoids are nutrients essential for life.
4. Foods derived from animals tend to contain less anti-nutritive factors than plant-based foods.
5. None of the above

Answer 17

2 : thought it was correct but its wrong, didnt provide explanation. Nutrients essential to life : vitamins, minerals, protein, fats, water, and carbohydrates. MINERALS DO NOT PROVIDE ENERGY

3 : There are recommendations that flavonoids might be beneficial to health but there is no proof that they are essential to life.

Question 18

ch14.1 : FOOD ENGINEERING

In a continuous individual quick-freezing (IQF) tunnel, hamburger patties are transported on a conveyor belt and passed through a tunnel of fast moving cold air as shown in the attached picture. Which of the following statements is true? (More than one option may apply)

1. This IQF tunnel will have a higher throughput than a batch blast freezer of similar size.
2. Thicker patties will need to be frozen using a faster convery belt speed than thinner patties
3. Thicker patties will need to be frozen using a slower convery belt speed than thinner patties
4. Thickness of the patties does not affect the conveyor belt speed required for freezing.

Answer 18

Thicker patties need more time to be frozen so they need to spend more time in the freezer.

Question 19

CH14.1 : FOOD ENGINEERING

Which of the following statements are true about the IQF tunnel freezer when it is operating under steady state. (More than one option may apply)

1. The IQF freezer cannot achieve steady state because the hamburger patties are continuously being fed and removed from the system.
2. The amount of heat transferred from the patty to the cold air is constant and does not vary with time.
3. The temperature of the cold air is constant and does not vary with time.
4. The velocity of the cold air is constant and does not vary with time

Answer 19

• Didnt choose 4 at first

air velocity : distance traveled per unit of time

factors such as temperature, pressure, flow rate all CONSTANT

Question 20

CHAP 14.2 : FOOD ENGINEERING

You are asked to prepare a 15 % w/v sucrose solution. Which of the following steps best describe how this can be done.

1. Weigh 15 g of sucrose and add 100 g of water to it
2. Weigh 15 g of sucrose into a 100 ml volumetric flask and top it up to the mark with water
3. Weigh 15 g of sucrose and add 85 ml of water to it

Answer 20

3 seems probable but is less accurate?

Question 21

CHAP 14.2 : FOOD ENGINEERING

According to Singapore Food Regulations, fruit juice may contain a maximum of 400 ppm of benzoic acid. A food manufactuer in Singapore makes apple juice by diluting apple juice concentrate in water, pasteurizing it and packing it for sale.

The apple juice concentrate has a dissolved solid content (also known as Brix value) of 70 % w/w. The diluted apple juice has a dissolved solid content of 13.3 % w/w. What is the maximum level of benzoic acid permitted in the apple juice concentrate.

1. 2.1 g per kg of concentrate
2. 21.0 g per 100 kg of concentrate
3. 400 mg per kg of concentrate
4. 21,000 mg per kg of concentrate

Question 22

Dried mangoes are manufactured by first soaking sliced mangoes in a 60% w/w sugar syrup for 6 hours to carry out osmotic dehydration. The mangoes are then drained of syrup, spread on drying trays, and dried to a final moisture content of 12% w/w using hot air.

Additional information is given below:
1. Raw mangoes contain 15% w/w soluble solids, 2% insoluble solids and the remaining is moisture
2. The mangoes are mixed with the syrup at 1:3 weight ratio
3. For every 100 kg of fresh mangoes, 90 kg of osmotic dried mangoes were obtained (i.e. 90% yield)
4. The osmotic dried mangoes had a moisture content of 70% w/w
5. Process flow chart of the manufacturing process is as shown.

– SEE LECT SWAY FOR DIAG–

Question: What is the sugar concentration of the spent syrup in %w/w?

Hint: Do a mass balance of the total solid content (insoluble and soluble) for the osmotic drying step. Remember sugar contributes to soluble solids content.

1. 49.3 % w/w
2. 54.8 % w/w
3. 56.7 % w/w
4. 58.1 % w/w

Answer 22

2