Midterm 2

Question 1

Which of the following combinations of flour yield and ash corresponds to a high quality wheat from a miller’s perspective? Circle or underline the correct response.

Answer 1

High flour yield, low ash

Question 2

What are typical particle size index values for durum wheat, hard common wheat for breadmaking and soft wheat?

Answer 2

durum wheat - 35-45
hard common wheat - 50-60
soft wheat - 65-75

Question 3

 Besides particle size of flour, what are other important influences of wheat hardness for utilization quality

Answer 3

hard wheats have slower rates of water penetration into endosperm; longer time for moisture equilibration
lower psi=harder wheat
starch damage-higher water absorption, higher flour yield, good for bread making

Question 4

Damaged starch levels in flours of hard and soft wheats are ______% and ______%, respectively.

Answer 4

6-10% AND 2-5%

Question 5

Damaged starch typically absorbs ______% of its weight in water

Answer 5

absorb ~ 2X to 3X its weight

Question 6

Why does damaged starch affect the gassing power of dough?

Answer 6

Damaged starch is hydrolyzed by amylase enzymes in dough to produce more sugar substrate for yeast fermentation
More carbon dioxide is produced; can result in higher volume bread

Question 7

The name of the protein that binds with starch granules on its surface and affects wheat hardness is _________.

Answer 7

friabilin protein

Question 8

List the benefits of dough strength for commercial bread making.

Answer 8

–Doughs tolerate overmixing
 Fermentation tolerance (over-fermentation)
 Higher general tolerance to abuse during processing
 Lesser need to adjust conditions precisely to “optimum”
 As dough strength increases (up to a point), bread loaf volume increases

Question 9

Briefly list reasons why a dough can have too strong mixing properties for commercial bread making.

Answer 9

increased protein content

increased stability

Question 10

Wheat kernel colour is mainly due to _________ compounds in the seed coat of bran.

Answer 10

flavonoid(phenolic)pigments

Question 11

The colour of wheat endosperm is mainly due to _______________ compounds which are enhanced in concentration in durum wheats and uncooked pasta.

Answer 11

carotene pigments

Question 12

Under what circumstances does wheat grain colour become a factor in wheat utilization?

Answer 12

Wheat color becomes important only when high extraction (high yield) flours are produced during milling.

Question 13

What is the official name of the western Canadian wheat class that can be used practically to make a white looking whole wheat bread?

Answer 13

CW Hard White Spring

Question 14

Who was the Swiss physician and chemist in the 16th century who coined the term “the dose makes the poison”?

Answer 14

Paracelsus

Question 15

Expand (but do not define) the following abbreviations: NOAEL, ADI, MRL

Answer 15

No Observed Adverse
Effect Level

Acceptable Daily Intake

Maximum Residue Limit

Question 16

What are the units for NOAEL or ADI?

Answer 16

Units = mg/kg body wt/day

Question 17

Who was the German chemist who did pioneering work on food adulteration in the early 1800s and published a book on the topic?

Answer 17

Friedrich Accum

Question 18

Which country (U.K., U.S. or Canada) was first to put into law, rules and regulations for food safety in the form of a “Food and Drug(s) Act”? In which year (circle the correct answer)? 1860, 1906, 1920.

Answer 18

1860, U.K.

Question 19

Very briefly explain the main role of Health Canada in relation to oversight of food safety in Canada.

Answer 19

responsible for setting policy & standards for safety, nutritional quality, standards of identity, labelling of processed foods

Question 20

What is the name of the government act that Health Canada administers in its oversight of food safety in Canada?

Answer 20

Food and Drugs Act and Regulations

Question 21

The name of the Canadian department or agency that is responsible for The Canada Food Guide is _______________.

Answer 21

Health Canada

Question 22

Which Canadian department or agency is responsible for administering, but not enforcing, provisions of the Food and Drugs Act and Regulations? Use no abbreviations.

Answer 22

Health Canada

Question 23

Which Canadian department or agency is responsible for enforcing provisions of the Food and Drugs Act and Regulations? Use no abbreviations.

Answer 23

Canadian Food Inspection Agency

Question 24

Very briefly explain the main role of the Canadian Food Inspection Agency in relation to oversight of food safety in Canada.

Answer 24

Enforces rules and regulations for ~ 7 acts of Parliament to protect consumers by contributing to food safety (includes meat and poultry inspection for export)

Question 25

List five distinctly different food safety issues (excluding those of a microbiological nature) that Health Canada or CFIA would have an interest in.

Answer 25

Allergens
Pesticides
Pollutants (PCBs)
Additives, Colours and flavours
Tampering

Question 26

Define the following terms in relation to food safety: Absolute Safety.

Answer 26

Absolute safety

no likelihood of harm

Question 27

Which of the above terms is a fixed characteristic of a chemical additive or residue in food and which is a variable characteristic. Explain the difference using a practical example.

Answer 27

Toxicity = measure of poisoning strength of a substance/agent; unchanging characteristic
 Hazard = variable feature of a substance
What is likelihood that a chemical will cause harm given its toxicity and the amount and manner in which it is handled and/or consumed

Question 28

List two specific reliable sources of toxicity data for chemical residues in food.

Answer 28

Consult authoritative agencies, esp. WHO International Program on Chemical Safety (IPCS)

Regulatory agencies (Health Canada, U.S. Food and Drug Administration, U.S. Environmental Protection Agency, U.S. Department of Agriculture)

Question 29

The name of the English scientist who invented the term LD50 is _________________.

Answer 29

John William Trevan

Question 30

The name of the English scientist who first introduced dose-response curves to standardize toxicity testing of drugs and chemicals is _______________________.

Answer 30

John William Trevan

Question 31

What does the term LD50 refer to (use words only)?

Answer 31

Lethal Dose, median LD that kills 50%

Question 32

Draw a typical dose response curve for a chemical residue in food, label the x- and y-axes, and indicate on the correct axis where you would find the LD50 and NOAEL points.

Answer 32

Notes

Question 33

Which is more toxic: a chemical residue with a high or a low LD50 value? Provide an example for each.

Answer 33

Substance with a high LD value is more safe. Eg-sugar 1.9kg per 68 bw per day vs caffeine at 13 g per 68 kg per day

Question 34

True or false: most natural occurring compounds in food have been tested for their safety.

Answer 34

False

Question 35

The concentration of caffeine in a cup of coffee was determined to be 200 mg/L (1 L of coffee weighs 1 kg). Express that concentration in percent units and in parts per million.

Answer 35

200 parts per million
.02% units

10exp-4

Question 36

Complete the following sentence. The ADI refers to the amount of a substance that can be consumed every__________________________________________ __________________________________

Answer 36

every day for an entire lifetime with practical certainty (based on known facts) that no harm will result.

Question 37

True or false. The ADI for a non-carcinogenic food containing chemical is typically higher in value compared to the NOAEL for the same compound.

Answer 37

False

Question 38

If the NOAEL for a non-carcinogenic compound was 5000 μg/kg body weight, what would be the typical ADI value? Include units in your answer.

Answer 38

5000/100=50micrgram/kg per kg body weight per day???

or 50,000 mg/kg bw/day

Question 39

If the NOAEL for a carcinogenic compound was 5000 μg/kg body weight, what would be the typical ADI value? Include units in your answer.

Answer 39

5000/5000= 1 microg/kg bw/day

or
1000 mg/kg bw/day

Question 40

Do you think Health Canada should ban the use of bisphenol A in food can liner material (yes or no)? Very briefly justify your response using information provided in class.

Answer 40

No, but there needs to be more research. Health Canada has concluded that BPA does not pose a health risk through dietary exposure from food packaging, which conclusion is consistent with other countries such as Japan, US and EU.

Question 41

Define relative safety

Answer 41

no likelihood of harm when used normally

Question 42

Define toxicity

Answer 42

Capacity of a substance/agent to produce harm
(could be acute or chronic effect). Includes e.g.  Adverse health effects
 DNA damage, cancer

Question 43

Define hazard

Answer 43

It is relatively probable that harm will result when substance/agent is present at some level (or used in a proposed manner and quantity)

Question 44

What does HACCP stand for?

Answer 44

Hazard Analysis and Critical Control Points

Question 45

HACCP aims to control the likely presence of three broad types of hazards in food. Name them.

Answer 45

in which food safety is addressed through analysis and control of biological, chemical, and physical hazards

Question 46

HACCP was pioneered by the American statistician and professor

Answer 46

William Deming

Question 47

Very briefly explain why the U.S. space program in the early 1960s was interested in a quality assurance program which became HACCP.

Answer 47

‘ZERO DEFECTS’
in order to ensure food safety for their astronauts- a proactive approach
Pillsbury introduced and adopted HACCP as the system that would provide the greatest safety while reducing dependence on end-product inspection and testing.