Midterm 2 Flashcards
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.
High flour yield, low ash
What are typical particle size index values for durum wheat, hard common wheat for breadmaking and soft wheat?
durum wheat - 35-45
hard common wheat - 50-60
soft wheat - 65-75
Besides particle size of flour, what are other important influences of wheat hardness for utilization quality
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
Damaged starch levels in flours of hard and soft wheats are ______% and ______%, respectively.
6-10% AND 2-5%
Damaged starch typically absorbs ______% of its weight in water
absorb ~ 2X to 3X its weight
Why does damaged starch affect the gassing power of dough?
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
The name of the protein that binds with starch granules on its surface and affects wheat hardness is _________.
friabilin protein
List the benefits of dough strength for commercial bread making.
–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
Briefly list reasons why a dough can have too strong mixing properties for commercial bread making.
increased protein content
increased stability
Wheat kernel colour is mainly due to _________ compounds in the seed coat of bran.
flavonoid(phenolic)pigments
The colour of wheat endosperm is mainly due to _______________ compounds which are enhanced in concentration in durum wheats and uncooked pasta.
carotene pigments
Under what circumstances does wheat grain colour become a factor in wheat utilization?
Wheat color becomes important only when high extraction (high yield) flours are produced during milling.
What is the official name of the western Canadian wheat class that can be used practically to make a white looking whole wheat bread?
CW Hard White Spring
Who was the Swiss physician and chemist in the 16th century who coined the term “the dose makes the poison”?
Paracelsus
Expand (but do not define) the following abbreviations: NOAEL, ADI, MRL
No Observed Adverse
Effect Level
Acceptable Daily Intake
Maximum Residue Limit
What are the units for NOAEL or ADI?
Units = mg/kg body wt/day
Who was the German chemist who did pioneering work on food adulteration in the early 1800s and published a book on the topic?
Friedrich Accum
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.
1860, U.K.
Very briefly explain the main role of Health Canada in relation to oversight of food safety in Canada.
responsible for setting policy & standards for safety, nutritional quality, standards of identity, labelling of processed foods
What is the name of the government act that Health Canada administers in its oversight of food safety in Canada?
Food and Drugs Act and Regulations
The name of the Canadian department or agency that is responsible for The Canada Food Guide is _______________.
Health Canada
Which Canadian department or agency is responsible for administering, but not enforcing, provisions of the Food and Drugs Act and Regulations? Use no abbreviations.
Health Canada
Which Canadian department or agency is responsible for enforcing provisions of the Food and Drugs Act and Regulations? Use no abbreviations.
Canadian Food Inspection Agency
Very briefly explain the main role of the Canadian Food Inspection Agency in relation to oversight of food safety in Canada.
Enforces rules and regulations for ~ 7 acts of Parliament to protect consumers by contributing to food safety (includes meat and poultry inspection for export)
List five distinctly different food safety issues (excluding those of a microbiological nature) that Health Canada or CFIA would have an interest in.
Allergens Pesticides Pollutants (PCBs) Additives, Colours and flavours Tampering
Define the following terms in relation to food safety: Absolute Safety.
Absolute safety
no likelihood of harm
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.
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
List two specific reliable sources of toxicity data for chemical residues in food.
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)
The name of the English scientist who invented the term LD50 is _________________.
John William Trevan
The name of the English scientist who first introduced dose-response curves to standardize toxicity testing of drugs and chemicals is _______________________.
John William Trevan
What does the term LD50 refer to (use words only)?
Lethal Dose, median LD that kills 50%
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.
Notes
Which is more toxic: a chemical residue with a high or a low LD50 value? Provide an example for each.
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
True or false: most natural occurring compounds in food have been tested for their safety.
False
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.
200 parts per million
.02% units
10exp-4
Complete the following sentence. The ADI refers to the amount of a substance that can be consumed every__________________________________________ __________________________________
every day for an entire lifetime with practical certainty (based on known facts) that no harm will result.
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.
False
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.
5000/100=50micrgram/kg per kg body weight per day???
or 50,000 mg/kg bw/day
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.
5000/5000= 1 microg/kg bw/day
or
1000 mg/kg bw/day
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.
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.
Define relative safety
no likelihood of harm when used normally
Define toxicity
Capacity of a substance/agent to produce harm
(could be acute or chronic effect). Includes e.g. Adverse health effects
DNA damage, cancer
Define hazard
It is relatively probable that harm will result when substance/agent is present at some level (or used in a proposed manner and quantity)
What does HACCP stand for?
Hazard Analysis and Critical Control Points
HACCP aims to control the likely presence of three broad types of hazards in food. Name them.
in which food safety is addressed through analysis and control of biological, chemical, and physical hazards
HACCP was pioneered by the American statistician and professor
William Deming
Very briefly explain why the U.S. space program in the early 1960s was interested in a quality assurance program which became HACCP.
‘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.
