Lesson 12 & 13

Question 1

Is it possible for foods to be completely safe?

i.e. zero risk of harm, free of harmful chemicals

Answer 1

• all foods consists consist of chemicals
• all substances (chemicals) are toxic at some level and potentially harmful
• zero risk is unattainable in food safety (and in life)!

Question 2

Toxicant

from Latin “toxicum” (poison)

Answer 2

substance that can produce a whole spectrum of effects (minor to death)

Question 3

Toxicity

Answer 3

ability of a chemical to damage a biological system
* substances vary in toxicity and individuals vary in sensitivity
* measures short-term poisoning (acute toxicity) by LD50 (mg/kg b.w. or ppm)

the lower the LD, the stronger the toxicity! any substance with LD50= 50 ppm/kg or lower is considered poison

Question 4

Hazard

Answer 4

probability that injury will result from the use of a chemical at a given exposure

Question 5

2 criteria in assessing a hazard

Answer 5

1. toxicity or inherent capacity to cause harm
2. probability of contact between substance and target object

Question 6

Strychnine

plant from SE Asia

hazard example

Answer 6

• extremely toxic chemical with LD50= 1.2 mg/kg (small amount causes a severe effect)
• no hazard when sealed in an un-openable vial, preventing contact and allowing it to be freely handled with no chance of poisoning

BUT its toxicity remains unchanged

Question 7

Boric acid (borax)

hazard example

Answer 7

• mild acid used as an antiseptic, insecticide, flame retardant
• or additive in some cultures (e.g. firming agent, preservative, tenderizer)
  not highly toxic (LD50= 1240 mg/kg) but very hazardous when used in a manner that makes it easily available for accidental ingestion

Question 8

Dose-response curve in terms of toxicity vs hazard

Answer 8

every substance is toxic at some dose but not every substance is hazardous at commonly used doses

Question 9

Constituents

naturally occuring toxicant

Answer 9

part of the normal composition of food

Question 10

Contaminants

naturally occurring toxicant

Answer 10

• not originally part of food
• due to bacterial or mould growth on plants and animals within an environment that allow them to become part of food

may lead to foodborne and waterborne diseases

Question 11

Environmental toxicants

Answer 11

• not originally part of food
• introduced in the environment as a result of human activities

Question 12

Solanine

naturally occurring constituent

Answer 12

• cholinesterase inhibitor, which inhibits the enzyme cholinesterase through nerve transmission/impulses
• can cause neurological and GI disorders

Question 13

Solanine in potatoes

naturally occurring constituent

Answer 13

• present in low levels (e.g. 2-13 mg/100g fresh weight in potato skin)
• increases with sunlight exposure, as signalled by green color (80-100 mg/100g f.w.)

Question 14

Toxicity and hazard of solanine in potatoes

and symptoms

Answer 14

• toxic (LD50= 42 mg/kg) but relatively low hazard/risk (unless green)
• experience drowsiness, difficult breathing, increased sensory sensitivity at 2-8 mg/kg b.w.

Question 15

How can you reduce solanine levels in potatoes?

Answer 15

• insoluble in water but can reduce concentration by peeling
• not destroyed by heat/cooking

Question 16

Cyanogenic glycosides

naturally occurring constituents

Answer 16

compounds that yield HCN (hydrogen cyanide) upon enzymatic action (beta-glucocidase) or acidic conditions

e.g. amygdalin in bitter almonds and fruit pits, linmarin in cassava, lima beans

Question 17

Toxicity and hazard of cyanogenic glycosides

Answer 17

• toxic (LD50= 0.81 mg/kg) but low hazard from accidental consumption of fruit seeds
• fatal in humans at 0.5-3.5 mg/kg (e.g 100g bitter almonds or dried bitter cassava root) but non-fatal at lower doses

increase in hazard if bitter almonds, cassava, lima beans, etc. are part of staple diet

Question 18

2 most common mycotoxins

naturally ocurring contaminant

Answer 18

produced by moulds
* Ergotism alkaloid (St. Anthony’s Fire) produced by Claviceps purpurea
* Aflatoxins produced by Aspergillus flavus

Question 19

Ergotism alkaloid (Claviceps purpurea)

mycotoxin

Answer 19

a grain of ryegrass infected with ergot (Claviceps purpurea)
* vaso-constricting (constricts blood flow to brain) and precursor for LSD 25, causing hallucinations

linked to salem witch hunt “hysteria”

Question 20

Aflatoxins (Aspergillus flavus)

Answer 20

highly toxic and potently carcinogenic (liver cancer)

found in peanuts, corn, wheat, rice, cottonseed, nuts, milk, eggs, cheese

Question 21

Examples of seafood toxins

naturally occurring contaminants

Answer 21

• Histamine
• Saxitoxin
• Domoic acid
• Tetrodoxin

Question 22

Histamine

seafood toxins

Answer 22

from histidine, a naturally occurring amino acid, produced in high levels by bacteria action on fish flesh (e.g. scombroid fish like tuna, bonito, mackerel, skipjack)

bacteria converts histidine > histamine

Question 23

Symptoms of scromboid poisoning

histamine in scombroid fish

Answer 23

eating scombroid fish = nausea, vomiting, facial flushing, thirst, skin itchiness

must ensure it’s completely cooked or from a reputable source

effects subside ~12 hrs

Question 24

Saxitoxin

seafood toxin

Answer 24

• produced by dinoflagellates, found in plankton responsible for red tides
• prevalent in shellfish (e.g. mussels, clams, oysters), which are “filtering organisms” that absorb saxitoxin and concentrate it in their tissues

Question 25

Red tide | i.e. bloom

Answer 25

source of saxitoxin * when microscopic plankton (containing dinoflagellates) bloom, forming a red tide

Question 26

Paralytic shellfish poisoning (PSP) ## Footnote saxitoxin in shellfish

Answer 26

* lethal at a certain dose (toxic) but hazard depends on your love for shellfish and its source (when/where its harvested) * can cause muscular and nerve paralysis | e.g. ignoring red tide warning signs

Question 27

Amnesic shellfish poisoning ## Footnote domoic acid in blue mussels

Answer 27

domoic acid, a neurotoxin produced by plankton, can cause lesions in the CNS, resulting in permanent memory loss ## Footnote **hazard** depends on consumption of shellfish (e.g. ignoring signs indicating closure of areas to shellfish harvesting)

Question 28

Fugu poisoning ## Footnote tetrodotoxin in puffer fish

Answer 28

* produced by a bacteria associated with the ovaries, liver, intestine, skin of puffer fish * toxic at low dose and hazard depends on passion for puffer fish, its proper cleaning and gutting | its meat is considered a delicacy!

Question 29

5 kinds of environmental toxicants

Answer 29

1. **food packaging residues** (e.g. monomers of plastic resins) 2. **pesticide** (e.g. herbicides, insecticides, fungicides) **residues** (e.g. malathion on fruit) 3. **heavy metals** (e.g. lead, mercury, cadmium) 4. **animal drugs** (e.g. antibiotics, hormones, penicillin in milk) 5. **radioisotopes** (e.g. from soil or radioactive fallout)

Question 29

Symptoms of fugu poisoning ## Footnote tetratodoxin in puffer fish

Answer 29

* tingling sensations (fingers, toes, lips, tongue) minutes after eating * reflexes of pupil and cornea are lost * paralysis, respiratory distress, death

Question 30

3 kinds of processing-induced toxicants

Answer 30

1. acrylamide (heated starch) 2. benzene (irradiated food) 3. ACBs (irradiated food) | acrylamide can be produced from maillard reaction

Question 31

Main causes of foodborne illnesses ## Footnote general public vs regulatory agency

Answer 31

* **food additives** according to general public * **microorganisms** according to regulatory agency ## Footnote MOs like salmonella, shigella, e. coli, vibrio, cyclospora, hepatitis A, listeria

Question 32

Incident

Answer 32

simple occurrence of foodborne illness | an isolated case

Question 33

Outbreak

Answer 33

foodborne illness in 2 or more people after ingestion of the same food with epidemiological evidence ## Footnote **outbreak of unknown etiology** has no epidemiological evidence

Question 34

3 reasons why foodborne diseases are emerging

Answer 34

1. globalization of food supply (pathogens introduced to new areas) 2. travel 3. change in lifestyle

Question 35

3 reasons why only some FBD outbreaks are documented

Answer 35

1. lack of reporting (only 1-4% reported) 2. mistaken diagnosis (e.g. mild cases of FBD wrongly attributed to 24hr flu, virus, eating too much) 3. physicians fail to report the case to local health units (not enough evidence/research available)

Question 36

Who is at highest risk of FBD?

Answer 36

* very old * very young * those with weakened immune systems * expectant (pregnant) mothers

Question 37

Food intoxication ## Footnote kind of FBD

Answer 37

due to **toxins/toxicants**, produced in foods as **by-products of MOs**, plants plants, or animals, which cause disease upon ingestion

Question 38

Food infection ## Footnote kind of FBD

Answer 38

* due to **multiplication** of pathogenic MOs * viable MOs in the food at the time of consumption cause growth in the host, which leads to illness

Question 39

Which foods is Clostridium botulinum commonly in? ## Footnote food intoxication

Answer 39

low acid foods and anaerobic conditions, potatoes, carrots | found in soil, where carrots and potatoes can harbor C. botulinum

Question 40

Symptoms of Clostridium botulinum

Answer 40

double vision, dry mouth, paralysis | a neurotoxin! ## Footnote **LD** for humans= 1 ng/kg b.w.

Question 41

Prevention of Clostridium botulinum

Answer 41

* its spores are heat resistant and must undergo botulinum cook (12D process) * Keep pasteurized (refrigerated) | pasteurization not enough to destroy!

Question 42

What foods is Escherichia coli 0157:H7 commonly in? ## Footnote food intoxication

Answer 42

undercooked ground beef, unpasteurized milk and fruit juice, alfalfa sprouts, spinach, drinking water ## Footnote **acid-tolerant** (often survive in acidic foods like apple juice)

Question 43

Symtoms of Escherichia coli 0157:H7

Answer 43

bloody diarrhea > kidney failure (if not treated), hemolytic uremic syndrome (especially in children) | used to be "hamburger disease"

Question 44

Prevention of Escherichia coli 0157:H7

Answer 44

not spore-forming so easily inactivated by heat (pasteurization) and irradiation * ensure ground beef is cooked well * refrigerate (doesn't grow well at temperatures < 8-10C) * sanitary food handling

Question 45

Meat glue

Answer 45

* an **enzyme called transglutaminase** used to bind small meat scraps into a whole new piece * produced by cultivating bacteria from the blood plasma of pigs and cattle (coagulant that causes blood to clot) * used in powdered form in the food industry and can be dangerous to inhale ## Footnote a **permitted food additive** (e.g. in meat products, bread, white flour) but poses risk of poisoning, especially when cooked rare

Question 46

Mechanical tenderization ## Footnote why is it hazardous?

Answer 46

a process used to soften meat texture by running through a machine that punctures it with blades or needles ## Footnote * bacteria, deadly pathogens can be pushed deep inside, making them difficult to kill if meat is not cooked thoroughly * not labelled and cannot be visually identified

Question 47

What foods is Staphylococcus aureus common in? ## Footnote food intoxication

Answer 47

contaminated and undercooked food exposed to open wounds and nasal fluid ## Footnote produce **heat-resistant enterotoxin**

Question 48

Symptoms of Staphylococcus aureus

Answer 48

rapid onset of nausea, vomiting, abdominal pain, cramps, and diarrhea ## Footnote **20 ng** can cause illness (very potent)

Question 49

Prevention of Staphylococcus aureus

Answer 49

easily inactivated by heat (pasteurization) * must cook food well * refrigerate (doesn't grow well < 4C) * sanitary food handling

Question 50

Which foods is Salmonella common in? ## Footnote food infection

Answer 50

raw or undercooked poultry, eggs, hogs, ground beef, milk, dairy products

Question 51

Symptoms of Salmonella

Answer 51

cramps, chills, vomiting, diarrhea, fever ## Footnote symptoms typically start within **6-72 hrs after exposure** and most end within 4-7 days

Question 52

Prevention of Salmonella

Answer 52

* killed by heat (cooking, pasteurization) and irradiation * ensure sanitary food handling

Question 53

Which foods is Listeria common in? ## Footnote food infection

Answer 53

refrigerated smoked fish, raw or unpasteurized milk, soft and unpasteurized cheeses, ready-to-eat meats | can grow at refrigerated temp!

Question 54

Symptoms of Listeria

Answer 54

fever, nausea, cramps, diarrhea, vomiting, miscarriage and stillbirth (in pregnant women) ## Footnote symptoms of severe listeriosis may appear up to **70 days after exposure**

Question 55

Prevention of Listeria

Answer 55

* killed by heat (cooking, pasteurization) and irradiation * ensure sanitary food handling ## Footnote control measures in place in ready-to-eat foods

Question 56

Viruses

Answer 56

**do not multiply in food**, instead usually oral-fecal route of contamination that infects upon ingestion (e.g. shellfish from contaminated water) ## Footnote e.g. hepatitis A, norovirus (prev. norwalk-like viruses)

Question 57

Prevention of viruses

Answer 57

* inactivated by thermal processing * hygiene (sanitary food handling)

Question 58

Which foods is Norovirus commonly in?

Answer 58

raw shellfish, any food prepared or touched by an infected person ## Footnote easily spread from the infected person up to **at least 3 days after recovery**

Question 59

Symptoms of norovirus

Answer 59

diarrhea, vomiting (usually more in children), nausea, stomach cramps, low-grade fever, headache, chills, muscle aches, fatigue ## Footnote **gastroenteritis within 24-48 hrs** but symptoms can start as early as **12 hrs after exposure** (illness often begins suddenly)

Question 60

5 factors in FBD

Answer 60

1. inadequate cooling of foods 2. preparation of food several hours in advance 3. poor personal hygiene and cross-contamination 4. insufficient cooking or reheating of food 5. improper hot storage ## Footnote most **pathogenic MOs don't alter** the color, aroma, flavor, texture of food (unlike spoilage) so no visual cues to rely on

Question 61

Top 4 places where food can be mishandled and lead to FBD

Answer 61

1. food service establishments 2. food processing establishments 3. retail food establishments 4. homes

Question 62

4 safe food handling practices ## Footnote preparing, cooking, serving, storage

Answer 62

1. **clean** hands, utensils, cooking surfaces with soap and hot water, or sanitize with a mild bleach solution 2. **separate** raw and cooked food to avoid cross-contamination 3. **cook** thoroughly, prepare quickly, serve immediately 4. **chill**, refrigerate (< 4C) or freeze (-18C) within 2 hrs ## Footnote avoid **temperature danger zone (TDZ)** between **4-60C**

Question 63

Hazard analysis and critical control points (HACCP) system

Answer 63

processing flow diagram designed to anticipate and control problems before they happen

Question 64

7 HACCP steps

Answer 64

1. identify hazard (FATTOM) 2. determine CCP 3. institute control measures 4. monitor CCP 5. take corrrective action 6. keep records 7. verify procedures | **FATTOM=** food, acidity, time, temperature, oxygen, moisture ## Footnote **most crucial step is preservation** (e.g. receiving > clarification > homogenization > **pasteurization** > packaging)

Question 65

3 conditions of FOSHU (Japan) | leading country in functional foods

Answer 65

1. derived from naturally occurring ingredient 2. consumed as part of the daily diet 3. has health-enhancing function

Question 66

Natural health products ## Footnote prev. nutraceuticals

Answer 66

* isolated or purified from foods * sold in medicinal forms not usually associated with foods * have proven physiological benefits ## Footnote require a natural product number (NPN) or homeopathic medicine number (DIN-HM)

Question 67

Funtional food

Answer 67

a food consumed as part of the daily diet and is demonstrated to have physiological benefits and/or reduces risk of chronic disease beyond basic nutritional functions | e.g. omega-3 eggs ## Footnote fortified with **3 essential antioxidants (vitamin C, E, selenium)** to promote a healthy immune system, protect cells and tissues

Question 68

4 classifications of functional foods | according to source

Answer 68

1. traditional raw (non-processed) foods (e.g. oat bran, flax seed, garlic, fish with omega-3s) 2. processed food w/ no added ingredients (e.g. high fiber cereal, soy products, flaxseed oil) 3. processed foods with added ingredients (e.g. Ca-fortified OJ, omega-3s in yogurt) 4. genetically-engineered foods (e.g. tomatoes with lycopene)

Question 68

Claim about soy

Answer 68

soy protein decreases cholesterol and are anticarcinogens

Question 69

Claim about flaxseed

Answer 69

has high amount of omega-3 FAs and lignan, which reduces cholesterol (substantiated) and breast cancer (not)

Question 70

Claim about tomatoes

Answer 70

lycopene in tomatoes is an anticarcinogen

Question 71

Claim about garlic

Answer 71

alicin and sulfur containing compound = antibiotic, anticarcinogen, antihypertensive (lower cholesterol)

Question 72

Claim about beef and whole milk

Answer 72

conjugated linoleic acid (CLA) is an anticarcinogenic and facilitates weight reduction

Question 73

Probiotics

Answer 73

* products containing **health-promoting microorganisms** (improve intestinal microflora balance) * **high # viable organisms required** for benefits: reduced risk of colon cancer and GI disorders, stimulate immune system ## Footnote e.g. **Lactobacillus and Bifidobacterium** in yogurt, fermented milk (also available as natural health products)

Question 74

Novel food | Health Canada

Answer 74

a substance, including a MO, that doesn't have a history of safe use as a food yet