Sonoma State University
Departments of Biology Hanes

Outline:

I. Colors

A. Uses - to look fresh, decoration, look more natural as in orange drinks basically to sell products

B. 7 coloring agents in use in 1906, In 1950's several toxicities from overuse resulted in 1958 amendment to pure food and drug act.

1. FDA could now control colors limited to specific uses
2. Eliminated reference to "natural" & "artificial"
3. Could limit quantity as well as type of color
4. Delaney clause - no use of additives causing cancer in animals
5. Established a GRAS list (generally regarded as safe). These chemicals were grandfathered in and did not need to be retested. The idea was that the chemicals had been used for a long time and there were no recorded instances of problems.

C. Some examples

1. Many coal tar dyes are used as Amaranth, Erythrosine, fast green, red dye number 4
2. Examples of colors from "natural" products

a. Beta carotene - also a Vitamin A. used in butter, margarine
b. Caramel - from burned sugar
c. Grape skin extract
d. Paprika
e. Saffron - although awfully expensive and not used much
f. Titanium oxide - 1% maximum, not absorbed, white
g. Turmeric

II. Enzymes - used in baking, etc.

A. Oriental condiments as Soya, Bean curd, Tofu etc.
B. Baking yeasts, breads, brewing
C. Meat tenderizer - Papain, destroyed by heat, but not by stomach

III. Antimicrobials

A. Sodium benzoate

1. Effective pH range 2.5- 4.0, on the acid side
2. Limited to less than 0.1% by weight - Rat LD50 = 3.45g/Kg
3. Occurs naturally in cranberries, prunes, ripe olives, some plums
4. Most effective against bacteria and yeasts - not molds
5. Rats after 90 days of 8% of diet show decreased weight gain
6. Humans at 0.5g/day no measurable effect, effect found at 4g/day
7. Used in canned meats etc. to prevent botulism

a. A bacterial exotoxin that is produced sporadically by bacteria growing anaerobically in nonacid medium, requires at least 15 minutes of boiling to destroy toxin; fatal dose as little as 5 ml of food; blocks effect of Acetylcholine; causes paralysis, hemorrhage in CNS, liver & kidney damage; 12- 24 hrs double vision; 60% die

B. Sorbic acid and salts as sodium sorbate

1. Good against yeasts and molds, poorer against bacteria
2. Rat LD50 10.5 g/Kg for acid and 5.9 g/Kg for salt
3. No toxicity at 8% of diet in rats
4. Maximum is 0.3% of food by weight - it is metabolized like a fatty acid

C. Proprionic acid and its salts

1. Maximum 0.32% in breads and wheat products - not limited in others
2. Good against molds
3. Found naturally at 1% in Swiss cheese

D. SO2, sulfites

1. Can taste at 500 ppm, more effective in acid pH
2. No toxicity in dogs at 1 g/day
3. Used in wines, dehydrated fruits, salads
4. Some people are quite allergic to sulfites and react to extremely small quantities.

E. Nitrites and Nitrates - nitrites are most effective. Gut bacteria convert nitrates to nitrites in the gut

1. mildly bacteriostatic - converts hemoglobin to methemoglobin and myoglobin to nitrosomyoglobin. Makes meet look red and fresh.
2. Rat LD50 200 mg/Kg nitrate; 300 mg/Kg nitrite
3. Maximum limits 500 ppm nitrates; 200 ppm nitrites
4. Also converts your hemoglobin to methemoglobin which doesn't carry oxygen
5. Possibly supplies more nitrate to make nitrosamines (cancer cause)

IV. Antioxidants

A. Butylated hydroxyanisole (BHA) & butylated hydroxytoluene (BHT)

1. In dogs, 1 year, 100 mg/Kg/day no adverse effects, no storage
2. 2% of diet for 6 mo. - no effect
3. Rat LD50 4130 mg/Kg in corn oil
4. Maximum legal limit .02%
5. Slows O₂ in oils converting unsaturated fatty acids to peroxides which are cancer causing.

B. Ascorbic acid also helps reduce oxidation. It is also vitamin C.

V. Unintentional Additives

A. Animal and insect filth
B. Antibiotics like Stibesterol given to livestock
C. Growth promoting hormones given to birds and animals. Growth hormone is given to cattle to increase milk production.
D. Bacteria, Parasites,
E. Pesticide residues
F. Radio nuclides
G. Migrant chemicals from packing materials
H. Metals

VI. Others

A. Acids, alkalis, buffers - acetic acid, citric acid, carbonates
B. Anti caking agents - Magnesium carbonate
C. Bleaching and maturing agents - benzoyl peroxide
D. Sequestering agents - EDTA, tartaric acid - remove dissolved metals
E. Surfactants - polysorbitols, mono- di- glycerides, gums
F. Flavoring agents
G. Flavor enhancers - MSG
H. Sweeteners - saccharin, aspartame, cyclamates, xyletol, sorbitol, corn syrup, various sweeteners and dextrin's. Let me tell you the story of the banning of cyclamates.

Exercises:

1. List a number of uses of food additives and give an example of each?

2. What additives are used to control bacteria? molds? yeasts?

3. What additives do you feel are the most harmful? the least harmful?

4. Match a food additive with its general category.

5. What kind of damage can nitrites do to you? Papain?

6. Discuss botulism food poisoning. aflatoxin. Ptomaine.