Overview

• Preliminaries.
  • Admin.
  • Questions.

Preliminaries

Admin

• Note takers (send me five main points): CO and TD.
• Welcome to Prof. Leslie Lyons, our guest speaker for the week.
• The nanotechnology reading was for Wednesday. If you sent questions on tha reading, please send questions on the other two readings for Wednesday.
• Extra credit:
  • Swimming Friday and Saturday. (DS and DP start times tbd.)
  • CS Table Friday at noon: Law, Order, and Computers
  • Others?

Questions

Dr. Lyons

• Her research had an impact on the batteries in our laptops and phones.

Important Ideas (CO)

1) Food consumption has become safer over time as science has allowed for better analyzation of the chemicals (and potential consequences) found in certain foods. However, only a small portion of food borne illnesses are actually verified because many do not seek medical attention or fail to recognize food as the cause of their symptoms.

2) Two regulatory approaches concerning food production are the "precautionary" principle and the "proof of harm" principle. The precautionary principle suggests that precautionary measures should be undertaken if there is any potential harm to be had on the environment or human health. The proof of harm principle takes the opposite stance, suggesting that harm must be proven before actions are taken.

3) Large food chains in the United States are at increased risk for spreading food borne illness to multiple states at a time. The distance many foods travel allows for more mishaps in the preservation/transportation of the product. If a product is recalled and it has been distributed to multiple states, tracking and taking that product off appears to be a difficult process.

4) While there are global regulations for food production/distribution, many nations have their own set of legislation. Even further, territories inside of nations may also have their own set of regulations. The United States, for example, has the FDA which controls all food related activities, but individual states may have regulations that do no align with the national government.

5) Professor Lyons highlighted the dangerous toxins that are in many of our daily, healthy foods, but she does not insist that this is a reason to not eat certain foods. Most foods are good in moderation and the nutritional benefits often outweigh the potential negative side affects of the dangerous toxins.

Important Ideas (EL)

Food born illness is super common in England and United States media.

Salmonella is likely in any food that isn't cooked, stored for a while, transported and stored longer. One outbreak of Salmonella can affect many people, as well as other food born illnesses.

Climates may have particular types of foods for a reason--such as hot peppers being placed in foods in hot climates, acting as a preservative.

Two main regulatory approaches & principles

• Precautionary: Food regulations are created precautionarily despite the lack of a proven cause and effect relationship with a given new food. (European Union method)
• Proof of Harm: Food regulations are created after science has proved definitively that it can cause harm. (United States method)

Important Ideas (SR)

There's more technology involved in food than you might think, particularly with regards to making food "safe".

There are a wide variety of issues for which we might need technology. The technologies for making food safe can relate to the bacteria and other organisms that can form in food, to the adulterants that become part of food, to natural aspects of the food, and more.

Decisions on technologies for making food "safe" are not necessarily made in a rational matter. There's more than "science" involved. Decisions are also affected by the popular press, by biased notions of risk, by overall philosophies on approaches to safety, and more.

Food has been contaminated for more-or-less as long as there's been food, but contamination increased significantly when we started industrializing the production of the food. Contaminations can happen intentionally (e.g., when a producer adds something cheaper or to improve appearance) or unintentionally (e.g., when the equipment leaches materials into the food; Lyons/Jackson noted lead presses for olive oil and plastic containers for storing food).

Different governments and regulatory agencies have very different philosophies about ensuring safety. For example, do you assume risk and need science to prove safety (the "precautionary" approach), or do you assume safety and need science to prove risk (the "proof of harm" approach)? Similarly, do you assume that exposure to something has a linear effect or that there is a threshold below which exposure is unlikely to be harmful?

Food technology is a regular subject for news articles. (Do you think it's more positive or negative?)

Lyons: Food and Technologies

• We are going to walk through ideas from the Krebs, Jackson, and Chaudhry articles. (Chaudhry will be on Wednesday.)
• Along the way, we'll consider some other issues.

[Figure 3 from Krebs, p. 1136]

• How do people think about risk?
• Risk a huge underlying issue in any technology.
• Two axes: Known to Unknown, ? to Dread
• DNA technology, radioactive waste, and pesticides are both unknown and dread
• Comfort foods, while not in the slide are in the known, not very dreaded.

[Table 1 from Krebs: How many deaths create a news story and Table 2 from Krebs: Food Risks]

• Yesterday's DSM Register had two articles on food.
• Food technology issues are common in the popular press.
• Articles about deaths do not relate to the number of deaths.
• Note: No deaths are directly attributable to GMOs, pesticides, etc., although those are normally in the media.

Slide: Food Preservation and Safety. (New Pictures)

• There are bacteria everywhere, all the time.
• Most are safe (or at least comparatively so).
• Some are downright nasty, such as Campylobacter jejuni
• For food poisoning cases, we have a pyramid of knowledge
  • At the top, very few are confirmed by lab tests
  • In the middle, a moderate number of cases are studied late enough that you can tell.
  • At the bottom, you have a much larger number of people who don't really think about it as food poisoning, just an upset stomach.

Slide: Food Poisoning Cases and Food Sources

• Poultry, Other meat, Milk & Dairy, Eggs, Others
• Salmonella is the most common
• Others include Bacillus, C. perfingens, Saph, etc.

Slide: Factors contributing to outbreaks of food poisoning [unknown source]

• Biggest factor in England/Wales: Preparation too far in advance (less in US)
• Also storage at ambient temperature and inadequate cooling (63% of cases)
• Worries about cross contamination, undercooking
• Contaminated processed foord, Contaminated canned food, inadequate thawing, food consumed raw, improper warm handling, infected food handlers, use of left-overs, extra large quantities
• Food handlers: If they've been infected, they are more likely to spread. Looks much worse in the US (26% of cases vs. England/Wales: 4%). May be that we use more central distribution.

Slide Table 3.1 Factors affecting the development of microbial asosciations

• Intrinsic factors
  • Oxygen, etc.
• Environmental factors
• Implicit factors
• Processing factors
  • Surface areas

Slide Table 4.1 Mechanisms of food preservation

• Lots of them.
• E.g., cooling - low temperature retards growth
• E.g., drying, curing, and conserving - Reduced water delays or prevents growth. All old fashioned ideas that alter the environment of the food.
• More recent technical advancements: Changing the gas environment: Vacuum packing, carbon dioxide or nitrogen.
• Acids or fermentation change the pH. An old strategy. Consider yogurt, cheese, etc.
• Emulsification
• Preservatives - Spices work as preservative agents. That's one of the reasons we see hot food in tropical areas.
• Technical ways: Pasteurization, Radiation, High-pressure/Pascaliszation
  • Pasteurization dates to Napoleonic france.

What do you want to do? Table 4.2: Heat processes applied to food

• Changes the chemical composition
• Changes the water
• Changes the gas environment (particularly with smoke)
• Usually below 100 degrees centigrade, so it's not steralized.
  • Still opportunity for
• Pasteurization is gentle 60-80 degrees centragde. Eliminates most of the bacteria in milk.
• FIRST NEWS ITEM - Artisan movement to allow the sale of raw milk in Iowa. Editorial in Sunday Des Moines Register opposed to it.
  • Movement in six states: Pennysylvania, Alaska, Tenn, CA, ...
  • It's a risky thing to do.
  • At the farm, it's fresh, it's probably safe.
  • But as it gets moved around.

Slide: What happens to raw milk?

• Pasteurizing may change the flavor, but makes it much safer. (Temp.)
• Also cheese, youghurt, dried milk, sweetened condensed milk, cream (and butter), evaporated milk, even ultra-high-temperature sterilized milk (the stuff that can sit on your shelf).

Slide: Organic and Food Preservatives

• Enhance taste, appearance, shelf life.
• The natural substances that used to be added were analyzed by chemists so that we can identify the important thinks.
• Salt is a great preservative. And you can have a lot and it's stilll safe.
• Vinegar (Acetic acid), also safe.
• Lactic acid. "No limit to how much you an use.
• Some other substances have regularotry limits: Propionic acid, as well as some very specific things, p-Hydroxybenzoic acid

Slide: Regulatory Approaches: Principles

• Taken from http://www.sehn.org/ppfaqs.html
• Precautionary principle: When an activity raises threats of harm, take precautionary measures even if relationships are not established scientifically. [UK et al.]
• Proof of harm. Science must provide definitive proof of harm before protective action is taken. [US]
• These are very different attitudes.
• And regulations are different at different levels (country, state, etc.)

Slide: Reglator Approaches: Exposure [Figure 7 from Krebs]

• What dose/response curve do you believe in?
• Traditionally known at the high end of the curve.
• Do you think it should be extrapolated linearly, and assume that even low exposure leads to results?
• In contrast, do you think there's a threshold below which you don't think harm is likely (or in which response is not measurable)?
• EPA uses the linear model. FDA, World Healt Organization, etc. tend to use the threshold model.
• E.g., in US Radon is allowed only at 4 picocuries/litre; in the UK, it's 18.

Slide: Food Adulterants and Key US Legislation [Table 1 from Jackson]

• For both intentional and unintentional readings, things get added to products.
• Some are harmful (lead in candy) some are simply cheating the consumer (sugar in maple syrup)
• Lots of policy to deal with this
  • 1906 Pure Food and Drugs Act, Meat Inspection Act
    • Meat Inspection act builds upon Upton Sinclair's "The Jungle"
    • See protection of fod for us
  • 1938 Food Drug and Consmetic Ac
    • Update to food and drug actt
  • 1954 Miller Pesticide Amendment
  • 1958 Food additives amendment
  • 1960 Color additive amendment and the Delany clause
• Management of food pretty much established by 1960

Slide: Safe List [Table 20-11 A Partial List of Additives Generally Recognized as Safe]

• Things that have been being used for a long time. The "GRAS list"
• If you use things on this list, you do not need to petition the FDA.
• Some things have moved off of the list.
  
  • Saccharin is now known to cause cancer in mice.
  • So when you buy those little pink packets, they have wranings
• Partially hydrogenated oils
  • Process adds hydrogen to vegetable oils
  • You get cool double bonds / trans fats
  • Trans fats will be off the GRAS list
  • And may soon be out of the food supply
  • Producers are looking for alternatives.
  • We are seeing an upswing in palm oil. But trans fats were introduced to reduce use of palm oil.
• NEWS ARTICLE: GMO Soybean that produces an oil that is more like palm/trans fats.

Slide: Examples of GRAS Substances.

• Things that are generally qualified as safe.
• Substance, Structure, Classifcation
• E.g., Acetaldehyde, Anise, Cinnamon, Ethyl acetate, ...

Slide: Chemical Hazards in Food [Table 2 from Jackson]

• Agrochemical - Things that the plants and animals experience can carry on into the foodstuff.
  • Antibiotics are a big issue here.
• Environmental and industrial contaminants
  • Things are raised in an environment. Things exist in that environment, such as heavy metals. Often result of industries.
• Produced during processing and storage
  • What happens to potatoes and starchy products when fried? Known carcinogens!
• Packing-derived hazard. Are you introducing hazards from the packaging? We package in plastic, which is not naturally occuring.
  • BPA is an example.
  • Clear water bottles.
• Allergens. We see increasing issues, particularly with GM foods.
• Natural toxins. These come as foods and grains are stored, particularly in grains.
• Unconventional chemical hazards. Particularly post 9-11, people are getting more concerned.
  
  • Also fraud.
  • Melamine example in pet food - global issues.
  • Attacks on the food supply are relatively easy to introduce.

Slide: Current Issues (Jackson)

• Chemists play a huge role in this.
• E.g., finding the presence of chemicals in food.
• Since 1950's, tremendous devleopment of analytical tools.
  • Everything mentioned in the article is probably in our chem department.
  • So our Chem students often look for these.

Slide: Toxic or Carcinogenic Chemicals that Occur Naturally

• Allyl isothiocyante in brown mustard, horseradish, and garlic forms tumors
• Benzo(a)pyrene in smoked and broiled meat causes gastrointestinal cancer (all that nice chared stuff is not good for you)
• Apple seeds have cyanide. Don't eat too many of them!
• Lactose. Some portion of the population is lactose intolerant.
  (Lactaid pill helps with this.)
• Moderate consumption should be okay. Of course, it's a balancing act.

Slide: Chemicals Used to Improve Nutrition

• Ascorbic acid in citrus fruit - Now added directly as Viamin C.
• Current and Future Technology: Nutraceuticals.

Slide: Food Irradiation (last slide for today)