16-Controversial+Preservatives-F-24+to+post

Controversial Preservatives in Food

Nitrite, Antibiotics, and Irradiation

  • Topics covered:

    • Goals of food preservation

    • Controversial methods of preservation:

      1. Addition of nitrite/nitrate

      2. Addition of antibiotics

      3. Irradiation

Goals of Food Preservation

  1. Prevent contamination of food

  2. Remove contaminants

  3. Inhibit growth of natural flora and contaminants

  4. Preserve natural flora and contaminants

Controversial Methods of Preservation

I. The Use of Nitrates and Nitrites

  • Nitrates are used in certain foods as preservatives because they:

    • Inhibit the growth of specific bacteria

    • Preserve the meat's color and flavor

  • Nitrite or nitrate can be used in:

    • Canned meats, hot dogs, bacon, fermented sausage

    • Stabilizes color by reacting with myoglobin to give a reddish color

    • Most importantly inhibits the germination of endospores (e.g., Clostridium botulinum)

A. Nitrate/Nitrite Usage

  1. Function as preservatives

  • Used in processed meat and meat products

  • Protects against foodborne pathogens

B. Concerns with Nitrate/Nitrite Usage

  1. Health risks:

  • Nitrites can form carcinogens during human digestion

  • Reaction with amino acids can produce nitrosamines, which are mutagenic and carcinogenic

  • Little effect at levels used for preserving meat

  1. Nitrates/Nitrites legality and consumer concerns:

  • Despite potential risks, they are legal additives in food

  • Alternatives include using natural sources like celery juice, which is naturally high in nitrates

II. Antibiotics in Food

A. Antibiotics as Food Additives

  1. Value of Antibiotics:

  • Used to control bacterial growth in processed foods

  1. Concerns:

  • Widespread use can lead to antibiotic resistance among bacteria

    • Example: Resistance transfer among bacteria via plasmids

  • Some individuals may have allergic reactions to antibiotics used

  1. Current Situation:

  • Legal to add certain antibiotics to food

  • Common antibiotics:

    • Nisin (effective against Gram-positive bacteria)

      • Used in dairy products, processed cheese, etc.

    • Natamycin (produced by certain molds)

      • Protects against fungal contamination in dairy products

B. Antibiotics as Animal Feed Supplements

  1. Advantages:

  • Used for treatment and prevention of diseases in livestock

  1. Concerns:

  • Use may create antibiotic-resistant pathogens, posing risks to public health

III. Ionizing Irradiation in Food Preservation

  1. Basic Method:

  • Expose food to ionizing energy which does not heat food ("cold pasteurization")

  • Kills pathogens via ionization and free radical generation

A. Value of Irradiation

  • Kills microbes to:

    • Increase shelf life

    • Control pathogens similar to commercial sterilization

    • Sterilize foods for long-term storage

B. Concerns about Irradiation

  1. Misconceptions:

  • Food becoming radioactive: Irradiated food does not become radioactive

  • Unpleasant changes: Minimal effect on food appearance, color, and vitamin content

Current Situation of Irradiation

  • FDA has found food irradiation to be safe, improving food safety and extending shelf life

  • Various federal agencies endorse its safety, including the CDC and WHO

  • Foods irradiated internationally include:

    • Fruits, vegetables, meats, and seafood

  • FDA approved irradiation for:

    • Specific food types with legal limits: e.g., spices (30 kGy), fruits/vegetables (1 kGy)

How to Identify Irradiated Food

  • Irradiation Symbol: International symbol (Radura)

    • Food packages labeled as "Treated by Irradiation" to indicate treatment

Other Uses of Irradiation

  • Everyday products like band-aids and drinking straws

  • Micro lab supplies sterilized by gamma radiation