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Chapter 12: Food and Water Safety and Food Technology

Learning Objectives

  • LO 12.1: Describe microbial foodborne illnesses and practices that can prevent them.

  • LO 12.2: Identify the categories of foods that most often cause foodborne illnesses.

  • LO 12.3: Outline technological advances aimed at reducing microbial food contamination.

  • LO 12.4: Describe natural toxins, pesticide residues, and contaminants in food.

  • LO 12.5: Compare potential advantages and drawbacks of organic and conventional foods.

  • LO 12.6: Compare the safety of drinking water from different sources.

  • LO 12.7: Describe the uses and safety characteristics of some common food additives.

  • LO 12.8: Describe applications of food-safety practices in various settings.

  • LO 12.9: Summarize the advantages and disadvantages of producing foods through bioengineering.

Microbes and Food Safety

Foodborne Illness

  • Definition: Illness caused by microorganisms.

  • Types of Microbes:   - Pathogens: Caused by infection, e.g., Salmonella bacteria, hepatitis virus, worms.   - Intoxication: Caused by enterotoxins or neurotoxins.

  • Seriousness: Life-threatening for certain populations.

Dangerous Symptoms of Foodborne Illness

  • Some instances may be mild, resolving on their own; however, the following symptoms require medical attention:   - Bloody stools.   - Dehydration.   - Diarrhea lasting more than 3 days.   - Fever lasting more than 24 hours.   - Headache accompanying muscle stiffness and fever.   - Neurological symptoms: Numbness, muscle weakness, tingling sensations in the skin.   - Cardiovascular symptoms: Rapid heart rate, fainting, dizziness.   - Severe intestinal cramps.

  • Warning signs of botulism (a medical emergency):   - Difficulty breathing.   - Difficulty swallowing.   - Double vision.   - Weak muscles.

  • Resource: Complete home canning instructions are available from the USDA’s Complete Guide to Home Canning.

Food Safety from Farm to Plate

Safe Food Practices for Individuals

  • Food provides ideal conditions for microbial growth due to:   - Nutrients   - Moisture   - Temperature Range: 40°F to 140°F (4°C to 60°C)

  • Core Practices to Prevent Bacterial Growth:   - Clean: Wash hands and cooking spaces.   - Separate: Keep raw foods away from ready-to-eat foods to avoid cross-contamination.   - Cook: Ensure foods are cooked at proper temperatures; maintain at 140°F (60°C) or higher.   - Chill: Store foods at temperatures of 40°F (4°C) or below.

Foods Most Likely to Cause Illness

Animal Protein Foods

  • Ground meats: e.g., E. coli.

  • Stuffed poultry: e.g., Salmonella.

  • Raw and undercooked eggs: e.g., Salmonella.

  • Raw seafood: e.g., Worms, Norovirus.

  • Raw milk products: e.g., E. coli.

Other Foods

  • Raw produce: Potentially contaminated with eColi or Salmonella.

  • Sprouts: e.g., E. coli, Salmonella, Listeria.

  • Honey: Risk of Botulism.

  • Canned food: Risk of Botulism.

  • Lunch meats: High risk for Listeria.

  • Take-out foods and leftovers: Need caution.

Advances in Microbial Food Safety

Irradiation

  • Benefits:   - Controls foodborne illnesses.   - Acts as a preservation method.   - Controls insect infestations.   - Delays sprouting and ripening.   - Sterilizes food products.

  • Concerns: Public perception and acceptance issues.

Modified Atmosphere Packaging (MAP)

  • Benefits:   - Inhibits growth of aerobic microbes.   - Prevents discoloration.   - Mitigates spoilage of fats.   - Slows down the ripening of produce.

Toxins, Residues, and Contaminants in Foods and Water

Pesticides

  • Benefits vs. Risks: Balancing agricultural efficiency and health safety.   - Risks for vulnerable individuals (children, the elderly).   - Residues: Must be regulated by agencies such as the EPA, USDA, and FDA.   - Reference Dose: Level considered safe for exposure.   - Natural pesticides: Use in organic gardening.   - Persistent contaminants: Long-term residues present in the environment.

Ways to Reduce Pesticide Residue Exposure

  • Trim fat from meat and remove skin from poultry and fish.

  • Select intact fruits and vegetables.

  • Wash fresh produce with running water and use a soft brush.

  • Avoid biting into peels; use a knife to peel fruits like oranges or grapefruits.

  • Discard outer leaves of leafy vegetables like lettuce and cabbage.

  • Peel waxed fruits and vegetables; wax seals in residues.

  • Peel when necessary, though this can remove some nutrients.

  • Choose organically grown foods when possible.

  • Soaking produce in baking soda solution may help to remove pesticides.

Animal Drugs and Environmental Contaminants

  • Various Animal Drugs: Include antibiotics, bovine growth hormones (BGH), and arsenic.

  • Environmental Contaminants:   - Bioaccumulation and Toxicity: Heavy metals such as mercury and PCBs.

Water Safety and Sources

Overview

  • Drinking Water: Only 1% is considered potable; sources include surface water or groundwater.

  • Safety of Tap Water: Generally treated with chlorination to ensure safety.

  • Bottled Water: Not necessarily safer or healthier; potential contamination from microplastics.

Food Additives

Regulation and Usage

  • FDA Requirements:   - Manufacturers must prove the additive is effective.   - Additives must be measurable in the final product.   - Generally Recognized as Safe (GRAS) List: Substances safe for consumption.   - Consideration of Margin of Safety: Evaluating risks versus benefits.

Functions of Food Additives (Selected Examples)

Antimicrobial Agents (Preservatives)

  • Prevent microbial spoilage.

  • Examples: Acetic acid (vinegar), nitrates, sugar.

Antioxidants (Preservatives)

  • Delay rancidity and oxidative changes in foods.

  • Examples: BHA, BHT, vitamin C.

Artificial Colors and Flavors

  • Add color and flavor enhancement to foods.

  • Examples: Synthetic dyes like tartrazine, MSG for flavor enhancement.

Nutrient Additives

  • Include vitamins and minerals to improve nutritional value.

Food Additives and Their Other Functions

  • Bleaching Agents: Whiten flour or cheese.

  • Chelating Agents: Prevent off-flavors and rancidity, e.g., citric acid.

  • Stabilizing Agents: Maintain food texture and consistency, such as pectin and gums.

The Pros and Cons of Bioengineered Foods

Overview of Bioengineered Foods

  • Most people consume bioengineered food due to:   - Recombinant DNA (rDNA) Technology.   - Selective Breeding Techniques.

  • Positive Outcomes:   - Introduction of Golden Rice.   - Mass production of therapeutic proteins (insulin).   - Increased crop yields which can combat food shortages.

Concerns About GMOs (Genetically Modified Organisms)

  • Potential overdoses of nutrients or phytochemicals.

  • Residual herbicides affecting the environment.

  • Risk of outcrossing with wild populations.

  • Impact on wildlife and natural ecosystems.

  • Ethical debates surrounding genetic modification.

Summary

  • Review all content provided in the exam module for comprehensive understanding of food, water safety, and food technology topics discussed above.