Food Chain, Production, Preservation, and Additives

Posted on Jan 30, 2025 in Geology

The Food Chain

The food chain is a representation of the action of eating in nature, in which matter and energy shift from one organism to another. It consists of:

  1. Producers: Plants and algae (autotrophs)
  2. Primary Consumers: Herbivores (heterotrophs)
  3. Secondary Consumers: Carnivores (heterotrophs)
  4. Decomposers: Some bacteria and fungi

Food Sources for Humans

An increasing population, caused by improved sanitary conditions and advancements in medicine, has led to an increased need for food. This is achieved by:

  1. Increasing agricultural production: Achieved through the use of high-yielding plants, agrochemicals (fertilizers and pesticides), greenhouses, and genetically engineered plants (Green Revolution).
  2. Intensive farming: Involves raising large quantities of a single type of livestock using housing techniques and feeding them with specialized feed.
  3. Greater use of marine resources.

Negative Effects of Intensive Food Production

  1. Agrochemicals: Used in the field, nitrates and phosphates can lead to eutrophication, where aquatic plants grow excessively, consuming oxygen in the water.
  2. Genetically Modified (GM) Foods:
    • Benefits: Pest resistance and enhanced development.
    • Disadvantages: Potential for allergies and antibiotic resistance.
  3. Feedlot Cattle Feed: The use of anabolics like clenbuterol to fatten cattle, and feeding livestock with offal, can lead to diseases like mad cow disease (BSE), which is fatal to them.
  4. Fish Parasites: The appearance of fish infected by a parasitic worm (Anisakis) can cause severe and potentially fatal allergies in humans. The worm is only killed if cooked above 60 degrees Celsius or frozen at -20 degrees Celsius for 24 hours.

Food Contamination and Spoilage

Fresh foods can become contaminated through biological or chemical means, or they can degrade.

  • Biological contamination: Caused by viruses, bacteria, etc. It can lead to parasitic diseases (tapeworm, trichinosis), infectious diseases (cholera, typhoid), and toxin-related illnesses (botulism).
  • Chemical contamination: Food poisoning from chemicals like heavy metals (e.g., mercury).
  • Degradation: Enzymes accelerate the decomposition of food.

To prevent food degradation, various preservation techniques are used. A preserved food is one that has undergone adequate treatment and is kept under proper sanitary conditions for a variable time.

Methods of Food Preservation

  1. Cold:
    • Chilling: (0 to 6 degrees Celsius)
    • Freezing: (-20 to -30 degrees Celsius) stops deterioration.
  2. Radiation: Prevents root sprouting and delays fruit ripening.
  3. Heat:
    • Pasteurization: (70-90 degrees Celsius) for a few seconds, destroys yeasts, molds, and some bacteria.
    • Sterilization: (110 degrees Celsius) for longer than pasteurization, destroys bacteria, yeasts, molds, and spores. Food lasts longer but its taste and composition may be altered.
    • UHT (Ultra-High Temperature) Sterilization: (150 degrees Celsius) for less than 1 second, provides a much longer shelf life without significantly altering taste or composition.
  4. Water Removal:
    • Drying: Food is exposed to sun or air and eventually dehydrates (e.g., sausage, salami, peppers).
    • Lyophilization: Food is quickly frozen and then undergoes sublimation.
    • Salting and Brining: Salt surrounds the food, and water leaves by osmosis, drying it (e.g., cod, bonito, ham, sausages, eggs, dried tuna).
  5. Other Procedures:
    • Smoking: Food is subjected to the heat of smoke (e.g., salmon).
    • Pickling: The acidity of vinegar kills microorganisms (e.g., marinated sardines).
    • Marinating: A solution of garlic, paprika, salt, oil, vinegar, thyme, etc. (e.g., meat).
    • Sugaring: Used for jams, quince, fruit, etc.

Food Additives

Food additives are substances added to foods to promote preservation, enhance color, improve properties, or facilitate manufacturing processes.

  • Dyes: Unnecessary from a nutritional standpoint.
  • Colorings: Enhance or provide a new color to food.
  • Preservatives: Prevent the appearance of organisms harmful to health.
  • Antioxidants: Prevent oxidation (caused by oxygen in the air).
  • Thickeners: Increase viscosity.
  • Stabilizers: Inhibit changes in the shape of food.
  • Emulsifiers: Emulsify fats and improve texture.
  • Gelling Agents: Help form gels.
  • Flavor Enhancers: Intensify taste or mask unwanted flavors.
  • Sweeteners: Reinforce the sweetening power of food.