1.1 - PRODUCTION & PROCESSING METHOD OF OIL

FST 548 PRODUCTION & PROCESSING METHODS OF FATS & OILS

Palm Oil Issues

  • Biodiversity in Indonesia: Home to one of the richest and most biodiverse rainforests in the world.

    • Endemic Species: Over 80 endemic species including endangered wildlife such as orangutans, elephants, and tigers.

  • Environmental Impact:

    • Rapid deforestation: 300 football fields of forest lost every hour in Southeast Asia for palm oil plantations.

    • Palm oil prevalence: Found in over half of all packaged items in supermarkets, from snack foods to soaps.

    • Loss of habitat: 3.5 M hectares of forest destroyed in 20 years, leading to a significant decline in orangutan populations (80% reduction in habitat, 6,000 lost annually) and the near extinction of Sumatran tigers (only 400 left).

  • Call for Action: Urgency to join the palm oil resistance movement to halt such devastation.

Production Methods for Fats & Oils

  • Basic methods to extract fats and oils from:

    • Animal sources

    • Marine sources

    • Vegetable sources

  • Major extraction methods include:

    • Rendering.

    • Pressing or Expelling.

    • Solvent Extraction.

  • Refining and Modifying Procedures: Follow extraction processes to refine and modify extracted oils.

Rendering Processes

  • Types of Rendering:

    • Lard: Obtained from pigs.

    • Tallow: Derived from beef.

    • Process: Involves heating fatty animal tissues to melt fat, allowing fat to rise above remaining tissues which are then separated by:

      • Skimming.

      • Centrifugation.

  • Types of Rendering:

    • Dry Heat Rendering: Cooks tissue under vacuum to remove moisture.

    • Wet Rendering: Uses hot water or steam to extract fatty tissues.

Pressing or Expelling

  • Mechanically extracts oil from oilseeds using presses and expellers.

  • Preparation involves:

    • Cooking or Grinding seeds to break down cell structure for easier oil release.

  • Considerations:

    • Excessive heat can lead to darker oil color due to pigments.

    • Clarification process: Involves filtering pressed oil through cloth.

    • Not all oil can be extracted solely through pressing.

Solvent Extraction

  • Purpose: Achieve higher oil yields compared to pressing alone.

  • Efficiency:

    • Residual oils after pressing range from 3-8%.

    • Mechanical means alone cannot extract all oils from seeds.

  • Solvent Characteristics:

    • Must have a narrow boiling point range (85-86°C), be liquid at lower temperatures, neutral to oil chemistry, stable with metal surfaces, and non-toxic.

  • Common Solvents Used:

    • Light petroleum hydrocarbons like hexane, 2- & 3-methylpentane, cyclohexane, etc.

  • Extracting Method:

    • Solvent percolates through seeds, then distilled to recover the solvent for reuse. Remaining meal is processed for animal feed.

Refining of Oils

  • Goals of Refining: Maximize the elimination of unwanted components (non-triacylglycerols) while preserving valuable nutrients and antioxidants.

  • Processes: Combine physical and chemical methods to remove undesirable components from crude oil.

  • Components to remove:

    • Free Fatty Acids (FFAs).

    • Phosphoacylglycerols.

    • Sterols.

    • Pigments (chlorophyll), flavors, waxes, heavy metals, pesticides, hydrocarbons.

Steps in Conventional Refining

  • Steps:

    1. Degumming: Removal of phosphatides.

    2. Deacidification (Alkali Neutralization): Removal of FFAs.

    3. Bleaching: Color removal.

    4. Deodorization: Distillation of unwanted odors and flavors.

Degumming Process

  • Phospholipids: Present in all vegetable oils, becomes gummy or slimy when wetted, can be removed through hydration.

    • Major source of lecithin is soybean oil, widely used for emulsifying.

  • Types of Gums:

    • Hydratable: Easy to remove.

    • Non-Hydratable: More challenging and sometimes require acid to render them hydratable.

Deacidification and Neutralization

  • Removal of Free Fatty Acids (FFAs) through the addition of alkali (typically NaOH).

  • Methods:

    • Batch or continuous processes.

    • Neutralization, washing (to remove soap traces), and drying (to eliminate moisture).

Bleaching Process

  • Color changes during degumming and neutralization, necessitating bleaching to improve market appeal.

  • Methods for Bleaching:

    • Adsorption on solids (like charcoal).

    • Heating.

    • Use of bleaching chemical agents.

Deodorization Process

  • Involves stripping odoriferous compounds using live steam at elevated temperatures and reduced pressure.

  • Purposes:

    • To remove undesirable odors and residual FFAs.

    • To enhance flavor stability during shelf life.