Vegetative oil

Learning Objectives

  • Understand the importance and processing of vegetable oil in manufacturing soaps and detergents.

  • Comprehend the production process of soaps and detergents.

  • Identify major processes in South Africa that use coal and understand the production processes involved.

  • Grasp the cement production process.

Vegetable Oils Overview

Definition

  • Vegetable oils (plant oils) are triglycerides extracted from plant seeds or fruits.

  • A triglyceride is an ester derived from glycerol and three fatty acids.

Extraction Process

  • Involves physical changes or unit operations in the extraction phase.

  • Chemical conversions occur during the refining or further processing stages.

Composition of Vegetable Oils

Hydrocarbon Structure

  • Vegetable oils consist of hydrocarbons.

  • Unsaturated oils: Contain carbon joined by double carbon-carbon bonds, detectable with bromine solution.

  • Saturated oils: Comprise single carbon-carbon bonds.

Health Implications

  • Unsaturated oils tend to be healthier than saturated oils, impacting health based on their form at room temperature.

Testing for Unsaturation

Bromine Test

  • Bromine water is added to the oil; a color change indicates saturation:

    • Colorless = Unsaturated oil

    • Red = Saturated oil

  • Higher amounts of bromine indicate greater unsaturation in the oil.

Iodine Value Measurement

Definition

  • The iodine value determines the degree of unsaturation in oils, fats, and waxes.

  • Unsaturated oils can absorb iodine; saturated oils cannot, resulting in an iodine value of zero.

Classifications by Iodine Value

  • Oils categorized based on iodine values (IV):

    • Drying oils (IV > 150): Linseed, tung.

    • Semi-drying oils (IV 100 - 150): Soybean, sunflower.

    • Non-drying oils (IV 70 - 100): Canola, olive.

Types of Vegetable Oils

Examples

  • Olive oil, avocado seed oil, coconut oil, sunflower oil, etc.

Global Consumption Trends (2020)

  • Notable oils: Soybean oil (28.6%), Palm oil (36.2%), Sunflower oil (12.8%).

Edible vs Non-Edible Oils

Characteristics

  • Edible oils: Used for cooking and consumption; contain nutritional elements and require minimal processing.

  • Non-edible oils: Used industrially (e.g., in soaps, fuels) and may need chemical processing.

Applications of Vegetable Oils

  • Edible oils: Cooking, flavoring.

  • Non-edible oils: Industrial applications, including biodiesel production and cosmetics.

Vegetable Oil Production Steps

Major Steps

  1. Preparation Process: Planting, harvesting, cleaning of seeds.

  2. Pressing Process: Crushing seeds to extract oil, resulting in raw pressed oil and press cake.

  3. Extraction Process: Methods include mechanical (pressing) and chemical extraction (using hexane).

  4. Refining Process: Cleaning oil involves degumming, neutralization, bleaching, winterization, and deodorization.

Detailing the Pressing Process

  • Seeds crushed between rotating screw and stationary ring in an expeller.

Extraction Methods

Mechanical Extraction

  • Cold press: Pressed at room temperature, retaining higher nutritional value.

  • Hot press: Involves roasting, producing less nutritious oils.

Chemical Extraction

  • Involves hexane to remove oil from pressed cakes.

Refining Steps

Key Processes

  • Degumming: Removes gums using water/acid.

  • Neutralization: Removes fatty acids with alkali solution.

  • Bleaching: Removes color pigments.

  • Winterization: Removes wax components.

  • Deodorization: Uses steam to eliminate odors.

Health Concerns Related to Vegetable Oils

Saturated vs Unsaturated Fats

  • Saturated fats can raise cholesterol levels, linked to heart disease.

  • Unsaturated fats (especially omega-3) are beneficial, helping to lower cholesterol.

Fatty Acid Classification

  • Saturated, unsaturated (monounsaturated, polyunsaturated).

  • Importance of omega-6 and omega-3 fatty acids in diet.

Hydrogenation of Vegetable Oils

Process Overview

  • Transform liquid unsaturated oils into solid forms by adding hydrogen, increasing their shelf life and melting point (e.g., margarine).

Animal Fats and Waxes

Types of Fats

  • Tallow, lard, caul fat, and leaf fat.

Industrial Uses of Oils, Fats, and Waxes

Applications

  • Soaps, greases, paints, culinary uses (e.g., coconut oil in soaps and detergents).

Quality Control Parameters

Key Measures

  • Free Fatty Acid (FFA) content, Iodine value, Peroxide value, p-Anisidine value, and more.

  • Each parameter ensures quality and stability of oils.

Waste Management in Oil Production

Key Concerns

  • Managing organic waste and by-products effectively for energy generation or commercial by-products.

Techniques to Minimize Waste

  • Improving production/storage control and utilizing residues for animal feed or soil amendments.