Fats, Oils, and Waxes: History & Overview

Fats, Oils, and Waxes Overview

• Fats, oils, and waxes are integral to human life, serving roles such as food staples, protective coatings, and essential ingredients in candles and cosmetics.
• These naturally occurring lipids have wide applications, and their extraction methods evolved to meet the growing demands of various industries.

History of Fats and Oils

• 1826: Began with the erection of a cottonseed mill in South Carolina, though the industry expanded after 1865.
• 1850: Caustic soda was introduced from France to remove free acids from oil.
• 1850: Millers recognized the value of linters and hulls, using them for cattle feed.
• 1885 (Chicago): The oleomargarine(margarine) industry boosted the cottonseed-oil industry.
• 1893: Discovered oil deodorization could be achieved by blowing steam at high temperatures; deodorization under reduced pressure improved flavor and odor.
• 1900: The discovery that oils could be upgraded via hydrogenation revolutionized the oil and fat industry, leading to hydrogenated shortenings and made lesser-known oils marketable.

History of Waxes

• Early 1990s: The Brazilian wax was introduced in New York City.
• 1960s: Wax strips became widely used for hair removal.
• 1940s-1960s: Wax-based hair removal solutions gained popularity during World War II due to nylon shortages.
• Early 1900s: Dr. F. Felix Gouraud invented the first depilatory cream.
• 1894: Barbour established J. Barbour & Sons and began manufacturing wax-treated cotton garments.
• 2005: Significant modification to paraffin wax production occurred when cupro-ammonia was removed from the process.

Companies

• Nutriasia: A Philippine privately held multinational food processing company.
• Oleo-Fats Inc: A leading cooking oils, fats, and food ingredients supplier in the Philippines.

Fats and Oils: Chemical Composition and Properties

• Both fats and oils are lipids, insoluble in water but soluble in organic solvents, due to their hydrophobic hydrocarbon chains of 14 to 22 carbon atoms or more.
• Composed of three fatty acids esterified to a glycerol molecule, forming a structure known as a triglyceride.

Components of Fats and Oils

• Glycerol is an organic compound, also called propane-1,2,3-triol, where each of its three hydroxyl groups are esterified via dehydration synthesis and linked to fatty acids.
• Fatty acids are long hydrocarbon chains with an even number of carbons, a methyl group (-CH3) on one end, and a carboxylic acid functional group (-COOH) on the other end.
• Fatty acids can be saturated (no double bonds) or unsaturated (with double bonds).
• Unsaturated fats typically take the cis configuration, creating a bent structure, but hydrogenation transforms them into the trans configuration, creating a straight form.
• Fats are either solid or semi-solid at room temperature, while oils are generally liquid.
• Fats remain solid due to the abundance of saturated fatty acids.
• Saturated fats are more stable and have higher melting points because molecules can pack closely together due to lack of kinks or bends.
• Oils contain a higher proportion of unsaturated fatty acids; the kinks or bends create gaps, making them less compact and resulting in lower melting points.
• Fats are generally of animal origin or hardened vegetable oils, while oils are plant-based or derived from fish.

Classification of Oils

• Edible: Sunflower and canola oil
• Inedible: Castor and linseed oil

Characteristics Distinguishing Oils

• Distinctions come from their source, smoke point, and the amount and type of fatty acids.

Sources of Fats and Oils

• Plant-derived sources include seeds (sesame, sunflower, flaxseed), fruits (avocado, coconut, olives), nuts (peanut, almond, cashew), and grains (corn, soybean, wheat).
• Animal sources include pork, beef, fish, and poultry.

Smoke Point of Fats and Oils

• The temperature at which oil starts smoking or burning; related to the amount of free fatty acids (FFA) and saturated or unsaturated fatty acids.
• Higher FFA (related to spoilage and rancidity) makes the oil burn faster.
• Oils with more saturated fatty acids typically have higher smoking points.
• Refined oils have higher smoke points compared to unrefined oils due to the removal of impurities and free fatty acids.
• Oils with higher smoking points are often used for frying at high temperatures, while those with lower smoking points are used for salad dressings or low-heat cooking.

Fatty Acids

• The type and amount distinguishes oils and fats.

Other Classifications of Oils and Fats

• Virgin oils are obtained, without altering the nature of the oil, by mechanical procedures and heat applications and may be purified by washing, settling, filtering, and centrifuging only.
• Cold-pressed oils are obtained, without altering the oil, by mechanical procedures without the application of heat, purified by washing, settling, filtering, and centrifuging only.
• Refined oils are obtained by using solvents and other extensive processes to remove impurities and unwanted aromas.

Fat and Oil Synthesis and Decomposition

• Synthesis (Esterification): Triglyceride synthesis where hydroxyl groups of glycerol interact with hydrogen in the hydroxyl group of the fatty acid, forming ester bonds, also considered a dehydration synthesis (or condensation) reaction producing three water molecules.
• Lipases are enzymes catalyzing this reaction.
• Decomposition (Hydrolysis): Breakdown of fats when exposed to water, ester bonds are hydrolyzed, releasing free fatty acids (FFA) and a free glycerol molecule.
• Lipases catalyze the hydrolysis of ester bonds in a triglyceride.

Waxes

• Waxes are complex mixtures of esters of long-chain carboxylic acids and long-chain alcohols.
• Contain R' and R representing long chain carbons of approximately 30 carbons, making it an extremely hydrophobic lipid with a high degree of water repellency.
• Serve as protective coatings for both plants and animals.
• In plants, waxes coat stems, leaves, and fruit.
• In animals, waxes are found on fur, feathers, skin, and as protective coatings produced by some insects.
• Mineral waxes are obtained from petroleum (such as peat, coal, and lignite).
• Mineral waxes are not true waxes (esters) but are classified as such because of their physical characteristics.

Properties of Waxes

• Solid at room temperature.
• Low melting point.
• Water repellent (hydrophobic).
• Insoluble in water; soluble in nonpolar organic solvents.

Unit Processes: Oilseeds

• Seed Cleaning and Preparation:
  • Freshly harvested oilseeds must be thoroughly cleaned to remove trash, dirt, and debris to prevent ignition during drying and to avoid accelerating seed heating in storage.
  • Seeds are dried to reduce moisture content to about 7-10% for long-term storage, preventing fermentation and spoilage and to maintains lower levels of free fatty acid.
  • Magnetic separators equipped with magnets and electronic metal detectors remove tramp metal.
• Dehulling (Decortication):
  • Process of removing the hull or outer layer of seeds by cracking seeds using mechanical force in impact dehullers.
  • Removal of the outer covering is achieved through screening to separate larger hulls from the "meat" of the seeds.
  • Aspiration uses airflow/pressure to separate materials based on density.
• Cold Dehulling (Traditional:)
  • Requires 24-72 hours of tempering.
  • Tempering helps the hulls gain moisture and loosen the bond between the hull and the meat of the seed, requiring pre-cleaning and cleaning processes.
• Hot Dehulling (Modern):
  • Newly developed systems can crack and loosen hulls without the need to temper the seed.
  • Involves heating the seeds to loosen the kernel, done with aspiration steps that uses heated air and specialized equipment to improve hull removal.
  • Appropriate for high moisture content seeds which have harder hulls can bypass the tempering process.
• Heating/Conditioning:
  • After dehulling, seeds are subjected to steam injection to soften the seed and increase its moisture content.
  • Traditional Heating: Seeds heated to around 74°C (165°F) activates phospholipases.
  • Modern Practice: Seeds now heated to below 57°C (135°F) or above 85°C (185°F) to avoid phospholipase activity, which can interfere with oil degumming and refining.
• Flaking:
  • Conditioned seeds are passed through flakers, reducing the seed thickness to increase the seed's surface area.
  • Flakes improves the oil's acessibility for solvent extraction by breaking open cells and releasing oil.
• Extraction (Mechanical):
  • Hard Pressing: Method often used for seeds with higher oil content with mechanical pressure, also used for seeds like castor or for small-scale or low-volume extraction.
  • Hydraulic Presses: Still used for industrial crops (like castor seeds) or in smaller scale operations, especially where solvent extraction may not be available due to safety or cost concerns.
• Semi-Chemical:
  • Prepress-Solvent Extraction: Seeds with high oil content are first prepressed and the remaining oil is extracted using solvents (hexane) which helps to reduce the residual oil content in the press cake to less than 1%.
• Chemical:
  • Direct Solvent Extraction: For seeds with lower oil content, a direct solvent extraction method is used and can achieve less than 0.75% residual oil content in the meal.
• Solvent Extraction:
  • This process removes a constituent contained in a solid with the use of a liquid solvent using diffusion, here the solvent dissolves the oil from the seed.
  • Hexane: Widely used in solvent extraction because due to its features.
• Shallow Bed-type Extractors: Uses a 0.5-1.5 meter thick layer of collets or flakes extracted by countercurrent flow of miscella.
• Diffusion Belt-Type Extractors: Uses deeper beds of collets/flakes on a woven mesh/pan belt, drenched with miscella countercurrently.
• Deep Bed-Type Extractors (Carousel Extractors): Pie-shaped cells filled with collets/flakes extracted in a countercurrent flow.
• Desolventizing-Toasting: Used in oilseed processing to remove residual solvents from the extracted marc and improves nutrition.
• Miscella Refining: Removing hexane from the oil using distillation, concentrating the oil to about 65%, followed by alkali refining to remove free fatty acids (FFA), evaporating the remaining solvent, and any leftover gases are passed through a mineral oil stripper to recover final traces.

Olive Oil Extraction

• Traditional: Stone "edge rollers" or metal grinders are used to crush olives (including seeds) to form a paste, followed by mxing and heating to help oil coalesce, compressed to obtain an oily liquid.
• Modern: Olives and seeds are crushed using hammer mills, paste is mixed and heated to aid oil extraction, uses bladder presses and desolventized pomace to fuel steam boilers.

Preparation of Animal-Derived Fats

• Involves sorting, cleaning/washing, and separating edible and inedible fats, also cutting to smaller pieces to improve heat penetration.
• Refining has two main types: wet and dry rendering processes

Wet Rendering

• Uses water or steam to heat the animal fat done either by batch processing, where raw material is precut and placed in an autoclave OR involving minced raw material separated into solids and liquids through mechanical methods.

Dry Rendering

• Process involves indirect heating without water, rotating agitator, liberating in 1.5-2 hours for low quality and slower production.

Waxes Extraction Processes

• Extraction processes vary from gently boiling to solvent processing.
• Process for Beeswax is via honeycombs, Carnuba wax (from Palm tree) is a myricyl cerotate, Spermaceti (From whale head cavity) is cetyl palmitate.
• Ozocerite: Naturally occurring mineral wax.
• Paraffin Wax: From lubricating-oil fractions via distillation.
• Montan Wax: Extracted from bituminous lignite or shale.
• Candelilla Wax: 3rd most important U.S. wax (by tonnage), extracted from Candelilla plant (Mexico, Southwestern U.S.).

Refining Process

• Refing allows for purification that remove residues and undesirables, and minimizes oil loss
• Objectives: Removal of multiple fatty contaminants and improve aesthetics.
• Chemical Refining Processes generally starts with degumming generally, also alkali Neutrilization (treating with alkali solution), then decolorisation to reduce color to remove impurities.
• Process then leads to deodorization (using vacuum steam distillation), finally ending with Winterization to improve quality due to triglyceride removals.

Hydrogenation

• Reaction converts unsaturated fats into saturated fats by introducing hydrogen gas and increasing the saturation of fatty acids, enhancing the oxidative stability of the oil.

Standards for Oils and Fats

• Based from the CODEX
• Concerns for Heavy Metal Contaminants (lead and arsenic), and Coloring

Table of Maxium Allowable Levels

• Curcumin/Tumeric - 5mg/kg
• Beta-Carotene - 25mg/kg
• Annatto Extracts - 10mg/kg
• and others per table

Standards of Taste & Impurities

• Insoluble Impurities
• Soap Content
• Iron and Copper
• Acid Value
• Peroxide Value

Industrial Applications - Biodiesels

• Transesterification is when triglycerides (fats or oils) react with an alcohol to produce biodiesel, specifically fatty acid methyl esters (FAME), and glycerol (byproduct).

Key Considerations for Biodiesel Prodution:

• Molar Ratio. Typically, a 6:1 methanol-to-oil ratio is used
• Catalyst Selection using strong or acid bases.
• Temperature typically between 50-60 degrees C
• Purity of process. The product must be washed