EMAK RAOT

• Triglyceride


  Compound of fatty acids and glycerol
• Lipids


  Group of organic compounds that triglycerides belong to
• Fatty acids


  • Made up of a chain of carbon atoms, with a methyl group at one end and an acid group at the other
  • Each atom in between has either one or two hydrogen atoms attached
• Formation of triglyceride


  Three fatty acids combine with one molecule of glycerol
• Fat


  All edible lipids that are solid at room temperature
• Oil


  All edible lipids that remain liquid at room temperature
• Saturated fat


  Fatty acid that has all the hydrogen atoms it can hold
• Unsaturated fat


  Some of the hydrogen atoms are missing and have been replaced by a double bond between the carbon atoms
• Monounsaturated fatty acid


  Fatty acid with one double bond
• Polyunsaturated fatty acid


  Fatty acid with more than one double bond
• All fats contain both saturated and unsaturated fatty acids but are usually described as 'saturated' or 'unsaturated' according to the proportions of fatty acids present
• Triglyceride


  Compound of fatty acids and glycerol
• Lipids


  Group of organic compounds that triglycerides belong to
• Fatty Acids


  • Made up of a chain of carbon atoms, with a methyl group at one end and an acid group at the other
  • Each atom in between has either one or two hydrogen atoms attached
• Formation of triglyceride


  Three fatty acids combine with one molecule of glycerol
• Fat


  Edible lipid that is solid at room temperature
• Butter is often described as a 'saturated' fat because it has more saturated fatty acids than unsaturated fatty acids, while most vegetable oils are described as 'unsaturated' as they have more monounsaturated or polyunsaturated fatty acids
• Oil


  Edible lipid that remains liquid at room temperature
• Hydrogenation


  Process of adding hydrogen atoms to some of the double bonds in unsaturated fatty acids to 'harden' vegetable and fish oils
• Saturated fat


  Fatty acid that has all the hydrogen atoms it can hold
• Unsaturated fat


  Some of the hydrogen atoms are missing and have been replaced by a double bond between the carbon atoms
• Classification of fats and oils according to culinary use

  • Table fats - spreads (butter and margarine)
  • Cooking oils - for frying
  • Shortening - plastic fat (baked products)
  • Salad oils, corn oils and soybean oil
• Monounsaturated fatty acid


  Fatty acid with one double bond
• Classification of fats and oils according to appearance

  • Visible fat - visually distinctive (i.e., butter, tallow, coconut oil, etc.)
  • Invisible fat - indistinguishable unless separated by chemical means (i.e., avocado, egg yolk, lean meats); nutritionally significant but not for culinary use
• Polyunsaturated fatty acid


  Fatty acid with more than one double bond
• All fats contain both saturated and unsaturated fatty acids but are usually described as 'saturated' or 'unsaturated' according to the proportions of fatty acids present
• Melting point of fats and oils

  • Temperature at which fat becomes liquid
  • Determined by the strength of bonding forces between fatty acids within crystals
  • Increases as the number of carbons increases and the number of double bonds decrease
  • Fats that have higher melting points are ideal for cooking
• Butter is often described as a 'saturated' fat because it has more saturated fatty acids than unsaturated fatty acids, while most vegetable oils are described as 'unsaturated' as they have more monounsaturated or polyunsaturated fatty acids
• High melting point


  Remains solid at room temperature; requires more heat to melt; high boiling point
• Low melting point


  Requires less heat to melt; liquid at room temperature; low boiling point
• Factors influencing melting point

  • Degree of saturation (highly saturated vs unsaturated)
  • Chain Length (length of carbon chain)
  • Hydrogenation (Addition of H+ at unsaturated points)
• Hydrogenation


  Process of adding hydrogen atoms to some of the double bonds in unsaturated fatty acids to 'harden' vegetable and fish oils
• Plasticity


  Property of a fat that allows it to be molded or pressed into various shapes without breaking; ability to retain its shape
• Plastic range


  The temperature range over which the fat remains solid and has a pliable, creamy texture
• Smoke point


  The temperature at which the oil is decomposed and where possibly toxicological relevant compounds (i.e., acrolein, polycyclic aromatic hydrocarbons (PAHs), free radicals) are formed
• Classification of fats and oils according to culinary use

  • Table fats - spreads (butter and margarine)
  • Cooking oils - for frying
  • Shortening - plastic fat (baked products)
  • Salad oils, corn oils and soybean oil
• Ways oils decompose during heating

  1. Pyrolysis (thermal breakdown)

  2. Oxidation

  3. Hydrolysis

  4. Reaction with Food Residue
• Rancidity


  Spoilage of fat caused by the process of oxidation, which is a reaction between unsaturated fatty acids and the oxygen in the air
• Classification of fats and oils according to appearance

  • Visible fat - visually distinctive (i.e., butter, tallow, coconut oil, etc.)
  • Invisible fat - indistinguishable unless separated by chemical means (i.e., avocado, egg yolk, lean meats)
• Types of rancidity


  • Hydrolytic - enzymatic; due to hydrolysis of triglycerides that liberates free fatty acids (saturated fatty acids) and glycerol; causes "soapy flavor"
  • Oxidative - due to oxidation of unsaturated fatty acids in fat by peroxides that in turn results in the formation of other molecules such as ketones, aldehydes, etc. producing the rancid odor and flavor