food and nutrition

• Shortening: fat coats flour to prevent it from absorbing water and reducing gluten devolpment. this alters the texture to create a characteristic crumbs and dough from being elastic. examples: pastry, cakes, shortbread.
• thermal properties: fat has a melting point which differs depending on type of fat. the fat determines the melting point of formulation. heat transfer allows fat to transfer during cooking. examples: vegetable oils, for salad dressing and fat like butter is lard and so solid at room temp, used for chocolate and icing.
• appereance: fat can be liquid or solid at room temp. its used to create a glossy or moist texture. aids in browning process, making food more appealing, eg butter on toastie.
• taste and flavour: each fat has a distintive taste, and flavour such as butter, olive oil, coconut oil. it can also absorb flavours from other food. example is butter used in butter cake for taste.
• aroma: compounds are dissolved in fat and released when cooked, higher the fat the more pleasent aroma
• texture: fat adds texture to food products. it gives food a lubricating mouthfeel by coating the tounge with oil or fat, which can make flavour last longer. it is responsible for creaminess of many products such as icecream, shakes, some desserts and sauces.
• viscosity: of saturated fats are straight -line up so they are more viscous or solid. mono-saturated fats bends so they are not viscous or are a liquid. its a property used in salad dressing and sauces.
• what are the functions of fat?

  provides heat, provides energy, protects bones and vital organs, provides a vessel for fat soluble vitamens (A,D,E,K)
• what are the properties of saturated fat

  • no double bonds between carbons, increases LDL (bad chloresteral), solid at room temp.
• what are food examples of staurated fats?

  meat, diary, coconut, palm oil and cheese
• what are the properties of mono-unsaturated fat?

  • one double carbon bond, decreases the LDL but increases HDL (good chloresteral), omega fatty acids in this group.
• what are food examples for mono-unsaturated fat?

  seed oils: sunflower, corn, and oily fish
• what are the properties of poly-unsaturated fats?

  • many double carbon bonds, liquid at room temperature
• what are food examples of poly-unsaturated fats?

  oilve oil, peanut oil, and canola oil
• what are the properties of trans fat?

  • worst fat, found naturally in some products like meat and dairy, occurs when liquid vegetable oils are partially hydogenated or soliodified during processing.
• what are some food examples of trans fat?

  proccessed food, cakes, pasteries, naturally found in meat and dairy
• properties of chlorestoral

  • 2 types; LDL which is made consumed in food and HDL is made by the body
• what occurs when fat is overconsumed?

  increase the risk of heart disease and high blood chlorestrol levels, linked to obesity, and higher risk of cancer (colon, prostate)
• what occurs when fat is under-consumed?

  deficiences in fat soluable vitamens (A,D,E,K) which can lead to different effects e.g sight because of vitamen A.
• what is hydrogenation?

  a process in the food industry that converts liquid fat (e.g vegetable oil) to a semi-solid, fat (e.g magerine). This is done by controlling the number of double carbon bonds through processing such as heat and incorperating hydrogen gas.
• what is Oxidation rancidity? 


  this occur when fat is exposed in the air and perioxides decompose. these are the result of oxidation of unsaturated fats and result in aldehydes, ketones, and hydro-carbons being produced. these chemicals are responsible for the oudours and flavours in rancid foods
• what is hydrolytic rancidity?

  this occurs with moisture, but with absence of air. the enzymes found in the natural plant oils between the oil and moisture. hydrolysis splits fatty acid chains allowing the free fatty acids to undergo further auto-oxidation.
• what is chocolate bloom?

  appears on the outside of chocolate and is made up of fat. it changes the texture and apperance. many factors can contribute to fat bloom such as temperature change, storage conditions, and mixture of fat.
• how can fat bloom/chocolate bloom be avioded?

  • storing chocolate in a cool dry place with a consistent temperature to aviod melting and seperation.
• what fat is this?

  • mono-unsaturated

  
• what fat is this?

  • saturated

  
• what fat is this?

  • poly-unsaturated