food tech 3.2

• Protein


  • One of the 3 macronutrients
  • Made from amino acids
• Amino acids


  • Peptide
  • Protein
  • 20 amino acids but not all can be made in the body, we can only take it in from the food we eat
  • Essential amino acids
• Essential amino acids


  Amino acids that cannot be made in the body, we can only take it in from the food we eat
• Essential amino acids needed

  • 10 for children
  • 8 for adults
• Children need more essential amino acids


  Because they require more growth than adults
• Protein functions


  • Normal growth and maintenance of health, bones and muscles
  • Provides energy
  • Important substances in the body are made from protein: hormones, enzymes, antibodies
• Protein sources


  • Animal products (very high levels)
  • Wheat and grains (low levels)
  • Soya bean (high levels)
• High biological value (HBV)


  Contains all 10 essential amino acids (animal products)
• Low biological value (LBV)


  Lacking 1 or more essential amino acids (not animal source)
• HBV protein sources


  • Meat (chicken), dairy (milk), fish, cheese, soya bean, tofu (made of soya bean)
• LBV protein sources


  • Grains (rice), wheat, beans, legumes, kidney bean, lentils
• Protein complementation


  2 or more LBV protein together
• Protein complementation


  • Beans on toast (both LBV)
• Protein alternatives for vegans/vegetarians

  • Tofu
  • Omni products (plant based)
  • Textured vegetable protein (TVP)
• Protein deficiency


  • Kwashiorkor (swollen belly)
  • Marasmus (mainly seen in children)
• Excess protein is stored on body as fat
• Chemical structure of fat

  3 fatty acids = triglyceride (glyceride) (fats)

  
• Types of fat


  • Saturated fats (solid at room temperature)
  • Unsaturated fats (liquid at room temperature)
  • Polyunsaturated fats (2 or more double bonds, unstable)
  • Monounsaturated fats (one double bond, stable)
• Saturated fats


  • Butter, lard (animal fat), vegetable spread, beef dripping, cacao butter
• Polyunsaturated fats


  • Sunflower oil, fish, walnuts, corn oil, Canola oil
• Monounsaturated fats


  • Avocados, almonds, sesame seed, pumpkin seed, peanut butter
• Essential fatty acids


  • Omega-3 (found in fish, nuts, seeds, plant oils)
  • Omega-6 (found in fish, nuts, seeds, green vegetables)

  
• Trans fat


  Made with process called hydrogenation (adding hydrogen in food to make it more stable), can lead to heart diseases and stroke
• Natural fats


  Opposite of trans fat, typically found in natural foods (good fat)
• Visible fats


  • Animal (butter, lard, sheep fat on meat)
  • Plant (Margarine, Coconut Cream, Cocoa butter)
• Invisible fats


  • Animal (cheese, sausages, pastries)
  • Plant (chocolate, donut, biscuit)
• Fat functions


  • Insulate our bodies
  • Protect our organs (how organs are wrapped around fat)
  • Provide energy
  • Make us look glowing in general (nails, hair etc.)
• Fat deficiency


  • Low levels of fat soluble vitamins (A, D, E, K)
  • Easily bruised, painful bones
• Excess fat


  • Obesity
  • Coronary heart disease
  • Low cholesterol
• Types of carbohydrates


  • Simple carbohydrates (monosaccharides, disaccharides - sugars)
  • Complex carbohydrates (polysaccharides - starch, fibre)
• Simple carbohydrates


  Quick release of energy, not really healthy (causes diabetes, cavities), soluble in water
• Monosaccharides


  • Glucose (fruits, vegetables)
  • Fructose (fruits, vegetables, honey)
  • Galactose (milk)
• Disaccharides


  • Maltose (barley, glucose + glucose)
  • Sucrose (sugar cane, sugar beet, glucose + fructose)
  • Lactose (milk, glucose + galactose)
• Complex carbohydrates


  Slow release of energy, feels more full, insoluble (starch, fibre)
• Starch


  Chains of glucose, not water soluble so they can be digested
• Non-starch polysaccharide (NSP)


  Also called dietary fibre, absorbs water, travels in body chemically unchanged
• NSP functions


  • Keep the muscles in our bowels (intestines) working properly
  • Prevent constipation
  • Promote growth of healthy bacteria in bowels
• Types of polysaccharide


  • Starch (cereal)
  • Dietary fibre (wholegrain cereal)
  • Pectin (citrus fruits)
  • Dextrin (formed when starchy foods are baked/toasted)
• Carbohydrate functions


  • Makes us full
  • Provides energy
  • Reduce cholesterol
  • Get rid of waste products
• Summary of carbs


  • Sugar (chocolate, honey, cakes, syrup, grapes, jam)
  • Starch (bread, rice, pasta, potatoes, breakfast cereals)
  • NSP (Wholemeal bread, peas, apricots, beans, bran products)