Chapter 15.4 Rx of Triglycerides

1. Hydrogenation of Oils Industrial process to convert liquid oils into solid fats Chemical Rx that converts double (cis) bonds into single bonds needs H2 gas, Ni catalyst , heat Complete Hydrogenation All double bonds become single bonds Incomplete/Partial Hydrogenation Some (cis) double bonds remain Some (cis) double bonds convert to trans bonds: forming Trans Fats

Warm-up Write a paragraph linking the following key-terms: Arteriosclerosis, CAD, plaque, heart attack, cholesterol

Why… Chemical process patented in the 1940’s used to convert oil surpluses from soybean farming into spreadable fats (margarines) to alleviate butter shortage

Problem… Trans Fats cannot be digested and raise LDL (bad cholesterol ) levels in the body Consumption of Trans Fats is correlated with a rise in CAD during 1960-2000 FDA prohibits use of Trans Fats/ requires labeling

Watch this trans fats in our food

If it has partially hydrogenated fats it has Trans Fats!!! No labelling required if it contains less than 0.5 g/serving Problem: it adds up and no amount of transfats is considered safe!

Transfats in our diet

2. Hydrolysis of Triglycerides Breaking the ester bond: yielding FA and Glycerol First step in the digestion of triglycerides in the body Carried out by the enzyme lipase

3. Saponification (sapon- soap) Reacting triglycerides with a strong base Yields glycerol and Fatty Acid Salts (soap) Glycerol + 3 NaOH → Glycerol + 3 Sodium tristearate stearate

What is a soap? Soap is an aliphatic molecules that has a polar part (facing water molecules) and a non-polar part (facing greasy dirt) Ancient soap making: Animal fats are heated with a base (potash in water KOH) Fatty acids salts: Potassium paltmitate: K+ -OOC-(CH2)14-CH3 soap making

Olestra Undigestible Fat = no calories! Composed of 6 to 8 long-chain Fatty Acids attached to sucrose rather than glycerol “Fake Fat” goes straight through our system GI problems are common 