11-Fats _ Oils-12

ch2 c oh h fst10 gmsgfr 2012 fst10 gmsgfr 2012

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Unformatted text preview: ings that happen with some acids like “conjugated linoleic acid” ! See FST100 and advanced nutrition courses Double Bonds ! ! Even though the number of atoms is the same there can be isomers Commonly referred to as CIS & TRANS double bonds Fatty Acid Cis & Trans Isomers H H CC 2HC FST10 ©GMS/GFR 2012 CH2 CIS 2HC H H CC CH2 TRANS FST10 ©GMS/GFR 2012 Even more about... Double Bonds trans- fat. What’s that? Some fatty acids have carbon-carbon double bonds they are not “saturated” with hydrogen. cis- and trans unsaturations have •different shapes •different chemistries, and are broken down by •different enzymes O saturated CH3 CH2 CH2 CH2 CH2 ... CH2 C OH trans -unsaturated Naturally-occurring fatty acids are cis- ! Cis double bonds are found in FAs in nature Trans double bonds are formed as byproducts of a synthetic chemistry processes called: ! “Hydrogenation” and are “Un-natural” or “Synthetic” H CH3 CH2 C O C cis -unsaturated Fatty acids may have more than one unsaturation (mono-,di-, ... poly) ! CH3 CH2 ... CH2 C OH H CH2 H C O C CH2 ... CH2 C OH H FST10 ©GMS/GFR 2012 FST10 ©GMS/GFR 2012 Catalytic Hydrogenation ! Lipids containing highly unsaturated FAs are liquids at room temperature - Oils. ! Lipids containing saturated FAs are solids at room temperature - Fats. ! Convert Vegetable oil to Margarine by catalytic hydrogenation - saturating SOME of the double bonds - partial hydrogenation. ! Partial hydrogenation also converts cisunsaturations to trans-double bonds - “transfat”. FST10 ©GMS/GFR 2012 Even more about double bonds ! ! ! European-led research is beginning to tell us something… Cis double bonds are formed in nature Trans double bonds are formed by synthetic chemistry —> hydrogenation and are “un-natural” On labels look for “partially hydrogenated” oils of some kind FST10 ©GMS/GFR 2012 FST10 ©GMS/GFR 2012 Changing perception — avoid cholesterol or trans fats? Previous exam examples FST10 ©GMS/GFR 2012 FST10 ©GMS/GFR 2012 5) Which meat grade below has the greatest amount of marbling? 3) Which term describes the distribution of fat throughout meat tissue? ! ! ! ! ! a) Myoglobin b) P...
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