Unformatted text preview: a catalyst OH
FST10 ©GMS/GFR 2013 FST10 ©GMS/GFR 2013 Partial Catalytic
Hydrogenation Turning Oils into Fats:
! ! !
! ! lower mp
more solid “Reduce” (hydrogenate) all C=C double bonds
! ! Convert Vegetable oil to Margarine by partial
catalytic hydrogenation - saturating only SOME
of the double bonds. ! But partial hydrogenation also converts remaining
cis- unsaturations to trans-double bonds “trans-fat” (since trans is more stable) ! trans-fat labeling now required (FDA, 2003). ! Consumers don’t like it ! Illegal in some cities. Fewer double bonds Too stiff
Too saturated...unhealthy So, only reduce (saturate) SOME of the double
(in this context “reduce” = “hydrogenate” = “saturate”)
FST10 ©GMS/GFR 2013 FST10 ©GMS/GFR 2013 Solution
! Split the oil into two batches ! Reduce ALL double bonds in one batch of oil
! ! No C=C double bonds at all Don’t treat the other batch
! Only cis-double bonds ! Mix the two batches ! Add enzymes to rearrange the FAs
FST10 ©GMS/GFR 2013 Even more about
! ! ! European-led research … Cis double bonds are
formed in nature
Trans double bonds are
formed by synthetic
hydrogenation and are
On labels look for “partially
hydrogenated” oils of
Generally no longer a concern...if you look for the “No trans fat” label
FST10 ©GMS/GFR 2013 FST10 ©GMS/GFR 2013 Changing perception — avoid
cholesterol or trans fats? Previous exam examples FST10 ©GMS/GFR 2013 FST10 ©GMS/GFR 2013 5) Which meat grade below has the
greatest amount of marbling? 3) Which term describes the distribution of
fat throughout meat tissue?
! a) Myoglobin
e) Retrogradation !
! FST10 ©GMS/GFR 2013 a) Select
e) Choice FST10 ©GMS/GFR 2013 6) This many calories are
found in one gram of fat:
! a) 1
e) 9 7) Diluting a food with water will
____ the % calories from fat.
! a) Increase
c) Not change
d) Exponentially increase
e) Signiﬁcantly decrease FST10 ©GMS/GFR 2013 FST10 ©GMS/GFR 2013 9) Which vitamin is not fatsoluble? 8) What causes the formation
of “chunky butter?”
! a) Retrogradation
b) Improper churning
c) Making butter from non-fat milk
d) Different forms of fat crystals
e) Low humidity storage !
! a) A
e) K FST10 ©GMS/GFR 2013 FST10 ©GMS/GFR 2013 10) Saturated fatty acids
have _____ double bonds.
! a) 0
e) Ω-3 11) Trans double bonds are synthetically
formed through a process called
! FST10 ©GMS/GFR 2013 a) Saponiﬁcation
b) Partial Hydrogenation
e) Marbling FST10 ©GMS/GFR 2013 Animal & Plant Fats & Oils Fini …
FST10 ©GMS/GFR 2013...
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