Lecture 8 - Protein

2 Pages
Unlock Document

Nutritional Science
Debbie Gurfinkel

NFS386 Lecture 815 Nov 2011Reactivity depends on mobility and solubility of molecule Amino acids Lys20 amino acidstwo amine groups in alpha and epsilon positionsa few additonal ones are made by postwhich one is more reactivetranslational modificationis free lysin more reactive or a peptideUse glutamate to test this Maillard reactionsnonenzymatic browning Lysine peptide experiemntrequire small amount of heat although they take place glutamic acid used because it contributes very little at any temperature including in the freezer if given reactivityenough timetemperature just speeds it upepsilon group free in one peptide alpha group free generally happens during cookingin the other peptidedifferent from carameliziaton carbohydrate interactions cook with glucose and test absorbance to see what only because it is interactins between protien and wavelengths are absorbed coloured compounds carbohydratesare producedfree Lys is most reactive becuse both amino groupsSteps of Maillard reaction are active1 Nsubstituted glucosylaminethe sugar attaches in the one with the linkage at the alpha group only directly to the nitrogren in the primary amine amine epsilon is activewith 1 R groupin the one with the linkage at the epsilon group addition of primary amine across double bond and only alpha is activedehydratesimineconverts to ring form epsilon group is more reaction than alphaamine2 Amadori rearrangementketoseamine 3 enolizationhydroxyldouble bond rearrangements Water activitybrowning reactions 3during cooking the dehydraton of the waterdue to increase with water activity but passes through a heat of cooking helps speed this reactionmaximum and slow down slightlydilution effectketoenol tautomerismwater is a solvent that brings solvents together to rearrangement of atoms and bonds to convert increase contact between substratesbut too ketose to enol 12 enolizaton in reference to much water means the substrates get too far apart location of the new double bondunstablefrom each othereliminiation of primary amine group3deoxyosone Protein classifications evaporationdehydration drives next histoically proteins were classified based on their rearra
More Less

Related notes for NFS386H1

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.