Pigments Flashcards
Degradation of chlorophyll
Low Ph, loses mg, replaced with h, ( dull olive brown pheophytin ) oxidase degredade chlorophyll, chlorophyllase removes the pheophytol group
3 classes of pigments
Chlorophyll, carotenoids, flavonoids
2 groups of carotenoids
Xanthophyll luetin, carotenes b carotene lycopene
Rate of oxygenation in carotenoids
Light heat and prooxidants , lox
Anthocyanuns
A glycosides blue is basic, acid is red och3 , bond with sugars, called glycosides addition of 1 sugar turns red, more then one blue , cyanidin is most common , acid causes positive charge on oxygen groups.
Anthocyanins with metal ions
Green blue slate , sulphites bleach , lox , Ascorbic acid to brown
ProanthocyNin
Colourless under most conditions. Converted by oxidizing to brown , astringent , haze in beer by reacting with proteins
Meat color
Myoglobin iron containing poryphorin
Meat in raw state, iron , cooked well done , if nitrates
2+, bound to 2 oxy gens , cooked 3+ , stay pink bound to No
Factors affecting meat color
Quantity of myoglobin - age of animal down affinity for oxygen with age , species, type of muscle, 2) chemical state of myoglobin ,3) mra 4) vitamin e 5) bacteria 6) wrapping film
Metaglobin reducing activity
Higher in support muscle
Vitamin e in feed
Keeps myoglobin out of meto
Meat color
Pigment content, ph, rate of ph decline, phys car of muscle, ingredients added
Binding sites hemoglobin
6
Muscle ph post mortem , if too fast
7.0-7.2 to around 5.7 within 24 hrs , if within 45 minutes, pse, pale soft extruded , low ph also pale , high ph dark and sticky dull firm dry
