Chapter 6 Flashcards
Color– color is what our __ ___ when ___ ___ strikes an ___.
-function of the ____ of the light reflected by the ___ of the ___.
eyes perceive visible light object wavelengths cones retine
Cones are sensitive to ___, ___, or ___ color.
red, green or blue
Lightness and darkness are registered in the ___.
rods
Light striking an object can be ___, ___, or ____.
absorbed, reflected or transmitted
Transmitted means goes ___.
Reflected ___ ___.
through
bounces back
Visible light occurs between the wavelengths ___ and ___ in the ___ ___.
380nm and 780nm
electromagnetic spectrum
Food reflects a variety of ____, which determines the ___ that we perceive.
-Ability to see many different shades of a certain color due to the fact that the ___ types of ___ overlap in their ___ to color.
wavelengths color three cones sensitivity
Color can be classified according to its ___, ___ and ___.
hue
chroma
intensity
Color can be classified according to ___ qualities:
- ____ – actual color name. (__, ___, ___)
- ____ – clarity and purity of color. (___)
- ___ – degree of lightness or darkness.
3
hue (red, blue, green)
chroma (saturation)
intensity
___ of ___ also affected by light distribution.
Surface of foods
Color of food is due to ____ molecules.
pigment
There are primarily ___ different kinds of pigment molecules in food:
- ______ - plants
- ____ – plants
Anthocyanins, anthoxanthins, betalains - _____ - plants
- _____– animals
4 Chlorophylls Phenolics Carotenoids Myoglobin
_____ can derive pigmented compounds from plant foods that they eat.
Animals
Myoglobin is a ___ ___ with an ___ containing a ____ group called ___ (iron porphyrin ring).
- Responsible for ___ ___ in ___ tissue.
- Ultimately responsible for the ___ color of muscle foods.
globular protein iron prosthetic heme storing oxygen muscle reddish
Myoglobin: Can bind ___ because of the ___ structure of ___ and because of the ___.
oxygen
tertiary
globin
heme
Myoglobin
- _____ polypeptide
- ___ and ___
- ______________ ring
- __ ___ units
- ___ in center – can bond to any atom able to donate electrons
Single Globin and heme iron porphyrin 4 pyrrole Fe
In living animals, myoglobin ____ oxygen. Upon ____, this no longer happens.
stores
slaughter
Slaughter:
- Meat exposed to oxygen – ___ ____
- Continued exposure – oxidation – ___/___
- Nitrate cured – ___ ____
bright red
grey/brownish
pink color
Whether or not myoglobin is ____ , the ____ state of the ___, and _____ of the ___ molecule all contribute to different ____ of meat.
oxygenated oxidation iron denaturation globin colors
Also, the ___ can be nitroslyated through ___, or bonded with ____ due to ____ action, which will affect the ___.
heme curing sulfur bacterial color
Heat and meat color:
Appearance changes in __ ways:
-____ denaturation (~___ degrees F)
-____ denaturation (~___ degrees F)
2
Myosin 120
myoglobin 140
Judging doneness by color: -Rare – \_\_ \_\_\_ -Medium – \_\_\_\_ -Well – \_\_\_\_\_\_ Can be \_\_\_\_\_
red juices
pink
clear
misleading
The color of fruits and vegetables is due to the ___ major groups of ____ compounds:
- _____
- _____
- _____
three pigment Phenolics Carotenoids chlorophylls.
All pigment compounds contain ___ ___ ___.
(_______)
- This allows for ___ ___ which in turn produces ___.
- ______ ____ are spread across the atoms.
- Their ____ across carbon-to-carbon bonds gives ____.
conjugated double bonds C=C=C=C electron resonance color -Resonance electrons movement color
Phenolics:
Anthocyanins - __ ___, ___ to ___-___ in color, ____, which contain at least ___ ___ rings.
- Valuable ___
- Readily ___ into surroundings
- e.g. ____
water soluble, purple, orange-red. flavonoids, two aromatic
antioxidant
bleed
blueberries
Phenolics:
Anthoxanthins – ___ ___, ___ to ___ in color, ___.
-e.g. ____
water soluble white yellow flavonoids cauliflower
Phenolics:
Betalains – ____ ____, ___ to ____, ____.
- Sensitive to ___ & ___
- e.g. ___
water soluble purple yellow flavonoids heat light beets
Chlorophylls:
- ___ soluble, ___, ____ with ___ at center plus ___ (hydrocarbon tail).
- Chlorophyll a – ___ ___ ___
- Chlorophyll b – ___ ___
Lipid green porphyrin Mg phytol bright blue green olive green
Chlorophylls:
- Susceptible to __ ___ changes during ___
- Loss of ____ tail
- Removal of ____ from center
2 chemical
cooking
hydrocarbon
Mg
Carotenoids:
- ___ soluble, ___ to ___, ____.
- Absorbs ___ & ___ wavelengths
- Relatively ___ & soluble in ___/___
- e.g. ____
Lipid orange yellow isoprenes blue green stable fats/oils tomatoes
Colorant:
A ____ used as a __ ___ to impart a particular ___ to food.
- ____ (ex: ___, ___, ___)
- ____
pigment food additive color natural tumeric, annatto, paprika synthetic
Food, Drugs, and Cosmetics Colorants (FD&C colorant):
- Colorants certified as ___ for use in food, drugs, and cosmetics.
- FDA classifies all colorants as either ____ colorants or ___ colorants.
- All FD&C are ____.
safe
FD&C
exempt
synthetic
Dyes: ___ soluble ___ used to ____ ___ food products.
-e.g. ____
Water chemicals color entire lollipops
Lakes: __ pigments used to ___ the ____ of foods or __ ___ products.
-e.g. ____
Precipitated color surface fat based chocolates
Exempt Colorants:
- These are generally of ____ origin such as ___ and __ ___ extracts.
- ____ ____ – derived from the controlled heating of glucose.
natural
annatto
grape skin
Caramel Color
Caramel color:
-Produces a complex of compounds due to the ___ ____.
caramelization reaction
Cochineal Extract:
- Formerly exempt as of ___ ___.
- Derived from ___ ____.
- Red color is due to ___ ___, which is a __ ___.
- Used in ____, marinades, ___, ____, pie fillings, etc.
Jan 2011 cochineal insects carminic acid phenolic acid beverages cookies desserts
Flavor: property of __ ___ and ___ ___ of the human body.
food material
receptor mechanisms
Flavor involves both ___ and ____ as well as other ____ factors all perceived by ____ sensors in our body.
taste
odor
sensory
physicochemical
Flavor: four basic tastes through taste receptors on the tongue.
- ____
- ___
- ___
- ____
sweet
salty
sour
bitter
