Influence of Dehydration on the nutritive value of food Flashcards
it results in increasing the concentration of nutrients in the remaining mass
Losses of moisture
Proteins, fats and carbohydrates are present in _______ per weight in dried than fresh counterpart
large amount
a loss in ____ content
vitamin
what happens to water soluble vitamins?
- is partially oxidized,
- diminished during blanching,
- enzyme inactivation,
- destruction (depends on caution
exercised during prep, dehydration process, conditions of storage)
what happens to Ascorbic acid and carotene during dehydration?
damage by oxidation process
what happens to Thiamin during dehydration?
is heat sensitive and destroyed by sulfuring
what happens to Fruits during sundrying?
causes large losses in carotene
content
great loss in Vit. C
what happens to Fruits during spray drying?
causes little losses in carotene
content
little loss in Vit. C
what happens to Fruits during freeze drying?
retain greater proportion of vit. C and other nutrients
what happens to vegetables if there’s no enzyme activation?
Carotene content decreased as much as 80%
How will ascorbic acid retain more in vegetable?
through rapid drying rather then slowdrying
in vegetable, vitamin _ lost in slow-sun drying
C
Vitamin A will be retained in good proportion in what drying methods?
drum-dried and spray-dried milk
In meat, _____ contains less vitamins that fresh
dried
In meat, there is a SMALL losses in?
riboflavin and niacin
In meat, ______ losses at HIGH drying temperature
Thiamin
How is vitamin c lost in meat?
DRYING
Dried meat lost vit c
In drying protein, _______ may increase
digestibility.
Low temperature
In drying protein, is it DEPENDENT or INDEPENDENT on the drying method?
DEPENDENT
In drying protein, Prolonged exposure to _________ renders the protein less useful
high temperature
Influence on fats that make it smell bad/old
Rancidity-problem
In drying fats, oxidation is greater _____ temperature than ____ temperature of dehydration
higher, lower
in CHO, ______ due to enzymatic browning or caramelization
Discoloration
what causes discoloration in drying CHO?
enzymatic browning or
caramelization
in CHO, what is one way of controlling the reaction of organic a cids and reducing sugar
Addition of sulfur dioxide
critical level moisture in CHO
1-30%
in CHO, ______ permits extensive deterioration UNLESS PROTECTED BY ____________
Slow sun drying, CRITICAL LEVEL MOISTURE
Molds will grow in _____ moisture
12%
Molds will be inhibited in ____ moisture
less than 5%
bacteria and yeast will grow in ____ moisture
30%
in grains, molds grown on storage with _____ moisture
16%
in fruits, molds grow with _____ moisture, high humidity, and exposure to air
16-25%
Influence on enzyme activity: a minute at ______ renders inactive
212ºF
2 indicator enzymes
catalase and peroxidase
which is more less resistant to heat? CATALASE or PEROXIDASE
Catalase
in drying, theses pigments are altered/injured
carotenoid, anthocyanins
in this pigment, the higher the temperature and the longer, the more it is altered
CAROTENOID
These 2 pigments usually retains during drying BUT is converted into pheophytin during moist heating
Chlorophyll alpha and beta
What lacks in chloropyll a and b that it converts into pheophytin during moist heating?
Magnesium
Chlorophyll A and B converts into ____ during moist heating
pheophytin
When chlorophyll A and B converts into pheophytin, what’s the color?
alters grass green color to brownish olive green
