Osmotic dehydration Flashcards

1
Q

typical concentration of osmotic dehydrating solutions

A

50-75g/100g

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

types of pre-treatment and why

A

blanching: inactivate enzymes
SO2: maintain colour, mild antimicrobial/antioxidant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

are products shelf stable after treatment

A

no, require furthur drying/freezing/canning treatment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

temp, time and conditions

A

15-140 minute
20-50C
agitation to promote heat and mass transfer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

ingredients that can be added for a functional purpose

A

sucrose: texture and flavour improver
fructo-oligosaccharides:pre-biotic
conc fruit juice: sweetness and aroma
de-acidified and desalted conc fruit juice: sweetness
sorbitol: pre-biotic, polyols inhibit tooth decay
galactosylosorbitol: pre-biotic
inverted sugar: sweet, texture, flavour improvement
oligofructose: pre-biotic, crystallisation prevention, and water holding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

equilibrium “distribution” coeffcients is a function of …

A

concentration
temp
type of solutes
geometry
food-syrup ratio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

two purposes of using solutes

A

impregnating
de watering

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what type of solutes favour impregnating

A

low molecular weight

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what type of solutes favour de watering

A

high molecular weight

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what can occur to biological material

A

parenchymatic cells (outer layer of apples and strawberries) can die due to osmotic shock
epidermis cells (onion outer) show no change in viability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

two major characteristics that make OD different from conventional drying

A

-soaking achieves a twofold transformation (dewatering and formulation)
-soaking does not generate a shelf-stable product

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

advantages to OD

A

quality improvement
energy savings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

explain direct formulation effect that results in quality improvement

A

increase sugar:acid
improved texture, pigment stability
may enhance rehydration properties
protective on natural tissue structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly