Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

5) Food Product Development > Technical Challenges (6) > Flashcards

Technical Challenges (6) Flashcards

You may prefer our related Brainscape-certified flashcards:
Gourmet Food flashcards
1
Q

what are some main functionalities of lipids?

A
  • lubricant and tenderizer
  • heat exchange medium
  • carriers of fat soluble vitamins
  • contributors to mouthfeel and flavor
  • textural ingredients of emulsions
  • emulsifiers and surfactants
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

define a surfactant

A

lowers the surface tension between two compounds (between liquids, gases or solids)

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

what factors should be considered in selection of an appropriate lipid ingredient?

A
  1. nutritional profile
  2. flavor profile
  3. crystallization behaviour
  4. oxidative stability
  5. bulk physicochemical properties
  6. oil quality
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what causes the distinctive flavour profiles of fats/oils?

A

their characteristic volatile breakdown products and impurities which can:

a) contribute directly
b) contribute indirectly

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

the partitioning of flavour molecules among oil, water and headspace regions during mastication depends on what?

A

the nature of the lipid phase (eg. polarity, viscosity, crystallinity)

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

what are important crystallization behaviours of lipids?

A
  • melting and crystallization temp
  • SFC (solid fat content) and temp profile
  • crystal morphology
  • polymorphic type
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how can you limit crystallization? (3 methods)

A
  1. using oils with low melting points
  2. by removing high melting fractions
  3. adding components that retard crystal formation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how can you favour crystallization?

A
  1. use an oil with desired crystallization characteristics

2. modulating composition by blending, fractionation, inter-esterifcation or hydrogenation of oils

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

what word defines “solid-to-liquid” lipid transition

A

melting

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

what word defines “liquid-to-solid” lipid transition?

A

crystallization

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

what are internal and external factors of the morphology of crystals?

A

internal: molecular structure, composition, interactions
external: temp-time profile, agitation, impurities

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

nucleation rate increases more rapidly with ___ (incr/decr) temp than the crystallization rate

A

decreasing

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

what is nucleation?

A

the start of a new phase forming

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

compare the sensory properties of large and small crystals

A

large: grainy or sandy
small: causes cooling sensation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is coalescence

A

when two or more particles merge during contact to form a single particle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

describe partial and extensive partial coalescence

A

partial coalescence: increase in viscosity of an emulsion

extensive partial coalescence: conversion of an o/w emulsion to a w/o emulsion (eg. butters and margarines)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what should be considered when choosing an oil based on oxidative stability?

A
  1. ensure that lipid oxidation has not already occurred

2. has good oxidative stability throughout lifetime of the pdt

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what affects the formation, stability and quality attributes of a food emulsion?

A

physico-chemical properties of the emulsion (such as viscosity, density, refractive index, etc…) which is affected by the type and conc of molecules within the oil phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

describe how oil quality have adversely affect suitability for a certain application

A

presence of off-flavours, pigments, phospholipids, FFAs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what 3 characteristics must a lipid ingredient have to be effective at enhancing formation and stability of emulsions?

A
  1. must rapidly absorb to the surface of the freshly formed emulsion droplets during homogenization
  2. must reduce interfacial tension by a significant amount
  3. must form an interfacial layer that prevents the droplets from aggregating under the conditions pertaining to the emulsion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what are functions of lipid ingredients as emulsifiers and surfactants?

A
  • emulsifiers to improve emulsion formation and stability
  • forming micelles
  • solubilizers
  • suspending agents
  • crystallization modifiers
  • wetting agents
  • dispersibility
  • complexing agents with biopolymers (starch and proteins)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is HLB? define it.

A

hydrophile lipophile balance = ratio of hydrophilic to lipophilic groups

(aka the measure of the degree to which a surfactant is hydrophilic or lipophilic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is krafft point?

A

the minimum temperature to form micelles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what important functional properties should be considered for selection of a lipid emulsifier?

A
  • surface activity and droplet stabilization (HLB: hydrophile-lipophile balance)
  • molecular organization of surfactants (packing parameter and phase inversion temp)
  • krafft point
  • surfactant solubility (bancroft’s rule)
  • cloud point
  • solubilization ability of surfactants
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what two factors should be considered when looking at the molecular organization of surfactants?

A

1) packing parameter

2) phase inversion temp

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what is cloud point

A

temp in which a cloudy appearance begins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what is bancroft’s rule about surfactant solubility

A

The phase in which an emulsifier is more soluble constitutes the continuous phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

which phase is defined as the continuous phase? what rule is this based on?

A

the phase where the emulsifier is more soluble

based on bancroft’s rule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

how can you increase stability of surface activity of a droplet (3)

A
  • minimize contact area b/w hydrophilic and hydrophobic regions
  • reduce interfacial tension
  • enhance stability against aggregation by electrostatic and steric stabilization
30
Q

what are 2 ways to determine HLB of a surfactant?

A

1) calculated from number and type of hydrophilic and lipophilic groups it contains
2) estimated from experimental measures

31
Q

what is the equation used to calculate HLB?

A

HLB = 7 + sum of hydrophilic group numbers - sum of lipophilic group numbers

32
Q

HLB provides useful indication of what? (2)

A
  1. solubility in either oil and/or water phases

2. type of emulsion that will be formed by a surfactant

33
Q

describe a surfactant with HLB below 3

A

very hydrophobic

34
Q

describe a surfactant with HLB of 3-6

A

hydrophobic

max emulsion w/o stability

35
Q

describe a surfactant with HLB of 7-9

A

a good wetting agent

36
Q

describe a surfactant with HLB of 10-18

A

hydrophilic

stabilizes o/w emulsions

forms micelles in water

37
Q

describe a surfactant with HLB above 18

A

very hydrophillic

38
Q

what are examples of products with high HLB numbers?

A

o/w emulsions: dressings, coffee whiteners, beverages

39
Q

what are examples of pdts with low HLB

A

w/o emulsions: margarines and spreads

40
Q

what are 3 drawbacks of HLB?

A

1) doesn’t take into account that the functional properties of a surfactant molecule are altered by changes in temp or solution conditions
2) optimum HLB # required for a surfactant to create a stable emulsion depends on the oil type
3) doesn’t provide insight into size or amount of surfactant required to form a stable emulsion or the stability of the emulsion droplets once formed

41
Q

what is CMC

A

critical micelle concentration

42
Q

what factors are included in the molecular organization of surfactants?

A
  • chemical structure of surfactant molecule
  • interactions of the surfactant molecules
  • nature of the continuous phase
  • solution composition
  • temp
43
Q

what is packing parameter?

A

p = v/a0*l

where:
v is the surfactant tail volume

l is the tail length

a0 is the cross sectional area of the hydrophilic head group

44
Q

describe the properties of a surfactant when packing parameter (p) < 1

A

optimum curvature is convex (H0 < 0)

o/w

45
Q

describe the properties of a surfactant when packing parameter (p) = 1

A

zero curvature (straight) (H0 = 0)

unstable

46
Q

describe the properties of a surfactant when packing parameter (p) > 1

A

optimum curvature is concave (H0 > 0)

w/o

forms reverse micelles

47
Q

packing paramter is equal to what?

A

packing parameter (p) = phase inversion temp (PIT)

48
Q

what is PIT

A

phase inversion temperature

49
Q

describe

a) a micellar system
b) a reverse micellar system

A

micellar:

  • p < 1
  • o/w

reverse micellar

  • p >1
  • w/o
50
Q

describe the PIT graph in terms of surface tension and coalescence instability

A

from low temp to PIT:

  • decreasing surface tension
  • increasing coalescence instability

from PIT to high temp

  • increasing surface tension
  • decreasing coalescence instability
51
Q

what does bancroft’s rule state?

A

the phase in which the surfactant is most soluble will form the continuous phase of an emulsion

52
Q

what type of surfactant should stabilize o/w emulsions?

A

water-soluble surfactant

53
Q

what type of surfactant should stabilize w/o emulsions?

A

oil-soluble surfactant

54
Q

what does Bancroft’s rule not provide?

A

insight into the relationship b/w the molecular structure of a surfactant and the long term stability of the emulsions formed

55
Q

what happens when you heat above cloud point?

A

dehydration of the hydrophilic head groups

56
Q

describe what happens when temp increases towards cloud point

A
  1. temp is increased towards cloud point
  2. interfacial tension decreases
  3. droplets are easier to disrupt but more prone to coalescence
57
Q

what factors determine the functional properties of swollen micellar solutions?

A
  1. location of the solubilizate within the micelles
  2. max amount of material that can be solubilized per unit mass of surfactant
  3. solubilization rate
58
Q

the solubilization ability of surfactants affects what?

A
  1. selective extraction of nonpolar molecules from oils
  2. controlled ingredient release
  3. incorporation of nonpolar substances into aqueous solutions
59
Q

what are common food grade lipid emulsifiers and surfactants?

A
  • monoglycerides
  • organic acid esters of monoglycerides
  • polyol esters of fatty acids
  • stearoyl lactylate salts
  • lecithin
60
Q

define a monoglyceride

A

surfactants produced by interesterification of fats or oils with glycerol

nonionic oil-soluble surfactants with low HLB numbers (2-5)

61
Q

monoglyceirdes can be esterified with organic acids to form what surfactants?

A
  1. ACETEM: acetylated monoglycerides
  2. LACTEM: lactylated monoglycerides
  3. DATEM: diacetyl tartaric acid monoglycerides
  4. CITREM: citric acid esters of monoglycerides
62
Q

ACETEM and LACTEM are what kind of surfactants?

DATEM and CITREM are what?

A

ACETEM and LACTEM are:

  • nonionic
  • oil soluble
  • low HLB

DATEM and CITREM are:

  • anionic
  • water dispersible surfactants
  • intermediate or high HLB
63
Q

what determines the functional characteristics of a surfactant?

A

type of polyol and fatty acids used

64
Q

surfactants with large polyol head groups tend to be _____ with ____ (high/low) HLB)

surfactants with small polyol head groups tend to be ____ with ___ (high/low) HLB)

A

water dispersible; high HLB

oil soluble; low HLB

65
Q

what is SSL

A
  • sodium stearoyl lactyate
  • anionic water dispersible surfactant
  • intermediate HLB
66
Q

what is CSL

A
  • calcium stearoyl lactylate
  • anionic oil soluble surfactant
  • low HLB
67
Q

what are lecithins? what can they be extracted from?

A
  • naturally occurring surface active molecules with a mix of phospholipids and other lipids
  • can be extracted from many sources (eg. soybeans, rapeseed, egg)
68
Q

what are examples of phospholipids in lecithin?

A
  • phosphatidylcholin (anionic)
  • phosphotidyl-ethanolamine (zwitterionic)
  • phosphatidyl-inositol (zwitterionic)
69
Q

describe the properties of natural lecithin

A
  • intermediate solubility
  • HLB = 8
  • not very suitable for stabilizing o/w or w/o emulsions when used by itself
70
Q

how can lecithin be modified to be more capable of stabilizing o/w emulsions?

A

it can be chemically or enzymatically hydrolyzed to break off one of the hydrocarbon tails to produce more hydrophilic surfactants

5) Food Product Development (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions