Brainscape's Knowledge GenomeTM

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


See full index

2150 > Lipids > Flashcards

Lipids Flashcards

0
Q

What is the trans isomer of Oleic acid, and what does it do in the body, where is it found

A

Eladic acid, raises vldl, low HDl and up cetp. Majorly found in hydrogen veg oils

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

Three kinds of lipids

A

Triacyl
Phospho
Sterols
Excluding butyrate, these are assumed to be 8+ carbons long

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

What desaturated do humans have, and what do they make

A

9 654, Oleic acid is a desaturated form of steric acid, which comes from palmitic acid.

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

Steps in gas crom analyzing lipids

A

Extraction, saponification, methylation, volatility

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

What do phospholipids contain, and what is their function

3 kinds, where are they found

A

They contain po4, 2 tags on sn12, and a nitrogen containing group, when n is gone it is phosophtidic acid
They are emulsifiers. Lecithin is an example. Can have choline as a head group, found in eggs and soybeans, extrCted with hexane
Ethanol amine, cephlin . In Pufas and bilayers

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

What are sterols, what do they make

A

Alcohol derivatives, d, bile, cholesterol

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

Types of fat rancidity

A

Oxidative, lipolytic

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

Oxidative rancidity- mechanism, products ( factors affecting ) auto oxidation

A

Heat, light, oxygen, ionization, loss of flavour and efas, toxic compounds, breaks fas from glycerol, intermediates formed = nasty odour , which condensates. Forms lipid hydroperoxides
Aldehydes provide Roma

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

Lipolytic rancidity, brought Bout, where found, mechanism

A

More prone to oxidation then o2, hydrolysis by oxy, gen free fas , produces various aromas, lipase activity in fluid phases very active - more in homogenized milk since finely dispersed

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

Hydrolysis of lipids generated by

A

Acid, bases , enzymes, thermal , gen short chain fas , lipase. Moisture in lipid

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

Oxidative rancidity mechanism.

A

Form lipid hydroperoxides , breakdown lipid hp. I,p,t

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

Initiation

A

Unsaturated lipids lose a hydrogen, forming a lipid radical, in the presence of an initiator, can also be incorporated into a ROOH, forms a hydroperoxide

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

Propagation

A

The lipid radical reacts with oxygen to form a lipid peroxyl radical LOO
Will attack fatty acid double bonds to get a h, produces another one of itself

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

TerminAtion

A

Can combine with another radical to terminate, or can run into an anti oxidant lool o2, or loo + ah – looh + a

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

How to stop auto oxidation,

A

Avoid initiators, saturate or hydrogenated fat , add vitamin e

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

Hydroperoxides function

A

Central mechanism of lipid breakdown, easily decompose to form hydroperoxide free radicals, breaks double bonds forms aldehydes , ketones carboxylic acids

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

Environmental factors in lipid oxidation

A

Oxidation, temp, light, moisture, analysts, nit oxidants, moisture

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

antioxidants

A

Slow rancidity, does not stop production of aldehydes and ketones rom hydroperoxides

18
Q

How do ntioxidants work

A

Retardation auto oxidation. Compete for oxy binding retardation free radicals inhibition of catalysts , stabilize hydroperoxides most importants is blocking of propagation.

19
Q

Blockage of propagation mechanism via anti ox

A

Ah acts as a hydrogen donor to loo or l, a does. A does not act as an initiatior itself enters a termination reaction. Can be regenerated if favourable

20
Q

What should food grade anti oxidants hAve. Also what is a contributor to lipid oxidation thru catalytic action

A

Should be fat soluble. Metallic ions, cu, iron.

Citric acid sequesters metals , enhance phenolic antiox activity

21
Q

Browning of fruits and veg when cut

A

EnzymTic action of phenolic compounds . Ascorbic acid prevents this , critic acid enhances the effectively of Ascorbic acid in preventing browning

22
Q

E numbers

A

300-399

23
Q

Synergism

A

The two nit oxidants together and greater then when used sepErately mixed free radical quenchers, mixed free rad and a metal cheating agent . A synergist may have more then one role , electron donor as well as Metal Che.ator

24
Q

Measuring lipid oxidation

A

Rate of oxy uptake , formation of per oxides, ydroperoxidsz , mall aldehydes conj dienes , free fatty acids

25
Q

Rte of oxygen uptKe tbars

A

Oxidized fat reacts with tba, forms tba acid, gives red coloured complex , correlates with degree of rancidity

26
Q

Types of fat in foods

A

Milk fat, Lauric acid ( coconut oil) , veg butter , Oleic linoleic, linolenic, animal fat Marine oils

27
Q

Milk fat

A

Palmitic Oleic , steRic, short chain , branched, odd numbered

28
Q

Lauric acid

A

Coconut oil. Babassu large number of saturated , low melting point

29
Q

Cocoa butter, narrow melting range, no tri saturated , large number of saturated

A

Above lol

30
Q

Lonoleic

A

Canola, olive, safflower, most abundant, less then 20 saturated

31
Q

Linolenic

A

Hemp, soy, whet germ

32
Q

Animal fats

A

C16, 18, some oleic and linoleic , mostly fully saturated tag , high mp. Small amounts of odd numbered

33
Q

Marine oils

A

Long chain Pufas up to 6 dbl bonds, a and d , less resistant to oxidTion usually have dha and EPA at sn2

34
Q

Plant tags

A

Seed oils have unsaturTed fatty acids at sn2 13 are sat

35
Q

Animal tags

A

Varies among animal/ where on animal , depot fat can be altered by changing dietary fat c16 at sn1, c14, sn2, short chain in milk is at sn3

36
Q

Pig fat

A

Unique

Sn1and 3 c18, sn2 c16

37
Q

Impurities in refining , steps in refining,

A 
FFA, phospholipids, carbohydrates,proteins, water, pigments, fat oxidation products 
Settling degumming
Neut using base 
Bleaching 
Deodorizing
Hydrogenation
38
Q

Settling and degumming

A

Water, protein materials and cho, oil is heated and allowed to stand

39
Q

Neutralization

A

Uses NaOH, created rootstock or soapstock, removes phospholipids and colouring materials

40
Q

Bleaching

A

Removes residual soapstock , phospholipids and oxidation products , oil is then filtered with activated carbon,

41
Q

Deodorization

A

Steam distilization , used to remove volatile compounds , critic acid is often used to bind metals

42
Q

Hydrogenation

A

Adding h+ to double bonds aids in stability
Liquid oil is converted to semi solid fat or plastic fats , shortening or margarine
Improves oxidative stability , decrease in the number of unsat fas

2150 (5 decks)

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