Water III Flashcards
_____________ are produced by treating monoglycerides with ethylene oxide
Polyoxyethylene monoglycerides
Treating monoglycerides with ethylene oxide leads to the polymerization of ethylene oxide as well as the connection of the polymer to the ____ group at either the __ or ___-position on the glycerol bacbone
OH
2
3
Polyoxyethylene chain length is 20 ______ units - exact product is a function of reaction conditions.
ethylene
_______ find their main application in cake production and emulsification and air incorporation
Polyoxyethylenes
What are other derivatives of emulsifiers based on glycerol esters?
- Lactylated monoglycerides
- Propylene glycol esters
Sorbitan derivaties are (ionic/non-ionic) emulsifiers
non-ionic
Emulsifiers based on glycerol esters are (ionic/non-ionic) emulsifiers
non-ionic
________ are produced by the reaction of sugar alcohol with stearic acid in the presence of a catalyst
Sorbitan derivaties
_______ are a sugar alcohol esterified to a fatty acid
Sorbitan derivatives
How can sorbitan derivatives be further modifed?
Reaction with ethylene oxidize to form polyoxyethylene derivatives
Esters of polyhydric compounds are (ionic/non-ionic) emulsifiers
non-ionic
Polyglycerol derivatives and sugar esters qualify as esters of _________
polyhydric compounds
How are polyglycerol derivatives formed?
- Glycerol is polymerized to form polyglycerol by the reaction of glycerol with an alkaline catalyst
- Polyglycerol is then esterified with a fatty acid
What kind of emulsifier is Olestra?
Sugar ester
Olestra is _________ esterified with _______ fatty acids
sucrose
6-8
What are the three categories within the ionic emulsifiers?
- Anionic (-)
- Amphoteric (+/-)
- Cationic (+)
________ emulsifiers are charged monoglyceride derivatives
Anionic
The most important anionic monoglyceride emulsifier is ___________, produced by the reaction of a monoglyceride with ________
succinylated monoglyceride (SMG) succinic anhydride
Sodium stearoyl-2-lactylate is an example of a non-glycerol-base _______ emulsifier
anionic
_________ forms very stable oil-in-water emulsions, which are very resistant to freeze/thaw cycles (good for frozen food)
sodium stearoyl-2-lactylate
The chief use of the ______ emulsifier ____________ is as a whipping aid for egg whites
anionic
sodium lauryl sulfate
How is sodium lauryl sulfate produced?
- Reduction of coconut oil fatty acids to their alcohols
- Followed by sulfonation of the alcohols produced
Why are cationic emulsifiers not used as food additives? What are they used as instead?
- Bactericidal/toxic
- Potent surface-active agents –> cleaning products
Quaternary ammonium compounds are examples of ______ emulsifiers
cationic
_____ is commonly produced as a by-product from soybean, corn, or safflower oil processing
Lecithin (phospholipid)
Phosphatidylinositol is ________
anionic
Phosphatidylcholine is ________
amphoteric
Phosphatidylethanolamine is ________
amphoteric
What is lecithin usually treated with to bleach the product?
- Hydrogen peroxide
- Benzoyl peroxide
What does bleaching of lecithin cause structurally?
Produces hydroxyl groups at the sites of fatty acid unsaturation
What is the effect of hydroxylated lecithin?
More dispersible in cold water and is a more effective emulsifier than lecithin itslef
Proteins fall under the category of ______ emulsifiers
ionic
What is the role played by proteins in sausage emulsions?
- Forming a protein film around oil droplets
- Prevents coalescence of the fat
Give an example of a protein with good foam-forming properties.
Egg albumin
What is the disadvantage of ionic emulsifiers?
Being relatively sensitive to pH and the presence of other ions
Are ionic emulsifiers or non-ionic more used by the food industry?
Non-ionic
What are hydrocolloids generally made of?
Polysaccharides (starch and gums)
________ are a group of compounds often used in conjunction with emulsifiers
Hydrocolloids
Are hydrocolloids emulsifiers?
No, they are termed stabilizing agents
What is the major contribution of hydrocolloids?
Enhancement of the viscosity of the hydrophilic phase (continuous phase)
What is the consequence of the increased viscosity by hydrocolloids?
Makes it more difficult for oil droplets to coalesce
__________ can form light gels, which trap _______
Hydrocolloids
oil droplets
What is the role of gums?
Form films around oil emulsion droplets
What is the HLB system?
Approach to figure out which emulsifier to select
The HLB system is mainly applicable to _______ emulsifiers
non-ionic
The HLB value represents the weight percentage of ________ groups in a non-ionic emulsifier molecule divided by ____
hydrophilic
5
What does HLB stand for?
Hydrophilic-lipophilic balance
What is a completely lipophilic HLB value?
0
What is a completely hydrophilic HLB value?
100/5 = 20
What does an HLB of 1-6 promote?
- Hydrophobic
- Promotes water-in-oil emulsions
What does an HLB of 12-20 promote?
- Hydrophilic
- Promotes oil-in-water emulsions
What does an HLB of 7-11 promote?
Can either produce an oil-in-water or water-in oil emulsion
Are additional tests required after HLB?
Yes, it provides guidance but a systematic investigation on the performance of the emulsifier must be tested
______ have an HLB range of 15-18
Solubilizers
_______ have an HLB range of 13-15
Detergents
______ have an HLB range of 7-9
Wetting agents
Emulsifiers as ___________ are used for bread doughs, dehydrated potatoes and processed cereals
conditioners
Emulsifiers as __________ allow more use of non-wheat proteins
conditioners
Emulsifiers as __________
increase water absorption and have the ability to improve the cohesive and film-forming strength of proteins such as gluten.
conditioners
Emulsifiers as __________ are used in gelatin dessert mixes, dry beverage mixes, cocoa powder, and pudding mixes
wetting agents
Emulsifiers as _________ increase the rate of dispersion and minimize clumping
wetting agents
