Food+Emulsifiers_csm

= FOOD EMULSIFIERS =

Emulsifiers

 * Emulsion---a dispersed 2-phase system, an intimate mixture of 2 liquids that are immiscible under normal conditions.
 * One phase dispersed in the other in the form of fine doplets.
 * Dispersed phase---dispersed droplets/inner phase.
 * Continuous phase---medium in which droplets are dispersed.
 * Reduce the surface tension at the interface, allow 2 immiscible liquids to mix and form emulsion.
 * Emulsifiers---surface-active agents or surfactants.

Stability of Emulsifiers

 * 1) Degree of division of the inner phase.
 * 2) Quality or stability of interfacial film.
 * 3) Viscosity of the outer phase.
 * 4) Ratio and specific weight of the volumes of the 2 phases.

Functions of Emulsifiers

 * 1) Promote emulsion stability, stabilize aerated system, control agglomeration of fat globules.
 * 2) Modify texture, shelf life, rheological properties by complexing with starch and protein components.
 * 3) Improve the texture of fat-based foods by controlling the polymorphism of fats.

How does Emulsifiers Work?

 * Reduce surface tension between 2 immiscible phases due to their molecular structure.
 * Have both polar group with an affinity for water (hydrophilic), and non-polar group with an affinity for oil (lipophilic).
 * Lipophilic tails---C16 (palmitic) or longer fatty acids.
 * Polar head group---anionic, cationic, amphoteric, or nonionic functional group.
 * Emulsifiers can orient at the phase interface and lower the interfacial energy that kead to instability.
 * It stabilize emulsion by means of monomolecular interfacial film and also formation of steric and/or electrical barriers that prevent coalescenceof dispersed droplets.

__1. Nonionic__
- Uncharged molecules, insensitive to pH and salt content. - Examples : mono- and diglycerides, sorbitan esters, sucrose esters, polysorbates, polyoxyethylene glycol oleates (all contain -OH functional group).

__ 2. Anionic __
- Possess a -ve charge. - Examples : stearoyl lactylates, diacetyl tartaric esters of monoglycerides (DATEM), succinylated monoglycerides. - Functionaity---influenced by pH and ionic strength.



__3. Cationic__
- Possess a +ve charge. - Example : amine compound.

__ 4. Amphoteric __
- Possess both +ve and -ve charges. - Examples : various lecithin (may act as anionic/cationic emulsifier depend on pH of system).

Hydrophilic-Lipophilic Balance (HLB)

 * Express the balance of size and strength of hydrophilic and lipophilic groups of emulsifier.
 * High HLB value (HLB>10)---relatively more polar molecules.
 * More lipophilic emulsifiers have HLB values from 1-10.
 * HLB values---to describe emulsifying properties of nonionic emulsifiers.
 * HLB 3-6 : good w/o emulsifier.
 * HLB 7-9 : good wetting agent, can be used for w/o or o/w emulsifier.
 * HLB 10-18 : good o/w emulsifier.

__Mono- & Di-glycerides__

 * High lipophilic with HLB values range from 1-10.
 * Produced by transesterification of glycerola nad triacylcerides.
 * Used in bakery products, frozen desserts, icings, toppings, peanut butter.





__Sucrose Esters__

 * Mono-, di-, and tri- esters of sucose with fatty acids.
 * HLB values from 7-13.
 * Mono-esters have HLB>16 for o/w emulsion.
 * Di-esters are good for w/o emulsion.
 * Tri-esters have HLB~1.



__Sorbitan Esters__

 * Sorbitan monostearate is the only sorbitan ester approved for food use.
 * Produced by reaction of sorbitol+stearic acid.
 * SPAN 60.
 * HLB=4.7
 * Used in conjunction with polysorbates in oil toppings, cake mixes, etc.





__Polysorbates__

 * Polyoxyethylene sorbitan esters.
 * Formed from reaction of sorbitan esters+ethylene oxide.

__Polysorbate 60__

 * Polyoxyethylene sorbitan monostearate or TWEEN 60.
 * HLB=14.9
 * Used in oil toppings, cake mixes, cake icings.



__Polysorbate 65__

 * Polyoxyethylene sorbitan tristearate or TWEEN 65.
 * Used in ice cream, frozen custard, ice milk, etc.



__Polysorbate 80__

 * Polyoxyethylene sorbitan monooleate or TWEEN 80.
 * HLB=15.0.
 * Used in special dietary foods, vitamin-mineral preparation, fat-soluble vitamins.



__Stearoyl Lactylates__

 * Ionic emulsifier.
 * Most hydrophilic emulsifiers used in food.
 * Lactic acid ester of monoglyceride with sodium or calcium.
 * Form strong complex with gluten in starch.
 * Used in bakery products.

__Lecithin and derivatives.__

 * Amphipilic emulsifiers.
 * Mixture of phospholipids including phosphatidyl choline, phosphatidyl ethanolamines, inositol phosphatides, etc.
 * Rich in egg yolk.
 * Derived from soybeans.
 * Used in baked goods, low-fat baked goods, chocolate, instant foods, confectionary products, cooking spray.



1.Dough con ditioning/strengthening.
- Emulsifier that aid in development of less tacky, more extensible dough processed through machinery without tearing or sticking. - Exert their effect during fermentation, mechanical handling, shaping, transport, during proofing and the first part baking time. - Eamples : calcium stearoyl lactylate, sodium stearoyl lactylate, polyoxyethylene sorbitan monostearate (PS 60), etc.

2. Crumb-softening
- Emulsifiers (anionic type) that complex with starch. - Interact with the flour components to create a longer lasting softness. - Emulsifier-starch (spacially amylose) complex retard starch crystallization or retrogradation which is responsible for staling. - Most effective softeners---lactylates and SMG, plastic mono- and diglycerides, DATEM.

__Cakes__

 * Cake batters---complex o/w emulsions or air-in-fat foamms, consist of suspended flour particles, dissolved sugars, proteins.
 * Emulsifiers added to fat-containing batters---stabilize aerated structure, promote finer distribution of fat droplets.
 * Alpha-tending emulsifiers (acetic acid esters of monoglycerides, lactic acid esters of monoglycerides, etc) promote finer distribution of fat droplets, increase viscosity of water phase---higher volume and more uniform cell structure in finished product.



__Confectionary Products & Coatings__

 * Emulsifiers---inhibit bloom, stabilize gloss, improve palatibility.
 * Bloom---occur when fat crystals undergo transition from beta' form to the most stable crystalline form, beta.



__Frozen Dairy Products - Ice Cream__

 * Emulsifiers---aerating agent and foam stabilizer.
 * Emulsifier stabilize the foam by destabilizing the product's emulsion.
 * It displace the protein from fat globule surface to the aqueous phase.
 * This increase liquid cream's viscosity, allows fat globules to agglomeratr.
 * Increased viscosity---promote aeration.
 * Agglomeration---stabilize air cells once the air is incorperated.



__Noodle & Pasta__

 * Emulsifiers---make a rigid complex with starch to protect starch granules, improve quality of starchy foods.
 * Fresh noodles---emulsifier makes it easier to handle dough, increase water absorption rate. Surface of noodle become smooth, unoform, less sticky.
 * Instant noodles---emulsifier improve absorption, decrease cooking time.
 * Macaroni & Spaghetti---emulsifier provide feeling of elasticity, smooth uniform surface inhibits sticking after boiling.