1. Functions on application
1.1. Emulsifier
1.2. Antistaling
1.3. Texture modification
1.4. Emulsion stabilization
1.5. Solid fluidization
1.6. Crystal modification
1.7. Palatability improvement
1.8. Agglomeration
1.9. Defoaming
1.10. Wetting
1.11. Solubilizing
1.12. Aeration or foaming
2. Properties of some common food emulsifier
2.1. Mono & Di-glycerides
2.1.1. most common used emulsifier
2.1.2. highly lipophilic with HLB values range from 1 to 10
2.1.3. produced by transesterification of gylcerol and triacylglycerides
2.1.4. used in bakery products,frozen desserts, icings, toppings and peanut butter
2.2. Sucrose Esters
2.2.1. mono-,di- and tri- esters of sucrose with fatty acids
2.2.2. HLB values from 7-13
2.2.3. mono-esters have HLB >16 for 0/w emulsions
2.2.4. di-esters are good for w/o emulsion
2.2.5. tri-esters have HLB ~1
2.3. Sorbitan Esters
2.3.1. sorbitan monostearate is the only sorbitan ester approved for food use
2.3.2. produced by the reaction of sorbitol and stearic acid
2.3.3. known as SPAN 60
2.3.4. HLB=4.7
2.3.5. used in conjunction with polysorbate in oil topping,cake mixes,etc
2.4. Polysorbate
2.4.1. polyoxyethylene sorbitan esters
2.4.2. formed from the reaction of sorbitan esters with ethylene oxide
2.5. Polysorbate 60
2.5.1. polyoxyethylene sorbitan monostearate ot TWEEN 60
2.5.2. HLB=14.9
2.5.3. applications:oil toppings,cake mixes and cake icing
2.6. Polysorbate 80
2.6.1. polyoxyethylene sorbitan monooleate ot TWEEN 80
2.6.2. HLB=15.0
2.6.3. applications for oils in special dietary foods, vitamin-mineral preparation and fat-soluble vitamins
2.7. Polysorbate 65
2.7.1. polyoxyethylene sorbitan tristearate ot TWEEN 65
2.7.2. permitted for use in ice cream, frozen custard, ice milk,etc
2.8. Stearoyl Lactylates
2.8.1. ionic emulsifier
2.8.2. the most hydrophilic emulsifier
2.8.3. lactic acid ester of monoglyceride with sodium or calcium
2.8.4. form strong complex with gluten in starch
2.8.5. valuable in bakery products
2.8.6. the most hydrophilic emulsifier
2.9. Lechitin & Derivatives
2.9.1. amphiphilic emulsifier
2.9.2. a mixture of phospholipid including phosphatidyl choline,phosphatidyl ethanolamine,inositol phosphatides,etc
2.9.3. rich in egg yolk
2.9.4. derived from sybean
2.9.5. can be chemically modified by provide a wide range of HLB
2.9.6. used in bakery goods,low-fat baked goods, chocolate,instant foods,confectionery products and cooking spray
3. Definition: Substances which reduce the interfacial tension of two normally immiscible phases, allowing them to mix and form an emulsion
4. Called surface active agent or surfactant
5. How does emulsifier work?
5.1. Emulsifier reduce interfacial tension between the two immiscible phases due to their molecular structure
5.2. They have both polar group with an affinity for water (hydrophilic) and a non polar group with an affinity for oil(lipophilic)
5.2.1. Lipophilic tails are composed of C16 (palmitic) or longer fatty acid
5.2.2. Polar head groups are composed of anionic, cationic, amphoteric or nonionic functional groups
5.3. The presence of both regions on the emulsifier molecule allows them to orient themselves at the phase interface & lower the interfacial energy that leads to instability
5.4. Emulsifier stabilise emulsions by means of monomolecular interfacial films & also by formation of steric and electrical barriers that prevent coalescence of the dispersed droplets
6. How to select an emulsifier?
6.1. Consult Malaysian Food Act & Regulations-use only approved emulsifier
6.2. Select an emulsifier after considering the functional requirements of the food system,the method of processing and the form of the finished product
6.3. Consult the supplier for approximate usage levels and methods of incorporating the emulsifier into the food
6.4. Determination the HLB requirements for the food system-involves screening emulsifier over a range of HLB values & several concentrations to determine approximate requirement-then verify through experimentation
6.5. Evaluate different combinations of two or more emulsifier to determine which gives the most stable emulsion
6.6. Optimize the usage level of the emulsifier.If the level is too low,the emulsifier may not perform the function;if too high,it may destroy the product.For example,polysorbate 80 acts as an aerating agent at 0.03-0.1%; however at 0.005%,it acts as a defoamer
6.7. Consult the supplier for approximate usage levels and methods of incorporating the emulsifier into the food
7. Emulsion
7.1. Definition:A dispersed two-phase system i.e. an intimate mixture of two liquids that are immiscible under normal conditions,whereby one phase is dispersed in the other in the form of fine droplets
7.1.1. the dispersed droplets: dispersed phase/inner phase
7.1.2. the medium in which the droplets are dispersed:continuous phase
7.2. Two types of simple emulsion
7.2.1. water in oil (w/o)
7.2.2. oil in water(o/w)
7.3. The stability of an emulsion depends on:
7.3.1. degree of division of the inner phase
7.3.2. quality/stability of the interfacial film
7.3.3. viscosity of the outer phase
7.3.4. ratio & the specific weight of the volume of the two phases
8. Type of emulsifiers
8.1. Nonionic
8.1.1. uncharged molecules relatively insensitive to effects of pH & salt content
8.1.2. most commonly used emulsifier
8.1.3. e.g. mono-and diglycerides,sorbitan esters,sucrose esters, polysorbates,polyoxyethylene glycol oleates(all conatin -OH functional group)
8.2. Anionic
8.2.1. posess a negative elctrical charge
8.2.2. e.g. stearoyl lactylate,diacetyl tartaric esters of monoglycerides(DATEM),succinylated monoglycerides
8.2.3. influenced by pH and ionic strength
8.3. Cationic
8.3.1. posess a positive electrical charge
8.3.2. e.g. amine compounds
8.3.3. not used for food additive(toxic)
8.4. Amphoteric
8.4.1. posess both positive and negative charges
8.4.2. e.g. various lechitin
8.4.3. may act as anionic or cationic emulsifier
8.4.4. depend on pH of the system
9. Functions
9.1. To promote emulsion stability,stabilized aerated systems and control agglomeration of fat globules
9.2. To modify texture,shelf life and rheological properties by complexing with starch and protein components
9.3. To improve the texture of fat-based foods by controlling the polymorphism of fats
10. Applications
10.1. Breads,Rolls & Buns
10.1.1. Functionality of emulsifier in bread and similar baked products are normally divided into two main groups (1) "dough conditioner" or "dough strenghteners", (2) "crumb softener"
10.1.2. Dough conditioning/strengthening-emulsifier that aid in development of less tacky,more extensible dough that are processed through machinery without tearing or sticking
10.1.3. e.g. calcium stearoyl lactylate,sodium stearoyl lactalyte(SSL),ethoxylated monoglycerides(EOM)
10.1.4. Crumb softening-emulsifier (anionic type) that complex with starch are referred to as "crumb softener"
10.1.5. Crumb softeners interact with the flour components in creating a longer lasting softness in the crumb of finished goods
10.1.6. Emulsifier-starch (specifically amylose) complex reatrd starch crystallization or retrogradation which is responsible for staling
10.1.7. The most effective softeners:lactylates and SMG.Plastic mono- & diglycerides,hydrated distilled monoglycerides and DATEM are also effective
10.1.8. Used from about 0.5-1% of flour weight
10.2. Cakes
10.2.1. Cake batters have been described as complex w/o emulsions or air-in-fat foams,consisting of suspended flour particles,dissolving sugar and proteins
10.2.2. Emulsifier added to fat-containing batters function to (1) stabilize the aerated structure (2) promotea finer distribution of the fat droplets
10.2.3. Alpha-tending emulsifier-e.g. acetic acid esters of monogylceride,lactic acid of monogylceride and propylene glycol esters promote finer distribution of fat droplets and an increase in viscosity of the water phase --> contribute to a higher volume and more uniform cell structure in the finished product
10.3. Confectionery Products & Coatings
10.3.1. Emulsifiers are used to inhibit bloom,stabilize gloss & improve palatability
10.3.2. Bloom, which occurs when fat crystals undergo transition from beta' form to the most stable crystalline form,beta form,causing the cocoa butter to separate from the brown nonfat phase
10.3.3. The bloom defect can be retarded with the use of emulsifier functioning as crystal modifiers-i.e.they stabilize the intermediate beta' crystalline form of the fat.These include distilled monoglycerides,,lactic acid esters of monogylceride,sorbitan monostearates & polysorbate 60
10.4. Frozen Dairy Products- Ice Cream
10.4.1. In ice cream,emulsifier function as aerating agent and foam stabilizer
10.4.2. In ice cream,emulsifier stabilize the foam by de-stabilizing the product's emulsion
10.4.3. Emulsifier displace the protein from the fat globule surface to the aqueous phase => increase the liquid cream's viscosity and allows the fat globules to agglomerate.The increased viscosity promotes aeration,while the agglomerates stabilize the air cells once the air is incorporated.
10.5. Noodle & Pasta
10.5.1. Emulsifier make a rigid complex with starch to protect starch granules and improve the quality of starchy foods
10.5.2. In fresh noodles,emulsifier makes easy to handle dough and increase the water absorption rate by 1 to 2%.The surface of the noodles become smooth and uniform and less sticky,resulting in improved for production.In instant noodles,emulsifier improves absorption and decrease cooking time.
10.5.3. For macaroni and spaghetti,emulsifier provide a feeling of elasticity,and a smooth uniform surface which inhibit sticking after boiling