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Easy Emulsifier Chemistry Demonstration
Soap is good at cleaning because it acts as an emulsifier , enabling one liquid to disperse into another immiscible liquid. While oil (which attracts dirt) doesn’t naturally mix with water, soap can suspend oil/dirt in such a way that it can be removed.
It’s easy to demonstrate the action of an emulsifer. All you need are two immiscible liquids and a little dishwashing detergent or soap.
Emulsifier Demo Materials
You only need simple home materials for this demo:
- oil or kerosene
- dishwashing detergent or soap
- flask or clear glass
If you like, you can add food coloring to this demonstration. It will color the water and not the oil or kerosene. You don’t need to add coloring to tell the water and oil apart, though. Some oils are naturally colored. Or, if you use kerosene, it’s often tinted so people can identify it on sight.
Perform the Demonstration
- Add some oil or kerosene together with some water in a flask. Swirl the contents around to try to mix them. What happens?
- Add a squirt of dishwashing liquid. Swirl or shake the flask to mix the ingredients. How has the layer of kerosene or oil been changed?
What could be easier, right?
Pepper and Water Emulsifier Trick
This video shows another fun way to illustrate emulsification. If you sprinkle pepper on a dish of water and touch your finger to the surface of the liquid, you get a wet finger but no reaction from the pepper. Next, if you put a drop of liquid dishwashing soap on the tip of your finger and touch the surface of the water, the pepper seems to scatter away.
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Emulsifiers in the kitchen
In association with Nuffield Foundation
- No comments
Test a range of common ingredients to see which ones stabilise an oil and water emulsion in this class practical
A mixture of oil and water usually separates quickly, but a range of substances act as emulsifiers. In this simple activity, students test a range of substances commonly found in the kitchen to see which ones stabilise an oil and water emulsion. Colloids such as these are often found in foods.
This experiment is very straightforward and does not take very long, although if students shake the boiling tubes too vigorously then the mixtures can take a while to separate. It is probably worth ensuring that students understand the meaning of the terms ‘emulsifier’ and ‘emulsion’ before they begin. They should be encouraged to record the results clearly, which probably means a results table.
Students should be warned against tasting anything – eg the sugar – in the laboratory. Eggs have a salmonella risk and should be marked with the lion symbol. Raw egg should be handled as little as possible, and a disposable pipette should be used to transfer it to the boiling tubes.
- Boiling tubes and bungs (see note 2 below)
- Disposable teat pipettes
- Spatulas or small spoons
- Cooking oil (see note 3)
- A range of detergents (see note 4)
- Mustard powder (see note 5)
- Egg white (see note 6)
Note: other substances can be used if preferred.
Health, safety and technical notes
- Read our standard health and safety guidance.
- Using boiling tubes rather than test-tubes means that more chemicals are consumed, but it is easier to see what is going on and much easier to clean up. The boiling tubes must be very clean and must not be contaminated with detergent.
- Corn oil is good because it is dark in colour and easier to see.
- Cheaper detergents do not usually work very well.
- Colman’s powder is good and powder lasts far longer than ordinary mustard so can be used from year to year.
- If you use fresh eggs it is fairly easy to separate these. Ensure no yolk contaminates the white – the other way round is less important. Due to the salmonella risk, handling raw egg should be kept to a minimum, so provide disposable pipettes with the egg for students to transfer it to the boiling tubes.
- Put about 2 cm 3 of oil into a boiling tube. Add about the same amount of water. Put a bung into the top of the tube and shake it – but not too vigorously. Remove the bung and leave the mixture to stand. Observe what happens.
- Repeat the experiment but add a small quantity of one of the substances you are testing before you shake the tube. (Suggested emulsifiers to test are: flour, sugar, mustard powder, egg white, egg yolk, a range of different detergents.)
- Test all the substances in the same way to find out which acts as an emulsifier.
Teaching notes
This experiment can easily be done in a kitchen as ‘making a salad dressing’ using oil and vinegar rather than oil and water. You can taste the resulting mixtures as well as observing them. If you do this, do not taste the ones containing raw egg; also do not taste those made with detergent as the emulsifier.
An emulsifier is a substance that stabilises an emulsion (a mixture of one liquid dispersed in another). Detergent, egg yolk and mustard are emulsifiers, the others are not. Students may observe colloidal mixtures in the other tubes, but they are not oil and water emulsions and two separate layers should be clearly seen.
Additional information
This is a resource from the Practical Chemistry project , developed by the Nuffield Foundation and the Royal Society of Chemistry. This collection of over 200 practical activities demonstrates a wide range of chemical concepts and processes. Each activity contains comprehensive information for teachers and technicians, including full technical notes and step-by-step procedures. Practical Chemistry activities accompany Practical Physics and Practical Biology .
© Nuffield Foundation and the Royal Society of Chemistry
- 11-14 years
- 14-16 years
- Practical experiments
- Compounds and mixtures
- Properties of matter
Specification
- An emulsifier can be used to prevent non-polar and polar liquids separating into layers.
- An emulsion contains small droplets of one liquid dispersed in another liquid.
- Emulsifiers for use in food can be made by reacting edible oils with glycerol. In the molecules formed, only one or two fatty acid groups are linked to each glycerol backbone. The hydroxyl groups present in the emulsifier are hydrophilic whilst the…
- 1.9.4 demonstrate knowledge and understanding of the terms soluble, insoluble, solute, solvent, solution, residue, filtrate, distillate, miscible, immiscible, evaporation and condensation;
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Fats and Oils: Emulsification
Home » Resources » Fats and Oils: Emulsification
Emulsions: making oil and water mix
By Laura Cassiday
In This Section
After reading this article, you will understand:
- the basic science of emulsions;
- how formulators choose which emulsifier to use for a particular emulsion;
- how emulsifiers are used in foods, nutraceuticals, personal and home care products, industrial lubricants, environmental technologies, biofuels, and other applications.
The immiscibility of oil and water has inspired the proverb “Oil and water don’t mix” and other expressions that reflect the general incompatibility of two entities, such as “My coworker and I are like oil and water.” Yet within our homes are numerous examples of products in which oil and water do mix: mayonnaise, milk, salad dressings, hand lotion, and hair conditioner, to name but a few. These examples represent emulsions, which are stable mixtures of tiny droplets of one immiscible fluid within another, made possible by chemicals called emulsifiers.
How emulsions and emulsifiers work
Simple emulsions are either oil suspended in an aqueous phase (o/w), or water suspended in oil (w/o). Milk is an example of an o/w emulsion, in which the fat phase or cream forms tiny droplets within the skim milk, or water phase. In contrast, margarine is a w/o emulsion containing droplets of water or skim milk in a blend of vegetable oils and fat. In both cases, emulsifiers are needed to prevent the suspended droplets from coalescing and breaking the emulsion.
Anybody who has made a simple oil-and-vinegar salad dressing knows that, with enough shaking or whisking, one can make a temporary emulsion. However, in the absence of emulsifiers, this unstable emulsion breaks down within minutes, and the oil forms a layer on top of the vinegar. For centuries, cooks have added natural emulsifiers, such as egg yolk, mustard, or honey, to help prevent this separation. Today, a wide variety of nature-based and synthetic emulsifiers are available for the diverse fields that benefit from them, including food, nutraceuticals, home and personal care, biofuel, environmental cleanup, and industrial lubricant applications.
Emulsifiers work by forming physical barriers that keep droplets from coalescing. A type of surfactant (see Sidebar), emulsifiers contain both a hydrophilic (water-loving, or polar) head group and a hydrophobic (oil-loving, or nonpolar) tail. Therefore, emulsifiers are attracted to both polar and nonpolar compounds. When added to an o/w emulsion, emulsifiers surround the oil droplet with their nonpolar tails extending into the oil, and their polar head groups facing the water (Fig. 1). For a w/o emulsion, the emulsifier’s orientation is reversed: nonpolar tails extend outward into the oil phase, while polar head groups point into the water droplet. In this way, emulsifiers lower the interfacial tension between the oil and water phases, stabilizing the droplets and preventing them from coalescing.
Emulsifiers can be cationic (positively charged polar head group), anionic (negatively charged head group), or non-ionic (uncharged head group). When charged emulsifiers coat droplets in an o/w emulsion, the positive or negative charges on the outside of the oil droplets electrostatically repel each other, helping to keep the droplets separated. Non-ionic emulsifiers tend to have large, bulky head groups that point away from the oil droplet. These polar head groups clash and tangle with head groups on other water droplets, sterically hindering the droplets from coming together. The type of emulsifier used depends on the application, with cationic emulsifiers typically used in low-to-neutral pH solutions and anionic emulsifiers in alkaline solutions. Non-ionic emulsifiers can be used alone or in combination with charged emulsifiers to increase emulsion stability.
How to choose the right emulsifier
How do product formulators choose which emulsifier to use for a particular emulsion? Calculating the hydrophilic-lipophilic balance (HLB) of an emulsifier or combination of emulsifiers can help. In an ideal emulsion, the emulsifier is equally attracted to the water phase and the oil phase. If the balance is tipped in either direction, the emulsifier may lose contact with the phase to which it is less attracted, causing the emulsion to break down.
Different emulsifiers have different HLB values, which can predict their ability to stabilize various kinds of emulsions (Fig. 2). The HLB scale ranges from 0 to 20, with 10 corresponding to an emulsifier that is equally attracted to water and oil. Emulsifiers with HLB values greater than 10 are more hydrophilic and thus better at stabilizing o/w emulsions. In contrast, emulsifiers with HLB values less than 10 are more hydrophobic and therefore better suited for w/o emulsions.
Furthermore, different oils have different HLB requirements. For example, vegetable oil emulsions need an emulsifier with an HLB of 7–8, whereas the required HLB value to form a stable castor oil emulsion is 14. By matching the HLB value of the emulsifier with that of the oil, formulators can greatly increase their chances of producing a stable emulsion.
According to George Smith, technical director for the Americas at Huntsman Performance Products in The Woodlands, Texas, USA, a combination of emulsifiers usually works better than any single emulsifier. “If you’re trying to make a mineral oil emulsion, for example, the HLB for mineral oil is 10,” he says. “So you’ll pick a pair of emulsifiers, one with an HLB higher than 10 and another with an HLB lower than 10. When you combine them, the average comes out around 10.”
The HLB system, which works primarily for non-ionic emulsifiers, has been around since 1954. In the 1970s, the hydrophilic-lipophilic difference (HLD) system was introduced. The HLD system works for ionic as well as non-ionic surfactants, and it is better able to take into account detailed characteristics of a particular emulsion such as salinity, oil type, surfactant concentration, and temperature.
The HLD equation includes terms for the salt concentration, “oiliness” of the oil (the effective alkane carbon number), and the characteristic curvature (Cc) of the emulsifier. The Cc value of an emulsifier reflects whether the emulsifier prefers to curve around an oil droplet in water (negative Cc) or to curve around a water droplet in a w/o emulsion (positive Cc). For example, a very hydrophilic emulsifier, sodium laurel sulfate, has a Cc of –2.3, whereas a very hydrophobic emulsifier, dioctyl sodium sulfosuccinate, has a Cc of 2.6. The Cc for combinations of emulsifiers is the weighted average for each emulsifier. The HLD scale centers on 0, which corresponds to the optimal emulsion. Online calculators exist to optimize the HLD for a particular emulsion (e.g., www.stevenabbott.co.uk/HLD-NAC.html).
Macro- and microemulsions
Increasingly, formulators are interested in making microemulsions, which offer greater stability than conventional macroemulsions. As the name suggests, microemulsions have smaller droplet sizes than regular emulsions, making them appear transparent rather than opaque. Unlike macroemulsions, microemulsions are thermodynamically stable. “Given enough time, a macroemulsion will break down into water and oil phases,” says David Sabatini, associate director of the Institute for Applied Surfactant Research at the University of Oklahoma, Norman, USA. “But time is not a factor in how long a microemulsion will remain in its current state.” In addition, if a temperature change causes an emulsion to break down, a microemulsion will spontaneously reform when the temperature changes back to its original value. In contrast, a macroemulsion requires an energy input to reappear.
Microemulsions are made differently from macroemulsions. Macroemulsions require high-intensity mixing. Because microemulsions are a thermodynamically stable end point that a system naturally migrates toward, they generally do not require vigorous mixing. However, formulators often use gentle agitation to evenly spread the components and speed up the process of microemulsion formation.
Compared to macroemulsions, microemulsions require more surfactant. “Time stability points in the direction of microemulsions, but surfactant requirement may point in favor of macroemulsions,” says Sabatini. “It may be that 3 or 6 months is plenty long enough for your application and time may not be a factor in that situation.” For example, food products will often go bad before a macroemulsion breaks down, he says.
Because of their remarkable stability, microemulsions are finding applications in diverse fields such as personal care products, oil field chemicals, and medicine. “Macroemulsion concepts have been around for centuries, but advanced microemulsion concepts are only about two to three decades old,” says Sabatini. “There’s growing interest in microemulsions because we’re just beginning to understand their capabilities.”
Many popular food items are emulsions, including mayonnaise, salad dressings, sauces such as Hollandaise, chocolate, and ice cream. Lecithin, a blend of naturally occurring phospholipids, is widely used in the food industry to promote o/w emulsions. Worldwide, most commercial lecithin comes from soybean oil. Egg yolk, the traditional emulsifier for mayonnaise and sauces, also contains lecithin. Other common emulsifiers in foods are proteins, fatty acid esters, sodium stearoyl lactylate, and mono- and diglycerides.
Making food emulsions can be challenging because “foods are complex systems with many different ingredients interacting,” says John Neddersen, senior application scientist in fats, oils, and emulsifiers at DuPont Nutrition and Health, based in New Century, Kansas, USA. “Although guidelines like the HLB scale can help, most of the time experience and experimentation are needed to find the optimal choice of emulsifiers and usage rates.” Neddersen notes that processing can be another challenge when working with food emulsions. “A company might have a single formula run at multiple locations and see different results at the different plants,” he says. These differences may arise from seemingly subtle variations in plant conditions.
DuPont sells a broad range of emulsifiers, including the Panodan ® DATEM (diacetyl tartaric acid ester of monoglycerides) line especially for bakery products and the Cremodan ® line for ice creams and other frozen desserts. As an alternative to lecithin in chocolates and other confectionary, DuPont offers Grindsted ® CITREM, a citric acid ester. This emulsifier can substitute for soy lecithin, which has recently come under fire, particularly in Europe, because most soy crops grown for export (especially the United States, Brazil, and Argentina) are genetically modified. Non-genetically modified soy is expensive and in short supply. Therefore, CITREM may prove an attractive alternative for confectioners who want to avoid ingredients made from genetically modified soy.
Sustainable sourcing of palm oil has also become a customer concern, as reports have surfaced that the development of palm oil plantations harms the environment and threatens endangered wildlife in Malaysia and Indonesia, where most palm oil originates. As a result, DuPont introduced a portfolio of emulsifiers based on sustainably sourced palm and non-palm oils. By 2015, DuPont has pledged to source 100% of its palm oil from plantations certified by the Roundtable on Sustainable Palm Oil (RSPO).
Reduced-fat emulsions are another hot topic for the food industry. When fat is removed from a food to make a reduced-fat or fat-free version, the taste, appearance, and texture often suffer. D. Julian McClements, professor of physico-chemistry at the University of Massachusetts Amherst, USA, says that there are several ways that emulsions or emulsifiers could help reduce the fat content of foods. For instance, researchers could structure water-in-oil-in-water (w/o/w) emulsions. “You could take some of the fat out of the droplets and replace it with water,” he says.
Another approach, called heteroaggregation, is to mix oil droplets coated with emulsifiers of opposite charge. “We mix a positive droplet and a negative droplet together, and they form a gel network,” says McClements. “The resulting emulsion has a very high viscosity and low fat content and mimics some of the characteristics of a high-fat product.”
Nutraceuticals
Researchers are exploring emulsions as delivery vehicles for vitamins, supplements, and other nutraceuticals. McClements’ lab has used emulsions to encapsulate vitamin E, carotenoids, omega-3 fatty acids, curcumin, coenzyme Q 10 , and other bioactive compounds. Eventually, he would like to incorporate nutraceuticals such as these into functional foods.
“One of our goals is to increase the stability of active compounds that are encapsulated in emulsions in food particles,” says McClements. “We’d also like to control their fate in the gastrointestinal tract once they’ve been digested.”
In addition to conventional emulsions, McClements’ lab makes more complex emulsions such as nanoemulsions, solid-lipid nanoparticles, filled hydrogel particles (Fig. 3), and multilayer emulsions. Different types of emulsions could have different applications. “Some of them can protect components from chemical degradation, some can deliver compounds to the colon, and some can control flavor release,” says McClements. “So you have to have a different kind of delivery system for each application.”
Multilayer emulsions consist of oil droplets coated with an emulsifier plus one or more biopolymer layers, dispersed in an aqueous solution. The emulsifier is typically electrically charged, and the polymer layer(s) have opposite charges that attract them to the surface of the oil droplet.
According to McClements, multilayer emulsions tend to have better physical stability than single-layer emulsions through fluctuations in pH, ionic strength, temperature, freezing and thawing, and dehydration. In addition, researchers can design multilayer emulsions to control their breakdown in the gastrointestinal tract. “You can make them so they’re digested very quickly, like a normal emulsion, or you can make them so they go further down the gastrointestinal tract,” he says. “The latter might be useful if you want to deliver something to the colon or you’re trying to control satiety by getting undigested compounds further down in the gastrointestinal tract.”
Personal care
Most personal care products, including lotions, creams, shampoos, and conditioners, are emulsions. Common emulsifiers for personal care products include ethoxylated alcohols, carboxylates, sodium isethionate, glycerol monostearate, cetyl alcohol, stearyl alcohol, and silicone emulsifiers such as dimethicones.
“The trend right now is most people would like to use an emulsifier that’s based on plant raw materials rather than petrochemicals,” says Smith. Synthetic emulsifiers such as ethoxylated alcohols and their naturally derived counterparts have identical structures, performance, and biodegradation. “The price swings back and forth depending on the price of palm kernel oil in Malaysia and the price of ethylene in North America,” says Smith. “At the moment, I think petrochemicals have the advantage, but it switches every two to three years.”
Juan Mateu, technical director at JEEN International in Fairfield, New Jersey, USA, says that there has been a move away from synthetic ethoxylated alcohols in recent years due to worries about residual 1,4-dioxane, a suspected carcinogen that is a by-product in their manufacture. Naturally derived glucosides have been suggested as replacements for some applications. However, “It’s too early to say that ethoxylated alcohols can be replaced,” says Mateu. “There are some emulsions you can make with glucosides, but for the most part the whole world is still using ethoxylates.”
In 2009, JEEN International launched its Jeesperse line of cold-process emulsifiers, which allows formulators to make emulsions containing waxy substances at ambient temperatures (25–30°C). Many common emulsifiers in personal care products, such as cetyl alcohol and glycerol monostearate, are waxes with relatively high melting points (up to 165°C). Prior to Jeesperse, manufacturers had to heat emulsifiers in the oil phase to melt them, and then add the melted emulsifier to the aqueous phase and cool the emulsion at a controlled rate down to room temperature. In contrast, Jeesperse allows the emulsion to be made in a single kettle at room temperature, resulting in significant savings of money and time.
The secret ingredients in Jeesperse products are polyelectrolytes, such as sodium polyacrylate. The polyelectrolytes are polar molecules that can induce polarity in nonpolar waxes, enabling them to dissolve in cold water (a polar solvent). Mateu says that in the lab, he can make an emulsion with the cold process in about 20 minutes, as opposed to several hours of mixing, heating, and cooling with the conventional process. “Aesthetically, the product is the same thing—it feels the same and looks the same—so why not?” he says.
A short video demonstrating the cold-process formulation of a lotion with a Jeesperse emulsifier.
Many household cleaners and laundry detergents contain surfactants that emulsify oily dirt particles so that they can be diluted and washed away. Ethoxylated alcohols are a common ingredient of laundry detergents. Many detergents contain a blend of nonionic and anionic emulsifiers to lift stains out of textiles.
According to Sabatini, removing triglycerides such as fats, bacon grease, and vegetable oils from fabrics is particularly challenging. His lab has shown that extended surfactants, which are surfactants with intermediate polarity groups (e.g., polypropylene oxide and polyethylene oxide) inserted between the hydrophilic head and hydrophobic tail, are effective in removing these types of oily stains.
Industrial lubricants
Metalworking fluids and other industrial lubricants are typically o/w emulsions. Emulsifiers allow metalworkers to make use of both the lubricating properties of oils and the cooling capabilities of water. Anionic and nonionic emulsifiers are often used together in metalworking fluids. Cationic emulsifiers are rarely used because they are unstable in the alkaline solutions (pH 8–9.5) required for metalworking fluids.
Environmental technologies
Emulsions and microemulsions have been applied to environmental technologies such as subsurface remediation and biofuel production. For example, when oil or gas is spilled, the oil becomes trapped in pores in the soil and rock. Sabatini’s lab has developed alcohol-free microemulsions that help remove oil contaminants from the subsurface in an environmentally friendly manner. “The oil is trapped in the pores because of the interfacial tension between water and oil,” says Sabatini. “If we can lower that interfacial tension with emulsifiers, we can increase our rate of cleaning up contamination.”
In 1997, Sabatini and several colleagues founded a company called Surbec Environmental, LLC, to implement this technology. Since then, Surbec has assisted with the environmental cleanup of multiple sites in the United States and abroad. Examples include a gas station with a leaky underground tank and a military site contaminated with jet fuel.
Sabatini has also applied his emulsions research to the more efficient production of biofuel. Biodiesel is a vegetable oil, such as soybean oil, that has been chemically modified through a transesterification reaction to reduce its viscosity. “In terms of combustion, you don’t need to modify the vegetable oil. You can use vegetable oil in a diesel engine, and it’ll work pretty well without modification,” says Sabatini. “It’s just that vegetable oil has viscosity problems, especially at lower temperatures.”
As it turns out, microemulsification of vegetable oils can reduce viscosity without the need for the transesterification reaction. This would save time and allow more of the raw material to be used as fuel. However, Sabatini notes that the research is still in its early stages.
Although humans have been making emulsions for hundreds, if not thousands, of years, we are only now beginning to appreciate their diverse applications in many fields. Complex emulsions, such as microemulsions and multilayer emulsions, promise to further expand the repertoire of applications, particularly in emerging areas such as functional foods and biodiesel production. Now if only we could find an emulsifier for that difficult coworker.
Laura Cassiday is a freelance science writer and editor based in Hudson, Colorado, USA. She has a Ph.D. in biochemistry from the Mayo Graduate School and can be contacted at [email protected] .
What’s the difference? The terms surfactant, emulsifier, and detergent are often used interchangeably, but there are distinctions.
Surfactant is the broadest term: Both emulsifiers and detergents are surfactants. Surfactants, or surface-active agents , are compounds that lower the surface tension between two liquids or between a liquid and a solid. Surfactants are amphiphilic, meaning that they contain hydrophilic (water-loving) head groups and hydrophobic (water-hating, or oil-loving) tails. Surfactants adsorb at the interface between oil and water, thereby decreasing the surface tension.
An emulsifier is a surfactant that stabilizes emulsions. Emulsifiers coat droplets within an emulsion and prevent them from coming together, or coalescing.
A detergent is a surfactant that has cleaning properties in dilute solutions.
Likewise, the terms emulsion, suspension, and foam are sometimes confused.
An emulsion is a mixture of two or more liquids, with or without an emulsifier, that are normally immiscible. One of the liquids, the “dispersed phase,” forms droplets in the other liquid, the “continuous phase.”
A suspension is a solid dispersed in a liquid. The particles are large enough for sedimentation.
A foam is a substance in which gas bubbles are suspended in a liquid.
Technical session highlights suspensions, emulsions, and foams You can learn about the latest developments in suspensions, emulsions, and foams by attending a joint technical session on these topics at the upcoming 2014 AOCS Annual Meeting & Expo in San Antonio, Texas, USA. The session, which will be held on Wednesday, May 7, from 1:55–5 p.m., will feature a wide range of technical topics—from the fabrication of reduced-fat products by controlled aggregation of lipid droplets to the formulation of lipopeptide biosurfactant mixtures for dispersing oil spills in seawater.
The session is jointly sponsored by AOCS’ Edible Applications Technology (EAT) and Surfactant & Detergent (S&D) divisions, and is cross listed in the program as EAT 5.0 and S&D 5.1. A complete list of presentations .
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Making an Emulsion
This Unilever Laboratory Experiment, published in 1966, demonstrates that mineral oil and water form an oil-in-water emulsion when sodium oleate is the emulsifier, and a water-in-oil emulsion when calcium oleate is the emulsifier. Water-soluble and oil-soluble dyes are used to distinguish the two types of emulsion.
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Please be aware that resources have been published on the website in the form that they were originally supplied. This means that procedures reflect general practice and standards applicable at the time resources were produced and cannot be assumed to be acceptable today. Website users are fully responsible for ensuring that any activity, including practical work, which they carry out is in accordance with current regulations related to health and safety and that an appropriate risk assessment has been carried out.
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| Subject(s) | Science, Practical work, Chemistry |
|---|---|
| Age | 16-19 |
| Published | 1960 - 1969 |
| Published by | |
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November 17, 2011
Emulsion Explosion: How to Make Butter
Another experiment from Crazy Aunt Lindsey's Mad Science Room
By Lindsey E. Murphy & CrazyAuntLindsey.com
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Key concepts Physical Science Molecules Emulsion Colloid Introduction Whoever told you oil and water don't mix might not have considered the term "emulsion." It is possible for tiny particles of two seemingly unmixable substances to suspend in one another—like oil and water! This super scientific experiment demonstrates the magic of the invisible globule while bringing a yummy result to the table. Background Milk is mostly water with about 5 to 10 percent protein and fat globules. Cream is milk that contains closer to 15 to 25 percent fat globules. What's a "globule"? A globule is a super tiny membrane filled with fat molecules—think of a microscopic water balloon. Because these globules are so small and fat is lighter than water, it floats! This forms a "stable suspension," a colloid! The bigger the globules, the slower it moves—and the thicker the milk or cream. When shaken, the globules' membranes smash against each other and break apart like bursting water balloons. The fat then spills out and clumps together with the contents of other burst globules, which causes the freed fat to separate from the water. As this process continues, two new substances are formed: a solid (butter) and the remaining liquid (buttermilk)! Materials • Jar or other airtight container • Heavy cream (at room temperature) Preparation • Make sure you are working with a clean jar or airtight container. • It is important that your heavy cream or whipping cream be room temperature. Procedure • Pour the cream into the jar. • Screw the lid onto the jar securely. • Now, hold on tight to your jar and "shake with force." No wimpy shakes here! Use your arms to make firm, vigorous strokes. Do this for between five and 20 minutes. You should start to see results in about 10 minutes. Can you see changes happening inside the container? Does it start to feel different when you are shaking it? The butter is done when it has completely separated from the liquid and forms a solid, single clump.
Observations and results You will have created two new substances—butter and buttermilk! The butter is the result of the globules having broken apart and their fatty contents adhering together. The buttermilk, then, is the liquid that is left over. How are the two substances different? Are they both different from the heavy cream you started out with? How so? What different things can you do with butter and with buttermilk? Can you think of other mixtures that are emulsions? (Hint: think of other oil and water substances.) Cleanup • If you intend to use them later, keep the butter and buttermilk in the refrigerator to prevent them from going bad—that's a whole other transformation, and one with results that are not quite so yummy. More to explore " How to Make Butter out of Cream, and Why It Works " from Crazy Aunt Lindsey " Salad Dressing Science Mixes Up Researchers " from Scientific American " Ice Cream Science " Scientific American " Making Butter at Home " from Boston Children's Museum This activity brought to you in partnership with CrazyAuntLindsey.com
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COMMENTS
3. Add whisked egg, vanilla essence and milk. 4. Gradually add flour mix. 5. Place in a greased lined cake tin (approx 19 x 9 x 5 cm). Bake at 190°C for about 30 mins. An emulsion can be defined as a mixture of oily and watery liquids. Here are some ideas for investigating emulsions.
Three five ml Measuring cylinders. Oil, Vinegar, an Egg (separated into white and yolk), Mustard, Salt, Pepper, Sugar, Paprika, Glyceryl Monostearate - GMS. Method. Measure 5ml of vinegar into each of a series of 10 test tubes in a rack. Add the various ingredients as indicated below and shake each tube 100 times.
Suggesting ways of creating an emulsion from two non-mixing, based on observations of the experiment. Introduction: This experiment can easily be done in a kitchen as 'making a salad dressing' using oil and vinegar rather than oil and water. You can taste the resulting mixtures as well as observing them.
Emulsion Definition. An emulsion is defined as a mixture of two or more normally immiscible (unmixable) liquids. Emulsions are colloids, which are homogeneous mixtures consisting of particles larger than molecules that scatter light, but are small enough that they don't separate. Emulsions consist of two parts: the dispersed phase and the ...
By vigorously mixing the emulsifier with the water and fat/oil, a stable emulsion can be made. Commonly used emulsifiers include egg yolk, or mustard. Emulsions are thicker than either the water or of fat/oil they contain, which is a useful property for some foods. Explore. In four glasses or test tubes place 2.5ml vinegar and 2.5ml oil.
Emulsifier Demo Materials. You only need simple home materials for this demo: water. oil or kerosene. dishwashing detergent or soap. flask or clear glass. If you like, you can add food coloring to this demonstration. It will color the water and not the oil or kerosene. You don't need to add coloring to tell the water and oil apart, though.
Put about 2 cm 3 of oil into a boiling tube. Add about the same amount of water. Put a bung into the top of the tube and shake it - but not too vigorously. Remove the bung and leave the mixture to stand. Observe what happens. Repeat the experiment but add a small quantity of one of the substances you are testing before you shake the tube.
and agitate to create an emulsion. Let the mixture stand and within a few moments, the layers will separate. 3. Add oil, water and dish soap to the second flask. 4. Shake the flask to mix the contents. In the presence of the emulsifier, the emulsion will
An emulsion can be defined as a mixture of oily and watery liquids. To make an emulsion you need an emulsifier and force such as whisking and beating to break the oil droplets apart so they mix with the watery liquid. There are two types of emulsions. The first is when water gets dispersed into fat/oil (such as butter, margarine or chocolate ...
Abstract In this cooking and food science fair project, you will explore the role of proteins as emulsifying agents. Emulsifying agents are substances that are soluble in both fat and water and enable fat to be uniformly dispersed in water as an emulsion. Foods that consist of such emulsions include butter, margarine, salad dressings, mayonnaise, and ice cream.
How emulsions and emulsifiers work. Simple emulsions are either oil suspended in an aqueous phase (o/w), or water suspended in oil (w/o). Milk is an example of an o/w emulsion, in which the fat phase or cream forms tiny droplets within the skim milk, or water phase. In contrast, margarine is a w/o emulsion containing droplets of water or skim ...
This Unilever Laboratory Experiment, published in 1966, demonstrates that mineral oil and water form an oil-in-water emulsion when sodium oleate is the emulsifier, and a water-in-oil emulsion when calcium oleate is the emulsifier. Water-soluble and oil-soluble dyes are used to distinguish the two types of emulsion.
Procedure. • Pour the cream into the jar. • Screw the lid onto the jar securely. • Now, hold on tight to your jar and "shake with force." No wimpy shakes here! Use your arms to make firm ...
Label each glass with the emulsifier that was added, and label the empty glass "control.". Label the data sheet with the emulsifiers you will be testing. Unseparated (left) and separated (right) mixtures of olive oil and balsamic vinegar. To each glass, add four tablespoons of vinegar, and swirl to fully mix in the emulsifier.
Give one numbered beaker to each group with pipette/medicine dropper. Have students drop one drop of emulsion into test tube/bottle of water. Have students put lids tightly on containers and shake vigorously. Observe water in test tube/bottle. If water is cloudy/milky then have the students record that emulsion as o/w.
This simple science experiment explores the properties of oil and water, and teaches colour theory. All in one simple, quick experiment that is perfect preschool and early elementary. ... To get a stable emulsion, you will have to add an emulsifier. An emulsifier is a molecule that has a hydrophobic (non-polar) end and a hydrophilic end. The ...
What is an emulsion? Two or more liquids that don't mix create an emulsion when one is added to the other. The properties of the new liquid are different to either of the liquids alone. Emulsions are a special type of colloid. Liquids that don't mix together are called immiscible liquids.
3/4 cup neutral oil such as safflower or canola. In a medium bowl, whisk together the egg yolk, lemon juice, mustard, salt and 1 teaspoon cold water until frothy. Whisking constantly, slowly dribble in the oil until mayonnaise is thick and oil is incorporated. When the mayonnaise emulsifies and starts to thicken, you can add the oil in a thin ...
In the three science lessons found here, students learn will the concepts of solubility and emulsion. These lessons involve science experiments on oil and water and can be used consecutively within a longer lab period, or used across the span of three individualized lessons. Either way they are presented, students will be active learners deepening their understanding of new science concepts.
Ask your kids to write down what they learned (some definitions to keep handy: molecules, immiscible, emulsion) during these oil and water experiments for kids. Keep the conversation, curiosity, and kitchen science going with a science journal to document your findings. You might just find that you have the next Marie Curie on your hands!
Add whisked egg, vanilla essence and milk. 4. Gradually add flour mix. 5. Place in a greased lined cake tin (approx 19 x 9 x 5 cm). Bake at 190°C for about 30 mins. Characterising emulsionsEmulsions are mixtures of immiscible materials such as oil and water. Such mixtures are possible by forming tiny droplets of one liquid (dispersed phase ...
At its most basic, an emulsion is a suspension two liquids within each other that would not naturally mix. Think of a liquid-a cup of vinegar, for instance-as made up of millions of tiny droplets. If you pour oil into the vinegar, at first the oil will float on the top of the vinegar because it's less dense. However, if you whisk them ...
By Anya Miksovsky '20While mayonnaise has become a staple of almost every American household, creating it manually can be an arduous process. If not using a food mixer or blender, serious time must be dedicated towards stirring vigorously by hand. The process requires laborious sacrifice but, to true mayonnaise connoisseurs, results in a product infinitely superior to the factory-produced ...
Emulsion is the term used to describe a system of two immiscible liquids where one liquid is dispersed in the other, such as oil-in-water (O/W), water-in-oil (W/O), and multiple emulsions (W/O/W or O/W/O). Food products, including mayonnaise, salad dressings, emulsified sausage, and ice cream, are prime examples of emulsions.
In your experiment, you will see the food dye in the water make its way to the leaves. Build a balloon-powered racecar What you need: tape, scissors, two skewers, cardboard, four bottle caps, one ...
The Rotating Wheel Rayleigh Taylor Instability Experiment - YouTube ... in a machine that accelerated the egg-and-oil emulsion until it started to flow. ... and was previously a senior writer for ...