Emulsification

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Emulsification

An emulsion, as defined by Food Technology, is a “temporarily stable mixture of immiscible fluids, such as oil and water, achieved by finely dividing one phase into very small droplets.”1 Nature designed multiple functions into the egg, including its ability to emulsify. While most commonly associated with mayonnaise,2the emulsifying capacity of whole eggs, egg yolks and even egg whites plays a role in baking and other applications. The absence of eggs in certain formulations such as mayonnaise can affect emulsion stability and final product appearance.2

Fresh liquid eggs, frozen eggs and spray-dried all have the capacity to emulsify, and according to Christine Alvarado, Ph.D., Texas A&M University, there is no essential difference found between them.3 The most popular forms however, include liquid, refrigerated whole eggs or frozen yolks. Frozen yolk has 10 percent added salt or sugar to promote a smooth, creamy, viscous yolk. Egg white emulsifies due to its albumin protein component, while for egg yolk it is its lecithoprotein content.4

Specifically the egg as emulsifier:

  • Acts as a stabilizing agent by reducing surface tension
  • Reduces the force required to create the droplets that comprise an emulsion

The reduction of surface tension is due to the lecithin or phosphatidylcholine contained within the egg yolk. This amphiphilic molecule has two ends, one hydrophobic and one hydrophilic, which minimizes the energy required to form an emulsion by reducing oil/water interfacial tension.5

There are multiple factors that can affect an emulsion’s stability such as temperature, mixing speed and time and more. Two critical pieces of the puzzle include viscosity and the size and uniformity of the droplet.

An emulsion is thicker or more viscous than its separate components, or the oil and water it contains. Egg yolks provide a viscous, continuous phase. This promotes stability in emulsions because it prevents the dispersed oil droplets from moving around and gathering, or coalescing. Adding egg yolk to whole eggs increases emulsion viscosity, lending it greater stability.

In addition, the smaller the droplet and more uniform in size, the better the emulsion and the better the mouthfeel and texture of the finished product. When mixed at the proper speed and adding ingredients in the proper order, formulators can control droplet size and dispersion. For example, oil must be added slowly to water so that the lecithin within the egg yolk can thoroughly coat the small droplets. This coating acts as a barrier to prevent the droplets from joining back together (flocculating or coalescing) to enhance emulsion stability and improve product appearance and texture.6

Some common applications for eggs as emulsifier beyond mayonnaise and sauces includes salad dressing, ice cream and baked goods such as muffins, bread, cinnamon rolls and cheesecake6 to name a few.

In ice cream, eggs added during the freezing process help promote a smoother texture and ensure the ice cream does not melt rapidly after serving. Emulsifiers also help improve freeze/thaw stability, an important quality for ice cream as well as sorbets, milkshakes, frozen mousse and frozen yogurt.7

Within the commercial baking industry, which relied upon eggs as the first emulsifier, a proper emulsion impacts both product and process. Eggs can help increase product volume, supply a tender crust and crumb, finer and more uniform cell structure, a bright crumb color and slow the crumb from firming, increasing product shelf life. In terms of process, emulsification activity enables proper blending of ingredients and protects the dough during mechanical handling.4

  1. Clark J. (2013). Emulsions: When Oil and Water Do Mix, Food Technology magazine, Volume 67, No. 8
  2. Munday E, Werblin L and Deno K. (2017). Mayonnaise Application Research: Comparing the Functionality of Eggs to Egg Replacers in Mayonnaise Formulations, CuliNex, LLC, Seattle, USA
  3. Alvarado C. (2016). Emulsification [PowerPoint presentation] College Station, TX
  4. Pyler EJ and Gorton LA. (2010). Baking Science & Technology, Fourth Edition, Volume 1, Sosland Publishing Co., Kansas City, Missouri, USA
  5. McKee S. (2016). Eggs as a Functional Emulsifier [PowerPoint presentation]. Auburn AL
  6. Munday E, Werblin L and Deno K. (2017). Cheesecake Application Research: Comparing the Functionality of Eggs to Egg Replacers in Cheesecake Formulations, CuliNex, LLC, Seattle, USA
  7. Stadelmen WJ and Cotterill OJ. (1995). Egg Science and Technology, Fourth Edition, Haworth Press, Inc., New York, USA

Whipping

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Whipping

Eggs and egg whites can be whipped into a foam for aeration and to improve product texture and appearance. Egg products’ whippability plays a role in baking and frozen desserts such as ice cream, in addition to certain confections. The various types of egg products display varying levels of whippability, with differences between egg white, whole egg and egg yolk. Dried eggs also perform in a different manner than liquid or frozen in terms of whippability.1

Pasteurization, a process applied to all further processed egg products, does not impact whippability.2 Egg white for example is very stable in a dried state and its whipping properties remain unaffected unless excessively high temperatures are applied. However the whipping properties of egg products containing yolk do witness a loss in efficacy when in dried form, so refrigerated and frozen are recommended for certain applications.

In angel food cake, egg whites comprise the sole egg ingredient. Dried egg white solids if chosen for application often are reconstituted prior to use. Proper mixing procedures help maximize foam volume. In commercial practice, egg white solids perform well with continuous batter mixing systems.3 When whipped, the proteins within the egg white unfold or denature to form a relatively stable foam structure useful in angel food cake, as well as sponge cake, certain confections and other baking applications.

Whippability has a bit of a different meaning when it comes to ice cream. Whippability refers to the whipping quality of the ice cream mixture itself. The proper emulsifier, such as egg yolk, results in reduced air cell sizes and a homogeneous distribution of air in the ice cream. The lecithin-protein complex in egg yolk solids improves the whippability of ice cream, also lending it a more dry appearance, smoother body and texture and a slower meltdown.4 One reference indicates eggs have a pronounced effect in improving the body and texture, have almost no effect on the freezing point and increase the viscosity—all positive benefits in terms of ice cream manufacture.5

There are mix calculations that help formulate ice cream and frozen dairy desserts, to determine the percentage required of the various ingredients.6 Egg yolk solids are especially desirable in mixes in which butter or buttermilk is used as a main source of fat. Egg yolks or whole eggs improve the rate of whipping more if they are sweetened with 10 percent sugar or corn syrup before they are frozen or dried.

Ice cream, according to the U.S. Code of Federal Regulations (CFR) can be called custard or “French” if the egg yolk content is at least 1.4%.7

1. Stadelmen WJ and Cotterill OJ. (1995). Egg Science and Technology, Fourth Edition, Haworth Press, Inc., New York, USA

2. Belitz H, Grosch W, Shieberle P. (2009). Food Chemistry, 4th revised and extended Edition, Springer Berling Heidelberg

3. Pyler EJ and Gorton LA. (2010). Baking Science & Technology, Fourth Edition, Volume 1, Sosland Publishing Co., Kansas City, Missouri, USA

4. Campbell J, Marshall R. (2016). Dairy Production and Processing: The Science of Milk and Milk Products, Waveland Press, Inc., Long Grove, Illinois, USA

5. Marshall R and Arbuckle WS, (2000) Ice Cream, Fourth Edition, Aspen Publishers, Inc., Gaithersburg, Maryland, USA

6. https://www.uoguelph.ca/foodscience/book-page/mix-calculations-ice-cream-and-frozen-dairy-desserts

7. http://www.milkfacts.info/Milk%20Processing/Ice%20Cream%20Production.htm

Addition, Not Subtraction to Best Support Clients

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Addition, Not Subtraction To Best Support Clients

Angela Gomez, RDN

Nutritious Dietary Patterns

 

Key messages

  • Focusing on what can be added rather than reduced or eliminated, when it comes to behavior change, may help build a growth mind-set and build self-efficacy in the clients we work with.
  • Supporting clients on their health journey by adding to the behaviors they are already engaged in is a more collaborative and positive approach that may increase success and reduce harm.

When discussing behavior change, emphasizing addition (rather than harping on subtraction), can create a mind shift in the individuals and families we work with. Focusing on the addition of health behaviors gives people more options and helps create an experimental environment, rather than a “pass-fail” environment. If we help develop this skill in parents or guardians, then they, in turn, can influence their family in a similar way. This is where the “think addition, not subtraction” phrase comes into play.

I have used this phrase in my work with private clients, youth sports teams, collegiate athletes, and clients with eating disorders. In my sessions, I’ll often redirect the “subtraction talk” and ask open-ended questions to elicit some “addition talk”. I am not as concerned with emphasizing the behavior a client wants to avoid; I am interested in the behavior they want to change – given what they have available to them now (i.e., time, food accessibility, etc.). There is hope and positivity in the idea of adding small behavior modifications, whereas only focusing on avoiding habitual behaviors can feel defeating.

Need more convincing on why we should emphasize addition over subtraction? Here are three reasons to consider implementing this mindset in your own practice:

1. Subtraction represents rules and restrictions, while addition calls attention to abundance and provides options. Restriction emphasizes the “don’t” without providing options for the “do”. There are simply more possibilities with addition. Supporting clients as they build a growth mindset fosters agency, self-efficacy, and honesty in their journey towards owning their positive health behaviors. In more vulnerable populations, such as clients with eating disorders, encouraging subtractions (or restrictions) will not aid in their recovery process.

Instead of: “Stop eating ‘junk food’ or no more ‘junk food’.”
Try: “What foods would you like to add? How do you feel about brainstorming some snack ideas together that incorporate the foods you’d like to add?”
Benefit: You are discussing foods the client is already interested in adding, instead of directing the client toward restrictions (and creating stress in the process).

2. Focusing on addition fosters a relationship of collaboration between the provider and the client. Many of our clients want to please their healthcare providers and don’t want to “fail”. We can encourage the people we work with to get out of this “pass or fail” mindset by emphasizing addition and treating goals like experiments. We can accept that clients are experts of their own bodies, experiences, and lives. We have the education and experience in our field, and more importantly, our clients have the experience of being in their own bodies and living their day-to-day life. Working collaboratively sets the client up for success as we guide and support them on their health journey.

Instead of: “You should eat breakfast every morning.”
Try: “What days work for you to eat something in the morning, even if it is not a full meal – like having some hard-boiled eggs? What are some foods that sound appealing to eat in the morning?”
Benefit: You open the door to possibilities that appeal to the client, and the client tells you what days they may be able to try and eat something for breakfast. Therefore, the focus is not eating breakfast seven days a week; instead it is creating manageable change by encouraging something in the morning when it works for the client.

3. Focusing on subtraction turns individualized care into generalized care. All of our clients do not have the same access or the same ability to work towards your idea of a desirable health behavior. If you are speaking to a family who has limited resources, it may be harmful to recommend specific subtractions (such as “don’t eat canned foods because they are too high in sodium”). If you are telling individuals to remove a food that strongly connects to their family or culture, it is unlikely they will comply. We need to work with the client to tailor the behavior modification to meet them where they are.

The health of the whole being is the most important. Relying on subtractions will restrict, and may ultimately hinder not only your relationship with the client, but also their personal progress. No one wants more rules to follow or more things to avoid. Shifting to addition will encourage our clients to focus on building positive, sustainable behaviors that work within their current lives, work for their families, and allow progress to occur at their own pace.

Angela Gomez, RDN is based out of both Peoria and Phoenix, Arizona and is a School Nutrition Dietitian, an Eating Disorder Dietitian, and a volunteer Dietitian for a collegiate soccer team.

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Eggs: A Perfect Ingredient For Powerful Produce Pairings

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Eggs: A Perfect Ingredient For Powerful Produce Pairings

Amy Myrdal Miller, MS, RDN, FAND, and Lauren Simin

Nutritious Dietary Patterns

Featured article in the Fall 2019 Issue of Nutrition Close-Up.

Too often, nutrition discussions emphasize single nutrients or foods. Focusing on recipes, meals, and dietary patterns are better approaches for ensuring nutrient needs are met. It is also essential to ensure recommendations focus on flavor and enjoyment. This is especially true when making recommendations to motivate people to choose foods from under-consumed categories like vegetables. Dietary intake data show overall vegetable intake is below the recommended intake for more than 80 percent of Americans.1

At the 2019 Produce for Better Health Foundation Consumer Connection conference, a culinary session highlighted five powerful produce pairings that use flavor synergy to create deliciousness in ways that may help increase vegetable consumption. The presenters, culinary nutrition expert Amy Myrdal Miller and Certified Master Chef Ron DeSantis, created pairings that featured the flavor as well as nutrient benefits for pairings like eggs and avocados. Our perception of flavor is impacted by all our senses from sight, smell, and sound to taste and touch. Of our five senses, our sense of smell has the greatest impact on our perception of flavor or deliciousness. About 80 percent of our flavor perception is influenced by what we smell, and what we smell is influenced by several aromatic organic compounds.2

Amy and Chef Ron knew that Hass avocados, at a certain stage of ripeness, contain a volatile organic compound that can mimic the flavor of cooked bacon. Who doesn’t love the classic pairing of bacon and eggs? But Amy and Chef Ron knew they could develop a pairing that had a better nutrition story to tell. Research has shown that consuming eggs with vegetables that contain vitamin E enhances the absorption of both alpha and gamma-tocopherol.3 Avocados contain several carotenoids, including alpha-tocopherol.4, 5

The final recipe, Avocado and Potato Hash with Sunny Side Eggs, also featured cooking techniques that contributed to the final flavor profile. Sautéing the diced avocado in extra virgin olive oil helped release the aromatic compounds in the avocado. When the sunny side eggs were placed on top of the potato-avocado hash, the flavors and textures of the eggs with their silky running yolks, and the seared avocados, perfectly complemented and enhanced each other.

The strategy of pairing eggs with vegetables is not a new one. In Mediterranean countries from Europe and the Middle East to North Africa, home cooks have been poaching eggs in a tomato-based sauce with herbs and aromatics for centuries. The Israelis call it shakshuka while the Greeks call the dish avgozoumo. Cooks in the North African countries of Algeria and Tunisia make a similar dish, but they use more vegetables in the sauce in which the eggs get poached or gently scrambled. Culinary historian Clifford Wright asserts that all forms of shakshuka originated in Turkey from a dish called menemen, which includes small peppers like the shishito and padron peppers found in the U.S.6

The possibilities for pairing eggs with vegetables are endless when we look for inspiration from world cuisines that, for centuries, have found ways to create delicious food through thoughtful ingredient selection and the use of culinary techniques that enhance flavor. Given the health-promoting benefits and consumer appeal of Mediterranean dietary patterns, recommending recipes from that part of the world can be an especially powerful health promotion strategy.

About the authors: Amy Myrdal Miller is president of Farmer’s Daughter Consulting in Carmichael, CA. Lauren Simin, a summer intern working with Amy, is completing her undergraduate degree in nutrition science at Baylor University in Waco, TX.

  1. Dietary Guidelines 2015-2020, Chapter 2: Shifts Needed to Align with Healthy Eating Patterns. https://health.gov/dietaryguidelines/2015/guidelines/chapter-2/current-eating-patterns-in-the-united-states/ (accessed online July 9, 2019).
  2. The Science Behind Great Ingredient Pairings http://blog.foodpairing.com/2016/03/the-secret-behind-great-ingredient-pairings/ (accessed July 9, 2019).
  3. Kim JE, et al. Egg Consumption Increases Vitamin E Absorption from Co-Consumed Raw Mixed Vegetables in Healthy Young Men. J Nutr. 2016 Nov;146(11):2199-2205.
  4. USDA National Nutrient Database for Standard Reference Legacy Release. https://ndb.nal.usda.gov/ndb/ (accessed July 9, 2019).
  5. Lu Q, et al. California Hass Avocado: Profiling of Carotenoids, tocopherol, fatty acid, and fat content during maturation and from different growing areas. J Agric Food Chem. 2009 Nov 11; 57(21): 10408–10413.
  6. Wright CA. Mediterranean Vegetables. Boston. The Harvard Common Press, 2001.

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