A Quick Guide to Eggcellent Emulsions

Mayonnaise is America’s favorite condiment, bringing in a total of $401,204,800 in sales annually (see link). There is something about this gooey, spreadable and very versatile condiment that people find irresistible. However, I have never liked mayonnaise and as a kid the mystery of what mayo actually was and what held it all together prevented me from allowing it a place on my sandwich. This post serves as a guide to three popular emulsions: mayonnaise, Hollandaise, and sauce mornay.

What is an emulsion?

An emulsion is a mixture of two incompatible liquids, with droplets of one liquid dispersed in a continuous phase of the other (McGee, p595). Milk, cream, and egg yolks are all examples of natural emulsions although most are commonly used as sauces. The two categories of emulsions are oil-in-water and water-in-oil, distinguished by which is the continuous phase.

Why use egg yolks?

In addition to two incompatible liquids, stable emulsions include a third ingredient, the emulsifier. You may notice that many sauce recipes include egg yolks. This is because egg yolks contain the emulsifier lecithin. Emulsifiers have an oil-like (hydrophobic) end and a water-soluble (hydrophilic end). The sauce is created when the oil droplets are broken up very small and surrounded by an emulsifier. Proteins and other bigger molecules also act as emulsifiers by getting in the way and breaking up smaller molecules, such as oil droplets.

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Diagram of the general properties of an emulsifier.

What makes emulsions challenging?

The fact that emulsions contain two substances that don’t want to go together on their own makes them particularly challenging, it is not a spontaneous process. Energy, in the form of mixing, must be added in order to overcome surface tension. If this force is not overcome, or the emulsion separates again, it is “broken”. However, even if the two phases have coalesced, it is possible to recreate the emulsion by adding more emulsifier and continuing to vigorously mix to break apart the oil droplets.

broken emulsions

Picture of “broken” mayo (left) and Hollandaise (right).

MayonnaiseThe mayonnaise was created five different ways, incorporating three different mixing techniques and two different types of oil. The three different mixing techniques were using a food processor, by hand and with a salad dressing vessel. The difference was noticeable in the final products. The mayo that was only shaken as if it were a salad dressing did not create a proper emulsion and the food processor was able to. In addition the mayo whisked by hand took a lot of effort to create the emulsion. In order to create a successful emulsion, the oil droplets must be broken up very small and if they are not then the surface tension will not be overcome.

Mixing methods

One mayo trial was whisked by hand (left) while three used the food processor (right).

The other change made was substitution extra-virgin olive oil. Extra-virgin olive oil is less acidic and more viscous than regular oil and therefore was able to be broken down into smaller oil droplets. The color was also an indicator of how well the oil droplets were broken down, because bigger droplets reflect light more.

Hollandaise

hollandaise

(1) Butter used as fat source, (2) homemade butter used as fat source, (3) clarified butter used as fat source, (4) margarine. The fifth trial was the “broken & fixed” sauce (seen in photo below).

The Hollandaise sauce was also created five different times, using four different fat sources. The different fats (butter, homemade butter, clarified butter, and margarine) changed the recipe by having different concentrations of fat. Regular butter includes milk fats, proteins, and lactose while clarified butter is only milk fat and homemade butter has more buttermilk and water. Therefore the clarified butter thickens the emulsion as it is added while the regular butter than clarified butter thinned the emulsion. The thickness of the clarified butter made it harder to break into small pieces and create the emulsion, resulting in a broken mixture. The margarine acted similar to the other butters.

Screen Shot 2015-04-14 at 8.45.35 PM

cheesey

The light roux, (2) medium roux, and (3) dark roux.

Sauce Mornay was created three times, varying the cook time and the color of the roux each time. This sauce is different than mayonnaise or hollandaise because it is not created using the lecithin from egg yolks as an emulsifier. Instead, it incorporates milk and cheese. The cooking time changed the flavor of the sauce because of the Millard reactions that occur and change the flavors. They also account for the changing of the color.

DSC_0572-1024x685In conclusion, America’s favorite condiment is actually a complex and delicate balance of oil and water forced by an emulsifier and blender to cooperate and join together as one spreadable substance.

How Would You Like That Cooked?

After working in the restaurant business for going on seven years, and serving for three, I have heard quite the range of answers to this question (for any kind of meat). I get anything from “NO RED,” “still mooing,” “some pink,” to “burnt.” Put simply, there are a lot of ways people like to describe their meat to look when it is sitting in front of them, and can be a serious problem when it does not look like what they expected. If only they understood that there are multiple components to how a cut of meat will cook, based on the type of cut from the cow, to the surface it is cooked on (flat top vs. a grill) and how done a person prefers it to be. One of my favorite parts of serving (cue sarcastic voice) is when someone orders a piece of prime rib, or NY Strip Steak medium-well (145-155°F) to well done (~160°F) and complain about the size of the meat or that it is dry… Little do they know (presumably) that at temperatures above 135-145°F meat will begin to shrink and lose its juices due to the denaturing of collagen in the cells’ connective tissue sheaths. Nothing like giving this explanation to the next customer that expresses that complaint!

Anyway! After reading about meat and cooking techniques, we decided to see how differences in cooking a cut of meat, shoulder roast in our case, affects the outcome of the meat.

uncut shoulder picture

Each individual cut was assigned a different cooking technique: microwave, boil, cast iron skillet (brined and normal), roasted/baked, regular grilled (rested and unrested), brine grilled and braised with Cabernet Sauvignon. Each technique created different tasting and looking cuts of meat!

pan seared cut

boiled

braised

temp and baked

grilling

Alright, so now that I have mentioned it in a couple of the picture captions, let’s talk about what is going on with this browning phenomenon and why some of the cooking methods did not produce the same color. When a piece of meat, or anything you’re cooking starts to get that brown color (seen in the iron skillet cooking method and with the grill marks shown above) something called the Maillard reaction is taking place. This reaction includes the reaction between a carbohydrate and amino acid, where each one could be free or bound as a sugar or protein, respectively. The combination of these two complexes will react to create new molecules that will continue to react and rearrange into hundreds of different molecules to produce an array of aromas and the brown color based on the way the molecules arrange to reflect light! This reaction is able to create even more complex and meaty flavors (compared to caramelization) due to the incorporation of nitrogen and sulfurs to the mix. You can see an overview of this below, and why steaming foods will not produce the same flavor or browning.

maillard

(Iona. 2011.“maillard reaction (TV set art) (4).” http://blog.ioanacolor.com/2011/06/maillard-reaction/)

Who knew a color and smell could hold SO much chemistry behind it!? Very cool.

So next time you’re roasting, baking, grilling or frying you’ll know where that wonderful aroma is coming from. This is also why high temperatures are usually used, as this will speed up the Maillard reaction, but don’t push your luck too much or else you could create an entirely different reaction that will bring you from a delicious aroma and taste to a plummeting burnt, bitter and charred piece of meat (around 355 °F).

Another interesting difference between the two regular pieces of shoulder that were grilled was between rested and unrested (cut into right after it came off the grill). Below are some pictures comparing the two:

rested v unrested

The rested cut was allowed to set after being grilled; this resulted in a higher internal temperature, as it cooked the inside of the meat more than the unrested cut. For this same reason the cut of meat was also given more time to absorb its juices, resulting in less being lost once we cut into it. Resting is a recommended technique as it also provides a cut of meat that is easier to slice.

We followed a similar alteration in cooking methods for Rainbow Trout looking at the following techniques: broiled, poached, microwave, fried, baked, boiled, pan seared, grilled and ceviche! As with the meat, each technique produced significantly different looking pieces of fish. However, the differences in cooking the trout impacted the taste in a negative way more so than the meat did. I found myself enjoying every bite of the differently cooked meat, but not so much the case with the trout, and this seemed to be a group consensus. Fish proteins are much difference than that of a cut of meat, especially a shoulder cut. Fish muscles are a fraction of an inch in length arranged in sheets, separated by sheets of connective tissue, resulting in delicate and thin fish muscles. This makes fish very sensitive when cooking, whether it is overcooked to a dry fibrous mess, or cooked correctly and sticks or flakes once being transferred from the pan/grill to your plate. This begins to explain why we saw such drastic differences among the cooked trout compared to the differences in the shoulder cuts where the proteins are long, and more compact bundles.

trout_cooking_techniques

Unsurprisingly, based on the Maillard reaction, the pieces of trout that appear more browned were the most flavorful and tasty! The one exception, personally, was the ceviche! The ceviche was soaked in lime juice and salt, uncooked trout… and took me by COMPLETE surprise, as it was extremely delicious. The pan seared appeared to be a popular favorite; this makes sense… look at that color! The Maillard reaction would definitely be better referred to as the “flavor reaction,” than “browning reaction;” the recombination of sugars and carbohydrates create marvelous differences in our food.

A Childhood Favorite

Milk. Our complex relationship with this white liquid starts at birth, and from an early age we are taught that it is an important part of a balanced diet. Milk is extremely versatile – it is the primary ingredient in cheese, butter, and ice cream and is added to countless recipes to enhance flavor and add a little something extra to the final dish. But before we can jump into the wonderful world of milk and cooking, we need to go over some basics when it comes to the chemistry of milk and modern methods of production.

We love milk!!

We love milk!!

The first thing to know about milk is that it is liquid at room temperature. The milks that most humans drink, cow being the most popular, are almost 90% water, so milk being liquid at room temperature (roughly 77 oF or 25 oC) shouldn’t come as much of a surprise. The other 10% of milk’s weight comes from fats (roughly 3.7% in cows), protein (3.4% in cows), lactose (4.8% in cows), and various minerals (0.7% in cows). These percentages are quite variable as cow breed changes, and even more variable between different species of milk-producing mammals. Different types of diets that the cows are fed are also a factor that influences the relative concentrations of the components in milk, as well as the overall flavor of the milk. Although differences exist between the types of milk available at the supermarket, this variation is largely not as common anymore due to modern methods of production.

Speaking of which, it is important to understand that milk production is highly modernized, consisting of large-scale dairy farms that collect milk from thousands of cows at once and follow strict FDA guidelines to ensure the safety of the product they produce.

Pasteurization, the heating of milk to a certain temperature for a period of time, preserves milk by killing pathogenic and spoilage microbes by inactivating milk enzymes that cause milk to go bad over time. Large-scale operations use the high-temperature, short-time (HTST) to pasteurize their milk. This process involves pumping milk continuously through a heat exchanger that is held at a minimum of 162 oF or 72 oC for 15 seconds.

The other process used by dairy farms is homogenization. Homogenization involves pumping hot milk at high pressure through small nozzles in order to tear apart the fat globules floating freely in the milk. This prevents the fat globules from congealing and creating an uneven consistency in the milk. Homogenization ensures that fat is evenly dispersed throughout milk.

Although these modern processes are marvelous for extending milk’s shelf life and ensuring an even consistency, they come at a price. Modern milk has less health benefits than less processed options and has far less flavor than “real milk” (milk that has been untouched by society’s innovations. But what plain old milk lacks in flavor, it surely makes up for in versatility. The goal of today’s class was to show the different ways that milk can be used in cooking, and to examine the chemistry behind the recipes.

The first thing we made was ice cream…eight different ways! Here are the recipes we used to make each ice cream mix:


Ice Cream Recipes

Ice Cream Recipies


 As you may notice, each recipe is a variation of a simple formula: cream + milk + sugar + vanilla = ice cream! Philadelphia-style, or standard, ice creams are usually served hard and have a rich and creamy flavor. Philly-style ice cream is ideally served at 8-10 oF (-13 oC) so that it doesn’t numb the tongue but still maintains its hard consistency. This type of ice cream can also be served at a warmer temperature, usually around 22 oF or -6 oC, and is known as soft-serve. At this temperature, about half of the water in the ice cream is in the liquid form, contributing to its soft and smooth texture.


Our ice cream mixes, cooling off in the snow.  Which one do you think is chocolate?

Our ice cream mixes, cooling off in the snow. Which one do you think is chocolate?


French ice cream, also known as custard, contains egg yolks. The proteins in the yolks help keep ice crystals small, which leads to a smooth, even, texture. The yolks also make the custard taste great, giving it a richer, eggier flavor. Gelato is a distinct style of custard and is high in butterfat. It has a very rich and dense profile, making it a favorite on summer afternoons!


Separating egg yolks for the custard-style ice cream mixes.

Separating egg yolks for the custard-style ice cream mixes.


Adding liquid nitrogen to the ice cream mix in the stand mixer.

Adding liquid nitrogen to the ice cream mix in the stand mixer.

The process of making ice cream is actually quite simple – once the mix is made and chilled (we used the cold weather to our advantage and put the mixes on the deck!), it’s as simple as putting the mix in a stand mixer and adding some liquid nitrogen!

***GASP***

Relax! It’s not nearly as dangerous as it sounds (but it is just as cool!) By adding the liquid nitrogen to the mixture while it is mixing, air pockets can form in the mix (which makes it smoother and more “fluffy”) and the cold is evenly distributed.


Condensed air, produced as the liquid nitrogen quickly heats to room temperature and turns to a gas.

Condensed moisture (fog), produced as the liquid nitrogen quickly vaporizes (turns to a gas) at room temperature and takes heat away from its surroundings.


Perfectly-cooled ice cream after adding liquid nitrogen

Perfectly-cooled ice cream after adding liquid nitrogen

A quick side note about nitrogen – at room temperature it exists as a gas, and to keep it in the liquid phase it must be super cooled to at least -320.4 oF or -195.8 oC!!  This temperature is the boiling point of liquid nitrogen, so when it comes in contact with the ice cream mix (and the air around it) that is warmer (relatively speaking) than it, the liquid nitrogen changes phase and with that phase change comes a drastic decrease in temperature of its surroundings.  Using this to our advantage, we were able to almost instantaneously solidify the liquid ice cream mixes.


Some ice crystals formed because we added too much liquid nitrogen too fast...simple fix - let it heat up a little!

Some of the cream froze solid because we added too much liquid nitrogen too fast…simple fix – let it heat up a little and mix as you go!


After the excitement of cooking with liquid nitrogen, it’s hard to believe that anything could be more interesting! The way we made butter, although not quite as cool (pun intended), was really interesting because we made it in a jar, only using slightly cultured cream and a smidge of sour cream! In an attempt to culture the cream, we left container of it open on the kitchen counter for a day or so, and adding a small dollop of sour cream about halfway through.

Our jar, containing buttermilk (liquid) and butter (mass) after a few minutes of shaking.

Our jar, containing buttermilk (liquid) and butter (mass) after a few minutes of shaking.

During class we all took turns churning the cream by vigorously shaking the jar. Agitating the cream damaged the fat globules in the cream, causing them to rupture and release the fat they stored. These globs of fat stuck together and soon connected with other globs, and before we knew it we had a large mass of solid butter in our jar!


Carly posing with our jar of aerated sweet cream!

Carly posing with our jar of aerated slightly cultured cream!

Before it solidified, the cream aerated so much that it resembled a whipped spread that took up nearly the entire container. At this point the aerated cream took up almost 100% of the space in the jar, so mixing it more was quite difficult. By churning the cream more, the network of air pockets we had created collapsed, allowing the fat globs to coagulate and group together. This resulted in a more solidified texture to emerge.


Draining the buttermilk from the jar, leaving only the mass of butter behind.

Draining the buttermilk from the jar, leaving only the mass of butter behind.


After pouring out the buttermilk, all that was left in the jar was the solid mass of butter we had just made!

After pouring out the buttermilk, all that was left in the jar was the solid mass of butter we had just made!

As the butter became harder and less aerated, white milk, known as buttermilk, appeared. True buttermilk, like the one we made, has the consistency of skim milk with a sweeter flavor. Because all of the fat from the cream was in the butter glob, only water, amino acids, and trace other materials remained in the buttermilk.


This beautiful golden dollop of butter had a light, airy texture.

This beautiful golden dollop of butter had a light, airy texture.


Anola working her magic on the butter.

Anola working her magic on the butter.

After we removed the butter glob from the jar, we kneaded in some salt.  Adding salt has a few benefits. First, it adds a salty flavor that complements the butter’s rich profile and, when the butter is used in conjunction with other ingredients, it brings out much of the natural flavors that would otherwise be hidden.  Adding salt also helps prevent the growth of bacteria and other organisms that could cause the butter to spoil.

Mixing the butter by hand also helps create an even consistency, allowing for a more hands-on (pun intended) approach.


Milk has so many wonderful characteristics that make it an ideal ingredient in countless recipes.  From the very beginning of our lives, we humans rely on milk to provide us with the sustenance we need to grow strong.  Although our dependence on milk dwindles as we age (in fact nearly 90% of American adults are lactose intolerant!), our fascination with the white suspension of fats and proteins in water remains with us throughout our lives.

Thanks for reading about our adventures with milk, and be sure to check back next week for our exploits with emulsions, foams, and other mixtures!  And remember…

Stay thirsty my friends


Butter…. or Oil?

“What is this?” The professor asks the group as he shakes a pot full of what looked like pure fat in front of us. There were many responses (one “disgusting!”) but we came to a consensus that it was some kind of fat and, for the most part, we were right. What it really was though, was chicken skin. He had just unthawed it today after it was frozen for quite a while. So why was he showing us this? We had just started the day talking about fats and about how they were made of a glycerol and fatty acid chains (three in the case of triglyceride seen below), and so the chicken skin was a way to look at this fat in a food. The skin of the chicken is mostly made up of water (50 %) and fat (40 %) and collagen protein (3 %) and it acts as an envelope around the bird, holding a layer of fat beneath it. This is why the skin tastes so good when eating it off of a cooked chicken.

Next, it was announced that we were going to be making chicken gribenes. Basically we would be heating the skin to the point where all the water contained in it would boil off and that the skin itself, made largely of collagen proteins, would fry in its own fat. The resulting fried skin would be separated from the fat (or schmaltz) and would be salted and left to crisp up for a delicious treat.

pic 1

The picture above shows what the skin looked like after being heated for only a couple of minutes and the temperature was 100 oF, and as you can see the fat has begun to separate from the skin.

2

Here it is evident that water has started to boil off, however at a temperature of 220 oF it is not yet hot enough for the skin to begin browning.

3

At 265 oF the water has continued to boil off as evident by the level in the pot and also there is a considerable amount of browning occurring on the skin.

4

By 340 oF almost all of the water has boiled off and the skin is seriously browning.

5

The finished product! After straining off the skin, adding kosher salt ground to a fine powder with a mortar and pestle, and allowing it to crisp up for a couple minutes, the final product was ready. The crunchy, salty taste of the skin was to die for!

The chicken was not to be rushed, so while we waited for the chicken to brown what else was there to do except make scrumptious chocolate chip cookies! Two batches of chocolate chip cookies were made, one using oil and the other using butter. Oil and butter are two fats that are often substituted for each other in cooking and baking. Some swear by butter, others by oil. So which one is really better? What difference does it make in the product?

Since both of them are fats, they perform the same desired function as a tenderizer, keeping cookies nice and soft. Fats and sugar prevent a strong gluten network from forming, thus preventing cookies from being too dense and over-chewy.

A baguette is an example of a baked good with minimal fat and sugar; the lack thereof causes it to harden easily and be much chewier. Mixing water and flour without fat causes gluten to form because hydrophobic fat-like groups along the flour molecules bind with each other, holding the proteins together and excluding water. The presence of a fat source like oil or butter prevents this from happening; fat molecules bind to these groups and prevent them from binding to each other. This keeps cookies from hardening like a baguette.

So the question still stands of why two different batches were made? Cookies are cookies and they’re always yummy, so why does it matter?

It matters because one of them creates a sort of illusion, while the other is literally melting in your mouth.

When fat and sugar are beaten together, air gets incorporated into the mix. As a semisolid fat, butter allows the air to stay in the mixture, whereas oil does not. Air introduced by the sugar and the beater becomes suspended in the mixture of crystalline and liquid fat in butter. This is possible because butter forms larger fat crystals than oil. The structure of butter is shown in the photo below, illustrating the air-trapping fat crystals.

butter 1

McGee, Harold: On Food and Cooking. Page 34.

You’ll notice that there are water droplets in the photo. This is not because our butter was wet- butter is actually made up of approximately 15% water. The fat crystals shown in the photo allow air to stay trapped in the dough. Oil, on the other hand, has no air-holding ability. It tenderizes products because it is never a solid to begin with. The two photos below show the cookie dough with butter (left, pre-chocolate chip addition) and with oil (right, post-chocolate chip addition).

cookie 1 cookie 2

You’ll notice that the cookie dough made using butter is visibly fluffier and has a much lighter color, while the dough made with oil is gooey and darker. This is because of the air that is caught in the dough. Light reflects off of the increased surfaces created by the air, causing the batter to appear lighter.

The moist feel of a baked good made with oil is simply an oily residue that stays in your mouth, an illusion. Butter, on the other hand, is literally melting in your mouth, with a melting point just below body temperature.

Butter’s semisolid state at room temperature also causes the dough to be more solid before it goes in the oven, then spread out much more after being in the oven. Cookies made with oil do not change in size nearly as much between pre and post-bake. The photo below shows the two finished products side by side. Can you guess which is which? The ones with butter are slightly more flat and you can almost see the melting action of the butter, whereas the ones made with oil are chunkier

.cookie three

The question of which recipe makes better cookies is almost impossible to answer. Tasting just one of each type was practically just a tease, and certainly insufficient evidence to draw a conclusion about the relationship between recipe and yumminess. The only solution to this issue is to increase the sample size, therefore many more cookies must be made. Try it yourself at home and you can decide for yourself! Do you prefer the ever-moist oil option? Or the melt-in-your-mouth buttery option?
Our homework for this week was incredible, to say the least. The assignment was to make caramel (yum!).  We made three types of caramel sauce, varying the cooking time and therefore the color of the caramel: a traditional, a light caramel, and a burnt caramel. Photos of the three are shown below, respectively.

light product dark product burned product

Pass the Cheese, Please!

“Chemistry class in the kitchen?” “At my Professor’s house?”  “What on earth does “Bonding with Food” entail?”  “If we have to cook for class, do we also get to eat?”  “I’m hungry.”

These were the thoughts of the new group of students on the way to class this past Thursday afternoon. No one could quite figure out what the next few hours and coming weeks would entail.  I would be lying if I said none of us were nervous.  Even as a senior, I was uneasy with this new type of class setting, but as we pulled up to Professor Miller’s house everyone put on a brave face and marched inside.

We began the class seated at the table with an assortment of pantry food and began the task of organizing the food into groups. We organized based on food types, how healthy they were, the ingredients…the list goes on. We then discussed what we knew about the food, what we thought we knew and what we hoped to learn about food from the class. It was interesting to compare notes among classmates. Each of us coming from different backgrounds, majors, and classes meant that we all had something to offer to the discussion.  After some serious inquiry and of course a lot of laughter we were feeling comfortable with our new surroundings and finally got the chance to enter into the kitchen.

By this time, bellies were grumbling for some homemade cottage cheese.  We began by pouring a gallon of skim milk into a large pot and heating the milk to 120 degrees Fahrenheit.  After the milk came to temperature, we stirred in ¾ cup of vinegar.  The milk felt thicker and began to bubble quickly forming curdles.

Stirring milk and vinegar

Stirring milk and vinegar

These curdles where a result of an acid-base reaction occurring between the acetic acid of vinegar and the basic properties of milk.  These basic properties stem from the proteins within the milk which possess amino acids with acidic side chains.  The reason acidic side chains cause the basic properties is that at neutral pH these side chains possess a negative charge and when the pH of the solution is lowered (by adding the vinegar) the acidic side chains move into their protonated state, thus removing their negative charge.  The curds were the precipitate formed from this reaction.

Cheese Curds

Cheese Curds

With these new formed curds, the class suddenly took a new path in cheese making.  Instead of making cottage cheese, the class tried out a new process for all involved to discover the joys of mozzarella making.  In this process, the curds were squeezed to remove water and stretched through a massaging motion.  After each stretch the curds were refolded to align the fibers.

Squeezing water out of curds

Squeezing water out of curds

Stretching and folding cheese

Stretching and folding cheese

IMG_3699

After what seemed like eternity to our hungry bellies, the mozzarella was finished and to all of our surprise the cheese we had formed actually looked like mozzarella string cheese. However, the response to the first taste was not quite as positive, “wow it tastes horrible!” We had forgotten one important ingredient…salt.

Mozzarella Cheese

Mozzarella Cheese

With the addition of some finely ground salt, the mozzarella began to taste better, but the class favorite was without a doubt the melted form.  Just a few seconds in the microwave produced the best reaction of the experiment: “this tastes like cheese!”

Melted Cheese

Melted Cheese

We ended the day with a little organic chemistry refresher: the carbohydrate game, my personal favorite, which allowed us to look at the breakdown path of some carbohydrate molecules in food. For example, when heated (or cooked) fructose breaks down into lactate and glyceraldehyde, piperonal can be generated from piperine (a pungent compound in black pepper), and gingerol (major flavor compoenet of ginger) can be cooked to generate zingerone, which is milder and sweeter, or dried to produce shogaol.  Our final activity was to watch an episode of Good Eats called “Water Works II,” all about how great water is and how to keep it tasting delicious and healthy in your home.  The host Alton Brown was brimming with excitement and enthusiasm that the rest of us could only hope to have when talking about water, although I must say, at least it was not a dry topic.

The show offered the class a little look into how we might present our upcoming food projects with pizazz for all ages. I’m excited to see what my classmates come up with our future projects when the time comes, but for right now we all must put our noses to our cook books, keep our minds open and bellies empty for next Thursday.

Take Your PIC

Take your PIC: Bonding with Food presents the Public Information Campaign

PIC Presentations

Presenting at the Public Information Campaign

As part of an initiative to inform the public about current food issues, the Public Information Campaign was a night of presentations aimed to educate about topics such as fats, pesticides, organic vs. conventional foods, high fructose corn syrup, and artificial sweeteners, which are detailed below.

High Fructose Corn Syrup. Sounds scary right? But it’s in so much of our food, from candy to fruit juice, bread to chicken nuggets.

Sweet surprise or deadly demise?

Sweet surprise or deadly demise?

So what is “High Fructose Corn Syrup”? To be honest, I didn’t really know prior to this assignment. I had some vague idea about some sugar/starch conspiracy that caused diabetes. And considering the popular media, it’s not surprising that this was my concept of High Fructose Corn Syrup, or HFCS.

This video, above, is a response to an ad, below, by the Corn Grower’s Association, a national group that represents the corn refining industry in America, attempting to dispel HFCS’s negative image.

But where is the truth? Is HFCS poisoning our food or is it the same as sugar? Initially, I thought it had to be some cover-up by the corn industry and that it was actually causing diabetes and cancer and everything other health malady, but by digging deeper, I learned that the issue is much more complicated than it initially appears.

High Fructose Corn Syrup, or HFCS, is a liquid sweetener derived from #2 corn (commodity corn) which is grown in higher yield than sweet corn. Where table sugar (sucrose) is a disaccharide (double sugar) made of glucose and fructose bonded together, HFCS has both of these sugars, but individually rather than bonded.

Sweet Structures

Sweet Structures

While HFCS does not have identical structure to table sugar, it is made up of the same components. So is it the same?

Due to its nature as a mixture of two sugars, glucose and fructose, there are two pathways by which HFCS is metabolized.

Metabolism

Differences in digestion between glucose and fructose

Due to these differences, HFCS has been blamed for the rise of obesity, heart disease, diabetes, and other chronic diseases as rates or these rose at the same time that HFCS was rising in use, but does this imply a causal link?

Lemons Graph

The graph above shows an apparent trend of a decrease in US highway fatalities and the number of lemons imported from Mexico increases. Clearly, the imported lemons have no effect on highway safety, but since the increase of one is concurrent with the decrease of the other, it could be assumed that there is a causal link between them. A similar coincidence may have occurred with the concurrent rise of HFCS and chronic disease, such that HFCS might appear to cause these diseases due to a mere coincidence.

However, it is important to note that while HFCS may not directly be causing these issues, increased sugar intake as a result of the increased use of HFCS could certainly create this health concerns. The average American consumes about 19 teaspoons (75 grams) of sugar a day, and since HFCS represents 42% of those sugars, at the very least the calories from HFCS are having a negative effect on our health, if not the substance itself.

Studies have supported both the idea that HFCS causes chronic disease and the idea that it has no effect, and there is no conclusive evidence yet, so while both the use of HFCS and chronic disease have increase in the past 40 years, there is not yet a proven causal link and the complexity of the issue has yet to be fully explained.

So what I know now is that I didn’t actually know what I thought I knew! My views of high fructose corn syrup were unfairly biased based on information that didn’t actually exist. And interestingly, I had a similar experience with the other topics at the Public Information Campaign, finding that what I thought I knew was just inaccurate. Here’s some of the highlights:

I thought that I knew that some artificial sweeteners eat holes in your brain, but apparently  the truth is that while some studies have shown that artificial sweeteners such as Spenda have negative health effects, but these used doses as high as 3000 mg/kg body weight/day or 17,200 packets in an average person per day, indicating that the level necessary for this effect is impossibly high for normal consumption. I mean, if you drank that much water in a day, it would have “negative health effects” (death) a whole lot sooner! In fact Stevia, a sweetener derived from the Stevia plant, been shown to have positive health effect like increasing glucose tolerance and anti-hypertensive/inflammatory/tumor/hyperglycemic effects.

And I was always under the impression that “0” means “none”, but apparently not according to the FDA: FDA regulations state that foods can be labeled as “0 grams trans fat” as long as there are <0.5 grams of trans fats per serving (a trans fat is a particular shape of fat produced by partial hydrogenation resulting in a rearrangement of unsaturated fat structure).

Gir Scout Cookies

“Partially Hydrogenated Oil” means trans fat, so how can it say 0?

Trans Fat

A trans-unsaturated fatty acid
Red circles indicate trans (zigzag) double bond structure.

As there is partially hydrogenated oil in the cookies, there are actually trans fats, despite the misleading label.

In terms of  meat production, while farms are required to test their products for contaminants, such as E. Coli., Listeria, and Salmonella, they do not have to wait for the results of these tests before sending the products to market, and choose instead to recall the product if it is later found to test positive for these contaminants.

Personally, I eat two or three apples a day, so I was disappointed to learn that they top the list for the twelve foods with the most pesticide contamination, according to a list created by The Environmental Working Group. They also created a list of the fifteen foods with the most pesticide contamination (“Clean Fifteen”). Go onions!

The Clean Fifteen

The “Clean Fifteen”

The Dirty Dozen

The “Dirty Dozen”

But if you want to get pesticides off your food, water is just as good as a commercial fruit and vegetable wash, according to a study by Dr. Walter Krol of the Department of Analytical Chemistry at the Connecticut Agricultural Experiment Station. Apparently the mechanical force of running water was effective in removing pesticides.

Veggie wash or wash your veggies?

Veggie wash or wash your veggies?

Overall, some themes occurred again and again throughout the presentations, including:

Read food labels: One of the fastest and easiest ways to find out what you’re eating is to read the label. Even serial numbers can tell you something. In fact, if the serial number has a “9” in front, it’s an organic food!

Look critically at studies: While everyone likes to use “scientific studies” as “proof”, sometimes the studies can be misleading. Of course artificial sweeteners are bad for you if you eat 17,000 packets of them in one day!

Consider bias in all information: Any interest group is going to want you to think that their product is good (or at least not bad) for you. And their opponents will want you to think that it’s awful so that you buy theirs instead. So who funded that add that told you corn sugar is the same as regular sugar? Was it the Corn Refiner’s Association? Just because it was, does that mean the information is necessarily inaccurate? No, it just means that you should be aware of what they might want you to think.

“The best choice” depends on what you are looking to add or avoid: No trans fat! High in vitamins! Diet! No carbs! Low fat! Sugar-free! These are all advertizing slogans, but what’s really important? Well, that’s up to you. Do you want to trade sugar for Splenda and avoid calories? Go for it! But that doesn’t mean that everyone should.

“Clean” is relative: So back to my apples. If I’m concerned about pesticides on them what can I do? First off, wash them! Will it help? Probably, but if I’m still worried, I can switch to organic apples, which certified as being grown without the use of synthetic chemicals. But I’m going to wash those organic apples too, because manure is organic but that doesn’t mean I want to eat it.

Everything in moderation: Yep, it’s still true! Whether it’s sugar or fats, even vitamins, enough of anything will kill you. So do you have to avoid Oreos for life because they have trans fats? Not if you don’t want to! But you probably also shouldn’t eat them three meals a day, everyday, for ten years.

Overall, I loved this assignment because it confused me. I’m glad that it attacked my “this is good, that is bad” ideas about certain foods, because the truth is somewhere in between.

Aside

Who Said Oil and Water Don’t Mix?

 

There is an old saying that water and oil don’t mix. From a scientific standpoint this is almost always true. The polarity of water makes it repel from other lipid or fatty liquids that are otherwise non-polar. This however is not always the case. Have you ever heard of emulsions? An emulsion is a combination of two liquids that would not ordinarily mix together. Oil and water may be the best example of two liquids that normally do not mesh, but can be made into savory recipes such as mayonnaise and hollandaise sauce.

In an emulsion a liquid, such as oil, is broken into millions of small particles and the other liquid, such as water, then surrounds each one of these water particles. This is essentially the same as a suspension, such as salad dressing. The difference between a suspension and an emulsion is that a suspension will eventually separate and the two liquids have to be re-mixed or suspended. An emulsion on the other hand stays as this oil/water solution. The key factor in making an emulsion is the emulsifier. The emulsifier keeps the droplets of liquid from coming together with one another and then crashing out of the solution.

Let’s take a look at what’s going on at the molecular level…

            Emulsifiers are molecules that contain both a polar and non-polar end. The hydrophobic tail of the emulsifier surrounds the oil droplets, thus not allowing the oil to make larger droplets. With this emulsifier coating, the oil droplets bounce off one another instead of sticking together and making larger macro-droplets (oil repels away from the hydrophilic head sticking out of the other oil droplets). The hydrophilic head of the emulsifier is then able to interact with the water droplets, preventing them from combining. The water normally has a strong inward pull or surface tension between the water molecules that keeps them compact and stuck together. When the emulsifier dissolves in the water it impedes this inward pull that allows the individual water droplets to get dispersed throughout the mixture.  So as we are looking at an emulsion such as mayonnaise we may think the water and oil have become miscible with one another, but on the molecular level there is some trickery going on. The two compounds give the effect of one solution but are not actually mixed together as one solution. The liquids are rather evenly dispersed and forced to stay close together with the aid of an emulsifier.

 

Common emulsifiers used in cooking are mustard, honey, and vinegar. But the mac-daddy of all emulsifiers is the egg yolk. The egg yolk is the most widely used emulsifier in the kitchen and for good reason. Egg yolks contain lecithin, which is an excellent emulsifier.

 

Why Buy Hellman’s (mayonnaise) When Homemade Is SO Much Better

The key to making any good emulsion is first making sure to completely disperse and break-up the oil into tiny droplets. A convenient way of doing this is by using a food processor (although a whisk and a little elbow grease works fine too).  

What you will need:    1 egg, 1 tsp NaCl, 1 tsp mustard, ¼ tsp sugar, 2 tbsp lemon, 2 tbsp vinegar, 2 cups vegetable oil

Start by mixing the egg in the food processor until well blended. Next add the NaCl, mustard, sugar, lemon, and vinegar and mix again. Then slowly add your oil while the processor is mixing. The mixture will then appear right before your eyes as one mass of mayonnaise! Changing the type of oil can also give you knew and tasty mayonnaises. For those who like something a little spicy, try using a hot pepper flake olive oil. Or if you’re looking for a new bread dip, using olive oil creates a scrumptious little spread (though you should use high quality olive oil and be careful not to process too long, as olive oil mayo may become bitter).

 

 

A Yummy and VERY Lemony Hollandaise Sauce…

What you will need:      3 egg yolks, 60g lemon juice, 113 g butter, ½ tsp NaCl, 1 tbsp H2O

Begin by placing the egg yolks, lemon juice, and water in a double boiler. Melt the butter and then drizzle the butter into the egg yolk mixture, being aware to constantly stir with a metal whisk. The sauce will begin to thicken, at this point remove the sauce from the double boiler and continue to whisk as it cools down. As the sauce cools down add NaCl while whisking.

 

References:

  1. McGee, Harold. On Food and Cooking: The Science and Lore of the Kitchen. New York: Scribner, 2004. Print.
  2. Corriher, Shirley O. Cookwise: The Hows and Whys of Successful Cooking. New York: William Morrow, 1997. Print.