Coffee and Tea

Today in class we examined the cooking methods of various coffees and teas.

The group I was in started with coffee. We took green coffee beans and roasted them. We removed some beans early for a lighter roast, and cooked the other beans longer to form a darker roast. We then tried both coffee and espresso. The espresso, despite being held in high regard by coffee enthusiast, was too bitter for my taste. However, I greatly preferred the dark roast coffee to the light roast. The dark had a much stronger, fuller flavor and a much more powerful coffee smell.

Next we tried four teas.

The first was Pu-erh tea, which is made from the large-leaf variety of the Camellia plant, which is grown in southwestern China. The leaves had already been fermented; the smell reminded me of tobacco (possibly due to the fermentation process) and was also a little smoky. After steeping the leaves in hot water, the tea took on the smell of a horse farm, something along the lines of decaying grass and manure. Unfortunately, the tea tasted like it smelled, although it didn't have a very strong flavor. The tea is often pressed into small cakes and aged for potentially years.

The second tea was Golden Yunnan, which is a black tea from the Yunnan region of China. Yunnan is in southern China bordering Vietnam, and contains China's oldest wild tea tree. The tea smelled light and sweet, and a bit like a mixture of spices. After steeping, the tea maintained this smell, but was less strong. The flavor of the tea seemed weak and generic to me, like something out of a normal black tea package. That being said, I don't drink tea on a regular basis and may have failed to pick up on some nuances to the flavor.

Thirdly, we tried Gunpowder Chinese Green Tea, a green tea produced in Eastern China. The leaves themselves are rolled tightly into little bundles, as rolling the leaves makes them less susceptible to damage, and the leaves can therefore maintain their flavor more fully. This type of tea dates back to at least the Tang Dynasty (618-907AD). The Gunpowder leaves smelled very similar to the Pu-erh, this time with a slightly more herbal aspect to the horse farm scent. Again, the scent remained after steeping the tea. The tea did not taste like it smelled, however, and reminded me of generic green tea. Again, if there were any special nuances to the flavor, I missed them completely.

Lastly, we tried White Peony Indian White Tea, which is produced in the Darjeeling region of India. The leaves for white tea are picked before they open fully, and there is no fermentation process. The aroma of the White Peony was much more pleasant than the other teas, as it had a light, soft, sweet, and slightly spicy aroma. After steeping, the tea smelled more herbal and floral and not as sweet. The taste, though weak, was good, as the tea was sweeter than the others. Otherwise, there were not really any stand-out flavors to the tea.

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Coffee originated in Ethiopia, and today is the seventh-largest coffee producer in the world. Partly due to the fact that Ethiopia almost exclusively grows Arabica coffee, Ethiopian coffee is generally considered to be of high quality. Nearly all Ethiopian coffee can be considered 'organic,' as coffee is still grown by hand in Ethiopia.

Since coffee was introduced in 1727, Brazil has become the largest coffee producer in the world, and is most known for producing lower-grade coffee. As such, many canned coffees and espressos contain a significant percentage of Brazilian coffee beans. Despite this reputation, Brazil still exports a large amount of high-quality specialty coffees. Unlike in Ethiopia, many mechanical harvesters are used to gather the coffee beans.

Coffee and Tea, Pre-Class

Coffee was first discovered and brewed in the middle east around the middle of the fifteenth century. Originally, coffee beans were considered to be food. Coffee beans were banned from export from Arabia, but were successfully smuggled out to other parts of the world in 1670.

10,000 Daltons is about 10,000 atoms.

Espresso contains a smaller amount of caffeine than might be expected due to its brewing process. With Espresso, the beans are only exposed to the water for a brief amount of time. As caffeine is slow to dissolve, not much gets dissolved in the water.

Many of the volatile molecules in coffee have significant non-polar regions that make it unfavorable to interact with water, but the molecules are still relatively light. Furthermore, they often have shapes that cannot interact well with similar molecules.

Old coffee beans lose many of their volatile molecules, thus the scent and flavor of the coffee is less enjoyable.

There are ten carbons in terpene.

I'm not sure that I could overcome the mental block of not wanting to eat coffee beans excreted by an animal, and thus I doubt I would want to try kopi luwak.

Tea was first discovered hundreds of years before Christ, and was mostly introduced to the west through the Dutch, thanks to their trading with the east.

During the Han dynasty the finest tea was given to the emperor as a tribute.

Charles II, working with Oliver Cromwell of the East India Trading Company, at the behest of Catherine of Braganza, brought to to the west. William Pitt the Younger later made imports of tea much cheaper.

Americans chose to boycott taxed goods, because they did not like taxation without representation. However, the Company arrived at port with tea the Americans did not want. By the trade agreement, the ships could not leave unless the tea had been offloaded, but if the tea came ashore, the tax must be paid. Therefore, the locals came up with the famous solution - throw the tea in the water.

The British created an opium addiction.

Caffeine and polyphenols reduce mental and physical stress.

Theanine boosts the immune system/ Tea has also been linked to many other health benefits, including lower stress and antidepressant properties.

"For green tea manufacture, the withered leaf is steamed and rolled before drying or firing. This is done to prevent the veins in the leaf breaking and thus stopping any oxidization of the leaf." -Pg. 35, History of Tea.

Black tea leaves are plucked and allowed to dry and wither. Next, they are broken into pieces to allow juices to escape. Then they are rolled up and allowed to become oxidized. Finally, the leaf is dried.

Based on this key, I have no idea how I prefer my tea - I drink tea almost exclusively when I am sick, and infrequently even at that. Thus, I do not have a strongly developed preference for what constitutes a 'better' cup of tea.

Taste and Aroma

Today in class we explored tastes and aromas.

For our first exercise we examined taste. Specifically, we mapped out bitter, sour, sweet, salty, and umami flavors, and tried the flavors with and without our noses plugged both before and after brushing our teeth.

The taste map provided did not seem accurate. Sour and salty tastes could be detected with the front of the tongue, and bitter seemed to cover a much larger area.

Flavors, as a whole, were much weaker with my nose plugged, although all still had a distinct flavor. The tonic water had barely any flavor, and was maybe a little sweet (as an aside, I can't stand brussel sprouts).

After brushing my teeth, I noticed some differences, and the group confirmed my observation. The soy sauce seemed to only have a salty flavor, as opposed to salt and umami, and the orange juice tasted more bitter. The coffee seemed not to have a flavor, and nor did the tonic water. Finally, the lemon seemed more sour. As proteins more in the membrane are effected less by toothpaste, it makes sense that sweet and umami flavors are less pronounced, although I was surprised that this, in turns, makes sour and salty flavors more pronounced. Mysteriously, bitter flavors also seemed to be less strong after tooth-brushing, and this seems to contradict my hypothesis.

In the second part of the experiment, we had to identify different flavors with a blindfold on. None of our group members were able to correctly identify the various fruit spreads with our noses plugged, although we had a 100% success rate with our noses unplugged. However, one group member was able to identify applesauce with his nose plugged due to its texture. I also correctly identified a spoonful of garlic with my nose plugged. At first I couldn't really taste anything, but when the garlic got to the back of my mouth I suddenly realized what I was eating. Texture played a large role in the enjoyment (or lack thereof) of the food. The garlic, for example, I found quite disgusting when I was blindfolded (although just fine when I could see it). The various fruit spreads all had textures I did not enjoy.

For our third activity, we taste-tested several types of potato chips. The chips had unique enough textures that they could be correctly identified, even when holding a different flavor under the testers' nose.

Next, we examined desensitization of smell in regards to garlic consumed. I had a sample of garlic spread, and could smell the garlic for quite some time (in fact, I still can, an hour and a half later). The other group members could also smell the garlic on my breath, although their perception of the intensity dropped more quickly than mine did. After they tried garlic, they could no longer smell my garlic breath.

For the fifth part of the experiment, we examined desensitization to salt taste. After dissolving 1.02 grams of salt in 10 ounces of water, I diluted the solution to half its original strength, and continued this until I could no longer taste the salt. After the third dilution I could no longer taste the salt (this corresponds to about 1/8th of a gram of salt in 10 ounces of water).

For the final part of the experiment we smelled many different compounds. Although there were a few scents I could not place, I was surprised at how many scents I was able to identify rather easily.

The two forms of caravone smell different because the atoms in the molecule are arranged differently, and thus they bind to different receptors in the nose. However, the identical part of the molecule can bind the same receptor, and thus the two forms smell similar to one another.

Based on the molecular structures provided, molecules with conjugated double bonds seem to be easily detected by the nose.

I sniffed vanillin until I couldn't smell it any more. After about four sniffs I could barely detect it. With napthalene I was able to keep sniffing for a couple minutes and the strength of the smell did not seem to have abated at all. I hypothesize that scents that our bodies deem dangerous can be detected for a longer period of time.

Olfaction Pre-class

1. A taste map of the tongue has appeared in countless books:

	http://www.understandingfoodadditives.org/pages/Ch2p3-1.htm

In your experience, is this map correct? Taste a few things if you need to.

No, this does not seem correct, although the front of my tongue seems more sensitive.

2. During your next meal, after eating a few items, try them again with your nose plugged. Record your observations.

With my nose plugged the flavors were much less enjoyable. With my apple juice, for example, I could still detect sweetness, but that full-bodied apple ‘flavor’ was missing. Again with my cereal, sweetness was still obvious with my nose plugged. The flavor was again less enjoyable, and I found myself more focused on the actual texture of the flakes.

3. Read “More than meets the mouth” by Michael Eisenstein (posted on Moodle).

· What are the 5 tastes (according to current thought) and 2 tastes for which the jury is still out?

o Sweet, sour, bitter, salty, and umami are the five main tastes, with fatty acids, calcium, and carbonation all potentially tastes as well.

· Eisenstein suggests that “the wisdom of the body” leads people to prefer foods that contain the most nutrients. Consider things with a pleasant taste vs. those with a bitter taste--how might this wisdom also lead us eat things with calories and avoid those with poisons?

o Poisonous foods are generally associated with a bitter taste, thus, we seek out sweet foods. Furthermore, our bodies innately prefer sweet foods – this is a handy ability when fruits are the sweetest food around, but is unhealthy given the modern food industry.

· Broccoli is well known to be rich in bitter compounds. Use what you learned in this paper to explain why people could have such opposing reactions to broccoli, as demonstrated by this quote from President George H. W. Bush: “I do not like broccoli and I haven’t liked it since I was a little kid and my mother made me eat it. And I’m President of the United States and I’m not going to eat any more broccoli…My family is divided. For the broccoli vote out there: Barbara loves broccoli. She has tried to make me eat it. She eats it all the time herself.”

So far, 25 bitter taste receptors have been identified, and the sensors all detect different bitter compounds. Genetic factors have been linked to malfunctioning bitter receptors, and geographic and ethnic factors have been shown to change the distribution of bitter receptors. These differences explain why people can have opposing reactions to the same food – one may not taste the bitter compound, and therefore enjoy the food, while the bitter-taster may not like the food at all.

4. Consider vision, gustation, and olfaction. Which two systems are the most alike? Why?

Vision and olfaction are most similar. In these systems, different receptors work together to create a particular color or scent. A unique combination of ligands binding to the receptors causes a unique response. With taste, there are only several possible catagories that a flavor can fall under.

5. Describe an analogy that you could use to explain olfaction to someone outside of this class.

Olfaction is like a protein. In a protein, many different atoms combine in a very particular way to assemble into one unique protein. With olfaction, many molecules, in combination with one another, bind to a particular set of receptors, generating a unique smell.

Green Beans

Today in class we ran various test on green beans in order to determine what happens when the beans are cooked in boiling water. Our tests revealed that there are many nuances to consider when cooking with salt.

Our first test was salted beans versus unsalted beans. After adding salt to one pot, we boiled two pots of water and added the green beans to cook for seven minutes (an amount of time suggested by an internet search). Our two taste testers, having no idea which beans were which, were able to tell a clear difference between the flavors; however, they both guessed backwards as to which beans were salted rather than unsalted. The salty beans had a stronger, sweeter flavor that made them much more enjoyable to eat, and were a bit harder in texture.

Our second test was a comparison of different salt types and their effect on the flavoring of the beans. In one pot we had beans cooked in sea salt, which has large crystals, and in another pot we had 'Lite' salt, which had much smaller crystals. Again, our subjects accurately identified which beans were of which type, but failed to assign the correct identity. The larger salt crystals lead to better tasting beans. I found this surprising, as it was my understanding (from the article I read before class) that finer crystals cause more intense flavoring. I postulate that this is the case for additives to solid foods, whereas larger crystals are superior for boiling foods.

Third, we boiled beans in one pot without a lid, and in another pot with the lid. All other factors were identical. The beans with the lid moved much more vigorously, due to the water boiling more vigorously. After cooking the beans were a little bit lighter, but the difference was minimal.

For our next test, we added salt and baking soda to one pot in order to make an alkaline solution, and had salt and vinegar in the other pot in order to form an acidic solution. After five minutes of boiling, the baking soda beans were clearly brighter green than their no-baking soda counterparts, and the acidic beans were much more brown.

Salt also changes the boiling point of water, to a small extent. Adding more salt raises the boiling point.

Day 3.

1. 20 Carbons, trigonal planar arrangement.

2. If the signal channel were stuck in the open position, the cell would keep sending a strong signal to the brain. However, the cell would quickly reach a point where its chemical-electrical gradient is no longer proper for other cellular functions. If the channel were stuck the closed position, no signal would reach the brain.

3. The channel is the leak, the pump is the bucket, and the inside of the cell represents the boat.

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Optical Illusions:

The checker shadow illusion was very convincing, although I had already seen the illusion before and was aware that the squares marked A and B were in fact the same. Still, cutting out the individual squares to prove this fact was a valuable exercise. As I worked through more optical illusions it became clear to me that it is actually fairly simple to dupe the brain into perceiving things incorrectly. I was struck by how the brain, rather than simply interpreting things as they actually are, interprets images in relation to one another, and then attempts an explanation. Furthermore, despite knowing the 'trick' of the illusion, I still found myself unable to perceive the image properly. One partial exception to this is the checker shadow illusion, where I found the focusing solely on square B allowed me to see it as a darker square, which was nearly identical to square A.

The curve ball illusion was my favorite, in part because it had a fairly simple explanation (switching from central vision to peripheral vision) and in part because of its applicability (the curve ball and even fast ball in baseball). I'm curious how often tricks like this manifest themselves in every day life - for example, how do we interpret information from our peripheral vision while driving, and how close to correct is it? I'm also curious about how people with only peripheral vision (I know an adult that lost his central vision) perceive illusions.

Other illusions were able to use all sorts of tricks - by altering color, depth perception, and curves, many illusions could be created. One of the most intriguing illusions was the spinning cat illusion, in which a cat, in theory, could be perceived as spinning either clockwise or counterclockwise. I was only able to see counterclockwise, aside from about half a second where it suddenly reversed and then switched back again. Despite staring at the cat for several minutes, I never was able to control the spin. My lab partner (Melissa) was able to see it change directions. I found it intriguing haw different people perceive things.

I was intrigued by the examples of color blindness. Although I have seen the dot tests before, I had not seen such a collection of pictures for various forms of color blindness. This greatly enhanced by understanding of the significance of color blindness, and made me very thankful for the fact that I am not color blind.

FOOD/FLUORESCENCE

During lab time we extracted coloring from cabbage and spinach, and placed the colors in solutions with a pH ranging from 1 to 11. The cabbage extract ranged from dark pink at pH 1, though light pink, purple, blue, teal, and light green at pH 11. The color range was less significant for the spinach extract, which was an orange-ish brown color at pH 1, a light yellow-green color at pHs of 3 and 5, green through pH 9, and a dark, bright green at pH 10 and 11.

Bleach and hydrogen peroxide both neutralized color, although the bleach acted more quickly and more strongly. This effect is due to the oxidation process, as both agents oxidize the conjugated double bonds that are largely responsible for causing light to reflect in the visible spectrum.

We also observed several objects and solutions under a black light. Fluorescent proteins fluoresce brightly at their particular color, quinine in tonic water fluoresces a bright blue, as does a white towel. Chlorophyll fluoresces a very dark red color.

The color white can reflect light very efficiently in a manner that does not overwhelm us. In other words, the color white redirects light energy as opposed to acting like a mirror and shining it right back in our faces.

Rods perceive blue-green light most easily.

The double bonds in many colored fruits and vegetables serve as an outlet for oxidizing agents in the body. An omnipresence of these chemicals will reduce the oxidizing reactions that might otherwise occur with DNA.

-COOH can hydrogen bond with H2O, increasing solubility. Raising the alkalinity will cause the base to abstract a hydrogen from the –COOH, leaving a negative charge on the pectin. Two pectin molecules at a time can therefore form a favorable interaction with the Calcium ion.

All of the -COOH and -OH groups allow pectin to easily Hyrdogen bond with water.

RCOOH +NaHCO3 à RCOONa + H2O(l) +CO2(g)

The product will be less soluble, as the RCOONa will be less able to Hydrogen bond. The result is that the pectin will be less soluble, and will not become as mushy during cooking time.

All salts are not created the same. As the paper points out, there is a difference in salt based upon how fine the crystals are. Furthermore, there are various other salts used in cooking (such as sodium nitrite) that have different properties. That being said, the various salts in the slideshow seemed nearly identical. Although some contain traces of elements such as Magnesium and Calcium, overall there was little difference in the salts, and the properties of the salts should be very similar.

Day 2 - Meijer Gardens

On Thursday, January 6th, our class took a field trip to Fredrick Meijer Gardens. Our main objective was to become acquainted with the various odors surrounding us.

The first room I entered was the Victorian room. The room was warm and moist; the smell was dense and woody, almost like mulch. To me, the scent seemed peaceful and pleasant, reminding me of cedar. The first flower I smelled was an orchid, which had a soft, sweet smell.

The next plant I smelled was a Norfolk Island Pine, which had the deep, woody smell of most pines, but to my surprise, the scent was rather warm.

Following the Pine, I smelled a Cypress tree, which reminded me very much of the pine. However, the scent was both stronger and sharper. A Montgomery Spruce was next, which had a subtle but soft and woody scent.

After the Victorian room, I walked into the desert room. My first stop was at an aloe plant. Although the scent was soft, I was quickly reminded of the smell of lotions. Continuing to walk through the desert room, I smelled a Red Fairy Duster, which smelled rather sweet, and reminded me of the orchid.

Next up I visited the carnivorous plants room. Immediately upon entering I noticed a smell that reminded me of decaying leaves, but the smell was also rather warm. I smelled a Tropical Pitcher Plant, which had a sharp although weak odor, ever so slightly sweet.

Following the carnivorous plants room, I entered the main tropical room. Again I smelled decaying leaves. My first stop, at a Japanese Loquat, gave a rather sharp smell, but still reminded me of certain perfumes. I next encountered the allspice tree, although I did not realize until later that the tree was, in fact, the allspice tree. However, having smelled it, I commented that the smell was very gentle and soothing, very similar to several spices, particularly those that you might put in tea. Later I compared the allspice leaf scent to some ground cinnamon. The allspice smelled fresher and softer, and also a little warmer than the cinnamon.

The next plant was a Fiji Fan Palm, which smelled quite terrible, as though it were decaying. Fortunately the odor was only of a medium strength. The smell was somewhat cold, and reminded my of the smell of dirty socks.

I then approached the Crinum Lily, which was giving off a very powerful scent, which I was easily able to distinguish from several feet away. The scent was very warm and soothing, and quite sweet. The Lily reminded me of some perfumes.

Just walking through the room without pausing to sniff any particular plants revealed many scents wafting through the air, giving a very three-dimensional texture to the room. I could detect decaying leaves, some sweet smells, and some citrus (although I believe that is from some Christmas decorations).

After having gone outside to clear my senses, I returned to the main Christmas room. While I had been outside I had noticed more of a lack of smell, aside from a few evergreens that I sniffed. However, returning to inside I immediately felt bombarded by scents. Although the smell was Christmas-y, I wasn't sure what any of the particular elements to the smell were. Then I thought I smelled some cleaning agents, and shortly thereafter noticed some cleaning supplies on a cart.

I encountered a tree known as the Rose of Venezuela, which had a strong, sweet smell similar to that of perfume.

Back in the Victorian room, I sniffed the Chocolate Orchid. The smell definitely did not remind me of chocolate, but it was very warm and sweet, and called to mind the scents of certain perfumes and lotions. The smell was very powerful.

In the desert room again, an employee showed me some starfish flowers, which she said emit a pungent odor when they blossom. Sadly, the flowers were not blossoming, and so did not emit enough of a scent for me to detect.

In all, this exercise caused me to be much more in tune with not just scents but senses in general. Having a nice slow walk around the gardens allowed me to take in the beauty of the plants and also enjoy the peaceful sounds of a waterfall and birds tweeting. During the course of the exercise, however, I noticed that I was becoming more aware of various scents. Returning a second time to sniff various plants brought more observations to me - although, if I spent too much time trying to smell a plant, its scent would fade from my ability to detect it. My perception of smells seemed most keen upon reentering the building from being outside.

I had two Christmas scents - cinnamon and a mystery scent. I think the mystery scent might be Eucalyptus (due to its Menthol-like smell), but it is not a scent I associate with Christmas. The cinnamon, on the other hand, brings back three main memories. First, a Christmas ornament I made many years ago using cinnamon sticks. Second, my mom making cinnamon rolls. Thirdly, and less happily, the scent of cinnamon reminds of a non-holiday occasion where I put way, way too much cinnamon in with my applesauce. However, my perceptions of the smells around me did not seem to be altered significantly.