52. Food Sensations

February 4, 2024

Components of Taste:

Flavors:  perinasal and retronasal.  Neural cells in the two olfactory regions.  Identification of aromas.  The role of the amygdala in the Proustian Effect.  

Taste buds.  Umami.  The four Aristotelian tastes.  Mixtures of tastes.

Texture.  Resistance to bite, size of particles causing grittiness.  How fat makes gelato taste smoother.  Chocolate notes (roasty, fruity, nutty).  Crystallization of cocoa butter:  how it affects the texture of chocolate.  Why does "young chocolate" melt in the mouth but "old chocolate" has a waxy texture?

News about PH&F:  sales numbers for  Depa and Pezoan and N'Douci

Transcript

SPEAKER_01 1:54

Welcome to podcast number fifty-two. Today's podcast is about sensations, sound, and taste. To start with, what you just heard was one of Chopin's greatest and most difficult preludes, number eight in F sharp minor. What makes this piece great? For one, it's the interplay, no pun intended, between the melody, background notes in the right hand, and foundational notes in the left hand. What makes it difficult? It's hard to play because you're doing three things at once, playing the melody and the background notes with the right hand and the foundational notes with the left hand. The melody played by the thumb of the right hand is a dotted eighth followed by an eighth. The background notes played by the four fingers of the right hand are 30-second notes, that is 32 notes to a whole note. That's a lot of notes. It's very hard to play the melody and the right hand background notes together so that each note gets precisely the same duration. A piece like this takes years to learn because you have to build in the discipline of playing absolutely evenly. As you can hear, I have some years to go before I master this piece. The left hand plays four sixteenth notes in each measure. These are descending arpeggios or broken chords. The left hand serves as a foundation to the piece. It foreshadows where the piece is going. Okay, well that's music. What about food? Is it as complex as music? Once we consider some examples, I think you will agree with me that the answer is yes. While music is comprised of sounds that are generated by vibrations and detected by a vibrating eardrum which then shakes the cochlea's hairs that turn into electrical signals and are processed by the brain, food sensations are made out of something else. Food sensations are partly flavors, partly tastes, and partly textures. These are not vibrations, but they do end up as electrical signals, like all our sensations. Flavors are volatile chemicals that either travel through the nasal passages to an area at the top of the sinus called the olfactory region. The volatiles that are sniffed through the nose are called perinasal flavors, and the volatiles that travel to the olfactory regions by way of the throat is called retronasal flavor because it comes up the back way, up the back of the throat. There are two olfactory regions, each corresponding to one of two nares, the holes through which you sniff and breathe. Each olfactory region is about the size of a postage stamp and is made of neural cells that project into the region of the brain that processes aromas. There are several million of these neural cells in each of the regions. And when you smell something, they are excited when the molecules dissolved in the mucus lining bind with regions in the cell body of each neural cell. Recognition and memory of aromas begins with patterned firings of these neural cells, whose axons project into the olfactory part of the brain. Identification of aromas results from processing and matching these patterned firings. The amygdala, which is an almond-shaped body in the brain, is where moods and emotions begin, and it is directly linked to the olfactory lobe, the portion of the brain that processes aromas. The connection of the amygdala to the olfactory lobe explains the Proustian effect, so-called because during his childhood, the French writer Marcel Proust used to visit his favorite aunt. She would serve him Maudelin cakes and TL cookies, TLT, and years later, every time he had Maudlins and TLT, he thought of his beloved aunt. The connection between aroma and emotions is very powerful. Flavors are recognized mostly by the type and size of molecule. Molecules that contain sulfur often produce a skunk-like or musky flavor. For example, mercaptins, carbon-based molecules with attached sulfur hydrogen groups, are found in the stent glands of skunks and are also associated with the aroma of rotten eggs, aged cheese, cooked corn, boiled milk, and cooked asparagus. Spices and perfumes contain terpenoids. These are compounds that are produced by plants to ward off insects or to kill them, but they have beneficial effects in humans. Spices make our food interesting to eat and help us define cultural origins. So we benefit greatly from eating the plant world's insecticides. When you fry onions with garum masala to make an Indian curry, you are using these turpenoids to produce appetite and to define the food's cultural origins. With music, our brains process notes, octaves, and chords to facilitate recognition. The first four notes of Beethoven's fifth identify his symphony and make it recognizable to a majority of people on Earth. Tastes are the electrical signals generated by the taste buds, located in structures called papilla found on the tongue. There are four kinds circumvalate found at the back of the tongue, foliate, mostly on the sides, and fungiform and filliform, which are scattered across the top. The filliform papillae have no taste buds, but are sensitive to touch, heat, and irritants such as capsaicin of chilies, piperine of black pepper, and zingiburone of ginger. Sweet is mostly detected at the tip of the tongue and bitterness at the back. A fifth taste, umami, was identified by the Japanese in the 1960s. Umami means delicious and is most associated with monosodium glutamate. Steak, meat broths and porchini mushrooms are especially rich in umami taste because they are very rich in the amino acid glutamate. When taste buds fire and produce electrical signals, these are conducted to the brain along the trigeminal nerve. Overall taste processing, recognizing and categorizing happens in the gustatoric cortex located on the side of the brain. A taste sensation results from the firings of many nerves to produce a firing pattern that with previous memories to enable that with previous memories enable categorization. So you're eating salty pretzels, a popular American treat. The trigeminal nerve carries a firing pattern that the gustatory cortex then classifies into a mixture of tastes. Salt, obviously because of the big salt crystals, but also bitterness from the alkali that are sprayed onto the pretzels so that they turn a rich brown when they enter the oven. And there's also a sweet sensation caused by dextrinization of starch molecules that is breaking into small pieces, which occurs at the surface of the pretzel. Texture is the third component of a food sensation. Texture is sensed by the skin cells lining the mouth cavity. Electrical signals conducted from those cells are processed in the somatosensory cortex located on the surface at the top of the brain. When you chew a food, certain skin cells found in the jaw at the base of the teeth fire in response to pressure. A tenderloin steak produces fewer pressure signals than a chuck steak, which has more connective tissue. Another type of texture sensation happens in response to particles of food. For example, potato chips, which shatter when chewed and produce sharp pieces of fried potato bits, cause a gritty sensation. The opposite of grittiness is smoothness. A fruit sorbet made with vegetable gums called a fru without vegetable gums called a fruit ice forms large ice crystals that produce a gritty sensation. The opposite of this is in Italian gelato, which is made with a very high fat mix. The fat globules of cream inhibit the formation of large ice crystals, as do the milk proteins, and the walls of the mouth fire off smooth signals, which explains why gelatos are so popular. Speaking of smoothness and popularity, let's talk chocolate. When you bite into a chocolate bar, you of course get all three food sensations, flavors, tastes, and textures. All three add up to perception of quality. For most chocolate aficionados, the best chocolate is smooth and creamy. As it melts across the palate, one detects multiple flavors that food scientists refer to as notes, such as roasty notes, fruity notes, and nutty notes. Freshly made chocolate melts quickly, resulting in a sauce whose flavors and tastes are immediately apparent. The flavors of cocoa beans that confer nutty and fruity notes stem from aldehydes and keep tones formed when alcohol produced from sugars present in the fruit surrounding the beans oxidize into acetic acid during the traditional six days of fermentation. Tastes include the saltiness of sodium chloride, the sweetness of residual sugars, as well as the sugar added during the grinding process, the tartness of acetic acid that forms during fermentation, and the bitterness of anthocyanins, which are mostly removed during fermentation. Grinding cocoa beans results in a fluid known as chocolate liquor. It is fluid because cocoa butter, which comprises more than 50% of the cocoa bean, melts. Suspended in the cocoa butter are particles of the seed's endosperm containing starch granules and clumps of protein. The smaller these particles, the smoother and shinier the chocolate. To mold chocolate, you have to chill it lightly. As cocoa butter cools, the fat molecules produce crystals, of which there are five types called types one through types five. Type 5. Types 1 and 2 are liquid at a low temperature, below 98.6 degrees Fahrenheit, human physiological temperature. As you continue to cool chocolate, types 3 and 4 begin to form, causing the chocolate to solidify. A freshly made bar consists mostly of crystal types 3 and 4, which melt just above 98.6, cool enough to form a bar that melts in the mouth but not in the hands. As the chocolate bar ages, more and more of the threes and fours become crystal types 5, type 5, and the temperature at which the chocolate melts rises. Thus, young chocolate, recently made and full of crystal types 3 and 4, melts rapidly in the mouth, releasing its gamut of flavors and tastes. Old chocolate, though, melts slowly, giving the bar a waxy texture and interfering with the release of flavors and notes. So mystery solved. Now you know why old chocolate doesn't melt in the mouth and why it tastes so bland. It's to prevent premature aging that manufacturers add lechatin, which delays the transition from three to four to five. And so we end this portion of the podcast, having learned just a little about the complexities of food and music. Now we turn to news about our nonprofit, which of course is the raison d'être of this podcast, to report on our efforts to make West African cocoa farmers actual chocolate producers. As you may know, we work with three villages DEPA, Pesoin, and Nducy. First, let's talk about the DEPA facility, which is owned by SOCO Plan, Societe Cooperative desplanteurs. That means Cocoa Farmers Cooperative. Jean-Paul Bolu, who is director of operations at SOCO Plan, tells me that during November and December of 2023, the cooperative produced 5,986 one-ounce bars of chocolate liquor, 70% bittersweet, and 60% milk chocolate. The percentage, by the way, refers to the weight of chocolate liquor, cocoa powder, and cocoa butter divided by formula weight. A couple years ago, Project Hope and Fairness purchased a 1,000 pound cocoa butter press and a cocoa powder grinder for Soco Plan. Just during those two months, November and December, Soco Plan sold 481 pounds of cocoa powder and 132 pounds of cocoa butter. Daipa makes a pretty good profit from selling cocoa butter, which is highly favored by Ivorean women for setting their hair. Soco Plan cocoa butter, because it is made with high-quality beans, has a wonderfully chocolatey fragrance, making it great for hair as well as for making chocolate. I buy the cocoa powder for my shop in Cord in France, where I live. And you'll learn something about the business. And I established it in order to develop a market for the village chocolate. My customers really appreciate the delicate floral notes of our cocoa, which is far superior to most cocoa, because its nutritional value and flavor have not been wiped out by the use of alkali. I use raw milk, whose flavor is quite superior to pasteurized milk, and I use organic sugar, which has a delicate caramel note lacking in refined sugar. A little background information about the village of Depa. In 2012, Project Open Fairness built a rice hauling facility there. A year later, I brought a little cocoa mill in my suitcase, and David Zigro and I made a few dozen chocolate discs, which we shared with local villages. DEPA was among the first villages in Côte d'Ivoire to have its own chocolate factory. In 2019, we funded the establishment of SOCOPlan, the cooperative in DEPA, and have since then purchased the equipment that has made Socoplan into a successful factory. Okay, so that's the uh DEPA. Now let's talk about the second village, Peswan. It's three kilometers down the road from DEPA. Between 2016 and 2019, we built a rice hauling facility and chocolate room. Um in 2022, Adama Yamba, who's also known as Cervando, um, established a cooperative in Peswan, which is called SCAP or Societe Cooperative Agricole de Pesuan, cooperative, agricultural cooperative in Peswan. That's what it means. Um here are some sales numbers of Pesuan during the last month. 565 African chocolate fudge bars and 30 100 gram chocolate tablets. Well, he has only one mold. That's why. The Peswan facility is smaller than Soco Plan, but we are working hard to help it grow. Back in 2022, I showed Cervando how to make the African Choco Fudge Bar. Um, it's got a chocolate shell on the outside, and then it has cocoa um fudge center, uh, which is very creamy, and then a flavor in the fudge. Um I made PDFs with pictures and text in French and sent them to him by WhatsApp. Uh Cervando's a really good student. He read the text, looked at the pictures, and he's been making delicious and beautiful chocolate bars ever since. On the PDFs, I showed Cervando how to candy orange peels, ginger, and pineapple. And uh with local fruits, he's making five different choco fudge bars. He forms the chocolate shell by coating the chocolate mold, and then he um lets it cool in the cooling room, and then he fills each cavity halfway with fudge and adds the flavor, which could be candied coconut, um, ginger, candied ginger, candied orange, uh, peanuts with his own peanut butter and vanilla cream. Now Cervando and his crew are working on manufacturing candied cocoa beans as a snack to be manufactured in Peswan and sold throughout the United States. Hopefully by the next podcast, I will have some exciting news about this product. Now let's talk about our third minifactory located in Ndu Sea, that's N D-O-U-C-I. It's a town of 100,000, about 90 miles north of Abidjan, Ivory Coast's biggest city. We built the factory last June. It's run by ONJ Ascof, ONG-Ascof A S-C-A-F. ONJ or ONG is the French way of writing NGO or non-governmental organization. Ascof stands for Association Caritative Chrétienne d'Afrique, which means African Christian charity. The president of Ascaf is Roger Courtois Niepo. I have known him since 2005 when he was running a school for several hundred boys orphaned when their parents were shot by guerrillas operating on the border between Ivory Coast and Liberia. At the time, Roger and I shared a common interest, how to rid the Ivorian cocoa business of the worst forms of child labor. Years later, Roger formed Ascof, which is based in Abidjan. His NGO represents and defends women who do domestic work for wealthy families and are mistreated. Ascof also runs a school for children of poor families. It's called Nadro La Source. According to Roger's latest report in the third trimester of 2023, the factory produced one thousand nine hundred and ninety five bars made in three different weights, as well as seven hundred and twenty-five seven gram chocolate discs. Two hundred and fifty of the bars were produced for the marriage of the director of the local police department, and the discs were sold to Nato La Source, the school. Also, several hundred bars were sold to women's groups selling to travelers on buses. Like so many countries in Africa, you will encounter women, girls, and boys selling products along roads at intersections and in bus stations. So that presents a really good market for our products. Since June of 2023, ONJ Asgave has purchased 3,300 pounds of cocoa beans from its the members of the cooperatives at a price exceeding the government's rate by 10%. In addition to the better price, ONJ Ascoff is also conducting microprojects to improve the lives of the villages in which the cooperatives are housed. Well, that's it for now. Thanks for listening. We end this podcast with another F Sharp. Minor prelude. The father of classical music. You'll note that unlike Coca's very romantic piece with its soaring and thinking melody, its optimism and its pessimism, its longing and its passions. Fox piece is somewhat mechanical and mathematics. Listening to the two preludes is like stepping a Pinot Noir and then a Merlot. Both are great, they're just different. That's it for now. See you next time.