Lavender Cream

Lemon curd pudding lavender cream
Photo credit: Sue O’ Bryan (Foodlander/Flickr)

How does sipping a cup of lavender tea with honey sound? Soothing? Fragrant? Then imagine stumbling upon an open field of lavender flowers. The lavender plant, genus Lavandula, comprises 39 flowering plant species, all of which are easily recognized by that trademark color and signature fragrance. The most popular species of lavender is L. angustifolia, commonly known as English lavender and lauded for having the sweetest fragrance among lavender plants. Lavender flowers are primarily grown in order to extract the essential oil for both medical and culinary uses.

The distinctive purple flower is popular for its calming abilities, extensively used in aromatherapy alongside other herbs. Lavender is additionally famed for its healing properties. French chemist, René-Maurice Gattefossé realized the usefulness of lavender oil as a healing essence when he plunged his burned arm into a tub of liquid containing lavender oil, later noting quick tissue regeneration with little scarring [1,2]. Following Gattefossé’s observation and subsequent experiments using lavender oil in military hospitals during World War I, lavender is also used today as an antiseptic and anti-inflammatory [1]. As an herb, lavender of course has a dedicated fan base in the culinary world; the fragrant flower is the star of recipes such as lavender cake, lavender shortbread, and even lavender and honey roasted chicken.

Analysis of lavender oil reveals the primary compounds responsible for the scent are linalyl acetate and linalool (pronounced lin-ah-low-awl). Both have been cited to contain various pharmacological properties that aid in relaxation, such as anti-anxiety, anti-depressant, [1] and relaxant of vascular smooth muscles [3].

Minor volatile components that contribute to the scent of lavender essential oil include (E)-β-ocimene, (Z)-β-ocimene, terpinen-4-ol, 1,8-cineole, camphor, and limonene.

Minor compounds

But make no mistake. There’s nothing “minor” about these compounds when it comes to lavender flavor. According to the flavor network by physicist Albert-László Barabási, North American and Western European cuisines like to pair ingredients that share many flavor compounds. Camphor confers a woody, evergreen scent and is one of the primary volatile compounds in dried rosemary leaves; this makes lavender and rosemary a comforting combination. Further, linalyl acetate, linalool, and many of the minor volatile components of lavender oil can also be found in lemon peels and lemon essential oil [4]. Lavender and lemon are such celebrated culinary companions that the two are practically best friends.

Want to try cooking with lavender for the first time? Relax; it’s not as challenging as it seems. Just take a deep breath and try out this simple lavender sugar recipe.

References cited

    1. Tankeu SY, Vermaak I, Kamatou GPP, Viljoen AM. Vibrational spectroscopy and chemometric modeling: An economical and robust quality control method for lavender oil. Industrial Crops and Products, 2014; 59: 234-240.
    2. René-Maurice Gattefossé. Oils and Plants. Accessed 2014, December 21.
    3. Koto R, Imamura M, Watanabe C, Obayashi S, Shiraishi M, Sasaki Y, Azuma H. Linalyl acetate as a major ingredient of lavender essential oil relaxes the rabbit vascular smooth muscle through dephosphorylation of myosin light chain. Journal of Cardiovascular Pharmacology, 2006; 48(1): 850-856.
    4. Oboh G, Olasehinde TA, Ademosun AO. Essential oil from lemon peels inhibit key enzymes linked to neurodegenerative conditions and pro-oxidant induced lipid peroxidation. Journal of Oleo Science, 2014; 63(4): 373-381.

Alice PhungAbout the author: Alice Phung once had her sights set on an English degree, but eventually switched over to chemistry and hasn’t looked back since.

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Caramel flavor is a major component of desserts and candies, ranging from smooth, thick sauces to crispy, dark brown glazes of crème brûlées. Through caramelization, a browning process where sugar is heated to around 170 °C and broken down, over 100 compounds are formed that contribute to the color, flavors, and textures of what we know as caramel [1].

Photo credit: APN MJM/Wikimedia Commons

Photo credit: APN MJM/Wikimedia Commons

One simple way to caramelize table sugar is by heating: this process removes water from the disaccharide sucrose (a substance composed of two simple sugars) and breaks it down into monosaccharides fructose and glucose. Next, the monosaccharides react with each other to form new compounds, such as caramelan, caramelen, and caramelin [2]. These compounds aggregate to form brown particles of various sizes due to additional water elimination, contributing to the characteristic brown color of caramel. The stickiness of caramel can be attributed to the ring form of these molecules combined with the presence of free radicals [3]. Further, when in the presence of alkali, sulphite, or ammonia, these compounds can also result in colorants used in food products such as soy sauce and Coca-Cola [4].

In addition to these classic caramel compounds, many other molecules are produced that result in different aromas that contribute to caramel’s complex flavor profile, such as furans (nutty), diacetyl (buttery), maltol (toasty), and ethyl acetate (fruity) [3].

How to tune the flavor of your caramel? The temperature the sugar is heated to determines caramel flavor. “Light caramel” (180°C) can be used for glazes, is rich in flavor, and pale amber to golden-brown in color. By contrast, “dark caramel” (188-204°C) is dark and bitter in flavor due to increased oxidation of the sucrose molecules; it is usually used for coloring. Additional heating past this point will turn the caramel into a black and bitter mess, as the sugar breaks down into pure carbon [2].

Interestingly, caramel candies made with milk or butter do not undergo the caramelization process. Instead, the heating of the dairy product in the recipe causes Maillard reactions between sugar and amines that result in the brown color and flavors produced [1].

Next time you enjoy caramel flavor, you can revel in the smell and taste of all the aromas that result from complex chemical processes. Or, simply make your own with sugar, water, and a stove.

References Cited

  1. Caramelization.” Accessed 21 October 2014.
  2. Caramelization.” Accessed 21 October 2014.
  3. The Chemistry of Caramel.” ScienceGeist. Accessed 21 October 2014.
  4. E150 Caramel.” Accessed 21 October 2014.

Catherine HuAbout the author: Catherine Hu is pursuing her B.S. in Psychobiology at UCLA. When she is not writing about food science, she enjoys exploring the city and can often be found enduring long wait times to try new mouthwatering dishes.

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Photo Credit: Thomas Abbs (tabsinthe/Flickr)

Photo Credit: Thomas Abbs (tabsinthe/Flickr)

Among fruits, bananas enjoy huge popularity. The Market and Policy Analyses of Raw Materials, Horticulture and Tropical (RAMHOT) Products Team even reported that within the U.S. in 2012, per capita banana consumption was calculated at 13.8kg [1]. The humble banana even reigns as the main fruit in international trade, according to the Food and Agriculture Organization of the United Nations (FAO) [2]. But as a flavor? Banana candies are often the last flavor left in the bowl.

The disparity between the pleasant and sickening feelings which banana flavoring can invoke lies in the intricacy of banana flavor chemistry. The fruit itself contains a mixture of volatile compounds that are responsible for its characteristic flavor. Up to 42 molecules have been identified to contribute to the aromatic profile of bananas [2]. Each of these molecules, when isolated, has been reported to give off their own unique scent [2,3]. Most of the scents are described as floral, sweet, and generally fruity, which are expected when analyzing aroma compounds derived from bananas. However, there are a few volatile compounds that emit odors not usually associated with bananas. For instance, eugenol, one of the significantly abundant aromatic compounds found in bananas, smells spicy, like cinnamon [2,3].

Of all the volatile compounds detected in bananas and analyzed, one stands out as the banana flavor molecule: isoamyl acetate. With a scent often described as “over-ripe bananas”, pure solutions of isoamyl acetate are sold as “banana oil”. Isoamyl acetate is widely used as a flavorant to confer that over-ripe banana flavor in foods. Yet, as many can attest, pure “banana flavor” tastes awful, nothing like the actual fruit. Despite its presence in the banana itself, how does the banana-flavor molecule miss the mark so badly in candy?

Isoamyl Acetate

Chemical complexity is one explanation, as there are 30-40 other aroma compounds that contribute to natural banana flavor. Additionally, in a ripe banana, although isoamyl acetate is one of the key molecules in banana aromatics, it is found in small amounts compared to the other volatile compounds [2,3]. Yet, even though isoamyl acetate is not the most abundant compound in the aromatic profile of bananas, it is a heady flavor on its own: this molecule can be tasted in concentrations as low as 2 parts per million [4].

So, maybe a banana-flavored Laffy Taffy contains a higher concentration of isoamyl acetate than an actual banana. Until scientists and flavor chemists figure out how to make banana-flavored foods actually taste like bananas, at least the yellow Laffy Taffy has its small but dedicated fan base.

References cited

  1. Banana Market Review and Banana Statistics 2012-2013. (2014). Retrieved October 2, 2014.
  2. Jordán MJ, Tandon K, Shaw PE, Goodner KL. Aromatic profile of aqueous banana essence and banana fruit by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O). J Agric Food Chem. Oct 2001;49(10):4813-7.
  3. Pino J, Febles Y. Odour-active compounds in banana fruit cv. Giant Cavendish. Food Chemistry. Mar 2013;141(2013):795-801.
  4. Bilbrey, J. (2014, July 30). Isoamyl acetate. Retrieved September 28, 2014.

Alice PhungAbout the author: Alice Phung once had her sights set on an English degree, but eventually switched over to chemistry and hasn’t looked back since.

Read more by Alice Phung


Photo Credit: Jim Lightfoot (112095551@N02/Flickr)

Photo Credit: Jim Lightfoot (112095551@N02/Flickr)

One rhizome, many tastes. Ginger can be charmingly sweet as candied ginger, gingerbread, and ginger ale. Just as easily, this root can be spiritedly pungent, as in gari (sushi ginger) or unsweetened ginger tea. From sugary snacks to savory dishes, ginger shares similar flavor versatility as cardamom, which should come as no surprise; the two spices are practically cousins. All ginger plants are of the genus Zingiber, which belongs to the same family as cardamom plants, Zingiberaceae [1]. However, the supermarket ginger that most people are familiar with is the knobby, root-like rhizome of Z. officinale, better known as the garden ginger.

Fresh ginger gets its pungency and aroma from the flavor compound, gingerol. Studies have extolled gingerol for its many pharmacological abilities, including antipyretic (fever reducer), analgesic (pain reliever), anti-inflammatory, and antibacterial [2]. The best part? Chemically altering gingerol ends up tweaking ginger’s flavor profile, which helps give ginger its flavor versatility. No laboratories or fancy equipment are needed; as long as there’s a kitchen and a love for ginger-flavored foods, fine-tuning the flavor of ginger is rather straightforward.


Heating a ginger rhizome causes gingerol to undergo a reverse aldol reaction, transforming it to zingerone, a molecule that is completely absent in fresh ginger. Like gingerol, zingerone is responsible for the pungency of cooked ginger, but it also lends a sweeter note to the flavor. For this reason, cooked ginger makes a delightful treat as candied ginger. Zingerone also boasts quite a few pharmacological benefits, notably, its many anti-obesity actions [3]. For instance, zingerone was shown to inhibit obesity-induced inflammation, as well as stimulate the release of catecholamine, a hormone that aids in decreasing fat cells [3].


Drying a piece of ginger triggers a dehydration reaction, changing gingerol to shogaol. Shogaol is twice as spicy as gingerol, which is why dried ginger packs more heat than its fresh counterpart. Additionally, shogaol retains gingerol’s bioactivity, reported to act as an antioxidant, anti-neuroinflammatory, and even memory-enhancing agent [4].


With a multitude of benefits and just as many ways to serve it, there’s really no wrong way to enjoy ginger.

References cited

  1. Zingiber. The Plant List (2010). Version 1. Published on the Internet; (accessed 13 August, 2014).
  2. Young H.-Y, et al. Analgesic and anti-inflammatory activities of [6]-gingerol. Journal of Ethnopharmacology. Jan 2005; 96(2):207-210.
  3. Pulbutr P. et al. Lipolytic Effects of zingerone in adipocytes isolated from normal diet-fed rats and high fat diet-fed rats. International Journal of Pharmacology. Jul 2011; 7(5):29-34.
  4. Moon M, et al. 6-Shogaol, an active constituent of ginger, attenuates neuroinflammation and cognitive deficits in animal models of dementia. Biochemical and Biophysical Research Communications. June 2014; 449(1):8-13.

Alice PhungAbout the author: Alice Phung once had her sights set on an English degree, but eventually switched over to chemistry and hasn’t looked back since.

Read more by Alice Phung


(Steve Evans/Flickr)

(Steve Evans/Flickr)

Nothing says “summer” quite like a big, juicy slice of watermelon. Even if you prefer it charred on the grill or blended into an icy agua fresca, watermelon is one of the best ways to beat the late-summer heat.

So what gives watermelon its refreshingly delicate flavor?

Turns out the answer is pretty complicated. Over the last few decades, scientists have identified dozens of flavor and aroma molecules that contribute to watermelon’s unique taste [1].

And here’s an interesting twist: a watermelon’s flavor has a lot to do with its color. Chow down on a yellow ‘Early Moonbeam,’ a pale ‘Cream of Saskatchewan,’ or a deep red ‘Crimson Sweet’ and you’ll likely notice different flavor profiles for each melon.

These watermelons don’t just look different, they taste different, too! (David MacTavish/Hutchinson Farm)

These watermelons don’t just look different, they taste different, too! (David MacTavish/Hutchinson Farm)

Several of watermelon’s flavor molecules form when colorful chemicals called carotenoids break down into smaller chemical compounds [2,3].

For example, the classic color of red watermelons comes from lycopene, the same molecule responsible for the color of red tomatoes. When lycopene breaks down, it forms key flavor compounds such as lemon-scented citral.

Orange melons don’t have much lycopene, but they make up for it with extra beta-carotene. This chemical – the same one that makes carrots orange – leads to a completely different set of flavor molecules, including floral beta-ionone.

Colorful molecules called carotenoids break down into different flavor compounds. Figure adapted from [2].

The chemistry of watermelon flavor is clearly complex, but scientists are still searching for individual molecules that mimic watermelon’s characteristic taste.

Most recently, a study identified a single molecule – dubbed “watermelon aldehyde” – that has a very distinct watermelon aroma [4]. Unfortunately (or fortunately, depending on your perspective), the molecule is too unstable to be used as a food additive. So for now, artificially flavored “watermelon” products will just have to keep on tasting nothing like watermelon.

Good thing there’s plenty of real, chemically complex watermelon to go around.


  1. Yajima I, Sakakibara H, Ide J, Yanai T, Hayashi K (1985) Volatile flavor components of watermelon (Citrullus vulgaris). Agric Biol Chem 49: 3145–3150. doi:10.1271/bbb1961.49.3145.
  2. Lewinsohn E, Sitrit Y, Bar E, Azulay Y, Meir A, et al. (2005) Carotenoid Pigmentation Affects the Volatile Composition of Tomato and Watermelon Fruits, As Revealed by Comparative Genetic Analyses. J Agric Food Chem 53: 3142–3148. doi:10.1021/jf047927t.
  3. Lewinsohn E, Sitrit Y, Bar E, Azulay Y, Ibdah M, et al. (2005) Not just colors—carotenoid degradation as a link between pigmentation and aroma in tomato and watermelon fruit. Trends Food Sci Technol 16: 407–415. doi:10.1016/j.tifs.2005.04.004.
  4. Genthner ER (2010) Identification of key odorants in fresh-cut watermelon aroma and structure-odor relationships of cis, cis-3, 6-nonadienal and ester analogs with cis, cis-3, 6-nonadiene, cis-3-nonene and cis-6-nonene backbone structures University of Illinois at Urbana-Champaign. Available:

Liz Roth-JohnsonAbout the author: Liz Roth-Johnson received her Ph.D. in Molecular Biology at UCLA. If she’s not in the lab, you can usually find her experimenting in the kitchen.

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Making vinegar. Photo Credit: Sharon Mollerus (clairity/Flickr)

Imagine yourself in elementary school parading through the auditorium during your school’s coveted science fair. You round the corner, nearly knocking over the perfectly aligned row of tri-fold poster boards, when you happen upon the fair’s pièce de résistance. Suddenly, science has never been so cool. It’s an erupting volcano! You’re ooh-ing and ahh-ing as you watch the “molten hot lava” spew out from the angry papier-mâché mountain. You inquire about the sour smell in the air and are told by your classmate that this tabletop magic was nothing more than a perfectly planned mixture of vinegar and baking soda.

Vinegar is an aqueous solution that contains acetic acid and water. Historically, vinegars were often produced by exposing wine to contamination by harmless, airborne bacteria known as Acetobacter. Drosophila melanogaster, a geneticist’s model friend, commonly known as the fruit fly, is regarded as a potent vector for the propagation of the bacterium. This particular strain of bacteria facilitates the conversion of ethanol, through aerobic oxidation, into the major component of vinegar: acetic acid. Water is often added to commercially available vinegars to make the substance more suitable for household handling and consumption [1].

The volcano experiment is a simple case of an acid-base reaction where the baking soda, a sodium bicarbonate (NaHCO3), reacts with acetic acid (C2H4O2) in the vinegar to produce an intermediate product known as carbonic acid (H2CO3). The intermediate decomposes and is converted into a carbon dioxide (CO2) gas, which rapidly escapes from the solution accounting for the reaction’s eruptive characteristic [2].

But enough about chemistry, what about the food?

Vinegar has a plethora of culinary applications and serves as an effective food preservative and delicious sour condiment. From soup dumplings to pickles, vinegar is here to stay! Quite literally, the acidic characteristic (pH less than 4) of vinegar prevents harmful bacterial growth that allows for an extended, indefinite shelf life. So store your vinegar properly and you will be able to keep it for a very long time!

The variety of vinegars is limitless and can be made from virtually anything that contains sugar. Alcoholic fermentation involves the conversion of carbohydrates into ethanol, which can later be converted into acetic acid. One of the most widely available vinegars in the Philippines is coconut vinegar and is made from fermented coconut water. It is typically used to tenderize meat, which is accomplished when peptide bonds in complex protein structuresare disrupted. But it often served as a side condiment to season many different dishes.

Two of my favorite Filipino dishes are called (I) KINILAW (key-knee-lauw) and (2) SISIG (see-seg) and are both prepared with ample amounts of vinegar. The kinilaw is a style of ceviche that infuses ginger and relies on the acidic nature of vinegar to “cook” the fish used in the dish. Lastly, sisig is popular dish in the city of Pampanga and translates to “to snack on something sour”. It is often served with sizzling vinegar marinated pork belly, spicy chili peppers, fresh red onions, cracked egg and native limes to add additional sourness.

Kinilaw: A Filipino-style ceviche cured in coconut vinegar. Credit: Jimmy Sianipar

Fried Potato Chips with Salmon Roe served with Kinilaw. Credit: Jimmy Sianipar

Thrice-Cooked Sizzling Pork Belly Sisig. Credit: Jimmy Sianipar

I recently prepared dinner for 30 friends for my project called PATAO and shared these two delightfully vinegar-y dishes with them! Thankfully no one was a sourpuss and received the dishes with much joy. Check out their reactions here:


Video Credit: Jimmy Sianipar

References cited

  1. Yakushi T, Matsushita K. Alcohol dehydrogenase of acetic acid bacteria: structure, mode of action, and applications in biotechnology. Appl Microbiol Biotechnol. 2010;86(5):1257-65.
  2. Why does baking soda and vinegar react to each other? UCSB Science Line.

Anthony MartinAbout the author: Anthony Martin received his Ph.D. in Genetic, Cellular and Molecular Biology at USC and is self-publishing a cookbook of his favorite Filipino dishes.

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Green & Black Cardamom

Photo Credit: Robin (FotoosVanRobin/Flickr)

Cardamom is the third most expensive spice by weight, behind only saffron and vanilla. But with a captivatingly complex flavor profile crammed into such a small package, there’s little mystery behind its steep price. This spice delivers a pungent taste that’s smokey, yet contains hints of coolness reminiscent of mint and lemon, packed inside the tiny black seeds of the small cardamom seed pod. The cardamom genera belong in the ginger family, Zingiberaceae. True cardamom, also known as green cardamom, falls within the genus Elettaria and is grown in India and Malaysia. Black cardamom is of the genus Amomum and grown primarily in Asia and Australia.

While popular in foods and drinks, cardamom is equally admired in traditional medicine. Therapeutic uses range from antiseptic, expectorant, stimulant, and tonic [1]. Cardamom oil is especially known to help alleviate digestive system problems, working as a laxative, colic, stomachic, and diuretic [1]. Perhaps most interesting is its airway relaxant potential in the treatment of asthma [2]. Cardamom contains flavenoids, which exhibit bronchodilatory activity, essential to asthma relief by relaxing constricted bronchial tubes [2]. Moreover, cardamom extracts were observed to relax carbachol- and potassium-induced contractions in tracheal tissues [2], effectively relieving bronchospasms in asthma attacks. Bronchospasms occur in instances of high levels of carbachol or potassium, which are able to cause tracheal tissue contractions by simultaneously opening L-type calcium channels and stimulating muscarinic receptors. Both calcium channels and muscarinic receptors regulate signals for smooth muscle thickening; carbachol and potassium interaction with these signaling pathways leads to airway constrictions. In the study, cardamom showed inhibitory effects against carbachol and potassium, enabling relaxation of the contracted tissues.

Whether the ailment is asthma, digestive problems, or simply thirst, cardamom is all the more reason to enjoy a spicy cup of masala chai.

References cited

  1. “Cardamom Essential Oil (a.k.a. Cardomon Essential Oil) Information.”Cardamom Oil (Elettaria Cardamomum). N.p., 29 May 2014.
  2. Khan A, Khan Q, Gilani A. Pharmacological Basis for the Medicinal Use of Cardamom in Asthma. Bangladesh Journal of Pharmacology. June 2011;6(1):34-37.

Alice PhungAbout the author: Alice Phung once had her sights set on an English degree, but eventually switched over to chemistry and hasn’t looked back since.

Read more by Alice Phung



Photo credit: Hans Braxmeier (Hans/Pixabay)

Sweet and spicy, cinnamon is one of the oldest spices known to humans; it is also a favorite topping or secret ingredient in both sweet and savory recipes. This warm spice is obtained from the dried inner bark of several species of trees within the Cinnamomum genus. True cinnamon however, sometimes known as Ceylon cinnamon, comes from C. verum (also, C. zeylanicum, the antiquated botanical name for the species), indigenous to Sri Lanka. Other Cinnamomum species that are cultivated for commercial purposes are C. burmannii (Indonesian cinnamon), C. loureiroi (Saigon cinnamon or Vietnamese cinnamon), and C. cassia (Cassia or Chinese cinnamon) [1].

Analysis of the fragrant essential oil from cinnamon bark reveals the main compound responsible for the sharp taste and scent of cinnamon comes from cinnamaldehyde (also known as cinnamic aldehyde). Since its identification in 1834 by French scientists, Jean-Baptiste Dumas and Eugene Péligot, cinnamaldehyde has been found to be a rather useful molecule outside of the spice rack. Studies have suggested that cinnamaldehyde has antioxidant properties, which makes it a promising anticancer agent [2]. Further, cinnamaldehyde has been shown to work effectively as pesticide, fungicide, and antimicrobial agent [3].

Of course, one of the most useful properties of cinnamaldehyde is making apple pies extra delicious.


References cited

  1. Culinary Herbs and Spices. The Seasoning and Spice Association.
  2. Nagle A, Fei-Fei G, Jones G, Choon-Leng S, Wells G, Eng-Hui C. Induction of Tumor Cell Death through Targeting Tubulin and Evoking Dysregulation of Cell Cycle Regulatory Proteins by Multifunctional Cinnamaldehydes. Plos ONE. Nov 2012;7(11):1-13.
  3. Shan B, Cai YZ, Brooks JD, Corke H. Antibacterial Properties and Major Bioactive Components of Cinnamon Stick (Cinnamomum burmannii): Activity against Foodborne Pathogenic Bacteria. Journal of Agricultural Food Chemistry. 2007;55(14): 5484-90

Alice PhungAbout the author: Alice Phung once had her sights set on an English degree, but eventually switched over to chemistry and hasn’t looked back since.

Read more by Alice Phung


Photo credit: Jun OHWADA (しそ山葵) (june29/Flickr)

Photo credit: Jun OHWADA (しそ山葵) (june29/Flickr)

Wasabi packs quite a punch, but where exactly does that wallop of heat come from? That green dollop that accompanies sushi comes from the wasabi plant, also known as Japanese horseradish, which is not to be confused with its distant cousin, the more common and well-known European horseradish (Armoracia rusticana). As a member of the Cruciferae family, wasabi is actually more closely related to cabbage, cauliflower, broccoli, and mustard [1][2].

Grown primarily in Japan, the wild-type species (Wasabia tenuis) are only found mountainside in streambeds and river sand bars [2]. Cultivated wasabi plants (W. japonica), similar to the wild-type variety, comprise a cluster of long-stemmed heart-shaped leaves and delicate, spring-blooming, white flowers branching from a gnarled, thick, root-like stem known as a rhizome [3]. Wasabi grown under semi-aquatic conditions are called sawa, while those grown in fields are called oka [1][3]. Sawa is considered higher quality, as they produce larger rhizomes, thereby often cultivated for culinary purposes. Oka is largely cultivated for nutraceutical purposes, such as herbal supplements [3].

Wasabi rhizomes. Photo Credit: Jaden (Steamy Kitchen)

Wasabi leaves and rhizomes. Photo credit: Jaden (Steamy Kitchen)

The plants are notoriously difficult to cultivate, as they thrive best in running water [4]. Even under ideal conditions, wasabi is difficult to farm, especially on large-scale operations for commercial purposes. As such, real wasabi is expensive and rare outside of Japan. Due to the taste similarities between wasabi and horseradish, common wasabi substitutes are usually a mixture of horseradish, mustard, starch, and green food coloring. So how does one differentiate between real and imitation wasabi? Simply taste it.

Real wasabi is made by grating the wasabi rhizome into a fine powder. Due to the high volatility of the flavor compounds, after grating the rhizome, the heat will only last for, at most, fifteen minutes, whereas horseradish-based wasabi can be left overnight and still retain its heat [1]. Additionally, though the chemical makeup of horseradish and wasabi may be similar, it is different enough that each has a unique flavor profile. Both horseradish and wasabi rhizomes contain thioglucosides, a sugar glucose with sulfur-containing organic compounds. Maceration of the rhizome, such as by grating, breaks the cell walls and releases these thioglucosides, as well as an enzyme known as myrosinase [1]. Myrosinase is responsible for breaking the thioglucosides into glucose and a complex mixture of a class of compounds called isothiocyanates. Horseradish and wasabi contain varying isothiocyanate amounts and compositions. There are 1.9g total isothiocyanates per kilogram of horseradish, as opposed to 2.1g/kg in wasabi. The most abundant and stable of these compounds, allyl isothiocyanate, gives real and imitation wasabi its infamous pungency [1][4]. The next most abundant isothiocyanate compound is 2-phenylethyl isothiocyanate, which is only found in horseradish [1]. All other types of isothiocyanates exist in higher concentrations in wasabi than horseradish.


Allyl isothiocyanate produces a hotness in wasabi that is distinct from the spiciness of hot peppers. Hot peppers contain capsaicin, an oil-based molecule which stimulates the tongue. This spiciness can only be washed away with foods containing oils or fats, such as dairy products. Unlike capsaicin, allyl isothiocyanate vapors stimulate the nasal passages. Fortunately for heat-seekers, the amount of pain is directly related to the amount of wasabi consumed, and a little will go a long way. Fortunately for mild-lovers, because allyl isothiocyanate is not oil-based, the burning can easily be cleansed by consuming more of any food or liquid. Although real wasabi is expensive and only found at specialty stores or prepared to order at high-end restaurants, that sinus-opening sharpness is worth experiencing, even if only once.

References Cited

  1. Arnaud, CH. What’s That Stuff? Wasabi. Chemical & Engineering News. March 2010; 88(12): 48.
  2. Fresh Wasabi and Real Wasabi Paste – Technical Info.” Pacific Farms by Beaverton Foods. Beaverton Foods.
  3. The Story of Wasabia Japonica.” Wasabia Japonica, Oka Wasabi, Semi-aquatic Sawa Wasabi. Pacific Coast Wasabi.
  4. Wasabi (Wasabia Japonica (Miq.) Matsum.).” Gewürzseiten: Wasabi (Wasabia Japonica, Japanischer Meerrettich/Kren, わさび, 山葵).

Alice PhungAbout the author: Alice Phung once had her sights set on an English degree, but eventually switched over to chemistry and hasn’t looked back since.

Read more by Alice Phung


Photo credit: Eli Duke (eliduke/Flickr)

Photo credit: Eli Duke (eliduke/Flickr)

There are few things sweeter in life than chocolate, which is probably why it’s one of the most popular flavors in the world. We can thank the cacao trees (Theobroma cacao) for this gift, which are only grown within a region known as the Cocoa Belt, 10° to 20° north and south of the equator [1]. Chocolate is produced from the seeds of the pods that grow from the cacao trees; these seeds are better known as cocoa beans.

Chocolate is a complex flavor, containing over 200 different flavor compounds [3]. While the type and mixture of cocoa beans that go into a chocolate bar play a role in determining the final flavor, chocolate is the kind of food where its taste is influenced by how it’s made rather than what it’s made of [4]. The chocolate-making process varies among types of chocolate (milk, dark, bittersweet, etc.), but also depends on the style of the chocolate maker. So while the general principles and chemical processes at each step remain the same, chocolate-making is a delicious art form.

Straight off the trees, cocoa beans are bitter. When cacao pods are harvested, they are cracked open and left to sit for a couple of days, depending on the tree varietal. (5–6 days for forastero versus 1-3 days for criollo [2].) This allows the cocoa beans to undergo fermentation, a process that is carried out by naturally occurring yeast and bacteria. During fermentation, the microorganisms digest the pulp in the pods, which aids in converting the sugars in cocoa beans into acids. These acids decrease the overall bitterness of the beans. Notable flavor compounds, such as pyrazines, are also generated during fermentation, making the beans slightly more floral in aroma [2]. After fermentation, the beans are scraped from the pods to dry. Drying releases certain molecules from the beans that would otherwise make chocolate taste smoky and sour [2].

Roasted cocoa beans. Photo credit: AnubisAbyss/Flickr

Roasted cocoa beans. Photo credit: AnubisAbyss/Flickr

The dried cocoa beans now taste nutty, bitter, and acidic; to drive out volatile (easily evaporating) acidic molecules, the dried beans are further processed by roasting. The elevated temperatures of roasting (120–150°C) also facilitate Maillard reactions that yield flavor molecules that are distinct to chocolate [2]. These reactions are sensitive to both temperature and pH, so both the roasting temperature and bean acidity contribute to the final composition of flavor molecules that form during these Maillard reactions. Typically, milk and certain dark chocolates are made from beans that have been roasted at lower temperatures [2]. The shells of roasted beans are then removed, leaving behind pieces called cocoa nibs. Depending on the chocolate-maker, cocoa nibs may undergo alkalization, whereby they are treated with an alkaline solution in order to further decrease their acidity. Alkalization also causes flavonoids to polymerize (link together), which reduces the astringency of the nibs [2].

The final phase in chocolate manufacturing is a two-step process known as conching. At this stage, the nibs have a gritty texture; the first step in conching turns this into a paste through grinding and heating. Acidic compounds and water are evaporated in this process. More importantly, many flavor compounds formed during fermentation and roasting that are responsible for astringent and acidic notes become oxidized during conching, which mellows the flavor of the final product [2]. In the second step, cocoa butter and soy lecithin are added, decreasing the viscosity of the chocolate mixture to make it flow more easily.

Cocoa beans go through quite a long journey, from the cacao tree to the candy wrapper, where each step plays a role in producing the final combination of flavor molecules that makes chocolate such a beloved treat. This is just one of many reasons to savor your next taste of chocolate.

References Cited

  1. “Cacaoweb.” About the Cacao Tree and Cacao Varieties. <>.
  2. Afoakwa EO, Paterson A, Fowler M, Ryan A. Flavor Formation and Character in Cocoa and Chocolate: A Critical Review. Critical Reviews in Food Science and Nutrition. October 2008; 48(9): 840-857, DOI: 10.1080/10408390701719272.
  3. Schieberle, P. and Pfnuer, P. Characterization of Key Odorants in Chocolate. Flavor Chemistry: 30 Years of Progress. 1999: 147–153, DOI: 10.1007/978-1-4615-4693-1_13.
  4. Ziegleder G, Biehl B. Analysis of Cocoa Flavour Components and Precursors. Analysis of Nonalcoholic Beverages: Modern Methods of Plant Analysis. 1988; 8: 321-393.

Alice PhungAbout the author: Alice Phung once had her sights set on an English degree, but eventually switched over to chemistry and hasn’t looked back since.

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