The Chemistry of Spices

Chemistry of Spices

Hello everyone. I would like to welcome you all to today’s webinar, The Chemistry of Spices. First I would like to introduce myself. I’m Peter Eskow, Marketing Manager for SPEX CertiPrep and I will be moderating the presentation today. Before we begin, I would like to get a few housekeeping items out of the way.  Everyone who registered for the webinar will get a copy of the presentation slides and the webinar is being recorded and it will be posted on our YouTube channel so that you can watch it again at your convenience. It will be uploaded in the next week or so and you will receive a follow-up email with the link once it is available. If you have any questions during the presentation, type them into the question box on your screen and we will answer as many as we can during the Q&A session.

With that out of the way, I would like to introduce Patricia Atkins, our presenter for today’s webinar. Patricia is our products application specialist for SPEX CertiPrep and a regular from a number of past webinars and research projects including our Trace Elements in Children’s Toys and The Chemistry of Wine. So without further adieu, I will turn the mic over to Patti.

Thank you very much and I would like to welcome everyone this morning about our webinar the Chemistry of Herbs and Spices. This is going to be the basic chemistry and the background history of herbs and spices and a little about the research we have done. I know that some people I have met over the course of the past few months have already seen some of our research and we will be getting into the real details of the heavy metals a little bit today, but we are going to wait for another webinar to really discuss all the scientific details and the processing of the spice samples.

So we will start out with what are herbs and spices. Spices are any aromatic vegetable product used to season or flavor foods and these are usually the non-leaf components. Things like your roots, your flowers, your buds, the stems, and things like that. Herbs on the other hand are your leaf products.

We are going to start out with a little quiz. What do you think is the world’s most popular spice? We will give everyone a chance to answer the question. What is the most consumed spice in the world? And we will close it in 5…4…3…2…1.

Ok, what does everybody think is the world’s most consumed spice? Black pepper was 79% followed by turmeric, and then cinnamon. And everyone would be right. The most consumed spice in the world is black pepper followed by cinnamon, cardamom, chili peppers and cloves. Worldwide, we consume between 10 and 20 grams per person per day. India being at the top of that scope at around 14-20 grams per person per day and there was a study done in Norway that showed about 3 grams per person per day of spices. Here in the US, we have a slightly different list of consumed spices. For some reason we think salt is a spice here in the US, followed by black pepper, paprika, cinnamon and chili peppers.

 In 2014, the US consumed 3 billion dollars worth of spices. From looking at the chemistry of spices, we can break it down into three areas. The areas of use, what are the active compounds that make cinnamon taste like cinnamon or rose oil smell like roses. What are those active compounds? Then you can also think about what contamination issues are brought about by production of spices. And finally, what might be done to a spice to adulterate it or counterfeit it, which would increase the value for the manufacturer or producer but actually decreases the value for the consumer.

First we will look at the active compounds, the compounds of use. Spice is often used as currency throughout history, we find it in beverages, teas, tisanes, colorants, medicines and supplements are very popular, fragrances and of course the largest use of spices and herbs is for seasoning.

Throughout history, there has been a long quest for expedition to find riches including silk, gold, jewels and spices. The silk road was established between the world of Europe and the east. Marco Polo is famous for his journeys into China in search of goods. But around 1453, that's when the game changed in exploration, especially in Europe. The Ottoman Empire actually took over Constantinople and blocked European spice access. So in 1453 the European royalty had no way of getting their spices and they started to look for other routes, which fueled expedition. You had De Gama in 1497 rounding the Cape of Good Hope and, of course, here in the United States, we had Christopher Columbus, sent by Spain, looking for a western trade route for spices. What he found of course was the Americas. By the 16 and 1700’s there were two main players when it comes to spices, the Dutch and the English. They both had their own companies for producing and selling spices. And one of the primary spices was actually nutmeg. Nutmeg was found in Indonesia, primarily, and the Dutch had a pretty good monopoly on nutmeg in Indonesia except for one island, called the Island of Run. That island was under great debate and hotly contested, and in 1664, the British actually took over the islands of Manhattan and Long Island and later in a treaty in 1667, the island of Manhattan and Long Island was traded for the Island of Run. So Manhattan was actually traded for nutmeg.

 Historically there was a lot of value in spices. They were only for the wealthy and for the rich, you would have them locked up in chests, they were commodities and salaries and taxes could be paid in bulk spices. In fact, the Roman word for salary comes from the base of “sal” for salt. You could also pay your taxes in cumin fees. Now during the Middle Ages, a pound of peppercorn could buy the freedom of a Serf or you could have a pound of nutmeg buy seven fat oxen for your farm.

Today, the economic value of spices is still pretty high. If you look at the value of some common commodities, copper, silver and platinum, and then look at the value of some spices, you would be surprised to find that five dollars a pounds would get you copper but ten dollars a pound will get you gourmet salt. All the way up to ninety dollars a pound for cardamom. Now if you have a little bit more expensive taste, you could buy some silver at two hundred and forty dollars a pound or you can buy a pound of vanilla beans at two hundred and sixty dollars. Now if you are really wealthy, you can buy yourself a pound of saffron at almost seven thousand dollars. Or you can buy yourself a pound of platinum for almost double that at sixteen thousand dollars.

If we look at the properties of colorants for spices, color is mostly either a dye or a pigment. Dyes are soluble in water or other solvents while pigments are not soluble in liquid matrix. When we think of color we are thinking about visible light. The color in the spectrum of four hundred to seven hundred nanometers those are the visible colors. So if you have a plant or a chemical that absorbs light between four hundred and four hundred and thirty-five nanometers, it’s absorbing violet light. So the color then that will be displayed will be a yellow-green color. The chemistry of that particular ability to produce color is called a chromophore and it’s because it either contains a conjugated pi-bond system, an alternating number of single and double bonds, like in an aromatic system such as like carotenes or it has a metal complex like chlorophyll which has magnesium. More often than not, there’s also something called an auxochrome which aids in the perception of color. These are functional groups, which change or change the perception of particular color, so you have carbonyls, carboxylic acids, amino groups and hydroxyl groups.

When we think about individual plants and the different chemistry of those plants, we will see that one of the predominant color of plants is, of course chlorophyll, which is green. And these are compounds from the chlorin pigment and again it’s that metal, magnesium complex that allows that color to be displayed. Another group of chemical plant dyes and pigments are anthracenes. They are aromatics and they are conjugated. Things like napthoquinones, which are red, very famous color from St. John’s Wort, or anthraquinones which are also red and a very historically famous color called madder red obtained from the madder root. Terpenes are very interesting because they actually cross many different boundaries from fragrances and flavors to dyes. They are aromatics and conjugated. Something like a carotenoid would absorb light between four hundred and five hundred and fifty nanometers and that will absorb the blues and the greens which will then produce the yellow, orange and red colors.  Carotenes are orange and red particularly of interest is that saffron, that very expensive spice, which crocin is the actual compound that produces that orange color of the saffron. Xanthophylls will produce yellow colors, such as a marigold. 

By far though, the largest group of natural color compounds are the flavonoids. They are fifteen, carbon backbone with two phenol groups and a heterocyclic ring and they’re usually in the pattern of C6-C3-C6, and they all contain a ketone group.  There are three primary classes: the bioflavonoids, the isoflavonoids and the neoflavonoids.  And, many of these compounds that I am speaking about, these dye colors, they are actually antioxidants. You’ll also find out that antioxidants are very common in groups for medicine, groups for fragrances and groups for flavor. Another very popular group of color, fragrance and flavor compounds are the terpenes. It’s become very popular over the last few years to talk about antioxidants in medical supplements, especially when it comes to things like the anthrocyanids or the polyphenols, things like wine, grapes and blueberries, that rich deep blue color that is considered to be a health benefit.

So when we talk about medical uses, there has been historically a very long use of plants and herbs as medicine. And even now today, it’s 80% the primary healthcare in countries of Asia and Africa. Since 2000, in India, the National Medicinal Plants Board was established. There was also a study done in 2010, which looked at a thousand common plant derived compounds. Out of which they only found one hundred and fifty-six published clinical trials for medical use. But it’s been estimated that more than twenty-five percent of US drugs have actually been derived from plants. Things like opium, aspirin, digitalis. And why are so many medical uses found for spices and herbs? Because they have a lot of properties that make them very beneficial in medical use, they’re antioxidants, thinks like ginger and turmeric are touted for their antioxidant benefits, blueberries, wine. They’re antimicrobials coconut oil has antimicrobial properties.  They are specified for certain disease treatment. There has been a lot of investigation about cinnamon for diabetes. And of course pain treatments have been in the news quite a bit over the last few years because we are talking about legal cannabis, medical cannabis and its use for pain treatment and disease treatment. And of course anybody who has used an athletic cream or a pain reducing cream knows about capsaicin and mint.

That brings us to combating pain with pain. The first compound we are going to talk about is capsaicin. And the reason why it is good in combating pain is because it acts directly on the nerve and causes an over stimulation reaction. When you experience pain, there is a substance called substance P, which is a neuropeptide. It is a neurotransmitter and a neuromodulator found in the sensory nerves in the brain and spinal column and it’s been associated with inflammatory pain response. By applying capsaicin to the body, it actually causes a depletion of substance P, reducing pain and limiting the action of the c-nerve fibers. Now c-nerve fibers are responsible for throbbing pain. If you look on the other side, the cooling effect, you have menthol and camphor. These are counter-irritant effect. It gives you a cool perception as opposed to the heat of inflammation. And again, it is possible through the stimulation through the stimulation of other nerve fibers and blocking those throbbing c-fibers. This type of sensation is called Chemesthesis and it’s when chemical compounds activate other tissues other then your taste buds. So they create sensations of pain touch or thermal perceptions of heat and the cold. For coolness you are actually activating the trigeminal nerve sensors for cold so you are turning your brain on to sense cold by the coolness of menthol or camphor. So these compounds activate ion channels on your nerve cells and you will perceive that cooling mint or that herbal gel kind of feel.  

For the spicy flavors, you're acting also expressly on nerves, the TRPV1 and the TRPA1 receptors in particular and this will produce pain. Pain in your mouth, your eyes, your membranes, that’s why when you’re cutting peppers or handing hot sauce you are told to be very careful not to touch your eyes, your nose and other tissues. Because it is not a taste bud response it’s actually a pain response and wherever you have a mucous membrane that can act on the nerves there and cause pain. And primarily these are capsaicins from your pepper products and piperine from your black pepper.

Now a lot of us really are interested in hot peppers and that heat comes from the capsaicin but there’s a bunch of other capsaicinoid compounds and you can see the list here but the primary one is the capsaicin with about 16 million scoville units and that’s about seventy percent of the heat compounds in a pepper. They are mostly found in the seeds and the membrane. Now the pungency of chili peppers, how hot they are, are measured in scoville units and it was discovered or popularized by Wilbur Scoville who was an American pharmacist and he presented this in 1912. Many of us do not know what scoville units mean and I am going to show you now what scoville units means. First to determine a scoville unit, they take an extraction of a dry pepper and put it into alcohol. They then dilute that extraction over multi-point dilutions in sugar water. Then they take an expert panel, whose job it is to be hot pepper or hot sauce tasters, they have five of these expert panel members and they are giving them empirical testing. This means there is no data behind this, this is a sensory type of test. And they are given increasing concentrations of the hot pepper or the hot pepper sauce. When three of those five testers can actually taste heat, that is considered a positive test and then the units are calculated on the dilution that they were given at that time. So you will have scoville units in hundred unit levels and the unit is called SHU scoville units. 

Scoville units for some very popular peppers can be seen here in this chart. For banana peppers they are pretty low, it is about a hundred, and as you go up the line to something like a cayenne pepper, we are at fifty thousand. A habanero or a scotch bonnet is three hundred thousand, a ghost pepper is at a million and the hottest pepper right now in the world is a Carolina reaper at two million scoville units. Just remember though pure capsaicin extracts at sixteen million scoville units and the pepper spray that police or the army would carry or even a very strong pepper spray can be up to five million units.

 So here’s time for another poll. What do you think about hot peppers and hot sauce? How much hot sauce do you use? You never touch it, you use it once in a while, maybe sometimes, you use it really frequently, or like the commercial says “I put it on everything”. I’ll give everybody a minute or so to answer the poll, 5…4…3…2…1. Closing the poll. So how much do we use? Most people said very frequently or like the commercial says “I put it on everything”. Some nineteen percent say sometimes, nineteen percent say once in a while and six percent of you never touch it. So I would have to say most of us belong to the cult of the hot sauce.

Of course if you like hot pepper or hot sauce, you know there are stores totally dedicated just to selling hot sauce, there are web pages, fan pages, there are million of websites that you can look at and videos on YouTube about the challenges of eating hotter and hotter hot sauce. Well what happens is that hot sauce fans actually acclimate to that reaction that we spoke of, that pain reaction, and more that they experience it, the more heat will take to actually activate that reaction so the hot sauce junkies are looking for the super hot all the time. There was a controversy in 2014 when the city of Irvindale in California refused to shut down the Sriracha factory. There were people who started hoarding their favorite hot sauce and sriracha in fear that it was going to be shut down for all time because of offensive odor. Well everyone was happy to report that the odors were dealt with and the sauce was back on the market in 2014. Of course the base of hot sauce is chili peppers discovered in the America’s. The main producer today is India so most of our chili peppers come from India. And there are five varieties of chili peppers, we have the bell and the cayenne that's the annum, the frutescens which is the tobacco, we have the scotch bonnets and where the Carolina reaper come in and the other two varieties I actually have no personal experience with, but the rocoto and the aji. But what other ingredients can be in hot sauce? One of the things that we did look at during our spice study this year was hot sauces, we looked at red peppers and hot sauces, and we were looking primarily for heavy metals. I was very unhappy then to find heavy metals in my favorite hot sauce. So primarily it was lead at 21 parts per million (ppm), now this was a packet, we had chain hot sauces, retail hot sauces, organic hot sauce, we had our fast food packet of hot sauce and Chinese food packet of hot sauce. Now our Chinese food restaurant happens to be right around the corner from SPEX CertiPrep’s offices so it is a popular place for us to go to lunch and they have this big box of these hot sauce packets for you to take and many of us would take a handful to go with out lunch and put them all over our food. Average use for this is about one to two packets or about twenty grams. Unfortunately my favorite Chinese hot sauce packet had twenty one parts per million of lead and sixty three parts per million of chromium which is about thirty percent my allowable daily limit for lead and chromium. Which is even more sad, when I looked at the actual ingredients, the actual peppers themselves are pretty far down the list of ingredients so you have water, food starch then your cayenne pepper, vinegar spices, colorings and preservatives. So the fact that there is that much lead and so little actual pepper is a little bit concerning. Some of the other flavor compounds that are very popular in spices or that we find in great quantities in spices are carbohydrates which are your sugars, your glucose, your ethyl maltol, those give you those cotton candy sugar taste. Carbonyls from ketones to carboxylic acids mostly those give you berry type tastes bitter almond, raspberry, wintergreen, apple, things like that. You have your organic acids and organic acid salts like ethyl decanoate, which is a pear flavor. Your ionic salts which of course are your sodium chlorides that give you that salty flavor. Proteins and amino acids like monosodium glutamate, which we all know as MSG. That gives us that umami, that mouth feel. And then your terpenes, like monoterpene, like myrocene. So if you like hops or if you’re a fan of cannabis, that earthy kind of taste that you get from a hop like in a beer is from the terpene myrcene. Most of the common flavor compounds are esters and it should be interesting to note that the raspberry ketone, if you go to buy the flavoring for raspberry ketone, the extract, it’s actually the most expensive natural flavorant in the world at nine to ten thousand dollars per pound.

Now how you perceive those tastes depends on what portion of your tongue your taste buds are tasting the different flavors. If you are tasting sweets, it’s primarily the front of your mouth and it’s from your proteins, your carbohydrates and your carbonyls and it’s a G-protein receptor in your taste buds. If you are tasting salty, it’s that blue area again near the front of your tongue, and those are ion channels taking the alkali metals like sodium, potassium, iron. If you are tasting sour, it’s mostly from acids on the side of your tongue, again from ion channels. If you are tasting bitter, things like catechins and phenols, you are tasting things because if your type-2 taste receptors in the back of your mouth. And that umami, that mouth feel, is from your amino acids, your nucleotides especially things like caffeine and that’s because the variance of the g-protein receptors in your taste buds are down the center of your mouth.

Speaking about the perception of taste…it’s time for another quiz or another poll. What does cilantro taste like to you? Fresh and earthy just like a normal herb, does it taste like soap and it’s completely inedible, does it taste like a lemon an herb with a little sour twist, or do you think it doesn't taste like any of these? Go ahead and vote now. Ok closing the poll in 5…4…3…2…1. Ok what does cilantro taste like? Oh, we have quite a bit of cilantro lovers here, fresh and earthy just like a normal herb. Only eighteen percent of the crowd actually thinks it tastes like soap and is inedible or yes it tastes like lemon with a little bit of a twist and six percent said none of these.

 So, if you don’t like cilantro, let’s tell you why. Cilantro is actually the leaves and the seeds are called coriander and you’ll find them in many cuisines, things like Mexican cuisine Middle Eastern cuisine. The debate often focuses around the aroma and the taste of the cilantro; is it a lemon lime citrus or is it soap and bugs? Well there was a survey from the University of Toronto and they asked their respondents what countries of origin or what backgrounds were they and whether or not the cilantro tasted like soap. Twenty-one percent of Eastern descent said, soap it is. Seventeen percent of Europeans said also, it’s soap. So for the most part, our polls are kind of in line about seventeen or eighteen percent overall of people believe that it tastes like soap. So the group that likes cilantro the most were of Middle Eastern descent where ninety seven percent said they love the taste of cilantro and three percent of them said it tasted like soap.  Well there is actually a good reason why cilantro tastes like soap. The primary compound or the active compounds in cilantro are aldehydes and there are a lot of components or a lot of aldehyde components that are part of soaps and bug sprays. There is an odorant aldehyde that actually is part of soaps and bug sprays. Primarily for cilantro though, it’s three aldehydes, especially the decanal, and there is some suggestion that if you crush the cilantro and you let the compound start to oxidize, that those aldehydes will convert into more pleasant scents giving you a more pleasant taste. In 2012 though, those of us who do not like cilantro and always said that there had to be something genetic about it, well it was found that there is legitimate genetic component to not liking cilantro. There are certain receptors that cannot process aldehydes so they are not able to take those unsaturated aldehydes and make them into a form that is more pleasant. What was surprising was these were not in the taste buds, these receptors were in your olfactory system and it kind of makes sense because eighty percent of what you taste has a contribution from odor. So if you ever think about it, whenever you have a very bad cold or you can’t smell, your food doesn’t taste as good because there is a significant component of fragrance to the ability to taste.

So that leads us to the compound of fragrance that we find in spices. Your olfactory system is a chemoreception system, so your odorants, the chemicals, enter your nasal passages, the mucus acts like a solvent matrix for those odors and chemicals, they diffuse through the mucus and then activate your olfactory receptors. What’s interesting to note though is that the olfactory system is actually the only sensory system directly connected to the human forebrain. All the rest of the sensory systems actually have to go through the processing centers of your brain before they are perceived but smell is the only scent or is the only system that goes directly to the human forebrain. And most of the natural fragrance chemicals come from flowers. They are usually volatile chemicals, less than three hundred mass units and most VOC’s come from plants. You will often see some scientific literature talking about natural air pollution. What they are usually talking about is VOC pollution or the off-gas from plants. Famously this is seen as the smoky mountains or the blue mountains where the haze hangs over the mountains and this is all the off-gassing of the pine trees and other trees, Mostly these are isoprene units, terpenes, terpenoids and terpenols. Terpenes are very important in fragrances. Most of the fragrances that we consider to be characteristic of a certain product or a certain smell are actually terpenes or terpenoids. Things like pinene for pine and rosemary, linalool gives you the mints and the lavendars, Limonen for the citrus and the lemons. If you drink beer it’s humulene from hops, if you like a good glass of wine or like a nice scented rose, it’s geraniol and like I said before, if you like a little bit of the medicinal cannabis, we are talking about the myrcenes.  

The next group of chemicals we’ll talk about when it comes to spices comes from contamination mostly through production. If you look at the areas of the world where spices are grown, seventy six percent of spices are grown in India with smaller amounts in China, Turkey, Bangladesh and other countries. Some regions of the world… (some missed audio recording here)… have some sanitation issues and this has been brought to light within the last few months because of the recall Mexican cilantro due to sanitation issues which is exposed people to salmonella poisoning. Are we being given a lesser quality product or part, so are you given the stem of the plant when the root is actually the spice that you want? Is it being stored appropriately? Are any contaminants being added like sand or dirt or fill? If we look at the spice processing there are many places where errors can happen or contamination can happen. Receiving and stockpiling is the first place. Is there any QC or inspection done so when a processor receives materials from a grower, from a harvester, are they actually getting what they think they are getting or are they being substituted with something, so is there a QC process, some identification process? Is there a quality process, are any hazards discussed or identified? How are those stockpiles stored? Are they stored over the course of years until there is enough to make a production? Are they stored in areas where climate should be controlled, or is the location where there might be pests or rodents or other contaminants that might be introduced. I did watch some videos of spice processes recently where spice processors talked about fumigating their raw materials because of pests, because of mice and rodents. So, are those fumigate materials actually legal or are they able to be used within spice products. Then you have your initial processing. Do they do any sorting, is it mechanical, is it physical? Is there any cleaning involved? If there is a cleaning, like if they fumigate their products for pests and they use some sort of chemical or water for cleaning, are those chemicals cleared from the actual spices where they are processed or would you have to look for residual solvents? Is there any drying involved, is it kiln dried or air dried. How are those spices processed, are they roasted? There are a lot of volatile compounds in spices. Many of these compounds have boiling points, melting points or volatile points under two hundred and fifty degrees Celsius.  Well a lot of roasters can go easily to two hundred and fifty degrees or higher, some roasters up to four thousand degrees Celsius. How the spice processed with grinding, is there a dedicated use grinder? Now there was a poster given not too long ago at a show I was at which talked about the cross contamination of nut allergens in spices. So if there is not a dedicated use grinder, you could be cross contaminating with nuts, other spices, or whatever that grinder was used for last. And if any cleaning was involved, are we going to see cleaning solvents. There is also the question of the age of the equipment, the older the equipment, the better the chance of being wear metals or heavy metals being contaminating the spices from the actual equipment. And then your final processing and packaging are they being blended with unreported ingredients? Is there any final QC being done and how is the packaging and storage conditions and storage time going to affect that product, is there going to be species contamination?

Potential contamination can take the form of microorganisms like viruses and bacteria. Seven percent of spice products are contaminated by salmonella, according to the FDA. And spices are twice as likely than any other food group to be contaminated by salmonella. Out of all the shipments that were done over three years, seven hundred and fifty shipments were refused and we have an example, like I said, of cilantro from Mexico because of salmonella. There is also issue of mold. Improper storage, improper moisture content can actually increase mold content. And you have filth, which is your insects, your dirt, etc. Twelve percent of imported spices actually do contain high levels of filth and two hundred and thirty eight shipments were refused over the course of three years. Then you have your cross contamination, your other spices, your food products or your nuts. Some potential chemical contamination can take the form of pesticides, illegal pesticides or non-permitted levels of legal pesticides. You have your solvents from manufacturing or cleaning residue. You have metals like heavy metals or wear metals from processes or contamination. Bulking, flow agents or preservatives, these could be unapproved additives, things that were never approved especially by the FDA in this country for use in foods, or you could have approved additives, things that generally recognized as safe (GRAS) but these additives are either not reported or under reported; things like sodium chloride or silica. So how do you know if its contamination, adulteration, is it an additive, it is a nutrient? Well mostly the toxic metals are all about concentration. Arsenic, cadmium, mercury those are clearly toxic metals and the higher concentration the more concern of safety. Things like lead, chromium, manganese and zinc, there are considered to be toxic metals but they also could be wear metals, they could be additives, they could be nutrients. And again, its about concentration and reporting. Wear metals are things like chromium, copper, aluminum, iron. Nutrients, of course, are things that are reported in databases like the USDA nutrient database. There are things like copper and iron and you will see there is a lot of overlap. So how do we know if our spices have been adulterated, if they have excess additives, nutrients or whatever? Well you look; do the spices fall within the normal distribution for a spice product? This year our projects have mostly been on the heavy metals and metal content of our spices and our phytomedicines. We looked at them by ICP and ICP-MS and they were very well received at several conferences this year. For us we had eight groups of spices and spice products. Things including teas and sauces, condiments, and everything from black pepper to salt. We had whole and ground spices and they ranged in price from dollar store all the way up to name brand and organic.

Our Sample prep was pretty straightforward, for our solid spice we used our SPEX SamplePrep Freezer/Mill and we ground them. We digested all of our samples using microwave digestion, we of course used our ICP-MS standards and we did our analysis on ICP-OES and ICP-MS. Our ICP-OES gave us our wear metals and our macroelements. And the ICP-MS was able to give us our toxins. So how did we determine what was what? How did we determine the contamination or the nutrient or the additives? Well first we looked were there any toxic metals and at what level? Were they are any large amounts of additive metals or wear metals that were not reported or were they under reported? Did we see any patterns that suggested adulteration? So to give you an example now of our chili powder sample; here we have seven chili powder samples, we have some solar store samples, we have a chain store, a chain is like Walmart or Target brand, we have a retail, which is if you go into a supermarket there are retail brands of spices, one of those, and then we have organic brand that we ordered online. We did find toxic metals. We found one point two (1.2) ppm of cadmium in our dollar store, in that same dollar store we saw point four (0.4) ppm of arsenic, we saw seven point one (7.1) ppm of chromium and unfortunately we did find almost two ppm of lead and that was unfortunately in our organic sample. What was disturbing though was the large amount of additive metals that were not reported or under reported. So out of all of these samples, the chain and the retail brand actually admitted to adding salt to the mix, so our chain, chain B, retail and organic, claimed salt and they had between one point two (1.2) and three point eight (3.8) percent of sodium in those mixes. Dollar store samples did not report any salt but you can see that it ranged from eleven to thirteen percent salt. 

Now it’s time for a poll about heavy metals and spices. In our study, what do you think was the heavy metal that the highest concentration was found in the most amount of spices. What do you think was the bad boy of our bad boy list? All right, we are going to end it in 5…4…3…2…1. So what did we find the most of? What do you think we found the most of? Seventy percent of you said lead, fourteen, arsenic, fourteen, cadmium, and three percent mercury. Well we have a very, very smart audience because what we did find the most of was lead. We found up to three ppm of lead in our cinnamon, and our turmeric we found lead in two point two (2.2) ppm in our red pepper so there was a lot of lead. I purposely took chromium out of the question and out of this graph because we did not speciate for chrome sticks, we did total chrome. There was actually quite a bit of chrome in these samples as well but not being able to speciate it I did not want to include it in the heavy metals.

So why will we see all of these heavy metals, why would we see excess sodium, why would we see these additives that are not reported? It comes down to money. Adulteration means value, at least value for the manufacturer and the producer, not necessarily the consumer.  The five most counterfeited foods that are documented here in the US are olive oil, honey, milk, juices and spices. Any why would they do that? You would think milk and juice are pretty cheap so why would they adulterate it? Well olive oil costs two hundred and fifteen dollars wholesale per one hundred pounds. The most common adulterant for olive oil is canola oil and canola oil is twenty-five dollars per hundred pounds. For honey, it’s one hundred and seventy five dollars for one hundred pounds, for corn syrup, it’s seventy five dollars per hundred pounds. Milk they’ll adulterate with urea and water and it costs them thirteen per hundred pounds whereas real milk costs them about one hundred dollars per hundred pounds. And orange juice one hundred and thirty dollars per hundred pounds where corn syrup is half that at seventy-five dollars.

There was a sampling of spices in New York and they found that seventy to eighty percent of the spices coming in through New York were contaminated in some way. Now the FDA defines food adulteration as substances at sufficient quantity to do harm. That would cover things like pesticides or heavy metals. Or the absence, substitution, or addition of constituents, so when a valuable constituent is either total or partially substituted or you are given a damaged or inferior product. Now some people are like well what is a damaged or inferior product? If you think of a particular spice, we’ll take garlic as an example, the garlic plant itself has a stem, it has leaves, it has flowers, it has roots, it has the outer covering, and then it actually has bulbs that we consider to be garlic. Well the stem, the covering, the leaves, the flowers, and all of that other material is not considered what we would think to be garlic, it’s an inferior product. But if they grind that up, they call it garlic. That would be a damaged or inferior product. Or a product that has been sitting and has grown mold so now it is damaged and they are still selling it so that is a damaged product. There are also the additions, which will increase the weight of a product, reduce its strength or reduce its quality. These are all intentional adulterations. The most common intentional adulterations for spices are things like saw dust or bran powder, silica or sand, starch or flower, salts like sodium, like sodium chloride, chalk or talcum powder, charcoal. It’s interesting with charcoal, there was an adulterant or counterfeit for cumin seeds where you take grass seeds and you call them charcoal so you make them look like cumin seeds but they are actually grass seeds. Brick powder is often substituted for things like chili powder or cumin powder. Then you have your illegal dyes; things like your lead chromate dyes, your azodyes, your metanil yellow; these are meant to take a product that maybe lost some of its color that would be natural for that spice and basically dye it back to make it look more appealing or more like the spice they are trying to pass it for.  Then there are illegal preservatives, preservatives that are not approved, maybe they have an old product that they want to make sure that it lasts in the warehouses or in their processing facilities for a year or more so they’ll add illegal preservatives or illegal pesticides, either illegal amounts of pesticides or totally illegal pesticides. So how do we find out if a sample is adulterated or counterfeited? Well you can build a spice profile. For that you need reliable sources of valid data for real products which can be very difficult to come by. Here in the United States, the USDA actually does provide spice profiles or food profiles. If you go to their national nutrition database they will give you what a typical spice or food product would look like in terms of all the nutritional information. And sometimes they also have a lot of statistics that go along with it. This one happens to be for caraway seed. You can also do journal searches for marker compounds. So there are things like the capsaicin which are indicative to hot peppers so that could be an organic marker compound if you are trying to test the validity or the actual product to see if it is counterfeit or not. You can examine your chemical data for your targets, do you see heavy metals, do you see wear metals, do you see unreported additives? And you compare your data against your profiles. Are there any profiles that suggest adulteration or counterfeiting, does the data suggest there’s contamination there? So I’m going to show you two spice profiles that we have built for our black pepper and cinnamon. Black pepper is the king of spices, it is twenty percent of the spice market, and it is the un-ripened cooked fruit of the flowering vine piper nigrum and the fruit is called the peppercorn. The largest producers of black pepper in the world are Vietnam and India and they're harvested from May to August and each vine will yield about ten kilograms of peppercorn a season. It takes twelve years for a vine to mature enough to actually product a harvest. There are technically three colors of black peppers but we know four (excuse me, or peppercorns), black pepper which is seventy-five percent of the peppercorns sold, white peppercorn which is twenty-five percent sold, now some people think white peppercorns are actually different than black peppercorn, it is the same peppercorn. What happens is they take those peppercorn and they soak them in running water, like a stream, to rot over the course of several weeks, that outer layer rots off and separates and you’re left with the white layer underneath. You also have your green peppercorns, which are pickled usually and they are a specialty food item. Then you have red and pink. These are not actually from the piper nigrum plant; they are from a different species all together. So the active compounds that you could build a profile around, the organic compounds for your flavor, is piperine, it’s five to 10 percent by mass and it is the outside layer of the plant so that blackened or that green layer is where that piperine compound comes from. So if you’re going to have a white peppercorn, you actually lost that outer layer. Now that compound actually is very reactive to light and will change very quickly, that is why they say you shouldn’t really buy ground pepper that is more than a few weeks or a few months old because it very quickly loses that flavor compound. Now if you’ve ever tasted real black pepper, freshly ground and then tried what most Americans grew up with as black pepper, that stuff that sits in the shaker for years, there is a very big difference. There is a different quality to the taste, there’s a different quality to the smell and that is mostly because these volatile compounds very quickly change to other things or volatilize off the pepper so you are better off getting a whole peppercorn in order to get that fruity fragrance and flavor. Now the peppercorn, if they’re being ground, you have to be concerned about what temperature is it being ground at or roasted at because the melting point for the piperine is one hundred and thirty degrees C. The scent compounds for pepper, which makes that spicy floral scent, is carophyllene and pinene and they are both terpenes. When we looked for contamination and additives, we found lead and chromium mostly in our dollar store brand at about one point two (1.2) ppm. So we did find some lead contamination. We used the USDA database for black pepper and they did have quite a few data points, they were able to give us statistics and from those statistics we calculate three standard deviations and we were able to build a profile for black pepper, what would be a normal distribution for black pepper. Now there were two elements that we were interested in, the silica and aluminum, and we could not find USDA data for, but we did find references in the literature for silica being at 20 micrograms per gram in seeds and between 100-200 micrograms per gram for fruit and grain. For aluminum, we found references for teas at 100 micrograms per gram and for a baking mix where aluminum is added that was about 800 micrograms per gram.  

When we took our data and compared it to the USDA, one product clearly fell out of distribution, the dollar ground E. The darker the purple compound, the farther away from three standard deviations so if was purple it fell outside three standard deviations.  And you can see out dollar ground E for every single compound fell out of three standard deviations. We also had magnesium and aluminum and silica fall out of three standard deviations for what normal black pepper should look like. In particular, what we found was that there were toxic metals, of course, the lead and we saw large amounts of additive metals that were not reported or under reported. If we look at the retail whole black pepper, that's the very last black pepper, you can see that the silica level for whole black pepper from a reliable retailer, with three hundred micrograms per gram. But, in our dollar store, in our dollar store ground E and something like our Farmers ground, it was close to one thousand micrograms per gram, if not over one thousand micrograms per gram, so clearly silica was added to this. When we look at the sodium level, the sodium levels for most of our reliable black peppers was the one hundred, one hundred and fifty, two hundred range. But the dollar ground E was closer to three hundred as well as the Farmers ground, closer to three hundred micrograms per gram. We also found patterns that suggested adulteration, it was the dollar store brands that we saw the high metals in, it was the dollar store brands that fell out of distribution. So our cheap spices were the ones that tend to be out of range. And we happened to read about a solvent test, test for the counterfeiting of black pepper. A popular process for counterfeiting black pepper, especially whole black pepper, is to take papaya seeds and dry them, they look very, very similar to black pepper, whole black pepper, and then you can substitute out all or part of the whole black pepper for these dried papaya seeds. The dried papaya seeds, however, will float in a solvent where real black pepper seeds will actually fall to the bottom. So hearing about this little experiment, we decided we would try it on our two whole black pepper samples, our whole dollar store and our whole retail, our whole retail is on the left, it fell to the bottom, but our whole dollar store floated to the top so we did have what we believed to be a counterfeited whole black pepper. 

Our second profile is cinnamon. For cinnamon, you are actually consuming the inner layer of the bark, and the largest producers in the world are Indonesia and China. And there are many varieties; they’re all based on different sizes, bark thicknesses, they have slightly different flavors and fragrances. What we think of as cinnamon or most of us is cassia. It's the most common it’s also called the Chinese cinnamon. There are other types of cinnamon that are more expensive, the Vietnamese cinnamon and things like that. Cinnamon is a tree that’s grown for two years and then its cut down to ground level. That will force the tree to send up much thinner shoots and then those are cut down to quills and graded for size. For our samples, we looked at seven spice samples; they ranged between one dollar and twenty-nine dollars for one hundred grams. We had an organic sample, two whole samples of cinnamon and different cinnamon products; a cinnamon tea, which was a mix of three cinnamons and a supplement, which was the loureiroi cinnamon.

When we built our profile, the flavor and fragrance compounds marker would be cinnamaldehyde and it’s up to one percent for the mass of the bark and it’s in the essential oil. Ninety percent of the essential oil is the compound cinnamaldehyde, and it has a boiling point of two hundred and forty-eight degrees C. So if it’s being roasted or dried in any in a kiln, it could be driving off some of this volatile compound. When we looked for our heavy metals, we did find all of our heavy metals in our cinnamon compound and the worst offenders were all of the metals for the cheaper brands, with the exception of, unfortunately, our organic brand again, seemed to have some lad at almost three ppm. You can see mercury in our three cheaper brands, the dollar E, the dollar 5 and the farmers. We found cadmium at point six (0.6) or point nine (0.9) percent of the daily allowable daily allowance. So there was quite a bit of metals in our cinnamon, Again we went to the USDA and we found our cinnamon distribution, found all of our different nutrient metals, and we calculated our three standard deviations. For this, we have several products that seemed to be questionable. Our supplements and our tea did fall out of distribution, now this might be because they are products and not “quote/un-quote” spices, or it might be that something has been done to those supplements and teas that does not characterize them as cinnamon anymore. Our dollar store E clearly fell out of distribution and then there were some wear metals or other compounds that were questionable. What is very surprising though are things like our silica. On our supplements, silica was not listed on the supplements ingredients list but we found it ten times higher than some of our other samples, our retail sample at one hundred micrograms per gram and here the supplement was ten times that amount at over one thousand micrograms per gram. Also surprising, the tea, which is considered to be a supplement or food product, had sodium in it that was not reported on the label. If you look at the sodium for a retail, you’re looking at between fifty and maybe one hundred and fifty micrograms per gram but for the supplement it’s over two hundred and for the tea it’s over six hundred micrograms per gram. So did we find any toxic metals for our cinnamon? Yes. Were their large amounts of additive metals not reported or under reported? Yes, especially the products were not in range and some of our cheaper spices were out of range. So what does that mean? That means there is an obvious cost when it came to the heavy metals. The cheaper samples, the dollar store samples, where more than fifty percent of the samples was high metals, particularly our dollar SI brand. This one brand did come up over and over again or our dollar E at thirty-one and twenty-three percent of the highest heavy metals that we found. Most of our cheaper samples were about seventy-seven percent of all of the high levels including our dollars and our chain stores, and it does show that there is economic motivation for adulterating or allowing increasing contamination into these samples. We will give you a little summary of some of our spice findings. Did we find toxic metals? Yes, mostly lead, then cadmium, some arsenic, a lot of chromium, but it was total chrome and not designated as chrome six or isolated as chrome six. Some of the levels, especially in the hot sauce, were of levels of concern. Were there are large amounts of under-reported or non-reported wear metals or additives? Yes, mostly sodium, silica, magnesium, and iron. Were there patterns of adulteration? Yes. There were some suspicious colors and consistencies of these spices. Some of the black pepper spices, especially the one that fell out of distribution, had a very uniform gray color, it did not actually look like black pepper, it looked more like charcoal. I didn’t have the characteristic flex that you would expect in black pepper. Some of our spice mixes, our chili mixes and chili powder mixes, had an odd color to them, very unrealistic looking colors and consistency. There were also products and spices that did not fall with what would be considered normal distribution with our USDA range, especially in the cheaper brands of spices, the dollar brands. And there were some clearly counterfeited or adulterated spices.

I am just wrapping it up for today but I hope you enjoyed our webinar and if you want to know more, specifically if you want to know about the experiment that we did, we are going to go into more detail in a second upcoming webinar where we will discuss our sample preparation, our dilutions, and all of the spices that we actually found heavy metals in and we will go into much more detail in an upcoming webinar. But I hope you have enjoyed this first webinar in our spice series.


"Spices are a commodity found in every home around the world and often are used multiple times each day. The variety of spices is often only limited by the imagination. Each separate fragrance, color and taste is the result of a myriad of chemical interactions and reactions that gives each spice its own special character and place in our lives.

Adulteration, counterfeiting and contamination of spices have dominated the headlines. The increased concern these past few decades has led to more research and increased scrutiny.

SPEX CertiPrep examined spices from a variety of spice groups using ICP-OES and ICP-MS to get the accurate result of adulteration, counterfeiting and contamination of spices."