Coumarin in Cinnamon-Containing Foods and Vanilla Extracts - April 1, 2014 to March 31, 2015

Food chemistry - Targeted surveys - Final report

Summary

Targeted surveys provide information on potential food hazards and enhance the Canadian Food Inspection Agency's (CFIA's) routine monitoring programs. These surveys provide evidence regarding the safety of the food supply, identify potential emerging hazards, and contribute new information and data to food categories where it may be limited or non-existent. They are often used by the Agency to focus surveillance on potential areas of higher risk. Surveys can also help to identify trends and provide information about how industry complies with Canadian regulations.

Coumarin is a natural compound found in plants such as cinnamon and tonka beans. Coumarin was utilized as a flavouring agent in the food and perfume industries for many years until evidence of toxicological properties and potential adverse effects on the liver led to its use in food to be discontinuedFootnote 1,Footnote 2. Low exposure to coumarin from natural sources is expected and not anticipated to represent a health risk. The CFIA considered it important to examine the coumarin levels in commonly available cinnamon-containing products and vanilla extracts to ensure that the populations consuming these foods more frequently are not being exposed to higher levels and are not at risk.

This 2014 to 2015 targeted survey on coumarin generated further baseline surveillance data on the concentration of coumarin in domestic and imported products on the Canadian market. Seven hundred and thirty-nine products were sampled and analyzed, including 148 cooking sauces, 38 dried beverage mixes, 239 cinnamon and vanilla oils and extracts, 104 spice mixes and 210 tea samples. Coumarin was detected in 63% of the samples, with levels ranging from 0.2 ppm to 2170 ppm. The highest levels were detected in spice mixes and tea samples. The average and maximum coumarin concentration in spice mixes, dried tea, and baked goods were comparable to previous targeted surveys. Comparison of the survey results to scientific literature showed that the levels of coumarin detected in Canadian retail products are similar to those reported in a variety of scientific studies.

Health Canada (HC) determined the levels of coumarin in food observed in this survey are not expected to pose a concern to human health, therefore there were no follow-up actions resulting from this survey.

What are targeted surveys

Targeted surveys are used by the CFIA to focus its surveillance activities on areas of highest health risk. The information gained from these surveys provides support for the allocation and prioritization of the Agency's activities to areas of greater concern. Originally started as a project under the Food Safety Action Plan (FSAP), targeted surveys have been embedded in our regular surveillance activities since 2013. Targeted surveys are a valuable tool for generating information on certain hazards in foods, identifying and characterizing new and emerging hazards, informing trend analysis, prompting and refining health risk assessments, highlighting potential contamination issues, as well as assessing and promoting compliance with Canadian regulations.

Food safety is a shared responsibility. We work with federal, provincial, territorial and municipal governments and provide regulatory oversight of the food industry to promote safe handling of foods throughout the food production chain. The food industry and retail sectors in Canada are responsible for the food they produce and sell, while individual consumers are responsible for the safe handling of the food they have in their possession.

Why did we conduct this survey

The main objectives of this targeted survey were to generate further baseline surveillance data on the level of coumarin in cinnamon-containing products and vanilla extracts available on the Canadian retail market, and to compare, where feasible, the prevalence of coumarin in foods targeted in this survey with that of similar products in previous targeted surveys and to the scientific literature.

Coumarin is a naturally occurring sweet-smelling compound found in many plants, including cinnamon, tonka beans, and sweet clover. High amounts of coumarin can be found in cassia cinnamon (also known as Chinese cinnamon and Saigon cinnamon), whereas the Ceylon cinnamon (also known as true cinnamon) typically contains only traces. Ceylon cinnamon is typically more expensive than cassia cinnamon, and has a milder flavour/spice profile. Due to economics and a preference of the public for a “spicier flavour profile”, most of the cinnamon sold today is cassia cinnamon.

In order to achieve a consistent flavour profile in processed foods, the use of flavouring extracts has been a common practice in the food industry. Coumarin, either naturally derived or synthetically produced, was used as a flavouring agent in the past; however, its use in food has been discontinued based on reports of adverse health effects in animal studiesFootnote 1,Footnote 2. Although the deliberate addition of coumarin to foods is not permitted in Canada, plants or herbs that are added to foods as flavours may contain naturally occurring coumarin. The primary source of naturally occurring coumarin in the human diet is cinnamonFootnote 2,Footnote 3. The vast majority of people can consume foods that naturally contain coumarin daily without adverse effects from exposure to coumarin; however, there is a small number of individuals who are sensitive to coumarin. For this coumarin-sensitive group, intake of significantly higher levels than would normally be found in food can lead to elevation of liver enzymes, and in severe cases to inflammation of the liverFootnote 1.

In 2004, the European Food Safety Authority (EFSA) established a Tolerable Daily Intake (TDI) of 0.1 mg for coumarinFootnote 4. In 2006, Germany's Federal Institute of Risk Assessment (BfR) concluded that high cinnamon consumption would result in excessive exposure, and warned against consuming excessive amounts of cassia cinnamon due to its relatively high content of coumarinFootnote 3. The Norwegian Scientific Committee for Food Safety also conducted a risk assessment and concluded that children and adults who regularly consume even moderate amounts of cinnamon may be at risk of elevated intake of coumarinFootnote 5.

Limited data is available on the occurrence of coumarin in vanilla extracts or in foods containing cinnamon. Cinnamon is a frequently used spice, and is often included in foods and beverages. It is widely used in cooking sauces, spice mixes, tea and other beverages for its unique flavourFootnote 6. Whereas, tonka beans, a natural source of coumarin, are used as substitutes for vanilla extracts. It was, therefore, considered important to examine the coumarin levels in commonly available cinnamon-containing products and vanilla extracts to ensure that the populations consuming these foods are not at risk. All the survey data was shared with HC.

What did we sample

A variety of domestic and imported cooking sauces, dried beverage mixes, cinnamon and vanilla oils and extracts, spice mixes and teas were sampled between August 1, 2014 and March 21, 2015. Samples of products were collected from local/regional retail locations located in 6 major cities across Canada. These cities encompassed 4 Canadian geographical areas: Atlantic (Halifax), Quebec (Montreal), Ontario (Toronto, Ottawa) and the West (Vancouver, and Calgary). The number of samples collected from these cities was in proportion to the relative population of the respective areas. The shelf life, storage conditions, and the cost of the food on the open market were not considered in this survey.

Table 1. Distribution of samples based on product type and origin
Product Type Number of domestic samples Number of imported samples Number of samples of unspecified Table Note a origin Total number of samples
Cooking sauces 6 118 24 148
Dried beverage mixes 17 10 11 38
Oils and extracts 28 64 147 239
Spice mixes 9 39 56 104
Tea 41 144 25 210
Grand total 101 375 263 739

Table Notes

Table Note a

Unspecified refers to those samples for which the country of origin could not be assigned from the product label or available sample information

Return to table note a  referrer

What analytical methods were used and how were samples assessed

Samples were analyzed by an ISO 17025 accredited food testing laboratory under contract with the Government of Canada. The analytical method cannot distinguish between deliberate addition of coumarin and naturally occurring levels. The results presented represent finished food products as sold and not as they would be consumed, whether the product sampled is considered an ingredient or requires preparation prior to consumption.

What were the survey results

The 2014 to 2015 coumarin survey involved analyzing 739 samples obtained at the Canadian retail level. Coumarin was detected in 63% of the samples. This was expected as most of the products sampled contained cinnamon, which is known to be a natural source of coumarin.

The results of this survey are summarized in Table 2. Coumarin concentrations in the survey samples ranged from 0.2 ppm to 2170 ppm. Most of the spice mix and tea samples contained detected levels of coumarin; 86% and 85% of samples, respectively. These commodities also had the highest average levels of products tested; spice mixes averaging 329 ppm and tea at 302 ppm, as well as, the highest levels of coumarin found in individual samples. Pumpkin spice mix and Chinese five-spice mix samples had the highest average content of coumarin, which is expected as these types of spices often have high content of cinnamon, up to 70%. Herbal tea contained the highest levels of coumarin in comparison to other dried teas.

Table 2. Summary of targeted survey results on coumarin levels in selected foods
Product type Number of samples Number of samples (%) with detected levels Minimum (ppm) Maximum (ppm) Average Table Note b (ppm)
Cooking sauces 148 125 (84) 0.2 50 4.7
Dried beverage mixes 38 24 (63) 0.2 239 17.8
Oils and extracts 239 46 (19) 0.2 1000 46.2
Spice mixes 104 89 (86) 0.8 2170 329
Tea 210 178 (85) 0.2 1920 302
Grand total 739 462 (63) 0.2 2170 149

Table Notes

Table Note b

Only positive results were used to calculate the average (hazard) levels

Return to table note b  referrer

The average coumarin concentration in cooking sauces and dried beverage mixes was 4.7 ppm and 17.8 ppm, respectively, which is low compared to other commodities tested.

Figure 1 illustrates the range of coumarin concentration detected in the survey samples by product type. High variability in the coumarin content was observed in spice mixes, tea, and oils and extracts.

Figure 1. Concentration of coumarin in survey samples by product type

Figure 1 illustrates the range of coumarin concentration detected in the survey samples by product type.
Description for image
Product type Level of coumarin found (ppm) Number of samples with coumarin detected at this level
Oils and extracts 0 193
Oils and extracts 0.2 3
Oils and extracts 0.3 1
Oils and extracts 0.8 1
Oils and extracts 1 2
Oils and extracts 1.4 2
Oils and extracts 1.5 1
Oils and extracts 1.6 4
Oils and extracts 1.7 1
Oils and extracts 2 2
Oils and extracts 2.2 1
Oils and extracts 4.3 1
Oils and extracts 78.8 1
Oils and extracts 166 1
Oils and extracts 255 1
Oils and extracts 295 1
Oils and extracts 307 1
Oils and extracts 310 1
Oils and extracts 313 1
Oils and extracts 315 1
Oils and extracts 319 1
Oils and extracts 331 1
Oils and extracts 335 1
Oils and extracts 340 1
Oils and extracts 341 2
Oils and extracts 342 1
Oils and extracts 354 1
Oils and extracts 355 1
Oils and extracts 357 1
Oils and extracts 439 1
Oils and extracts 452 1
Oils and extracts 463 1
Oils and extracts 493 1
Oils and extracts 505 1
Oils and extracts 531 1
Oils and extracts 691 1
Oils and extracts 992 1
Oils and extracts 1000 1
Cooking sauces 0 23
Cooking sauces 0.2 1
Cooking sauces 0.3 3
Cooking sauces 0.5 4
Cooking sauces 0.6 7
Cooking sauces 0.7 3
Cooking sauces 0.8 1
Cooking sauces 0.9 4
Cooking sauces 1 2
Cooking sauces 1.1 3
Cooking sauces 1.2 1
Cooking sauces 1.4 6
Cooking sauces 1.5 5
Cooking sauces 1.6 4
Cooking sauces 1.7 4
Cooking sauces 1.8 8
Cooking sauces 1.9 4
Cooking sauces 2 2
Cooking sauces 2.1 2
Cooking sauces 2.2 3
Cooking sauces 2.3 1
Cooking sauces 2.4 2
Cooking sauces 2.5 1
Cooking sauces 2.6 4
Cooking sauces 2.7 1
Cooking sauces 2.9 1
Cooking sauces 3 2
Cooking sauces 3.1 2
Cooking sauces 3.4 1
Cooking sauces 3.5 2
Cooking sauces 3.6 1
Cooking sauces 3.7 1
Cooking sauces 3.8 1
Cooking sauces 3.9 1
Cooking sauces 4 2
Cooking sauces 4.1 2
Cooking sauces 4.4 1
Cooking sauces 4.5 1
Cooking sauces 4.8 1
Cooking sauces 4.9 1
Cooking sauces 5.9 2
Cooking sauces 7.3 1
Cooking sauces 7.7 1
Cooking sauces 9.8 1
Cooking sauces 10.7 1
Cooking sauces 10.9 2
Cooking sauces 11.1 1
Cooking sauces 11.2 1
Cooking sauces 11.6 1
Cooking sauces 12 1
Cooking sauces 13.3 1
Cooking sauces 13.8 1
Cooking sauces 14.1 1
Cooking sauces 14.7 1
Cooking sauces 15.9 1
Cooking sauces 16.3 1
Cooking sauces 16.8 1
Cooking sauces 17.7 1
Cooking sauces 17.9 1
Cooking sauces 19.5 1
Cooking sauces 20.9 1
Cooking sauces 21.6 1
Cooking sauces 22.8 1
Cooking sauces 33.7 1
Cooking sauces 40.9 1
Cooking sauces 49.9 1
Cooking sauces 50 1
Dried beverage mixes 0 14
Dried beverage mixes 0.2 1
Dried beverage mixes 0.3 2
Dried beverage mixes 0.5 3
Dried beverage mixes 0.6 1
Dried beverage mixes 0.7 2
Dried beverage mixes 0.8 1
Dried beverage mixes 1.2 1
Dried beverage mixes 2 1
Dried beverage mixes 5.7 1
Dried beverage mixes 7.4 1
Dried beverage mixes 14.5 1
Dried beverage mixes 18 1
Dried beverage mixes 21 1
Dried beverage mixes 23.8 1
Dried beverage mixes 29.5 1
Dried beverage mixes 39.9 1
Dried beverage mixes 61.1 1
Dried beverage mixes 84.3 1
Dried beverage mixes 123 1
Dried beverage mixes 239 1
Spice mixes 0 15
Spice mixes 0.8 1
Spice mixes 0.9 1
Spice mixes 1.4 1
Spice mixes 2.7 1
Spice mixes 2.8 2
Spice mixes 3.6 2
Spice mixes 4.3 1
Spice mixes 4.4 1
Spice mixes 5.8 1
Spice mixes 6.5 1
Spice mixes 6.8 1
Spice mixes 8.9 1
Spice mixes 15 1
Spice mixes 16.4 1
Spice mixes 17.7 1
Spice mixes 19.7 2
Spice mixes 21.9 1
Spice mixes 22 1
Spice mixes 22.7 1
Spice mixes 25.5 1
Spice mixes 25.6 1
Spice mixes 26.8 1
Spice mixes 28.3 1
Spice mixes 29.6 1
Spice mixes 32.2 1
Spice mixes 33.8 1
Spice mixes 35.8 1
Spice mixes 42.6 1
Spice mixes 48.1 1
Spice mixes 61.8 1
Spice mixes 70.7 1
Spice mixes 71.3 1
Spice mixes 74.8 1
Spice mixes 76.4 1
Spice mixes 80.1 1
Spice mixes 82.3 1
Spice mixes 88 1
Spice mixes 124 1
Spice mixes 132 1
Spice mixes 150 1
Spice mixes 153 1
Spice mixes 160 1
Spice mixes 173 1
Spice mixes 188 1
Spice mixes 190 1
Spice mixes 203 1
Spice mixes 211 1
Spice mixes 214 1
Spice mixes 227 1
Spice mixes 237 1
Spice mixes 238 1
Spice mixes 266 1
Spice mixes 275 1
Spice mixes 285 1
Spice mixes 289 1
Spice mixes 307 1
Spice mixes 343 1
Spice mixes 347 1
Spice mixes 370 1
Spice mixes 411 1
Spice mixes 419 1
Spice mixes 481 1
Spice mixes 494 1
Spice mixes 659 1
Spice mixes 662 1
Spice mixes 777 1
Spice mixes 821 1
Spice mixes 899 1
Spice mixes 902 1
Spice mixes 908 1
Spice mixes 922 1
Spice mixes 1000 1
Spice mixes 1020 2
Spice mixes 1040 2
Spice mixes 1050 1
Spice mixes 1060 1
Spice mixes 1080 1
Spice mixes 1170 1
Spice mixes 1210 1
Spice mixes 1490 1
Spice mixes 1570 1
Spice mixes 1690 1
Spice mixes 2070 1
Spice mixes 2170 1
Tea 0 32
Tea 0.2 2
Tea 0.3 1
Tea 0.4 2
Tea 0.5 4
Tea 0.9 1
Tea 1.2 1
Tea 1.3 1
Tea 2 1
Tea 3.5 1
Tea 4.3 1
Tea 5.1 2
Tea 6.6 1
Tea 6.8 1
Tea 7.6 1
Tea 7.8 1
Tea 8.1 1
Tea 8.4 1
Tea 9 2
Tea 9.9 1
Tea 10.2 1
Tea 10.3 2
Tea 11.4 1
Tea 12.2 1
Tea 12.3 1
Tea 13.3 1
Tea 13.4 1
Tea 13.9 1
Tea 14 1
Tea 14.6 1
Tea 15 1
Tea 15.8 1
Tea 17.3 1
Tea 17.4 1
Tea 18.9 1
Tea 19.1 1
Tea 19.3 1
Tea 22.6 1
Tea 22.8 1
Tea 23.2 1
Tea 27.5 1
Tea 30.9 1
Tea 33.1 1
Tea 34.5 1
Tea 34.9 1
Tea 35.4 1
Tea 51.1 1
Tea 60.9 1
Tea 66 1
Tea 73.1 1
Tea 73.3 1
Tea 77.5 1
Tea 78.6 1
Tea 93 1
Tea 93.5 1
Tea 93.9 1
Tea 97.6 1
Tea 99.8 1
Tea 107 1
Tea 112 1
Tea 119 1
Tea 120 1
Tea 121 2
Tea 122 2
Tea 126 1
Tea 132 1
Tea 134 1
Tea 135 1
Tea 142 1
Tea 143 1
Tea 146 1
Tea 150 1
Tea 154 1
Tea 162 1
Tea 180 1
Tea 186 1
Tea 189 1
Tea 190 1
Tea 191 1
Tea 192 1
Tea 199 1
Tea 202 1
Tea 203 1
Tea 207 1
Tea 210 2
Tea 223 1
Tea 226 1
Tea 227 1
Tea 233 1
Tea 235 1
Tea 237 1
Tea 246 1
Tea 260 1
Tea 262 1
Tea 267 1
Tea 269 1
Tea 273 1
Tea 279 1
Tea 290 1
Tea 291 1
Tea 293 1
Tea 297 1
Tea 310 1
Tea 314 1
Tea 315 1
Tea 323 1
Tea 325 2
Tea 338 1
Tea 339 2
Tea 347 1
Tea 362 1
Tea 370 1
Tea 387 1
Tea 408 1
Tea 416 1
Tea 421 1
Tea 424 1
Tea 445 1
Tea 453 1
Tea 497 2
Tea 505 1
Tea 520 2
Tea 536 1
Tea 546 1
Tea 560 1
Tea 602 1
Tea 614 1
Tea 620 1
Tea 621 1
Tea 628 1
Tea 638 1
Tea 680 1
Tea 691 1
Tea 712 1
Tea 743 1
Tea 750 1
Tea 753 1
Tea 850 1
Tea 853 1
Tea 877 1
Tea 893 1
Tea 903 1
Tea 944 1
Tea 975 1
Tea 983 1
Tea 988 1
Tea 1010 1
Tea 1050 1
Tea 1100 1
Tea 1110 1
Tea 1130 2
Tea 1260 1
Tea 1380 1
Tea 1390 1
Tea 1420 1
Tea 1490 1
Tea 1500 2
Tea 1630 1
Tea 1650 1
Tea 1660 1
Tea 1900 1
Tea 1920 1

All cinnamon oils and extracts contained coumarin, with levels up to 1000 ppm and an average level of 281 ppm. Vanilla extracts included pure and artificial vanilla and most did not contain detected levels of coumarin. Only seven out of 200 samples of vanilla extracts contained detected amount of coumarin at low levels ranging from 0.2 ppm to 4.3 ppm. One sample of mixed cinnamon/vanilla extract tested contained 78.8 ppm.

What do the survey results mean

The samples tested show a wide range of coumarin content which agrees with data in the scientific literature and previous surveys resultsFootnote 7,Footnote 8,Footnote 9. The wide range of coumarin content found in these foods is due to natural variation, degree of processing, the cinnamon content and the type of cinnamon used in these foods.

The average and maximum coumarin concentration in dried beverage mixes, spice mixes and tea were comparable to previous targeted surveys. Considering the high cinnamon content of the food groups tested, the coumarin levels found are within the range reported in literature of up to 9090 ppm in pure Cassia cinnamonFootnote 10. The average coumarin levels found in these food commodities also compare well with the literature as reported in Table 3. Some differences observed are likely due to the sample size and the specific type of product tested.

The percentage of dried beverage mix, spice mix and tea samples with detected levels of coumarin in the 2013 to 2014 survey was 66%, 87% and 99%, respectively. These numbers are in close agreement with the results of this 2014 to 2015 survey of 63%, 86% and 85%, respectively.

HC's Bureau of Chemical Safety determined the levels of coumarin in food observed in this survey are not expected to pose a concern to human health, therefore no follow-up actions were required.

Table 3. Minimum, maximum and average concentration of coumarin across various studies
Product type Study Year Number of samples Minimum (ppm) Maximum (ppm) Average (ppm)
Ground cinnamon CFIA SurveyTable Note e 2011-2012 87 16.2 7816 3594 Table Note c
Ground cinnamon BlahováTable Note i 2012 60 2650 7057 3856
Cinnamon powder and sticks KrugerTable Note j 2018 28 8 5017 1449
Cinnamon cassia powder and sticks WoehrlinTable Note h 2010 69 <LOD 9900 3697
Cinnamon powder LungariniTable Note d 2008 20 5 3094 1456
Cooking sauce CFIA Survey 2014-2015 148 0.2 50 4.7 Table Note c
Cooking sauce FSATable Note k 2015 13 1.10 6.10 3.26
Dried beverage mix CFIA Survey 2014-2015 38 0.2 239 17.8 Table Note c
Dried beverage mix CFIA SurveyTable Note g 2013-2014 32 0.2 217 45.4 Table Note c
Oil/extract CFIA Survey 2014-2015 239 0.2 1000 46.2 Table Note c
Cassia leaf oil ChangTable Note l 2001 2 0 2600 2600
Spice mix CFIA Survey 2014-2015 324 0.2 2170 329 Table Note c
Spice mix CFIA SurveyTable Note g 2013-2014 103 0.2 2510 390 Table Note c
Spice mix CFIA SurveyTable Note f 2012-2013 53 30 3078 568 Table Note c
Spice mix CFIA SurveyTable Note l 2011-2012 24 <0.29 2014 352 Table Note c
Spice mix RatersTable Note m 2008 172 <0.03 4309 174
Tea CFIA Survey 2014-2015 508 0.2 1920 302 Table Note c
Tea CFIA SurveyTable Note g 2013-2014 115 0.3 2430 500 Table Note c
Tea CFIA SurveyTable Note e 2011 - 2012 11 <0.29 1040 380 Table Note c
Tea KrugerTable Note j 2018 8 20 137 62
Tea LungariniTable Note d 2008 5 30 192 81

Table Notes

Table Note c

Only positive results were used to calculate the average (hazard) levels

Return to table note c  referrer

Table Note d

Lungarini, S., Aureli, F., Coni, E. (2008). Coumarin and cinnamaldehyde in cinnamon marketed in Italy: A natural chemical hazard? Food Additives and Contaminants. 25(11), pp. 1297-1305.

Return to table note d referrer

Table Note e

2011-2012 Coumarin in Cinnamon and Cinnamon-Containing Products. (2018). Canada. Canadian Food Inspection Agency.

Return to table note e referrer

Table Note f

2012-2013 Coumarin in Cinnamon and Cinnamon-Containing Products. (2018). Canada. Canadian Food Inspection Agency.

Return to table note f referrer

Table Note g

2013-2014 Coumarin in Dried Beverages, Breads, Baking Mixes, Spice Mixes, Dried Tea, Baked Goods, and Breakfast Foods. (2018). Canada. Canadian Food Inspection Agency.

Return to table note g referrer

Table Note h

Woehrlin, F., Hildburg, F., Abraham, K., Preiss-Weigert, P. (2010). Quantification of Flavoring Constituents in Cinnamon: High Variation of Coumarin in Cassia Bark from the German Retail Market and in Authentic Samples from Indonesia. J. Agric. Food Chem. 58(19), pp. 10568–10575.

Return to table note h referrer

Table Note i

Blahova, J., Svobodova, Z. (2012). Assessment of coumarin levels in ground cinnamon available in the Czech retail market. Scientific World Journal. pp. 263851.

Return to table note i referrer

Table Note j

Krüger, S., Winheim, L., Morlock G.E. (2017). Planar chromatographic screening and quantification of coumarin in food, confirmed by mass spectrometry. Food Chemistry. 239, pp. 1182-1191.

Return to table note j referrer

Table Note k

Survey on the Consumption of Cinnamon-Containing Foods and Drinks by the UK Population (Apekey , T.A., Khokhar, S.) School of Food Science & Nutrition, University of Leeds. (PDF) (2015). Food Standards Agency.

Return to table note k referrer

Table Note l

Chang, S.T., Chen, P.F., Chang , S.C. (2001). Antibacterial activity of leaf essential oils and their constituents from Cinnamomum osmophloeum. J. Ethnopharmacol. 77, pp. 123-127.

Return to table note l referrer

Table Note m

Raters, M., Matissek, R. (2008). Analysis of coumarin in various foods using liquid chromatography with tandem mass spectrometric detection. European Food Research and Technology. 228, pp. 637-642.

Return to table note m referrer