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How Do QC Analysts Confirm Petrochemical Adulteration in Bitter Almond Oil?

Economically motivated adulteration of bitter almond oil is a major concern in the food and beverage industry. Quality control teams need a stringent method to confirm if their bitter almond oil ingredient is natural or has been artificially made from petrochemical derivatives. Although there are several techniques that can detect adulteration, only carbon-14 analysis can confirm petrochemical adulteration. The method measures the exact percentage of a material that is sourced from biomass (natural).  

There are two kinds of almond oil – sweet almond oil and bitter almond oil. Many believe that both essential oils have numerous health benefits but there are no conclusive scientific data to prove these claims. Both oils are used in various industries including cosmetics, food and beverage. Considering their commercial application, there is a growing demand for both types of almond oils. Analysts are projecting the global almond oil market to reach USD 2.21 billion by 2021 thanks to a number of factors which include increased availability in retail channels and a growing interest in aromatherapy. The growing demand has also resulted in economically motivated adulteration.

Natural vs Synthetic Benzaldehyde

Bitter almond oil is often used as a flavoring ingredient. It primarily consists of benzaldehyde and is naturally derived from a tree called Prunus amygdalus.2 Aside from almonds, kernels of peaches, plums, apricots and cherries can also be used as sources of bitter almond oil. 

There are three known procedures used to produce synthetic benzaldehyde. One is the direct oxidation of toluene, which is oftentimes derived from crude oil. Another is through the hydrolysis of benzal chloride, produced by the chlorination of toluene. The third method is the retro-aldol reaction of cinnamaldehyde, which can be obtained naturally through cinnamon oil.2

Because of increased demand and limited supply, natural benzaldehyde comes at a high price. Some manufacturers filled this demand by producing synthetic benzaldehyde. The use of synthetic benzaldehyde is legal. The problem lies in using the cheaper synthetics as flavoring agents without disclosing them as artificial.

Adulteration may lead to a financial disaster for manufacturing companies. When consumers start noticing issues with quality, they will eventually see through the false advertising of synthetic products posing as natural. This is why it is important for stakeholders in the industry to validate the “100% naturally sourced” claims of ingredient suppliers.

Carbon-14 Analysis of Bitter Almond Oil

Carbon-14 analysis can provide an accurate distinction between synthetic and naturally sourced benzaldehyde from bitter almond oil. For these substances to be considered authentic or 100% natural, they must be 100% biobased. Benzaldehyde derived solely from petrochemicals has no Carbon-14 and is 0% biobased. Adulterated products which contain a mixture of both natural and synthetic can have biobased content between 0% and 100%.

It must be noted that carbon-14 analysis does not distinguish between different natural sources, e.g. almond vs apricot kernels. It can only confirm whether the essential oil is biomass-derived or petrochemical-sourced or a mixture of the two.

Beta Analytic – A Carbon-14 Testing Laboratory

ISO 17025-accredited carbon-14 laboratory Beta Analytic offers natural product testing using two standardized analytical methods – ASTM D666 and ISO 16620-2. It is up to the client to choose which standard is applicable to their product. ASTM D6866 biobased results are reported as a fraction of the Total Organic Carbon (TOC) while ISO 16620-2 reports biobased carbon content as a fraction of Total Carbon or TOC.

For inquiries, please email the lab using its contact form.


  1. Business Wire. 2017. Global Almond Oil Market – Drivers and Forecast from Technavio. (accessed February 2018)
  2. Remaud, Gérald & Andres Debon, Antonio & Martin, Yves-loïc & G. Martin, Gilles & Martin, Gérard. 1997. Authentication of Bitter Almond Oil and Cinnamon Oil: Application of the SNIF-NMR Method to Benzaldehyde. Journal of Agricultural and Food Chemistry. (accessed February 2018)
  3. Butzenlechner M, Rossmann A, Schmidt HL. 1989. Assignment of bitter almond oil to natural and synthetic sources by stable isotope ratio analysis. Journal of Agricultural and Food Chemistry. (accessed February 2018)
  4. Zeeshan Ahmad. 2010. The uses and properties of almond oil. Complementary Therapies in Clinical Practice (accessed February 2018)

This entry was posted on Thursday, February 15th, 2018 and is filed under Essential Oil Testing, Flavor & Fragrance, Flavors Carbon-14 Analysis, Natural Product Testing .