Measuring the Color of Expensive Essential Oils Using Smaller Sample Sizes

measuring color essential oils
The expense of essential oils may make some manufacturers reluctant to devote material to spectrophotometric color quality control. Image Source: Shutterstock user natashamam

The use of essential oils is a growing trend within the health and wellness community. The therapeutic properties of these oils have been recognized and harnessed by practitioners of traditional medicine for centuries, but they have become increasingly appealing to patients, clinicians, and researchers who are looking for all-natural treatments. Indeed, studies suggest that essential oils are remarkably versatile, capable of everything from promoting relaxation to fighting skin infection to combating cancer.1

While it is clear that essential oils offer a variety of health and wellness benefits, one drawback of these compounds is that, by volume, they are extremely expensive. This can become a particular problem for essential oil manufacturers who are developing strategies for process monitoring and quality control. Given the high investment cost, it may not seem wise to test for certain properties, such as color. However, today’s spectrophotometers can enable manufacturers to overcome this problem by offering the opportunity to measure color using smaller sample sizes.

measuring color essential oils
Color can provide critical information about oil quality and significantly shape consumer perception. Image Source: Shutterstock user Chamille White

Controlling Costs for the Company and the Consumer

Essential oils are highly concentrated plant extracts, so only a tiny amount is needed in order to achieve a particular therapeutic purpose. Nevertheless, because of the complexities of the process of distilling these products, even a small quantity bears a high cost. For manufacturers, this means that each color measurement during the essential oil preparation process represents a considerable investment in terms of both financial expenditure and material resource loss. This can make it tempting for some companies to forego color measurement altogether.

At the same time, when considering the issue of consumer preference, it has never been more important for essential oil companies to guarantee color consistency. Consumers have become increasingly aware of the potential safety hazards of using essential oils, knowing that they offer significant opportunities to enhance health and wellness, but that these compounds’ high potential for toxicity can lead to major problems if things go wrong.2 However, since most users aren’t experts, they have little choice but to opt for the simplest evaluation method: visual inspection. A customer may become concerned if they notice inconsistencies in essential oil color. Therefore, adherence to consistent color can help essential oil companies maintain trust with their customer base.  

In order to balance the cost of measuring the color of expensive essential oils with the need to maintain a consistent color, today’s manufacturers can take advantage of instruments that measure small volumes. Due to advances in spectrophotometric technology, a number of modern spectrophotometers are now compatible with sample holders that hold smaller amounts of a product than could be analyzed by traditional spectrophotometers. As such, it becomes financially feasible for essential oil manufacturers to take the necessary measurements, both during and after the manufacturing process. Put simply, the ability to get an accurate color measurement for a tiny amount of an essential oil can completely upend the traditional cost-benefit analysis when it comes to making spectrophotometric measurements for these products.

HunterLab offers a number of instruments that are ideal for measuring the color of essential oils, including the Vista, a revolutionary new transmission color spectrophotometer. Because it is possible to fit the Vista with small sample holders capable of measuring as little as 0.6 mL of material, it can be used by essential oil manufacturers who need to conserve material in order to avoid extravagant expenses. An additional feature of HunterLab’s Vista that makes it particularly well-suited to the measurement of small quantities of essential oils is the fact that the instrument can simultaneously measure color and haze. That way, if a company needs to measure both parameters, it is only necessary to invest in a single sample.

measuring color essential oils
Creating a color standard for your oils can optimize accuracy and efficiency of measurement. Image Source: Shutterstock user Africa Studio

The Benefits of Color Standards for Expensive Oils

One of the ways to assure the consistency of an essential oil product using spectrophotometric color analysis is to develop a color standard for the product. With a color standard, it is possible to detect even the smallest discrepancies in color that could raise concerns about the quality of an essential oil for customers who are comparing batches. By creating a color standard for an essential oil, you can make the most of the information that is generated by each individual color test, maximizing the value of the investment of the small amount of essential oil that has to be dedicated to spectrophotometric testing. Advanced spectrophotometers like the Vista come with color measurement software uniquely designed to facilitate this process and store thousands of standards for future use.

Aside from addressing concerns related to the appearance of a particular essential oil, using a color standard can also aid in the detection of toxicity issues with the essential oil. For some essential oils, a change in color may signal a problem with potency or stability. This could affect the way that the essential oil impacts the user, which could have potential safety implications. However, if a color standard has already been developed, operators taking color measurements will be alerted to deviations when the essential oil is tested during the manufacturing process. The Vista, for example, can be operated on a Pass/Fail basis and will immediately flag unwanted color variations to allow operators to quarantine out-of-spec product and investigate the cause of the color discrepancy. In some cases, this can even present an opportunity to make changes that save a batch of expensive essential oil that might otherwise have to be discarded. Thus, when it comes to minimizing the expenses associated with the essential oil preparation process, a color standard clearly complements a spectrophotometer’s ability to measure small volumes.

HunterLab Innovation

Ultimately, for any essential oil, the high level of concentration of the compound means that a little goes a long way—but it also means that conserving as much material as possible over the course of the preparation process is a fundamental goal for cost-savvy companies. Advanced spectrophotometers like HunterLab’s Vista make it possible to measure small volumes of a product, ensuring that color analysis remains a financially practical option for essential oil companies. Get in touch with us today for more information about this innovative instrument.
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  1. “Essential oils and their constituents as anticancer agents: A mechanistic view,” 2014,
  2. “Introduction to the special issue: Application of essential oils in food systems,” 5 April 2018,