How Do UV Spectrophotometers Analyze Caffeine Levels? : Using Light Absorption to Measure Coffee

I am not really a morning person, so I require a little motivation every day to get myself up out of bed. My morning cup of coffee is one of my favorite rituals, and I’ll admit that the jolt of caffeine is an obvious bonus for kick-starting my day.

However, for the millions of other people who share a similar love for this hot beverage, noncaffeinated versions are sometimes a better option due to various considerations. Coffee producers need to offer a variety of options for consumers that either provide that major caffeine jolt or ensure that the caffeine intake is minimized, so that consumers may be assured they are getting what they’re expecting. This process is highly dependent on the use of UV spectrophotometry and light absorption measurements.

Using Light Absorption to Measure Caffeine Levels

Spectrophotometers use light absorption to measure wavelengths that are transmitted through a solution. When measuring the caffeine content in coffee, the molecules in the sample will absorb light at different wavelengths within the color spectrum, providing information that can then be used as quantifiable data for determining the concentration of caffeine. The ability to generate accurate light absorption measurements of the caffeine levels in decaffeinated coffee bean batches is essential for reducing the health risks in sensitive consumers by “preventing inconsistent caffeine levels among available ‘decaf’ blends.”

The FDA (Food and Drug Administration) requires coffee producers to reduce caffeine content to only 25 parts per million for decaffeinated blends in order to don the “decaf” label.  Light absorption methods of caffeine monitoring can provide instant analysis to indicate when the decaffeination cycle is complete, therefore maximizing production time and efficiency.

Measurement of caffeine in coffee is also important for determining the value of the product. In the article “Measurement of Caffeine in Coffee Beans with UV/vis Spectrometer,” it was reported that “chemical analysis of caffeine in coffee beans is also used as an additional tool for evaluating coffee quality.” However, to the average coffee drinker, many other factors affect the consumer perception of quality.

Other Applications of UV Spectroscopy for Coffee Measurement

The quality of coffee is dependent on many different factors, but color perception is often the prime component of consumer choice. Coffee color can change drastically depending on roasting time, growing location, and whole bean versus ground varieties. Light absorption measurement provides a valuable tool in the assessment of consistency due to these variables. Using spectrophotometers during the roasting process can help manufacturers determine when to stop to roasting process in order to obtain the highest quality of color for consumer satisfaction. Roasting times also vary depending on desired color for light, medium, or dark roasts and require color measurement tools that are quick, accurate, and easy to use. Human perception is often subjective and can vary, and therefore using the proper color measuring technology can alleviate errors and increase production time and consistency.

Roasting times vary depending on desired color. Spectrophotometers provide objective and accurate measurements for real-time results.
Image Source: Flickr user Breville USA

Measurement Device Options and Differences

Light absorption analysis of coffee is made possible with an assortment of measurement options ranging from large-scale machines to easy-to-use hand-held portable units. Spectrophotometric technology has advanced rapidly and now provides many options for coffee manufacturers to measure the color and quality of their products. 

At HunterLab, we have created devices specifically adapted for coffee measurement analysis. The ColorFlex L2 Coffee Spectrophotometer is designed to measure the reflected color of ground coffee, with the ability to analyze freeze-dried and instant varieties as well.

Enhanced Essentials 2.0 software and touchscreen operation make it easy to capture data and compare it to the industry's most accepted color scales. Built-in scales include the HunterLab Coffee Color Index (HCCI), Specialty Coffee Association (SCAA) Number, and SCAA Roast Classification. You can also add customized tolerances for more unique comparison needs or quality measures.

Additionally, ColorFlex L2 is ready to work right out of the box and offers incredible ease of use with a setup and training wizard to minimize learning time. Integrate it into your lab or on the floor to analyze color at each processing step. Measurement takes just a few minutes, keeping production on schedule or quickly revealing where adjustments may be necessary to uphold customer satisfaction and meet quality expectations.

This equipment also provides universal compatibility and connectivity to eliminate time-consuming manual data entry and the need to connect to a PC. Transfer information to other devices seamlessly or export data to statistical process control systems in just a few clicks. Internal recording capability allows you to make informed quality decisions in moments with rapid data sharing. ColorFlex L2 offers both USB and HDMI connections to simplify the process or add accessories like a keyboard or mouse.

Other benefits of ColorFlex L2 include:

• Real-time trend-spotting: A generous storage capacity makes it easy to compare current outcomes with historical readings and spot trends.
• Unparalleled accuracy: 45°a:0° annular illuminated optical geometry and an internal camera with positioning assistance help ensure greater measurement accuracy and data confidence.
• Space-saving design: We've engineered the ColorFlex L2 with a compact footprint that preserves space.
• Unmatched durability: Our spectrophotometers are built to withstand demanding manufacturing environments for long-lasting reliability.

Trust HunterLab for Accurate Coffee Color Measurement Solutions

HunterLab is the trusted name in color measurement and spectrophotometers, providing services around the world with over 70 years of expertise. We pride ourselves on our full line of highly accurate, user-friendly solutions with unprecedented measuring, monitoring, and analysis flexibility, plus unrivaled customer support and satisfaction. Contact Hunterlab to learn more about how color measurement can help you improve coffee production and quality today.