Measuring Caffeine in Teas, Coffee, and Energy Drinks Using FoodSense Generation 4 - Samples: CatSpring Yaupon - Texas Native Yaupon Tea: Marfa, Lost Maples, Pedernales

Samples: CatSpring Yaupon - Texas Native Yaupon Tea: Marfa, Lost Maples, Pedernales

In this study, we set out to answer a straightforward but important question:

How much caffeine is present in different drinks, and how clearly can it be distinguished from antioxidants?

Using the FoodSense Generation 4 system with a caffeine sensor, we analysed a range of beverages including specialty teas from the USA, instant coffee, decaffeinated coffee, and a synthetic energy drink (Red Bull). The results clearly demonstrate how FoodSense can rapidly and reliably differentiate caffeine from antioxidant signals across very different sample types.

Experimental Setup

Equipment

• FoodSense Generation 4

• FoodSense caffeine sensor

• Proprietary FoodSense buffer

• Smartphone app with cloud connectivity

Samples Tested

• Three specialty teas:

  • Mara

  • Pedernales

  • Lost Maples

• Instant coffee (caffeinated)

• Instant coffee (decaffeinated)

• Red Bull energy drink

Sample Preparation

To ensure consistency across all samples, the same preparation protocol was used.

• Each tea or coffee powder was prepared by dissolving 0.21 g in 25 mL of buffer, effectively creating a small “cup” of each drink.

• For each measurement:

  • 50 µL of sample was mixed with 50 µL of buffer

  • 50 µL of the final mixture was applied directly to a fresh caffeine sensor

This approach allowed direct and meaningful comparison between teas, coffees, and energy drinks.

How FoodSense Detects Caffeine

When a sample is applied, FoodSense records an electrochemical signal in real time. Two key features appear in the signal:

• Initial peak: Antioxidants (commonly present in teas and coffee)

• Secondary peak: Caffeine (if present)

Results are displayed instantly in the mobile app and uploaded automatically to the FoodSense cloud platform, where raw data can also be reviewed.

Results

Instant Coffee (Caffeinated)

• Clear and well‑defined caffeine peak

• Measured at approximately 0.133 mg/g

• Strong antioxidant signal also present

✅ Confirms accurate detection of caffeine in a known caffeinated product

Instant Coffee (Decaffeinated)

• No detectable caffeine peak

• Antioxidants still clearly visible

✅ Confirms sensor specificity and correct identification of decaffeinated samples

Red Bull (Energy Drink)

• Strong, isolated caffeine peak

• Minimal antioxidant signal

• Measured at approximately 0.25–0.3 mg/g, consistent with label claims

✅ Demonstrates excellent accuracy with synthetic caffeine sources

Specialty Tea Results

Mara

• Strong antioxidant signal

• No detectable caffeine peak

• Caffeine level comparable to decaffeinated coffee

Pedernales

• Antioxidants clearly present

• Very faint caffeine response

• Caffeine effectively negligible and close to decaffeinated levels

Lost Maples

• Antioxidants clearly present

• Very mild caffeine signal

• Estimated at roughly one‑tenth of Red Bull, similar to decaffeinated coffee

✅ Overall, all three teas showed high antioxidant content with very low caffeine, well below coffee or energy drink levels.

Visual Validation Using Raw Data

Reviewing the raw electrochemical signals further reinforces these conclusions:

• Coffee shows both antioxidant and caffeine peaks

• Decaffeinated coffee shows antioxidants but no caffeine peak

• Red Bull shows a strong caffeine peak with little antioxidant activity

• Teas show antioxidant activity with either no caffeine peak or only very weak signals

This side‑by‑side comparison makes it clear how FoodSense differentiates between naturally occurring antioxidants and caffeine.

Why This Matters

This study highlights several strengths of the FoodSense Generation 4 platform:

• Rapid testing: Multiple samples analysed in minutes

• Clear differentiation: Antioxidants and caffeine are easily distinguished

• Quantitative accuracy: Results align with known reference values

• Versatility: Works across natural and synthetic beverages

FoodSense enables fast answers to questions such as:

• Does this product contain caffeine?

• How much caffeine is present?

• Is the caffeine naturally occurring or added?

Summary

In this series of tests—covering three teas, two coffees, and an energy drink—FoodSense Generation 4 delivered clear, reliable, and interpretable results.

• Teas (Mara, Pedernales, Lost Maples): High antioxidants, very low caffeine

• Decaf coffee: Antioxidants present, caffeine absent

• Regular coffee: Moderate caffeine with antioxidants

• Red Bull: High caffeine, minimal antioxidants

This experiment demonstrates how FoodSense Generation 4 provides rapid, on‑site chemical insight with lab‑grade confidence.