HunterLab D25LT Colorimeter for Flavor & Fragrance Applications

Overview

The HunterLab D25LT is a benchtop spectrophotometric colorimeter engineered specifically for precise, repeatable color measurement of flavor and fragrance materials—including viscous liquids, suspensions, powdered extracts, and opaque or textured formulations. Unlike general-purpose colorimeters, the D25LT implements a rigorously controlled 45°/0° optical geometry with annular illumination and central viewing—designed to minimize directional bias and enhance robustness against surface texture, particle scatter, and sample heterogeneity. This geometry conforms to ASTM D2244 and ISO 7724-1 standards for instrumental color difference evaluation and is widely accepted by global flavor houses, regulatory reviewers, and QC laboratories for specification conformance testing. The instrument employs a thermally stabilized full-spectrum LED array (400–700 nm) with <0.5 nm spectral bandwidth, delivering stable, mercury-free illumination without warm-up delay or lamp degradation over time. Its large 9.5 cm (3.75 in) measurement aperture accommodates standard industry sample containers—including 10 mm, 25 mm, and 50 mm pathlength cuvettes—as well as open-top beakers and Petri dishes, enabling direct analysis of undiluted or minimally prepared samples.

Key Features

• Reconfigurable sample port orientation: vertically upward for liquid fill-level measurements; downward for overhead placement of powders, pastes, or irregular solids—eliminating need for sample transfer or reorientation fixtures.
• 10.4-inch high-resolution color LCD touchscreen with intuitive icon-driven UI, supporting multilingual operation (English, Spanish, French, German, Chinese) and real-time spectral preview.
• Built-in thermal printer for immediate hardcopy output of measurement reports, including metadata (date/time, operator ID, sample ID, tolerance status), spectral data, and pass/fail flags.
• Dual connectivity: native USB 2.0 for local PC integration and Gigabit-capable Ethernet for networked deployment within LIMS or centralized QA databases.
• Onboard operating system (Linux-based) with embedded database supporting >5,000 reference standards and >5,000 sample records—no external PC required for routine operation.
• Comprehensive statistical engine: calculates mean, standard deviation, min/max, and range across sequential readings; supports batch reporting compliant with GLP documentation requirements.

Sample Compatibility & Compliance

The D25LT is validated for use with non-homogeneous, light-scattering, and low-transmittance matrices common in flavor and fragrance manufacturing—including oleoresins, essential oil emulsions, caramelized sugar solutions, dried botanical powders, and encapsulated aroma systems. Its 45°/0° geometry inherently suppresses specular reflectance and reduces sensitivity to surface gloss or minor particulate settling—critical for reproducible assessment of turbid or sediment-prone samples. Regulatory alignment includes full support for ASTM E308 (standard practice for computing CIE colors), ISO 11664-4 (CIE colorimetric observers), and FDA-recommended color evaluation protocols for food-grade ingredients. When paired with Vision® software (v5.0+), the system can be configured to meet 21 CFR Part 11 requirements—including electronic signatures, audit trails, role-based access control, and immutable record archiving—making it suitable for GMP-regulated environments.

Software & Data Management

While fully functional as a standalone instrument, the D25LT integrates seamlessly with HunterLab’s Vision® software suite via USB or Ethernet. Vision enables advanced workflow automation: automated pass/fail decision logic across multiple metrics simultaneously, custom report templates (PDF/CSV/XLSX), SPC charting (X-bar/R, Cp/Cpk), and bidirectional synchronization with ERP or LIMS platforms using HL-XML or REST API interfaces. All raw spectral data (31-point reflectance/transmittance at 10 nm intervals) are stored onboard and exportable for third-party analysis. Data security protocols include encrypted local storage, password-protected user profiles, and configurable auto-logoff timers. Firmware updates are delivered via secure HTTPS download and verified through cryptographic signature validation.

Applications

• Batch release testing of natural and synthetic flavor concentrates against master color standards.
• Stability monitoring of heat-sensitive fragrances during accelerated aging studies (e.g., 40°C/75% RH).
• Raw material qualification of botanical extracts (e.g., turmeric, paprika, annatto) where hue consistency directly correlates with active compound concentration.
• Process validation of spray-drying, microencapsulation, or solvent evaporation steps where color shift indicates oxidation or Maillard reaction progression.
• Supplier qualification audits requiring objective, instrument-based color acceptance criteria—not subjective visual grading.
• Regulatory submission support: generation of traceable, auditable color data packages aligned with ICH Q5C and USP guidelines.

FAQ

Is the D25LT compliant with FDA 21 CFR Part 11 for electronic records?
Yes—when operated with Vision® software v5.3 or later and configured with audit trail logging, electronic signatures, and user access controls, the system meets core Part 11 requirements for closed systems.
Can the instrument measure both transmission and reflectance modes?
No—the D25LT operates exclusively in reflectance mode (45°/0°); transmission measurements require the complementary D25T model with integrated transmittance port.
What is the maximum sample thickness the upward-facing port can accommodate?
The vertical sample chamber accepts containers up to 120 mm tall with a base diameter ≤ 100 mm; standard 50 mL centrifuge tubes and 100 mm Petri dishes fit without modification.
Does the LED light source require recalibration or replacement during normal operation?
No—HunterLab’s solid-state LED array is rated for >100,000 hours of operation with no measurable spectral drift; factory calibration remains valid for 24 months under typical lab conditions.
How does the D25LT handle samples with strong fluorescence?
The instrument does not include UV excitation; its 400–700 nm LED spectrum excludes UV-A/B bands, eliminating interference from fluorescent brighteners or naturally fluorescent compounds (e.g., quinine sulfate derivatives).