HunterLab ColorFlex EZ Citrus Portable Spectrophotometer

Overview

The HunterLab ColorFlex EZ Citrus is a purpose-engineered portable spectrophotometer designed specifically for objective, repeatable color measurement of citrus juices—including orange, grapefruit, and lemon concentrates. Unlike subjective visual grading, this instrument quantifies color using the standardized Citrus Number (CN), Citrus Red (CR), and Citrus Yellow (CY) indices—originally developed for U.S. Department of Agriculture (USDA) and industry specifications for concentrated orange juice (COJ) quality assessment. Its optical architecture employs a dual-beam, 45° annular illumination / 0° viewing geometry with specular component excluded (SCE), ensuring high reproducibility across opaque and semi-opaque liquid samples. The system integrates a sealed optical path, a 256-element silicon photodiode array, and a high-resolution concave holographic grating to deliver spectral data from 400 nm to 700 nm at <3 nm spectral resolution and 10 nm effective bandwidth—fully compliant with CIE 15:2004, ISO 7724-1, ASTM E1164, DIN 5033-7, and JIS Z 8722 Condition C.

Key Features

• Optimized citrus-specific algorithms for CN, CR, and CY index calculation—traceable to USDA and AOAC reference methods
• 45°/0° SCE optical geometry with 31.8 mm (1.25″) illumination port and 25.4 mm (1.0″) measurement aperture
• Pulsed xenon lamp with >1 million flashes lifetime and single-flash per measurement for thermal stability and long-term calibration integrity
• Large backlit LCD display and sealed membrane keypad for cleanroom- and production-floor compatibility
• Compact footprint: occupies only 6 in (15.2 cm) of bench space; weighs under 5 kg for lab-to-line portability
• Integrated OJ4 calibration standard (A11-1011-509) with precision alignment screw for field recalibration traceable to NIST-certified standards
• Sample handling via dedicated tube holder (D02-1010-459) enabling consistent positioning of capped or open sample tubes

Sample Compatibility & Compliance

The ColorFlex EZ Citrus accommodates both transparent and turbid liquids—including clarified and unfiltered citrus juices, emulsions, and suspensions—without dilution or filtration. Its SCE configuration eliminates interference from surface gloss, making it suitable for viscous or lightly suspended matrices. All measurements conform to GLP-compliant workflows when paired with HunterLab’s EasyMatch QC software, supporting 21 CFR Part 11 audit trails, electronic signatures, and user-access controls. Instrument performance verification follows ASTM E259 practice and CIE Publication 44 guidelines, with factory calibration certified against NIST-traceable reference materials. Routine user verification is supported via the included OJ4 standard, which meets USDA specification for orange juice color reference.

Software & Data Management

The instrument operates standalone but interfaces seamlessly with HunterLab EasyMatch QC software (Windows-compatible) for advanced data analysis, statistical process control (SPC), and report generation. Software features include pass/fail tolerance setting against internal or customer-defined citrus index limits, spectral overlay comparison, batch trending, and export to CSV, PDF, or LIMS-compatible formats. Data logging includes full spectral curves (10 nm intervals), tristimulus values (L*, a*, b*, C*, h°), and all three citrus indices simultaneously. Audit-ready records capture operator ID, timestamp, instrument serial number, calibration status, and environmental metadata—enabling full compliance with FDA, ISO 9001, and HACCP documentation requirements.

Applications

• Quality control of concentrated orange juice (COJ) per USDA Standard Grade requirements
• Batch-to-batch consistency monitoring for grapefruit and lemon juice processing lines
• R&D evaluation of pigment stability during pasteurization, storage, or formulation changes
• Supplier qualification and raw material incoming inspection for citrus-derived ingredients
• Correlation studies between instrumental citrus indices and sensory panel outcomes
• General-purpose reflectance color measurement of non-transparent liquids (e.g., sauces, dairy beverages, plant extracts) using CIE L*a*b*, Hunter Lab, or other industry-standard scales

FAQ

What citrus indices does the ColorFlex EZ Citrus measure?
It calculates Citrus Number (CN), Citrus Red (CR), and Citrus Yellow (CY) in accordance with USDA and AOAC methodology.
Can it measure non-citrus liquids?
Yes—the instrument supports full-spectrum reflectance measurement (400–700 nm) and reports color in CIE L*a*b*, Hunter Lab, and other common scales for any opaque or semi-opaque liquid.
Is the instrument compliant with FDA 21 CFR Part 11?
When used with EasyMatch QC software configured for audit trail and electronic signature, the system meets 21 CFR Part 11 requirements for regulated environments.
How often does it require recalibration?
Factory calibration is stable for 12 months under normal use; daily verification with the included OJ4 standard is recommended before critical measurements.
Does it support network connectivity or LIMS integration?
Yes—via USB or RS-232 interface; EasyMatch QC supports automated data transfer to LIMS using configurable ASCII or XML protocols.