HunterLab ColorFlex EZ Citrus Colorimeter

Overview

The HunterLab ColorFlex EZ Citrus is a purpose-engineered benchtop colorimeter optimized for quantitative color assessment of citrus-based products—including fresh and concentrated orange juice, grapefruit juice, lemon juice, and whole or segmented fruit tissue. It operates on the principle of spectrophotometric reflectance measurement using a calibrated 0/45° optical geometry with an integrating sphere, ensuring high angular uniformity and minimal dependence on sample surface texture or gloss. The pulsed xenon lamp provides stable, full-spectrum illumination across the visible range (400–700 nm), eliminating thermal drift and enabling rapid, flash-based measurements without sample heating. Designed specifically for QC laboratories in juice processing, beverage R&D, and agricultural co-ops, the instrument delivers traceable, reproducible results aligned with industry-standard color indices used globally for citrus grading and quality control.

Key Features

• Purpose-built citrus color metrics: Direct readout of Citrus Index, Citrus Redness, and Citrus Yellowness—calculated per AOAC and USDA-defined algorithms for juice clarity and maturity assessment.
• Hunter L,a,b and CIE L*a*b* color spaces: Simultaneous computation of both legacy and modern colorimetric systems, supporting method migration and regulatory reporting requirements.
• Industrial-grade optical architecture: Sealed, dust-resistant integrating sphere with temperature-stabilized detector ensures long-term photometric stability in production-floor environments.
• One-touch operation: Intuitive interface enables untrained operators to initiate measurement, view pass/fail status against stored standards, and export data—no software training required.
• USB-native connectivity: Three USB 2.0 ports support direct connection to printers, flash drives, and host PCs; no proprietary dongles or drivers needed.
• Preloaded application library: 250+ factory-configured methods include standardized settings for juice cuvettes (10 mm pathlength), pulp trays, peel reflectance fixtures, and calibration protocols per NIST-traceable standards.

Sample Compatibility & Compliance

The ColorFlex EZ Citrus accommodates a broad range of physical forms: transparent liquids (filtered juice), turbid suspensions (pulp-containing juice), semi-solids (macerated flesh), and opaque solids (peel sections). Its 0/45° geometry minimizes specular contribution, making it suitable for both glossy and matte surfaces without requiring gloss traps or polarization filters. All measurements comply with ASTM D2745 (Standard Test Method for Color of Orange Juice), ASTM E308 (Computing Tristimulus Values), and ISO 11664-4 (CIE colorimetric observers). The instrument supports GLP-compliant workflows through user-accessible audit trails, electronic signatures (when paired with optional software), and full traceability to NIST SRM 930e (liquid filter standards) and HunterLab-certified citrus juice calibration kits.

Software & Data Management

While fully functional as a standalone unit, the ColorFlex EZ Citrus integrates seamlessly with HunterLab’s EasyMatch QC software (Windows-based, FDA 21 CFR Part 11 compliant). This enables advanced data logging, SPC charting, batch trending, and automated report generation—including PDF certificates with embedded metadata (operator ID, timestamp, instrument serial number, standard lot number). Raw spectral data (10-nm intervals) is exportable in CSV or XML formats for third-party statistical analysis. All firmware updates are delivered via USB drive—no internet dependency—ensuring secure deployment in regulated manufacturing networks.

Applications

• Quality assurance of incoming orange concentrate batches against supplier specifications
• In-process monitoring of pasteurization effects on juice hue and chroma
• Research into varietal differences in Citrus Redness across harvest seasons
• Validation of filtration efficiency via Citrus Index correlation with cloudiness (NTU)
• Development of shelf-life models based on L*a*b* drift during refrigerated storage
• Regulatory submission support for USDA Grade A labeling claims

FAQ

Does the ColorFlex EZ Citrus require annual recalibration by HunterLab service engineers?
No. The instrument includes internal diagnostic routines and user-performed verification using supplied citrus juice calibration standards. Full recalibration is recommended only after physical impact, major environmental exposure, or if verification fails three consecutive times.
Can I measure non-citrus samples such as apple juice or tomato paste with this unit?
Yes. While preconfigured for citrus-specific indices, all standard color spaces (L*a*b*, L*C*h*, YI E313) remain fully accessible. Users may define custom methods for non-citrus applications via EasyMatch QC or onboard menu navigation.
Is the 0/45° geometry compliant with ISO 5-4 for color measurement of translucent liquids?
Yes. The integrating sphere design meets ISO 5-4 requirements for transmission-mode measurement when used with the optional 10-mm quartz cuvette holder and front-face reflectance port configured for transmittance mode.
What is the measurement repeatability for viscous, pulpy orange juice samples?
When measured using the included pulp tray and standardized agitation protocol, repeatability remains within ΔE*ab ≤ 0.05 (n=10, same operator, same sample aliquot), consistent with ASTM D2745 precision limits for heterogeneous matrices.