230: Standardization Procedures in Instrumental Color Assessment of Beef Through Aerobic and Anaerobic Packaging Materials

Introduction

Instrumental color measurement of meat presents challenges concerning if scans should be standardized and taken through packaging materials. Discrepancies in measurement and standardization practices may result in compromised internal and external validity.

Methods

Treatments consisted of independent batches (n=3) of ground beef prepared as replicates. Patties (n=3) were packaged in 0.35 mil polyvinyl chloride film (aerobic) or 3 mil laminate vacuum bags (anaerobic). Three scans per patty were taken on days 1, 3, 5, and 7 using a HunterLab MiniScan EZ 4500L Colorimeter with illuminant A, 10°observer angle, 31.8 mm port size, and 25 mm viewed area. Prior to measurement, the colorimeter was standardized with the black glass and white tile either with (A) or without (B) the respective packaging material. Following this, patties were removed from the packaging and scanned directly on the meat surface using standardization procedure B to serve as the respective controls (CON) within each system. Data for aerobic and anaerobic systems were analyzed independently using a linear mixed model.

Results

Within aerobic, standardization with packaging (A) resulted in decreased CIE a*, CIE b*, and chroma values on days 1, 3, and 5, while standardizing without packaging (B) resulted in similar color attributes to CON throughout storage. Procedure A resulted in greater ΔE (total color change) from days 1 to 7 than B and CON within aerobic. Further, A had depressed reflectance at low wavelengths (400-440 nm) than CON. For anaerobic, B resulted in decreased CIE a*, CIE b*, and chroma to A and CON throughout storage, while A had increased values over CON on days 3, 5, and 7. The PCA plot prepared using CIELAB color space showed CON clustered equidistant between A and B. For reflectance, A clustered distinct from B and CON due to A showing negligible reflectance at short wavelengths.

Significance

Standardization procedures and measuring through packaging affect CIELAB color and reflectance of ground beef. For aerobic systems, if scanning through packaging, B appears more representative of measuring without packaging (CON) for CIELAB attributes than A. Similarly, for anaerobic, B may be advantageous for closer reflectance at low wavelengths to CON.

Authors: Gracyn Rongey, Jacob R. Tuell