Assessment of woody breast in broiler breast fillets using structured-illumination reflectance imaging coupled with surface profilometry

Abstract

Woody breast (WB) myopathy impairs the quality and marketability of poultry products, leading to significant economic losses for poultry industries worldwide due to product downgrading and consumer complaints. WB-affected broiler breast fillets are characterized by abnormal tissue hardness, muscle rigidity, and irregular shape. Manual evaluation based on tactile palpation and visual examination is the current practice for WB assessment at poultry processing facilities, but it is subjective, labor-intensive, and may induce contamination. Structured-illumination reflectance imaging (SIRI), which is capable of depth-resolved tissue characterization and three-dimensional sample topography, has emerged a potential means for poultry defect detection, as opposed to conventional uniform illumination-based imaging. This study presents a novel effort to assess WB in broiler meat using SIRI coupled with phase-measuring profilometry. An in-house assembled, broadband SIRI platform with phase-shifted sinusoidal illumination patterns at different spatial frequencies was used to acquire images from normal and WB-affected boneless chicken fillets. Acquired pattern images at each spatial frequency were demodulated into 1) one phase difference image that depicts sample surface geometry and 2) two intensity images [i.e., direct component (DC) and amplitude component (AC)]. Hand-crafted geometric and textural features were extracted from the phase difference and intensity images respectively, and used for differentiating between normal and WB-affected samples by regularized linear discriminant analysis models. The features from the phase difference images were more effective than the texture features from either DC or AC images, and the highest overall classification accuracy of nearly 93% was achieved by modeling an optimized set of features from the phase difference images, representing improvements of about 8%–11% over the accuracy obtained using the features from DC and AC images. This study demonstrated the effectiveness of sample surface topographic profiles, revealed by the phase difference images, for WB assessment. SIRI coupled with surface profilometry offers a useful tool for WB assessment of broiler breast meat. The dataset of this study has been made publicly available¹ to enourage the research into SIRI for poultry quality assessment.