Influence of Distance between Optical Fiber Probe and Sample on Pork Quality Detection Results

Abstract. Pork meat is highly consumed meat item in China. However, the quality of pork meat thatincludes the freshness, color, tenderness effects the purchasing decision by the consumer. Optical technology is gaining its popularity in research and meat industry for real time, non-invasive and rapiddetection of pork meat quality. However, small error during operation of optical instrument can affect the detection stability. The distance between optical probe and meat sample (DOS) is one of the important aspects toconsider while developing prediction model as well as during operation of the optical instrument. This study was focused to observe the reflectivity change rule at dorsal muscle at different DOS. VIS/NIR spectroscopy in the range of 400-1100 nm was used to collect spectral data from 32 pork dorsal muscles at different DOS (0.2-10mm range). The reflectivity of different DOS at wavelengths 490, 550, 580 and 620 nm was curve fitted using cubic function and exponential function.Results showed that the correlations coefficients inthe calibration set (R c ) and prediction set (R p ) were achieved as follows: R c = 0.98 and R p = 0.97 forcubic function; R c = 0.97 and R p = 0.96 for exponential function. Thus cubic polynomial model and exponential model can predict sample reflectivity in different DOS, which provides theoretical basis for online meat quality detection.