Lightweight portable nondestructivedetection technique for assessing meat freshness attributes based on light emitting diode array

摘要

Freshness of meat directly affects the economic benefits and vital interests of people. Meat color (L*, a* b*), and pH value are important reference attributes for evaluating meat freshness. This paper attempts to measure meat color and pH value in pork meat using a new self-designedportable and low cost detection device. The device was composed of Light Emitting Diode (LED) arrays with six different wavelengths 460, 525, 570, 590, 610, 630nm forming a ring light source, the silicon photodiode as detector was embedded in the center of light source and its spectral response range was 400nm-1100nm to receive diffuse light from pork meat surface, at the same time stabilized current supply circuit to provide a stable power supply for each LED light source, signal processing circuit to complete signal A/D conversion, data sample and data transmission functions. The control of all circuits based on a single chip computer development board P89C51RD2HBP were basically designed to supply, steady voltage andcurrent for the LED arrays and various protective, and control functions for their smooth operation. 42 pork samples with different freshness attributes were collected for data acquisition. Multiple Linear Regression (MLR) mathematical method was employed to build pork color content prediction model. The samples were divided into calibration and validation sets according to the proportion of 3:1 to achieve more reasonable prediction results. The correlation coefficients of validation (RV)for predictionof pork color (L* a* b*) and pH value were 0.9201, 0.8967, 0.8081, 0.6480 respectively. Compared with other spectral detection technique, the developed device has its own superiority such as simplicity in structure, convenient to use, small in size andlow cost. This studydemonstrates that it has the potential in nondestructive detection ofpork freshness attributes including color parameters(L*, a* b*) and pH value using LED arrays detection methods.lt also can significantly improve pork meat freshnessprediction performance in the future.