Effect of Nitric Oxide on Improving Chilled Pork Quality Based on OPLS-DA and Entropy-Weight Topsis Method

This study applied short-term nitric oxide (NO) modified atmosphere treatment to improve the color, extend the shelf life, and enhance the overall quality of chilled pork. Based on the results of single factor experiments involving gas flow rate, NO concentration, and processing time, orthogonal partial least squares-discriminant analysis (OPLS-DA), principal component analysis (PCA), and Pearson correlation analysis were applied to select redness value (a^*), storage loss, hardness, and volatile basic nitrogen (VBN) content as indicators for comprehensive quality evaluation of chilled pork, which were used, together with sensory evaluation score to establish a comprehensive quality evaluation system. The entropy weight-Topsis method was used to develop an evaluation model as follows: Y = 0.145 × a^* + 0.113 × storage loss + 0.112 × hardness + 0.130 × VBN content + 0.500 × sensory score. Using response surface methodology (RSM), the optimal processing conditions were determined as 1.10 m/s, 117 µL/L and 41 min for gas flow rate, NO concentration and treatment time, respectively. Under the optimized conditions, the total bacterial number and VBN content in chilled pork were decreased, the content of nitrosomyoglobin was increased. This study has provided a feasible solution to improve the quality of chilled pork and also presented a comprehensive evaluation model for its quality.