Evaluation of lipid oxidation and volatile compounds of traditional dry-cured pork belly: The hyperspectral imaging and multi-gas-sensory approaches

This study examined the feasibility of using hyperspectral imaging (HSI) to predict thiobarbituric acid reactive substances (TBARS) values as by-products of lipid oxidation during traditional processing of dry-cured meat. Using the spectral data of HSI and reference values of TBARS, models based on partial least square regression were tested. Prediction outcomes, R-p = 0.71, RMSEP = 1.10 and R-p = 0.77, RMSEP = 0.97 were obtained after preprocessing with first and second derivatives (second-order polynomial), respectively. Preprocessing with standard normal variate, and multiplicative scatter correction yielded lower values, R-p = 0.64, RMSEP = 1.21 and R-p = 0.52, RMSEP = 1.40, respectively. Results obtained indicated that the HSI was capable of monitoring TBARS values as a lipid oxidation index during meat processing. Volatile fingerprint results for all processing phases were also obtained following analysis by gas chromatography (GC) coupled to ion mobility spectrometry (IMS) and a mass spectrometry (MS) detector. The MS was deployed to provide names and proportions of the volatile components while IMS was used to visualize the topographic maps of the individual volatile components. The GC-IMS proved to be very versatile considering the little time it required to identify the volatile fingerprints of the various samples.