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

Abstract

AbstractThis 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, Rp = 0.71, RMSEP = 1.10 and Rp = 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, Rp = 0.64, RMSEP = 1.21 and Rp = 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.Practical applicationsThe conventional methods for determining lipid oxidation in meat are highly destructive and time‐consuming and require the use of hazardous chemicals. This study evaluated the feasibility of the hyperspectral imaging (HSI) and gas chromatography coupled to ion mobility spectrometry (GC‐IMS) and a mass spectrometry detector to rapidly predict thiobarbituric acid reactive substances (TBARS) and analyze volatile components during lipid oxidation. The HSI was successful in predicting TBARS values as by‐products of oxidation. The results obtained proved that the methods presented can be useful for industries to simultaneously estimate various quality attributes of samples to save time, labor, and cost, which reflects economic importance. Additionally, the recurrence of hexanal during analysis volatile compounds means industries should be mindful of it as it acts as a marker for lipid oxidation in muscle food products. Finally, the topographic plots generated by the GC‐IMS are also very useful for easy differentiation of samples.