Microwave heating and conduction heating pork belly: Non-volatile compounds and their correlation with taste characteristics, heat transfer modes, and matrix microstructure

This study investigated the difference in the taste characteristics of pork belly cooked by traditional pan-heating (TH), microwave heating (MH), and microwave combined with conduction heating (MH + CH). The results showed that MH destroyed the microstructure integrity and made the cooking loss (50.33%) and sodium ion concentration (10.8 mg/g) about 1.6 times that of MH + CH, thereby enhancing the saltiness. In addition, compared with TH, microwave heating could accelerate the hydrolysis of proteins and the thermal degradation of ribonucleotides, resulting in higher contents of free amino acids (880.71 and 714.85 mg/100 g) and nucleotides (181.41 and 145.52 mg/100 g) in MH and MH + CH. Combined with the results of non-volatile compounds and sensory evaluation, the MH + CH not only promoted the accumulation but also improved the dissolution uniformity of taste compounds, which enhanced the sensory umami. The inconsistency between non-volatile compounds, electronic tongue, and sensory evaluation indicated that the matrix effects caused by cooking also had significant influences on the taste quality of solid samples.