Insights into the mechanism of Penicillium inoculation on microbial succession, volatile compound evolutions and sensory development of Jinhua ham

Abstract

SummaryTo investigate the mechanism of Penicillium inoculation on the flavour improvement of Jinhua ham, the microbial succession, free amino acid contents, volatile compound evolutions, sensory attributes and the relationship between key volatiles and sensory properties were investigated during the processing of Jinhua ham with P. aethiopicum (PA) or P. chrysogenum (PC) inoculation. The total counts of fungal communities in CK, PA and PC groups significantly increased from 2.74 log CFU*g−1 of raw ham to 5.18, 5.39 and 5.50 log CFU*g−1 from day 0 to day 28, and then decreased by 2.06, 1.94 and 1.86 log CFU*g−1 from day 28 to the final products (P < 0.001). The total contents of free amino acids significantly increased from 1584.22 mg/100 g of CK to 2117.20 mg/100 g of PA and 2174.05 mg/100 g of PC (P < 0.01); the contents of alanine, glutamic acid, lysine, valine, leucine and phenylalanine in PC were significantly higher than those of CK and PA (P < 0.05). Sensory scores of meaty aroma, nutty aroma and overall acceptance showed the largest values in PC among three groups. GC–MS results indicated that aromatic aldehydes and pyrazines in PC showed the largest increase, compared with CK and PA groups. PLS‐DA and correlation analysis demonstrated that benzaldehyde, benzeneacetaldehyde and 2,5‐dimethyl pyrazine contributed to the improvement of aroma attributes of Jinhua ham with Penicillium inoculation. The KEGG analysis further revealed that the metabolism of valine and phenylalanine was mainly involved in developing aromatic aldehydes and pyrazines of Jinhua ham with Penicillium inoculation. These results indicated that the inoculation of Penicillium could enhance the flavour quality of Jinhua ham.