ZHAN Yishu, WU Zhiliang, HE Shengsheng, TONG Qiuxia, LIU Yuxuan, JIANG Yuji
This study investigated the changes in water content, water activity, pH, color, texture, total acidity, glucose, fructose, amino acids, and volatile flavor compounds of pickled Shanghang dried radish for 1, 2, 3, 4, 5, 6, 8, and 10 years.Results showed that water activity, water content, and pH of Shanghang dried radish continuously decreased during different storage years.Significant decreases were observed in L* value (lightness), b* value (yellowness), hardness, chewiness, and springiness, while a* value (redness) increased.Correlation analysis indicated positive correlations between water activity/moisture content/pH and L* value, b* value, hardness, chewiness, and springiness, but negative correlations with a*value.Changes in total acidity, glucose, and fructose content were not statistically significant.The total content of aromatic amino acids and bitter amino acids decreased, while the levels of sweet amino acids and umami amino acids remained relatively stable.A total of 46, 52, 53, 52, 49, 46, 41, and 39 volatile flavor compounds were detected in samples stored for 1 to 10 years, respectively.These compounds included alcohols, acids, esters, aldehydes, ketones, sulfur-containing compounds, and others.The diversity and concentration of volatile compounds were relatively higher between the 3rd and 5th years of storage, but subsequently decreased with prolonged storage.The overall flavor profile evolved from initially being dominated by pungency, spiciness, and fresh floral/fruity notes, transitioning towards roasted and mellow characteristics, and finally shifting towards caramel, nutty, and earthy/soil-like odors in the later stages.In conclusion, maintaining appropriate moisture content and pH is crucial during the long-term storage of pickled Shanghang dried radish to preserve desirable color and texture.Additionally, storage duration should be carefully controlled to prevent the development of undesirable off-flavors in the later stages.