Effects of different pickling methods on physicochemical properties and flavor profiles of Tongling white ginger: Dry-salting, brine-pickling, and inoculation-pickling.

Tongling white ginger is a Chinese fermented vegetable with unique flavors. However, little is known about its physicochemical properties, flavor characteristics, and sensory evaluation. The study examined the physicochemical (pH, titratable acidity [TA], nitrite, soluble protein, and color) and flavor characteristics (organic acids, free amino acids, and volatiles) of white ginger during fermentation. The results showed that the pH value and soluble protein in the dry-salted, brine-pickled, and inoculation-pickled decreased significantly while the TA value increased significantly, inoculation-pickled can effectively reduce the content of nitrite. After fermentation, inoculation-pickled produced the highest content of organic acids, while dry-salted produced the highest total amount of free amino acids. A total of 70, 68, 70, and 69 volatile compounds were identified in fresh, dry-salted, brine-pickled, and inoculation-pickled white ginger. The total contents of terpenoids of Tongling white ginger by three fermentation methods decreased; the total contents of alcohols and aldehydes were the highest in brine-pickled, and esters and ketones were more abundant in inoculation-pickled. The results showed that inoculation-pickled could shorten the fermentation time of Tongling white ginger, produce a unique flavor, and have the highest sensory score.