Effect of fermentation and storage on the nutritional value and contents of biologically-active compounds in lacto-fermented white asparagus (Asparagus officinalis L.)

In this study we determined contents of dry matter, ash, total protein, total sugars, lipids, B-group vitamins and vitamin C, polyphenolic compounds, and flavonoids, as well as active acidity, pH value, and antioxidant activity against ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)), DPPH (1,1-Diphenyl-2-picrylhydrazyl radical, 2,2-Diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl) radicals, FRAP (ferric ion reducing antioxidant power) in fresh and lacto-fermented white asparagus stored for 1 and 3 months. In addition, we analyzed the microbiological quality of fermented asparagus. The nutritional value and contents of biologically-active compounds were affected by both the fermentation process and the storage of fermented products. Fermentation had no significant effect on dry matter, total protein and fat contents, but contributed to an increase in ash content and a decrease in total sugars content. Fermentation caused a significant decrease in contents of B-group vitamins, polyphenolic compounds, and dehydroascorbic acid, whereas enhanced ability to reduce iron ions and decreased vitamin content were determined in fermented white asparagus during storage. Fermentation and storage did not affect the radical scavenging ability against DPPH and ABTS nor contents of total polyphenols and total flavonoids.