Evaluation of refrigerated storage in nitrogen-enriched atmospheres on the microbial quality, content of bioactive compounds and antioxidant activity of sauerkrauts

- Application of N2 atmospheres during sauerkraut refrigerated storage was studied.
- N2-stored sauerkraut showed better microbial quality than conventionally stored ones.
- N2-storage led to higher antioxidant activity than conventional storage.
- High retention of bioactive compounds were found in N2-stored sauerkrauts.
- N2-stored is a promising approach to improve the quality of sauerkraut.

The aim of this work was to investigate the influence of storage at 4 °C in conventional or nitrogen (N2)-enriched atmospheres for 3 months on the microbial status of sauerkraut obtained by natural fermentation or by Leuconostoc mesenteroides inoculation. The content of vitamin C, glucosinolate derivatives and the antioxidant activity of stored sauerkrauts were also evaluated. Aerobic/anaerobic mesophilic bacteria and lactic acid bacteria populations decreased sharply during N2 storage, whilst they increased during conventional storage. Ascorbigen and vitamin C levels decreased gradually during storage and no significant differences were found between both storage types. The concentration of nitriles and isothiocyanates decreased during storage and, in general, lower content of these compounds were found in N2-stored sauerkrauts. The antioxidant capacity of fermented cabbages was retained after storage at both conditions, and L. mesenteroides sauerkrauts presented significantly higher antioxidant activity at the end of the storage period when N2 atmosphere were used. Thus, the use of N2-atmosphere during refrigerated storage is a promising and cost-effective approach to improve the microbial quality of sauerkraut, and consequently, to extend its shelf-life. Sauerkrauts stored in these conditions had large antioxidant activity and retained high phytochemical concentrations.