Stability of Sauerkraut Packaged in Plastic Bags ¹

Commercially processed sauerkraut, packaged in plastic bags, was evaluated for product stability following storage at 2, 20, 32 C. When stored at 2 C in the presence of benzoic acid and potassium metabisulfite, the product was stable for more than 8 months, whereas at 20 and 32 C the shelf life was reduced to 20 and 13 weeks, respectively. The reductions in shelf life were due to development of excessive discoloration (browning) and objectionable flavor formation. These defects appear to be caused by chemical rather than microbiological actions. In addition to serving as effective anti-microbial agents, the chemical preservatives (presumably sulfur dioxide) showed protective effects in retarding losses of naturally-occurring ascorbic acid found in sauerkraut. Under similar temperatures of storage, fresh sauerkraut containing no chemical additives had shelf life values of 22, 1.5, and 0.75 weeks, respectively. When stored at 32 and 20 C, the major defects (swollen or broken bags) were attributed to the actions of yeasts. Storage at 2 C markedly arrested and reduced viable yeasts counts, thereby extending the shelf life of the bagged product.