Identification and Changes in the Viability of Lactic Acid Bacteria in Various Foods according to the Storage Period

Abstract

According to the National Health and Nutrition Examination Survey (KNHANES), the eating habit patterns and perspectives of consumers change according to dietary life changes. Consumers are becoming increasingly interested in healthy and functional foods. The lactic acid bacteria (LAB) and probiotics have health-promoting functions and can facilitate the growth of useful bacteria, inhibit harmful bacteria, and promote smooth bowel movements. This study compared the contents of LAB in various foods, including biscuit, sand, and chocolate, according to the storage period of LABcontaining products and analyzed the predominant LAB at the end of storage. Upon examining the changes in the viability of lactic acid bacteria over a storage period of 7 months, we found that cell viability was maintained at 5.20—9.04 Log CFU/g on MRS agar and 5.60—9.18 Log CFU/g on BCP agar. The results of cross-testing by a certified food safety agency by the MFDS, demonstrated that cell viability was maintained at 5.65—8.34 Log CFU/g; additionally, cross-validation comparison results showed a similarity of 76.0%—100%. This indicated high accuracy of results and maintenance of the constant viability of lactic acid bacteria. The detected lactic acid bacteria in various foods were identified as Lactiplantibacillus (96—100%), Weissella confusa (99%), and Streptococcus thermophiles (99%). The expressed content of LAB on the outer packaging paper of the products was suitable for determining LAB content.