Application of omija (Schiandra chinensis) and plum (Prunus mume) extracts for the improvement of Kimchi quality

The objective of this study was to investigate the effects of omija (Schiandra chinensis) and plum (Prunus mume) extracts on the fermentation and quality of Kimchi, especially with regard to extending its shelf-life. With the addition of omija and plum extracts, the final pH of Kimchi achieved levels of 4.18 (0.5% addition of omija extract: O-1), 4.36 (1.0% addition of omija extract: O-2), 4.33 (0.5% omija + 1.0% plum extract: O/P-1), and 4.33 (0.5% omija + 2.0% plum extract: O/P-2), respectively, which were higher than that of the Kimchi without extracts, 3.92, after 24 days of fermentation. The addition of the extracts caused a slight increase in titratable acidity and the growth of lactic acid bacteria as compared with the samples with no addition. Treatment O-2 showed a more profound inhibition effect on the growth of six strains, Leuconostoc mesenteroides, Lactobacillus plantarum, Weissella koreensis, Leuconostoc citreum, Klebsiella pneumoniae and Pichia membranifaciens than the use of O/P-1 and O/P-2. Bitterness was increased with increase in the amount of omija extract. As for the evaluation of overall taste, the addition of the plum extract to omija extract induced a reduction in the bitterness of the Kimchi. Therefore, the addition of both plum and omija extracts appears to be an acceptable approach to enhance the quality of Kimchi without reducing acceptability.