Naturally occurring propionic acid in foods marketed in South Korea

Propionic acid levels in fermented products, non-fermented products and foodstuffs, and medicinal herbs were analyzed total 263 samples retailed in Korean market. Propionic acid was detected in some Korean traditional fermented products such as salted and fermented fish sauce, Chunggukjang and salted and fermented fish. A small amount of propionic acid was also detected in fermented soybean paste, soy sauce, seasoned soybean paste, vinegar and fermented milk. Significantly, propionic acid in vinegar showed high levels among fermented products (P<0.05). Among non-fermented products and foodstuffs, propionic acid in shellfish showed high level, while propionic acid was not detected in cereal and sauce. A statistically significant difference was shown in propionic acid levels of shellfish. propionic acid in brackish water clam showed significantly higher levels than that of others. Ark shell and scallop also showed high levels in propionic acid. Among 10 kinds of medicinal herbs, propionic acid was detected in 3 samples (Lycium chinensis Miller, Astragali radix and Atractylodes rhizoma).