Profiles of flavor substances from sourdough fermented with Lactobacillus paralimentarius 412

The profiles of flavor substances in sourdough cultured with Lactobacillus paralimentarius 412 isolated from traditional fermented dough were analyzed using high performance liquid chromatography (HPLC) and gas chromatography mass spectrometry (GC-MS) after various carbohydrates (maltose, mannose and glucose) and enzymes (amylase, protease and lipase) were added to dough incubated at 30℃ for 12h.The contents of organic acids, calculated as lactic acid, in sourdoughs fermented with L.paralimentarius 412 depended on added carbohydrates.Addition of mannose to dough produced the most organic acids, with a level of 0.371g/L in 12h-incubated sourdoughs.An increased of mannose to 4g/100g leaded the fermented dough to have an increased organic acid content.Meanwhile, adding lipase to dough leaded to the highest organic acid with a level of 0.421g/L in 12h-incubated sourdough.18 volatile compounds were identified in the sourdough fermented with L.paralimentarius 412, including esters, carbonyls, alcohols, acids and heterocyclic compounds.The volatile compounds in L.paralimentarius 412-fermented sourdoughs depended on added carbohydrates.25 compounds were detected in sourdough prepared with mannose, and the levels of these volatile compounds increased as the increased mannose to the dough.Moreover, addition of protease, compared to amylase and lipase, contributed more flavor (23 volatile compounds) to sourdoughs fermented with L.paralimentarius 412.