Effect of Fermentation Temperature on Co-fermented sourdough properties and bread quality

• 1、School of Food Science and Technology, Jiangnan University, Wuxi 214122

Abstract：In this study, yeast isolates from Chinese liquor Daqu and Lactobacilli sanfranciscens were used as mixed starter cultures on sourdough bread making. Sourdough fermented with L. sanfranciscensis and chemically acidified sourdough were prepared as controls. The sourdough properties and bread quality were compared at three different fermentation temperatures (10℃, 20℃ and 30℃). The results showed that the mixed culture fermented sourdough had higher acidification effect, as well as the higher content of reducing sugar and total amino acids. More kinds of volatile aroma compounds were detected in the sourdough bread crumb fermented with mixed cultures. At lower fermentation temperature (10℃, 20℃), the content of total amino acids in sourdough were higher than that at 30℃. What’s more, the low fermentation temperature was benefit to the production and accumulation of alcohols, aldehydes, and esters. Specific volatiles such as 1-heptanol, 1-octen-3-ol, 3-ethoxy-1-propanol, 2-pentanone, benzene acetaldehyde, propyl lactate, isoamyl lactate, 2-hydroxy propanoate, ethyl 2-hydroxy propanoate, 3-methyl-1-butanyl acetate, 3-ethyl-cyclobutanol et al. were detected in the mixed culture fermented sourdough bread. The sensory evaluation results showed that the bread made with low-temperature and long-time fermented sourdough had better quality and preferred by consumers.

Keywords： Co-fermentation Aroma producing yeast Lactobacillus sanfranciscensis Low temperature fermentation Sourdough Bread quality