Abstract:

When mixing dough of Mantou, 20% Laomiantuan fermented by Saccharomyces cerevisiae (CGMCC 2.0562) and/ or Lactobacillus brevis (CGMCC 1.0579) was added in dough. The pH, total acidity and soluble sugars were determined to explore the growth and metabolism characteristics of microorganisms during dough fermentation of Laomian Mantou. Soluble sugars including maltose, sucrose, fructose and glucose were determined using high performance liquid chromatography (HPLC) with evaporative light scattering detector (ELSD). The detection conditions were as follows: mobile phase, acetonitrile/water mixture (70:30, V/V); flow rate 1.0 mL/min; column temperature, 25 ℃; ELSD drift tube temperature, 83.5 ℃; and flow rate of carrier gas, 2.2 L/min. Compared with the control group, the samples with the addition of Laomian exhibited a lower pH and higher total acidity, especially the samples with addition of Laomian derived solely from Lactobacillus brevis (CGMCC 1.0579). The contents of soluble sugars and corresponding change trend differed in different samples with the addition of different Laomian starters during the fermentation. Therefore, acid-producing metabolism and soluble sugar content during the fermentation of dough may affect the quality of Mantou.

Key words: Mantou dough, yeast, lactic acid bacteria, high performance liquid chromatography with evaporative light scattering detector (HPLC-ELSD), soluble sugars