Enzymatic and microbial conversions to achieve sugar reduction in bread

Abstract

A standard level of sugar addition to bread is 2% (flour base) but sweet baked goods including hamburger buns, hot dog buns and some sandwich bread contain more than 10% sucrose. This study aimed to provide an integrated assessment of different strategies for sugar-reduced bread by using isomaltooligosaccharides (IMO) as bulk sweetening agent, polysaccharide hydrolases to generate sugars from flour polysaccharides, and sourdough. Trained panel sensory analyses of the intensity of sour and sweet tastes were compared to the concentration of organic acids and the sugar concentration of bread. Sourdough fermentation reduced the sweet taste intensity of bread produced with 9% sucrose. This effect was more pronounced with Leuconostoc mesenteroides, which converts fructose to mannitol with concomitant production of acetate. Addition of up to 20% sourdough fermented with Weissella cibaria 10 M, which does not produce mannitol and less acetate when compared to L. mesenteroides, did not substantially reduce the sweet taste intensity. Bread produced with 9% IMO tasted less sweet than bread prepared with 9% sucrose but partial replacement of sucrose with IMO maintained the sweet taste intensity. Addition of 4.5% IMO in combination with W. cibaria sourdough, amyloglucosidase and the fructosidase FruA enabled production of bread with 50% reduced sucrose addition while maintaining the sweet taste intensity. In conclusion, the single use of a sweet bulking agent, of amyloglucosidase or fructanases or the use of sourdough alone, did not maintain the sweet taste intensity of sugar-reduced bread, however, a combination of the three approaches allowed a reduction of sucrose addition without reducing the sweet taste intensity.