اثرات متقابل باكتري هاي لاكتيك اسيد و مخمر نانوايي در تخمير خمير ترش مايع

Interaction between lactic acid bacteria and bakerʹs yeast in liquid sourdough fermentation

Background and objective: Sourdough fermentation. with interactions between lactic acid bacteria and yeasts. is considered to playa key role in producing bakery products with improved flavor, texture and shelf-life properties. This research focused on evaluation of acidification properties of different starter cultures in liquid sourdough fermentation and selecting an appropriate inoculum hased on quality and shelf-life properties of the resultant bread. Material and methods: Liquid sourdough samples were fermented by cultures including L.casei and Siccrevisiae (T Il. Lfermentum and Sʹcerevisiae (T2). Lcasei, Lfermentum and S.cerevisiae (T3) and addc to bread doughs (l5ʹ)!o w/w). Technological properties (moisture content. specific volume and organoleptic properties) and slielf-Iife of the sourdough breads were compared with those of a control bread. Results: Sourdoughs fermented by inoeulums TI and T3 had a similar pH-lowering rate (there were only small differences). Inoculum T3 showed tile highest acidification rate. In comparison. inoculum T2 showed a lower acidification rate (pH> 4). Liquid sourdough breads had higher specific volumes as compared to the control bread. and sourdough bread T3 ranked first organoleptically. Sourdough breads (TI and T3) had a lower staling rate than the control value. and bread T3 showed a highcr staling rate than T I (p< 0.(5). Conclusion: Sourdough addition can improve organoleptic properties-specific volume and shelflife of the breads.. Based on acidification properties and sensory analysis, inoculum Licasei, Ljʹ".,l1entllll1 and S.cercvis;ae produce the most desirable effects.