Effect of Inoculated Lactic Acid Fermentation on the Fermentable Saccharides and Polyols, Polyphenols and Antioxidant Activity Changes in Wheat Sourdough.

Ewa Pejcz,Agata Wojciechowicz-Budzisz,Sabina Lachowicz-Wiśniewska,Zygmunt Gil,Radosław Spychaj,Paulina Nowicka

doi:10.3390/molecules26144193

Abstract

Inoculation of sourdough allows the fermentation medium to be dominated by desired microorganisms, which enables determining the kinetics of the conversion of chemical compounds by individual microorganisms. This knowledge may allow the design of functional food products with health features dedicated to consumers with special needs. The aim of the study was to assess the dynamics of transformations of fermentable oligosaccharide, disaccharide, monosaccharide and polyol (FODMAP) compounds from wheat flour as well as their antioxidant activity during inoculated and spontaneous sourdough fermentation. The FODMAP content in grain products was determined by the fructan content with negligible amounts of sugars and polyols. To produce a low-FODMAP cereal product, the fermentation time is essential. The 72 h fermentation time of L. plantarum-inoculated sourdough reduced the FODMAP content by 91%. The sourdough fermentation time of at least 72 h also positively influenced the content of polyphenols and antioxidant activity, regardless of the type of fermentation. The inoculation of both L. plantarum and L. casei contributed to a similar degree to the reduction in FODMAP in sourdough compared to spontaneous fermentation.

Highlights

Sourdough is traditionally prepared by mixing flour with water, and subjecting this mixture to a multi-stage spontaneous fermentation, which is carried out by exogenous flour microflora, including mainly 104–107 CFU/g of bacteria and yeast [1]
Sourdough fermentation allows the fermentation medium to be dominated by desired microorganisms, which enables determining the kinetics of the conversion of chemical compounds of flour by individual microorganisms, and their targeted selection [5]
A further slight decrease in pH was observed in L. plantarum-inoculated sourdough when the fermentation time was extended to 72 h

Summary

Introduction

Sourdough is traditionally prepared by mixing flour with water, and subjecting this mixture to a multi-stage spontaneous fermentation, which is carried out by exogenous flour microflora, including mainly 104–107 CFU/g of bacteria and yeast [1]. A group of lactic acid bacteria (LAB) plays a key role in these processes and has a long and safe history of use and consumption in fermented foods and beverages [2]. Another solution is to inoculate fermented products, including bakery sourdoughs, with pure cultures of bacteria or yeast proliferated to a desired number of colony-forming units [3,4]. FODMAPs are fermentable, highly osmotic carbohydrates, including fructooligosaccharides (FOSs), galactooligosaccharides (GOSs), lactose, fructose and polyols (notably sorbitol and mannitol) [6,7,8]

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