Exploitation of sourdough lactic acid bacteria to reduce raffinose family oligosaccharides (RFOs) content in breads enriched with chickpea flour

Abstract

Wheat baked goods fortification with chickpea flour can improve their overall nutritional quality. However, some antinutritional factors, such as raffinose family oligosaccharides (RFOs), of this legume limit its supplementation in bread. The reduction of some of these drawbacks can be achieved using sourdough technology. Therefore, the aim of this study was to obtain a sourdough bread possessing the beneficial effect of chickpea flour addition together with a reduced content of RFOs, thanks to the activity of selected lactic acid bacteria. Sixty sourdough lactobacilli were screened for the capability of growing in a medium with raffinose as unique carbohydrates source. The most promising strains were inoculated in liquid chickpea sourdoughs. Lactobacillus plantarum M8 decreased up to 63.22% the initial amount of RFOs hence it was selected for the manufacture of wheat breads with different percentage of pre-fermented chickpea flour (0, 5, 10 and 20% on total flour). Chickpea flour addition significantly (p > 0.05) increased free amino acids, lysine and total phenolic content of breads compared to a control bread made only with wheat flour. Furthermore, RFOs total amount decreased in breads with increased percentage of pre-fermented chickpea flour in the recipe, confirming the ability of the selected L. plantarum M8 strain to reduce RFOs.