SOURDOUGH ON QUINOA AND BUCKWHEAT GLUTEN FREE BREADS: EFFECT ON BREAD NUTRITIONAL AND TECHNOLOGICAL PROPERTIES

LANCETTI, R; SALVUCCI, E; PEREZ, G; SCIARINI, L

Congreso; LVII SAIB Meeting - XVI SAMIGE Meeting; 2021

SAMIGE-SAIB

Gluten-free (GF) breads usually show low loaf volume, firm crumb, and low protein, fibre and mineral contents. Different flour sources are permanently under research to overcome these problems. In this work we used quinoa (Q) and buckwheat (BW) wholemeal flours since they produce breads with higher protein and fibre contents. The use of sourdough (SD) has some nutritional and technological benefits. The aim of this work was to evaluate the effect of two autochthonous LAB strains as sourdough starters on GF bread technological quality and in vitro digestibility and antioxidant activity. Two strains of Lactobacillus fermentum isolated from buckwheat (T5) and quinoa (Q3) flours were used. Lactobacillus plantarum ATCC 8014 was used as a reference starter culture. Sourdoughs were prepared from wholemeal Q or BW flours (DY 200). A strain inoculum of 10x8 CFU/g of each lactic acid bacterium (Q3, T5 and 8014) was added. Two controls were considered: one consisting in flour:water mixture (DY 200) without inoculum and fermented at 30 °C, and another dough chemically acidified to pH of 3.5. Bread formulation included a basic flour mixture of 75g refined rice flour, 15g whole grain quinoa, 15g whole grain buckwheat flour; 95% water, 2% salt, 3% compressed yeast, 2% shortening, 0.01% leavening agent, 0.5% SSL and 2% CMC (% flour basis). Breads technological properties were assessed by means of specific bread volume -SBV- (rapeseed displacement method), crumb structure (image analysis), crumb firming and firming rate (texturometer). Free-polyphenols contents and antioxidant activity (Folin, FRAP and ABTS) were measured, and starch in vitro digestibility and dialyzability were also evaluated. SBV ranged between 2.62 cm3/g to 2.73 cm3/g for Q-SD breads, and between 2.61 cm3/g to 2.75 cm3/g for BW-SD breads. SD decreased crumb firmness and firming rate compared to the control and chemically acidified (ChA) breads. Q-SD had overall higher quality than BW-SD breads, shown by a soft, well aerated crumb, with an open crumb structure and larger air area. Q breads showed higher polyphenols (as determined by Folin method) and FRAP values, whereas BW breads had significantly higher ABTS values (p