The effects of wheat variety, sourdough treatment and sourdough level on nutritional characteristics of whole wheat bread

This study aimed to investigate the effects of wheat variety (Tosunbey, Kenanbey, İkizce-96, Bezostaja-1), sourdough treatment (Lactiplantibacillus plantarum (LP), Fructilactobacillus sanfranciscensis (LS), Spontaneous fermentation (SP)), and sourdough level (0-10-20-30%) on phytic acid, dietary fiber, phenolic content and antioxidant activity of whole wheat bread. The whole wheat breads of Kenanbey and Bezostaja-1 had the lowest and highest phytic acid content (326 mg/100g and 449 mg/100g), respectively. Among the sourdough treatments, LS had the lowest (359 mg/100g) and SP had the highest (435 mg/100g) phytic acid content. While the phytic acid content was 463 mg/100g at %0 sourdough level, it was 329 mg/100g at 30% sourdough. The whole wheat bread of Bezostaja-1 had the highest total dietary fiber content (15.94%). The soluble dietary fiber content was higher in LP and LS treatments (2.47 and 2.50%), but there was no significant difference between the two (p > 0.05). The sourdough treatments had no significant effect on total phenolic content and total antioxidant activity (p > 0.05). However, the free phenolic content and free antioxidant activity of the breads produced with LP (703.1 mg GAE/kg and 177.4 μmol TE/100g) and LS (705.4 mg GAE/kg and 178.8 μmol TE/100g) were higher than SP (691.0 mg GAE/kg and 175.5 μmol TE/100g). The results indicated that all of the investigated factors had significant effects on phytic acid, soluble dietary fiber, free phenolic content and free antioxidant activity. It can be concluded that the nutritional characteristics of whole wheat bread can be improved using lactic starters and 30% sourdough.