The influence of certain LAB sourdough fermentation of the Jerusalem artichoke (Helianthus tuberosus L.) tubers on the quality and safety of wheat bread

Abstract

The main focus in this study was to investigate the effects on wheat bread safety and quality due to addition of Jerusalem artichoke (Helianthus tuberosus L.) tubers, fermented by different lactic acid bacteria (LAB) strains that produce bacteriocin-like inhibitory substance (BLIS). For the Jerusalem artichoke (JA) sourdough fermentation several different LAB (Pediococcus acidilactici KTU05-7, Pediococcus pentosaceus KTU05-8, Pediococcus pentosaceus KTU05-9, Lactobacillus sakei KTU05-6, Pediococcus pentosaceus KTU05-10) were used. The mass fraction of fermented or untreated tubers of JA in the wheat bread formula was 15%. We found experimentally that JA tubers fermented with LAB contained more L(+) lactic acid than D(-) lactic acid, which resulted in safer products than by spontaneous treatment. The concentrations of biogenic amines in all analysed fermented JA products were far below levels causing a health risk, while the products fermented with LAB contained lower amounts by 50; 55; 55; 68 and 54 %, respectively. We also found that the proteolytic activity of LAB does not correlate with acrylamide content in bread made with JA additives (R = 0.3683; P = 0.2015), but there was a strong correlation between acrylamide and the sourdough pH (R = 0.8801; P = 0.0056), and with LAB amylase activity excreted in JA material (R = 0.9719; P = 0.003). We conclude that the use of lactic acid fermentation allows wheat bread enrichment with 15 % JA fermented with LAB, without deterioration in bread quality parameters