Prolamin Hydrolysis and Pentosan Solubilization in Germinated-Rye Sourdoughs Determined by Chromatographic and Immunological Methods

Abstract

The assortment and quality of bakery products designed for celiac patients may be improved by designing whole grain ingredients with low residual prolamin contents. The main objective of this study was to evaluate the extent of prolamin hydrolysis and pentosan solubilization in germinated-rye sourdoughs (GRSDs). Size-exclusion chromatography analyses, the fate of fluorescent prolamin, and immunological analyses determined the extent of prolamin hydrolysis and pentosan solubilization. Hydrolysis of rye prolamins was extensive in GRSDs, and according to enzyme-linked immunosorbent assay analyses, more than 99.5% of the prolamins were hydrolyzed. Pentosan solubilization occurred in native-rye sourdoughs, whereas in GRSDs, pentosans were partially hydrolyzed to monosaccharides. Test baking showed that the use of GRSD improved the overall quality of oat bread and that an estimated daily gluten intake from 100 g of bread would be less than 10 mg. However, the clinical safety must be assured before making any recommendations for celiac patients to use such products.

A Grounded Guide to Gluten: How Modern Genotypes and Processing Impact Wheat Sensitivity

“…Prolonged incubation of wheat and durum fully degraded gliadins (Bigiarini and others ; Stenman and others ; Schwalb and others ). Germinated and fermented rye and wheat sourdough effectively degraded 99.5% and 95% of prolamins, respectively (Loponen and others , ). Specifically, the toxic 12‐mer of α‐gliadin QLQPFPQPQLPY was hydrolyzed in gliadin treated with germination enzymes (Stenman and others , ).…”

“…As a positive marketing aspect, germinated grain can improve flavor. Loponen and others () reported that rye sourdough made from germinated grain had enhanced flavor compared to bread made from nongerminated grain.…”

Oat protein solubility and emulsion properties improved by enzymatic deamidation

“…The oat protein samples were analyzed with SE-HPLC as described by Loponen et al (2009) with modifications. The oat protein samples were extracted 1:100 by 1.5% SDS, 50 mM sodium phosphate, pH 6.9 buffer, at 50 C overnight and then centrifuged at room temperature (10 min, 10 000 Â g).…”

Malt hydrolysates for gluten-free applications: Autolytic and proline endopeptidase assisted removal of prolamins from wheat, barley and rye

“…Previously, we showed that sourdough fermentation conditions are very favourable for the germination-induced enzymes to hydrolyse the prolamins. More specifically, we noted that 95% of the wheat and 99.5% of the rye prolamins degraded under sourdough conditions when enzyme active malts were used as raw materials (Loponen et al, 2007(Loponen et al, , 2009.…”