Behaviour of oat globulins in lactic acid fermentation of oat bran

• Published in: European food research & technology Vol. 225; no. 1; pp. 105 - 110
• Main Authors: LOPONEN, Jussi, LAINE, Pia, SONTAG-STROHM, Thula, SALOVAARA, Hannu
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.05.2007; Berlin Springer Nature B.V
• Subjects: Acidification; Biological and medical sciences; Buffers; Cereal and baking product industries; Dietary fiber; Extraction procedures; Fermentation; Food industries; Fundamental and applied biological sciences. Psychology; Gel electrophoresis; Globulins; Hydrolysis; Lactic acid; Lowry assay; Milk free; Oat bran; Oats; Probiotics; Product design; Protein interaction; Proteins; Sodium chloride; Sodium lauryl sulfate; Solubility; Cereal bran; Oat bran· Lactic acid fermentation· Globulin; Oat; Lactic fermentation; Cereal product; Solubility; Cereal; Lactic acid; Protein solubility; Globulin; Protein
• ISSN: 1438-2377; 1438-2385
• DOI: 10.1007/S00217-006-0387-9

Oat bran fermentation (OBF) is used to produce non-dairy yogurt-type products. Such products may be designed being rich in probiotic bacteria and/or dietary-fibre. Oat bran is, however, also rich in proteins, especially 12 S globulins. Understanding the behaviour of globulins in OBF would thus offer a basis for further exploitation of proteins in the product design. The behaviour of oat globulins was monitored during a model OBF in order to study changes in protein solubility and possible protein hydrolysis. Proteins were extracted from OBF samples with a buffered and a non-buffered extraction procedure. The extracts were analyzed with SDS-PAGE and a Lowry assay. Combined effect of pH and NaCl-concentration on the solubility of oat globulin isolate was studied. The solubility of oat globulins decreased during OBF; this appeared as their shift from the salt-soluble fraction to the residual protein fraction. The shift in oat globulin solubility was due to the acidifying conditions present in OBF, which lead to the unfolding of globulins and also apparently induced protein aggregation. No major protein hydrolysis was observed during OBF.