Jean Titze

Fibre, protein and mineral fortification of wheat bread through milled and fermented brewer’s spent grain enrichment

Brewer’s spent grain (BSG) represents 85xa0% of brewing industry by-products. Currently, BSG is underutilised as low-value animal fodder. The current study aims to expose additional nutritional and economic benefits of BSG as a food ingredient in wheat breads. The raw material properties were studied revealing that BSG by-product contains (on a w/w) 22.13xa0% protein (including exceptionally high levels of essential amino acids), 1.13xa0% minerals, 131.0xa0mg/L polyphenols, 28.22xa0% total fibre and 3.6xa0% essential fatty acids. Additionally, BSG was fermented (BSG SD), using the lactic acid bacteria, Lactobacillus plantarum FST 1.7, to elucidate the benefits of traditional sourdough for processing crude BSG. Fermentation resulted in softer breads with increased springiness. Farinograph results revealed that wheat flour incorporating BSG had increased water absorption. Rheological measurements showed a positively correlated increase in dough resistance in line with BSG or BSG SD incorporation. Supplemented breads had sensory acceptability up to levels of 10xa0% BSG or BSG SD, resulting in breads comparing favourably with wholemeal breads from a nutritional, technological and textural perspective. Using BSG as a main stream food ingredient would increase the market value of this by-product, thus enhancing its economic potential, a factor that is also discussed.

Physicochemical Properties of Oat Varieties and Their Potential for Breadmaking

ABSTRACT The breadmaking potential of six oat varieties was compared with and related to their physicochemical properties. The most significant differences in the bread characteristics were found in the crumb structure. The varieties Buggy, Energie, and Zorro resulted in good bread quality with an even gas-cell distribution characterized by a high number of relatively small pores. In contrast, Typhon, Ivory, and Nord 08/311 each had a large hole in the center of the crumb and accordingly poor quality. Breads differed little in specific volume, bake loss, and density. Rheological analysis revealed positive effects of low batter resistance to deformation on oat bread quality. On the basis of the physicochemical characterization, protein and fat contents were identified as key factors responsible for differences observed in bread quality, provided that starch damage and water-hydration capacity were low. Additionally, high setback and final viscosity, as determined by Rapid Visco Analyser (RVA) analysis, pos...

Wheat bread biofortification with rootlets, a malting by-product.

BACKGROUNDnBarley rootlets, a malting by-product, are currently discarded or used as fodder. In this study, milled rootlets and Lactobacillus plantarum FST 1.7-fermented rootlets were incorporated into wheat bread. The objective was to formulate a high-nutrition alternative to wholemeal breads with improved technological attributes.nnnRESULTSnChemical analyses showed that rootlets contribute nutrients and bioactive compounds, including proteins, amino acids, fatty acids, carbohydrates, dietary fibre, polyphenols and minerals. Rootlets are particularly rich in essential amino acids, especially lysine, the typically limiting essential amino acid of cereals. Additionally, rootlets offer potential dietary fibre health benefits such as protection against cardiovascular disease, cancers and digestive disorders.nnnCONCLUSIONnBreads prepared with a (fermented) rootlet inclusion level of up to 10% compared favourably with wholemeal breads from nutritive, technological and textural perspectives. Furthermore, they were well accepted by sensory panellists. Using rootlets as a food ingredient would have the added benefit of increasing this malting by-products market value.

Implementation of commercial oat and sorghum flours in brewing

Brewing with commercial flours has the potential to reduce mashing times and improve brewhouse efficiency. At present, however, no studies are available assessing the application of commercial oat and sorghum flours as brewing adjuncts. Therefore, the objectives of this study were to evaluate the quality and processability of mashes/worts produced with 10–90xa0% oat or sorghum flour as well as to reveal the advantages and limitations of their use as a substitute for barley malt. For these purposes, both flour types were fully analyzed in terms of brewing-relevant characteristics using standard methods, Lab-on-a-Chip capillary electrophoresis, and scanning electron microscopy. Laboratory-scale mashing trials were performed to assess the effect of up to 90xa0% flour adjunct on mash/wort quality. Equivalent factors were introduced to determine the performance efficiency of different oat/sorghum flour concentrations. Commercial oat flour sourced in Ireland exhibited significantly more protein, β-glucan, and fat, less starch, ash, and polyphenols, as well as a lower starch gelatinization temperature than commercial sorghum flour obtained from the USA. Worts produced with 10–90xa0% oat or sorghum flour had lighter colors, higher pH values, and lower concentrations of foam-positive proteins as well as free amino nitrogen compared to 100xa0% barley malt worts. In terms of extract yields, the use of up to 70xa0% oat flour and 50xa0% sorghum flour, respectively, has proven economically beneficial. Worts containing up to 70xa0% oat flour showed a very good or good fermentability, those containing 30–50xa0% sorghum flour resulted, however, in a lower alcohol production.

In situ production of human β defensin-3 in lager yeasts provides bactericidal activity against beer-spoiling bacteria under fermentation conditions.

To examine the use of a natural antimicrobial peptide, human β‐defensin‐3 (HBD3), as a means of preventing spoilage from bacterial contamination in brewery fermentations and in bottled beer.

Investigation of overfoaming activities and gushing mechanisms of individual beer ingredients as model substances in bottled carbonated water

BACKGROUNDnResearchers in several disciplines are interested in understanding the spontaneous and eruptive overfoaming (gushing) of carbonated beverages, as it is an essential problem of both the brewing and beverage industries. In order to understand the mechanism(s) taking place in gushing beer, several beer ingredients have been investigated as model substances in a much simpler matrix of carbonated water. For this purpose, sinapic acid, vanillic acid, ferulic acid, cinnamic acid and palmitic acid have been chosen as model beer ingredients.nnnRESULTSnGushing formation of the investigated beer ingredients depends on the degree of stabilized solvated molecular carbon dioxide in water. For this purpose, functional groups capable of forming hydrogen bonds with electronegative oxygen atoms of carbon dioxide are needed. However, the solubility of the substances plays an important role in the abundance of these functional groups in undissociated form to interact with molecular carbon dioxide.nnnCONCLUSIONnThe reported data provide valuable insights into the gushing problem and help to understand its formation pathways. Each gushing-positive substance has an individual mechanism related to its structural conformation and solubility level. Therefore possible gushing mechanisms have been proposed with respect to the structural changes in model substances to clarify the differences in observed overfoaming and gushing stability levels.

Mechanism of Nonpolar Model Substances to Inhibit Primary Gushing Induced by Hydrophobin HFBI.

In this work, the interactions of a well-studied hydrophobin with different types of nonpolar model substances and their impact on primary gushing is evaluated. The nature, length, and degree of saturation of nonpolar molecules are key parameters defining the gushing ability or inhibition. When mixed with hydrophobins, the nonpolar molecule-hydrophobin assembly acts as a less gushing or no gushing system. This effect can be explained in the framework of a competition effect between non-polar systems and CO2 to interact with the hydrophobic patch of the hydrophobin. Interactions of these molecules with hydrophobins are promoted as a result of the similar size of the nonpolar molecules with the hydrophobic patch of the protein, at the expense of the formation of nanobubbles with CO2. In order to prove the presence of interactions and to unravel the mechanisms behind them, a complete set of experimental techniques was used. Surface sensitive techniques clearly show the presence of the interactions, whose nature is not covalent nor hydrogen bonding according to infrared spectroscopy results. Interactions were also reflected by particle size analysis in which mixtures of particles displayed larger size than their pure component counterparts. Upon mixing with nonpolar molecules, the gushing ability of the protein is significantly disrupted.