Influence of sesame cake on physicochemical, antioxidant and sensorial characteristics of fortified wheat breads.

Incorporation of two sesame cake preparations, differing in fat, 11 % (LF) and 17 % (HF), and protein, 51 % (LF) and 44 % (HF), contents, respectively, into breads at 6, 12 and 20 % wheat flour substitution levels, led to enriched end-products with antioxidants, suitable also to carry the 'high protein' and 'fiber source' nutrition claims (at ≥ 12 % substitution level). Sesame cake decreased wheat dough resistance to mixing and extension, and peak viscosity (empirical rheology), in a concentration-dependent manner, being more pronounced for LF formulations. Breads with LF incorporation ≥ 12 % had lower specific volumes and harder crumb (texture analysis) throughout storage, than control (100 % wheat flour); however, such adverse effects were diminished in HF bread formulations due to the plasticizing and emulsifying action of the sesame cake fat. Calorimetry showed that the sesame cake had no effect on starch retrogradation, but enhanced amylose-lipid complex formation. Antioxidant activity (ABTS, DPPH and FRAP assays), and phenolic acids (ferulic, p-coumaric and sinapic) and lignan (sesaminol glucosides and sesamolin) contents, determined by HPLC-DAD-MS, were higher in LF breads than their HF counterparts. The presence of some sulfur (off-flavor) and pyrazine (nutty flavor) compounds (SPME-GC-MS), as well as the sesame flavor and bitterness (sensory analysis) were of higher intensity in HF breads, while the 6 % LF product received the highest overall acceptability score among all fortified products. Overall, the sesame cake can be a promising ingredient for production of functional wheat bread depending on its composition and fortification level.

Physicochemical Characteristics, Antioxidant Properties, Aroma Profile, and Sensory Qualities of Value-Added Wheat Breads Fortified with Post-Distillation Solid Wastes of Aromatic Plants.

The influence of incorporation of post-distillation solid wastes of the aromatic plants (SWAP), oregano, rosemary, lemon balm, and spearmint into wheat breads at 1% and 2% levels on their physicochemical and sensorial properties, and antioxidant and volatile profiles were investigated. SWAP breads had darker crumbs and crust and greener crumbs compared to the control, but rather similar loaf specific volume and textural attributes (crust puncture test and crumb Texture Profile Analysis). Although the mold growth on bread crumb surface was not inhibited by SWAP presence, LC-DAD-MS revealed a large increase in terpenoids, like carnosic acid (all SWAP), carnosol (rosemary) and carvacrol (oregano), phenolic (rosmarinic and salvianolic) acids and flavonoids in bread with SWAP inclusion, leading to enhanced antioxidant capacity (ABST, DPPH and FRAP assays). The distinct aromatic plant flavors were detected in the fortified breads by trained assessors and confirmed by SPME-GC/MS volatile analysis, showing high levels of terpenoids in SWAP breads, like carvacrol (oregano), caryophyllene (rosemary and lemon balm), and carvone (spearmint), and rendering the 2% fortification unacceptable by consumers. Nevertheless, breads with 1% oregano or rosemary waste had similar control overall acceptability scores, indicating that SWAP can be a promising ingredient for developing antioxidant-enriched wheat breads.

Enhancement of Textural and Sensory Characteristics of Wheat Bread Using a Chickpea Sourdough Fermented with a Selected Autochthonous Microorganism.

A traditional Greek sourdough, based on the fermentation of chickpea flour by an autochthonous culture, was evaluated as a wheat bread improver. The dominant indigenous microflora (Clostridium perfringens isolates) was identified by 16S rDNA analysis, and a selected strain (C. perfringens CP8) was employed to ferment chickpea flour to obtain a standardized starter culture (sourdough) for breadmaking. In accordance with toxin-typed strain identification, all isolates lacked the cpe gene; thus, there is no concern for a health hazard. Loaf-specific volumes increased with the addition of liquid, freeze-dried, and freeze-dried/maltodextrin sourdoughs compared to control bread leavened by baker's yeast only. Following storage (4 days/25 °C), the amylopectin retrogradation and crumb hardness changes (texture profile analysis) revealed a lower degree of staling for the sourdough-fortified breads. Modifications in the protein secondary structure of fortified doughs and breads were revealed by FTIR analysis. High amounts of organic acids were also found in the sourdough-supplemented breads; butyric and isobutyric acids seemed to be responsible for the characteristic 'butter-like' flavor of these products (sensory analysis). Overall, the addition of liquid or freeze-dried chickpea sourdough in wheat bread formulations can improve the specific volume, textural characteristics, and sensorial properties of loaves, along with extending bread shelf life.

A sourdough process based on fermented chickpea extract as leavening and anti-staling agent for improving the quality of gluten-free breads.

The use of a sourdough (SD) preparation based on a fermented chickpea extract (FCE) starter as a leavening and anti-staling agent in gluten-free breads was explored in this study. The FCE starter was prepared by a submerged fermentation (at 37 °C for 15 h) of coarsely ground chickpeas and the gluten-free bread formulations, based on rice and corn flours, were made using a rice sourdough produced with the FCE starter as additional leavening agent; the FCE-SD breads and samples containing merely baker's yeast as microbial leavener (control) were both prepared at three different levels of added water, i.e., 85, 92 and 100% (flour weight basis). The loaf specific volume significantly (p < 0.05) increased with sourdough inclusion into batters and by increasing the amount of added water. Moreover, inclusion of sourdough into the gluten-free formulations resulted in a finer porous crumb macrostructure and a lower crust moisture content than control breads. Upon bread storage (25 °C for 5 days), water migration from crumb to crust was noted. Staling events were also monitored by compression testing and differential scanning calorimetry, showing an increase in crumb firmness and the apparent melting enthalpy (ΔH) of retrograded amylopectin during bread storage; the values for both parameters decreased with inclusion of FCE-SD and with higher amounts of added water into the gluten-free formulations. Kinetic data in modelling crumb firmness and ΔH values by linear regression analysis and the Avrami equation, respectively, revealed a slower staling rate for breads with sourdough, compared to control formulations; moreover, with increasing level of added water to the batter, the firming rate was reduced, while the amylopectin retrogradation was enhanced. Finally, in vitro enzymatic starch digestibility of the crumb was lower for staled breads stored for 5 days, compared to fresh products, while there was no pronounced effect by sourdough inclusion. Overall, the incorporation of FCE-SD into gluten-free bread formulations seems to be a promising alternative for improving quality and extending the shelf life of gluten-free baked products.

Isolation, characterization and evaluation of the probiotic potential of a novel Lactobacillus strain isolated from Feta-type cheese.

In the present study 45 lactic acid bacteria (LAB) strains were isolated from Feta-type cheese and were screened for probiotic potential in a series of established in vitro tests, including resistance to low pH, resistance to pepsin and pancreatin and tolerance to bile salts. The strain K5, which displayed properties similar to or even better than the reference strain Lactobacillus plantarum ATCC 14917, was chosen for further analysis. Firstly, multiplex PCR analysis indicated that the novel strain belongs to the paracasei species. Secondly, the susceptibility against common antibiotics was determined to ensure a safe exploitation of the potentially probiotic strain. Additionally, the performance of L. paracasei K5 as starter in the fermentation of pomegranate juice was studied to evaluate its technological properties. Finally, a novel multiplex PCR assay, based on random amplified polymorphic DNA (RAPD) analysis was developed for its efficient and accurate detection in food products.