It is often quoted that classic bread‐loaf sectioning of excisional specimens assesses 0.5% of the margin, but careful mathematical analysis reveals that bread‐loaf sectioning appraises far more than ...that and is an effective and economical means to check margins.
As one of the most traditional biotechnologies, sourdough fermentation has deep effects on rheology, sensory and shelf life attributes of baked goods. The most recent literature has also highlighted ...the effects of sourdough fermentations on several functional/nutritional features of baked goods. While some aspects such as the potential to lower glycemic index, increase mineral bioavailability and decrease the gluten content have been proven almost definitively, others potentialities are emerging, which deserve novel insights. This reviews reports the main evidence on the use of sourdough fermentation for salt reduction in baked goods, management of irritable bowel syndrome (IBS), synthesis/release of bioactive compounds, especially the metabolism of phenolic compounds, and exploitation of the potential of non-conventional flours (legumes and pseudo-cereals) and milling by-products (bran and germ). A brief description on the spiritual, cultural and functional/nutritional significance of leavened bread throughout centuries has also given.
Sourdough is used in production of (steamed) bread as leavening agent (type I sourdoughs) or as baking improver to enhance flavour, texture, and shelf life of bread (type II sourdoughs). The ...long-term propagation of sourdoughs eliminates dispersal limitation and consistently leads to sourdough microbiota that are composed of host adapted lactobacilli. In contrast, community assembly in spontaneous cereal fermentations is limited by dispersal and nomadic or environmental lactic acid bacteria are the first colonizers of these sourdoughs.
Propagation of sourdoughs for use as sole leavening agent (type I sourdoughs) dictates fermentation conditions that select for rapid growth. Type I wheat- and rye sourdoughs are consistently populated by insect-adapted lactobacilli, particularly Lactobacillus sanfranciscensis, which is characterized by a small genome size and a restricted metabolic potential. The diverse fermentation conditions employed in industrial or artisanal Type II sourdough fermentation processes also result in a more diverse microbiota. Nevertheless, type II sourdoughs are typically populated by vertebrate host adapted lactobacilli of the L. delbrueckii and L. reuteri groups. Metabolic traits of host-adapted lactobacilli that enhance competitiveness in intestinal ecosystems also provide technological functionality in bread making. Examples include formation of exopolysaccharides, arginine-, glutamine- and glutamate based mechanisms of acid resistance, and glycosyl hydrolases that reduce FODMAP levels in sourdough and sourdough bread. In conclusion, consideration of the lifestyle of sourdough lactobacilli facilitates the selection of competitive and functional sourdough starter cultures.
Mexico City's colorful panaderías (bakeries) have long been vital neighborhood institutions. They were also crucial sites where labor, subsistence, and politics collided. From the 1880s well into the ...twentieth century, Basque immigrants dominated the bread trade, to the detriment of small Mexican bakers. By taking us inside the panadería, into the heart of bread strikes, and through government halls, Robert Weis reveals why authorities and organized workers supported the so-called Spanish monopoly in ways that countered the promises of law and ideology. He tells the gritty story of how class struggle and the politics of food shaped the state and the market. More than a book about bread, Bakers and Basques places food and labor at the center of the upheavals in Mexican history from independence to the aftermath of the Mexican Revolution.
This study aimed at investigating the addition of legume (chickpea, lentil and bean) flours to wheat flour bread. Type I sourdough containing legumes or wheat–legume flours were prepared and ...propagated (back slopped) in laboratory, according to traditional protocols that are routinely used for making typical Italian breads. Based on kinetic of acidification and culture-dependent data, the wheat–legume sourdough was further characterized and selected for bread making. As determined by RAPD-PCR and partial sequencing of 16S rDNA gene analyses, lactic acid bacteria in wheat–legume sourdough included Lactobacillus plantarum, Lactobacillus sanfranciscensis, Leuconostoc mesenteroides, Lactobacillus fermentum, Weissella cibaria, Lactobacillus pentosus, Lactobacillus coryneformis, Lactobacillus rossiae, Lactobacillus brevis, Lactobacillus parabuchneri and Lactobacillus paraplantarum. Two breads containing 15% (w/w) of legume (chickpea, lentil and bean) flours were produced using selected wheat–legume sourdough (WLSB) and traditional wheat sourdough (WSB). Compared to wheat yeasted bread (WYB), the level of total free amino acids (FAA) was higher in WSB and WLSB. Phytase and antioxidant activities were the highest in WLSB. Compared to bread WYB, the addition of legume flours decreased the in vitro protein digestibility (IVPD) (WYB versus WSB). However, the dough fermentation with WSLB favored an increase of IVPD. According to the levels of carbohydrates, dietary fibers and resistant starch, WSB and WLSB showed lower values of hydrolysis index (HI) compared to WYB. As showed by texture and image analyses and sensory evaluation of breads, a good acceptability was found for WSB and, especially, WLSB breads.
•A protocol for sourdough fermentation of a mixture of wheat and legume flours was set up.•The lactic acid bacteria microbiota of wheat–legume sourdough was characterized.•Legume and sourdough fermentation increased functional compounds of wheat bread.•Wheat–legume sourdough increased phytase and antioxidant activities of wheat bread.•Wheat–legume sourdough decreased the hydrolysis index of wheat bread.
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•Gluten-free (GF) sourdough (SD) was made by a fermented chickpea extract (FCE) starter.•FCE-SD addition into GF breads increased loaf volume and decreased crumb pore size.•Crumb ...firming and starch retrogradation decreased in breads made with FCE-SD.•FCE-SD inclusion into GF breads decreased the staling rate.•In vitro enzymatic starch digestibility of the crumb decreased upon bread storage.
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.
Lowering postprandial glucose and insulin responses may have significant beneficial implications for prevention and treatment of metabolic disorders. Bread is a staple food consumed worldwide in a ...daily basis, and the use of different baking technologies may modify the glucose and insulin response. The aim of this review was to critically record the human studies examining the application of different bread making processes on postprandial glucose and insulin response to bread. Literature is rich of results which show that the use of sourdough fermentation instead of leavening with Saccharomyces cerevisiae is able to modulate glucose response to bread, whereas evidence regarding its efficacy on lowering postprandial insulin response is less clear. The presence of organic acids is possibly involved, but the exact mechanism of action is still to be confirmed. The reviewed data also revealed that the alteration of other processing conditions (method of cooking, proofing period, partial baking freezing technology) can effectively decrease postprandial glucose response to bread, by influencing physical structure and retrogradation of starch. The development of healthier bread products that benefit postprandial metabolic responses is crucial and suggested baking conditions can be used by the bread industry for the promotion of public health.
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•Continuous propagation (CP) of Chinese traditional sourdough (CTS) was adopted to simulate the industrialization production of SSB.•Effect of CP on microbial community, metabolic ...changes of dough samples and reproducibility of SSB characteristics were studied.•Lactobacillus sanfranciscensis and Kazachstania humilis were the predominant bacterial and fungal species in mature sourdoughs during CP.•Establishment of a stable microbial ecosystem occurred within four days of continuous propagation.•Volumetric and textural properties as well as the volatile flavor compounds of SSB displayed rather high stability from the fourth day of CP onwards.
Continuous propagation of Chinese traditional sourdough (CTS) was adopted to simulate the industrial production of sourdough steamed bread made by retarded sponge-dough method (SSB). Establishment of a stable microbial ecosystem occurred in mature sourdough within four days of continuous propagation, as revealed by both microbial and metabolic analyses. Lactobacillus sanfranciscensis and Kazachstania humilis were the predominant bacterial and fungal species in mature sourdoughs. Their relative abundances changed significantly from the first to third day of continuous propagation while exhibited relatively constant from the fourth day onwards despite the use of flour/water for each back-slopping step. Major changes in the metabolites and fermentative characteristics were observed during the initial three days and dough samples showed little temporal metabolic and fermentative variations from the fourth days onwards. Consequently, volumetric and textural properties as well as the volatile flavor compounds of SSB displayed rather high stability from the fourth day onwards.
The sourdough fermentation in bread making is strongly motivated due to its beneficial aspects on flavor, texture, shelf life, and the nutritional properties of the obtained products. In this ...research, the yeasts Kluyveromyces marxianus and Dekkera bruxellensis, and the bacterium Lactobacillus plantarum were used as alternative starter cultures in bread making. Experimental designs generated from simplex-centroid mixture were used in the sensorial analyses of breads. Results have shown that bread obtained with pure cultures of L. plantarum presented the smallest specific volume, while the mixture of K. marxianus and L. plantarum positively influenced the formation of good specific volume of products. Sensorial analysis showed good acceptability for breads obtained with D. bruxellensis and K. marxianus mixture, as well as for the mixture of the three microorganisms. The results obtained in this research suggest the possibility of using defined starter cultures for sourdough fermentation, which is traditionally carried out without any process controls. Key words: natural fermentation, sourdough, starter cultures, sensory analysis. A fermentacao sourdough para a producao de paes e fortemente motivada por seus efeitos beneficos quanto ao sabor, textura, vida de prateleira e pelas propriedades nutricionais dos produtos obtidos. Nesta pesquisa, estudou-se a aplicacao dos micro-organismos Kluyveromyces marxianus, Dekkera bruxellensis e Lactobacillus plantarum como culturas starters alternativas na producao de paes. A partir de sete ensaios resultantes de um delineamento de mistura simplexcentroide, foram realizadas nos paes analises sensorial e instrumental. Observou-se que paes produzidos com L.plantarum apresentaram menor volume especifico, enquanto que a mistura entre K. marxianus e L. plantarum exerceu influencia positiva, possibilitando obter produtos de maior volume especifico. A analise sensorial demonstrou a boa aceitabilidade para os paes produzidos com a mistura entre D. bruxellensis e K. marxianus e para a mistura entre os tres micro-organismos. Os resultados deste trabalho demonstram a possibilidade do uso de culturas starters definidas para a fermentacao sourdough, que e tradicionalmente obtida sem controle de processo. Palavras-chave: fermentacao natural, sourdough; culturas starters, analise sensorial.
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