The molecular and technological characterization of lactic acid bacteria in einkorn sourdough: effect on bread quality

Nutritional composition, in vitro carbohydrates digestibility, textural and sensory characteristics of bread as affected by ancient wheat flour type and sourdough fermentation time

This study aimed to investigate the effect of ancient wheat flour type and sourdough fermentation time on the nutritional, textural and sensorial properties of fiber-rich sourdough bread. The proximate composition, minerals, carbohydrates, organic acids, volatiles, total phenolic content, simulated gastrointestinal digestion, textural and sensorial characteristics were investigated. Bread's minerals, total phenolics, cellulose contents and radical scavenging activity variations clearly indicates an increasing trend with sourdoughs fermentation time. Compared to maltose and glucose, fructose was predominant in all bread samples. Sourdough fermentation time and wheat type had non-significant influence on fructose content from digested fraction. Excepting emmer bread, fermentation time increased in vitro digestibility values for tested samples. The crumb textural parameters (hardness, gumminess, chewiness, cohesiveness and springiness index) were positively influenced by fermentation time. The specific clustering of the analysed characteristics distinguished emmer bread from other samples in terms of volatile compounds, textural and overall acceptability, being preferred by panellists.

Harnessing the Role of Three Lactic Acid Bacteria (LAB) Strains for Type II Sourdough Production and Influence of Sourdoughs on Bread Quality and Maillard Reaction Products

This study tested the effect of Companilactobacillus paralimentarius E-106, Lactiplantibacillus paraplantarum N-15 and Lactiplantibacillus plantarum SC-9 on the amount of Maillard reaction and aroma profile in bread making with main bread quality parameters. The specific volumes of sourdough and control breads were in the range of 2.97-3.04 cm3/g, and the control II bread had the highest hardness values on all days. The FAST index value was determined to be between 40.48% and 81.22% in all breads. The FAST index value was found to be higher in the control breads than in the sourdough breads. In the volatile compounds analysis, 72 volatile compounds were detected. The variety of volatile compounds in the breads with sourdough addition was higher than the control breads. Among the tested strains, Companilactobacillus paralimentarius E-106 demonstrated superior properties for bread characteristics in comparison to other strains as a type II sourdough starter. In summary, improved aroma profile and decreased Maillard reaction products can be provided by sourdough addition without changing the bread quality, along with meeting consumer demand for less additive use.

Sourdough starters exhibit similar succession patterns but develop flour-specific climax communities

The microbial fermentation behind sourdough bread is among our oldest technologies, yet there are many opportunities for sourdough science to learn from traditional bakers. We analyzed 16S rRNA sequences in R to assess the bacterial community structure and performance of 40 starters grown from 10 types of flour over 14 days, and identified six distinct stages of succession. At each stage, bacterial taxa correlate with determinants of bread quality including pH, rise, and aromatic profile. Day 1 starter cultures were dominated by microorganisms commonly associated with plants and flour, and by aromas similar to toasted grain/cereal. Bacterial diversity peaked from days 2-6 as taxa shifted from opportunistic/generalist bacteria associated with flour inputs, toward specialized climax bacterial communities (days 10-14) characterized by acid-tolerant taxa and fruity (p < 3.03e-03), sour (p < 1.60e-01), and fermented (p < 1.47e-05) aromas. This collection of traits changes predictably through time, regardless of flour type, highlighting patterns of bacterial constraints and dynamics that are conserved across systems and scales. Yet, while sourdough climax communities exhibit similar markers of maturity (i.e., pH ≤ 4 and enriched in Lactobacillus (mean abundance 48.1%), Pediococcus (mean abundance 22.7%), and/or Gluconobacter (mean abundance 19.1%)), we also detected specific taxa and aromas associated with each type of flour. Our results address important ecological questions about the relationship between community structure and starter performance, and may enable bakers to deliberately select for specific sourdough starter and bread characteristics.

Metabolic Profile of Einkorn, Spelt, Emmer Ancient Wheat Species Sourdough Fermented with Strain of Lactiplantibacillus plantarum ATCC 8014

The continuous development of bakery products as well as the increased demands from consumers transform ancient grains into alternatives with high nutritional potential for modern wheat species. The present study, therefore, follows the changes that occur in the sourdough obtained from these vegetable matrices fermented by Lactiplantibacillus plantarum ATCC 8014 during a 24 h. period. The samples were analyzed in terms of cell growth dynamics, carbohydrate content, crude cellulose, minerals, organic acids, volatile compounds, and rheological properties. The results revealed significant microbial growth in all samples, with an average value of 9 log cfu/g but also a high accumulation of organic acids with the increase in the fermentation period. Lactic acid content ranged from 2.89 to 6.65 mg/g, while acetic acid recorded values between 0.51 and 1.1 mg/g. Regarding the content of simple sugars, maltose was converted into glucose, and fructose was used as an electron acceptor or carbon source. Cellulose content decreased as a result of the solubilization of soluble fibers into insoluble fibers under enzymatic action, with percentages of 3.8 to 9.5%. All sourdough samples had a high content of minerals; the highest of which-Ca (246 mg/kg), Zn (36 mg/kg), Mn (46 mg/kg), and Fe (19 mg/kg)-were recorded in the einkorn sourdough.

Ancient Wheat Species: Biochemical Profile and Impact on Sourdough Bread Characteristics—A Review

In recent years, the attention of farmers, bakers and consumers towards ancient wheat species has been increasing. Low demands of pedo-climatic growth factors, the suitability for organic cultivation along with their high nutritional quality and their content in pro-health compounds make them extremely attractive for bakers and modern consumers, equally. On the other hand, in recent years, sourdough has gained attention due to its ability to produce new functionally active molecules with higher bioaccessibility and thus to produce bread with enhanced nutritional quality. This paper highlights the relevant nutritional profile of einkorn, spelt, emmer and Khorasan which could lead to bread with improved textural, sensorial, microbial and nutritional characteristics through sourdough fermentation. The ancient wheat species could be used as promising substitutes for common wheat flour for the design of innovative types of bread, even for special needs.

A Holistic Review on Euro-Asian Lactic Acid Bacteria Fermented Cereals and Vegetables

Lactic acid fermentation is one of the oldest methods used worldwide to preserve cereals and vegetables. Europe and Asia have long and huge traditions in the manufacturing of lactic acid bacteria (LAB)-fermented foods. They have different cultures, religions and ethnicities with the available resources that strongly influence their food habits. Many differences and similarities exist with respect to raw substrates, products and microbes involved in the manufacture of fermented products. Many of them are produced on industrial scale with starter cultures, while others rely on spontaneous fermentation, produced homemade or in traditional events. In Europe, common LAB-fermented products made from cereals include traditional breads, leavened sweet doughs, and low and non-alcoholic cereal-based beverages, whereas among vegetable ones prevail sauerkraut, cucumber pickles and olives. In Asia, the prevailing LAB-fermented cereals include acid-leavened steamed breads or pancakes from rice and wheat, whereas LAB-fermented vegetables are more multifarious, such as kimchi, sinki, khalpi, dakguadong, jiang-gua, soidon and sauerkraut. Here, an overview of the main Euro-Asiatic LAB-fermented cereals and vegetables was proposed, underlining the relevance of fermentation as a tool for improving cereals and vegetables, and highlighting some differences and similarities among the Euro-Asiatic products. The study culminated in "omics"-based and future-oriented studies of the fermented products.