The Inhibition of Amylase and ACE Enzyme and the Reduction of Immunoreactivity of Sourdough Bread

Assessment of Physicochemical Properties and Quality of the Breads Made from Organically Grown Wheat and Legumes

This study aimed to explore the feasibility of substituting wheat flour with varying levels (10%, 15%, 20%, and 25%) of flour derived from field bean, chickpea, lentil, and pea seeds. The investigation focused on assessing the physical properties of wheat dough and the physicochemical characteristics of bread samples. The addition of legume seed flours significantly influenced the dough's development time, particularly with chickpea flour causing a notable increase in this parameter. While dough stability was generally shorter for mixtures containing wheat flour and legume seed flour, chickpea flour was an exception, significantly prolonging dough stability time. Furthermore, the inclusion of legume flours resulted in increased protein, ash, fiber, fat, and phenolic contents in the enriched bread, while the carbohydrate content decreased. Additionally, the crumb exhibited increased redness and yellowness and decreased lightness due to the enrichment of the bread. Notably, the antioxidant activity of bread containing legume flour also increased, with the most significant increase observed when pea flour was utilized. Conversely, negative effects on bread volume, crumb density, and texture parameters were noted with the incorporation of legume additives. Taking into consideration the results of both physicochemical analyses and sensory evaluation, it is recommended that the incorporation of the specified legume flours should not exceed 15% in relation to the quantity of wheat flour used.

Label-free quantitative proteomics to exploit the impact of sourdough fermentation on reducing wheat allergenic fractions

The microbial consortia of lactic acid bacteria and yeast of sourdough can partially degrade gluten subunits associated with wheat-related diseases. This study evaluated how sourdough fermentation interferes with wheat protein profiles and if it can be related to the reduction expression of allergenic proteins. Samples from five bread doughs (Saccharomyces cerevisiae -C1; chemical acidification -C2, and three sourdoughs formulations -S1, S2, and S3) were sequentially extracted, digested, and submitted to shotgun label-free proteomic analysis. Eight-five proteins were identified as allergenic, mainly belonging to gliadin fraction, including seven containing the 33-mer peptide sequence. The highest immunogenic potential was found in dough C1 and S3, while the least reactive group consisted of S1 and C2. The two folds down expression of an α-gliadin containing the 33-mer sequence corroborates this. This finding may indicate the role of organic acids produced by the microbiota sourdough type II during fermentation in changing the protein profile.

Bread Biopreservation through the Addition of Lactic Acid Bacteria in Sourdough

Nowadays, the consumer seeks to replace synthetic preservatives with biopreservation methods, such as sourdough in bread. Lactic acid bacteria (LAB) are used as starter cultures in many food products. In this work, commercial yeast bread and sourdough breads were prepared as controls, as well as sourdough breads with L. plantarum 5L1 lyophilized. The impact of L. plantarum 5L1 on the properties of bread was studied. Antifungal compounds and the impact on the protein fraction by the different treatments in doughs and breads were also analyzed. In addition, the biopreservation capacity of the treatments in breads contaminated with fungi was studied and the mycotoxin content was analyzed. The results showed significant differences with respect to the controls in the properties of the bread and a higher total phenolic and lactic acid content in breads with higher amounts of L. plantarum 5L1. In addition, there was a higher content of alcohol and esters. Furthermore, adding this starter culture produced hydrolysis of the 50 kDa band proteins. Finally, the higher concentration of L. plantarum 5L1 delayed fungal growth and reduced the content of AFB1 and AFB2 compared to the control.

Nutritional benefits of sourdoughs: A systematic review

Food fermentation using sourdough-i.e., consortia of lactic bacteria and yeasts-is increasingly considered among the public as a natural transformation yielding nutritional benefits; however, it is unclear whether its alleged properties are validated by science. The aim of this study was to systematically review the clinical evidence related to the effect of sourdough bread on health. Bibliographic searches were performed in 2 different databases (The Lens and PubMed) up to February 2022. Eligible studies were randomized controlled trials involving adults, healthy or not, given any type of sourdough bread compared with those given any type of yeast bread. A total of 573 articles were retrieved and investigated, of which 25 clinical trials met the inclusion criteria. The 25 clinical trials included a total of 542 individuals. The main outcomes investigated in the retrieved studies were glucose response (N = 15), appetite (N = 3), gastrointestinal markers (N = 5), and cardiovascular markers (N = 2). Overall, it is currently difficult to establish a clear consensus with regards to the beneficial effects of sourdough per se on health when compared with other types of bread because a variety of factors, such as the microbial composition of sourdough, fermentation parameters, cereals, and flour types potentially influence the nutritional properties of bread. Nonetheless, in studies using specific strains and fermentation conditions, significant improvements were observed in parameters related to glycemic response, satiety, or gastrointestinal comfort after bread ingestion. The reviewed data suggest that sourdough has great potential to produce a variety of functional foods; however, its complex and dynamic ecosystem requires further standardization to conclude its clinical health benefits.

Submerged fermentation improves bioactivity of mulberry fruits and leaves

Objective

Mulberry (Morus spp.) fruits and leaves have been proven to possess nutraceutical properties. Due to its fast and easy growing characteristics, mulberry fruits (MF) and leaves (ML) potentially emerge as a great source of functional foods. This study aims to enhance bioactivities (antioxidant, anti-inflammation, and hypoglycemic activity) of MF and ML via submerged fermentation using bacteria (Lactobacillus plantarum TAR 4), yeast (Baker’s yeast and red yeast) and fungi (Tempeh and Tapai starter).

Methods

In this study, 25% (mass to volume ratio) of MF and ML were fermented (48 h) with 1% (mass to volume ratio) of different microbial cultures, respectively. Effects of different fermentations on MF and ML were determined based on the changes of total phenolics (TPC), flavonoids (TFC), anthocyanins, total sugar, DPPH activity, ferric reducing antioxidant power (FRAP), albumin denaturation inhibition activity (ADI), anti-lipoxygenase activity and α-amylase inhibition activity (AI).

Results

Generally, ML had higher AI than MF. However, MF exhibited higher DPPH, FRAP and anti-lipoxygenase activity than ML. After all forms of fermentation, DPPH and AI activity of MF and ML were increased significantly (P < 0.05). However, the effects of fermentation on TPC, FRAP, ADI and anti-lipoxygenase activity of MF were in contrast with ML. TPC, FRAP and anti-lipoxygenase activity of ML were enhanced, but reduced in MF after fermentation. Although the effects exerted by different microorganisms in MF and ML fermentation were different, the bioactivities of MF and ML were generally improved after fermentation. Fermentation by Tempeh starter enhanced TPC (by 2-fold), FRAP (by 2.3-fold), AI (at 10% increment) and anti-lipoxygenase activity (by 5-fold) of ML, whereas Tapai fermentation effectively enhanced the DPPH (at 17% increment) and ADI (by 2-fold) activity of MF.

Conclusion

Findings of this study provide an insight into the future process design of MF and ML processing into novel functional foods.

Statistical Approach to Potentially Enhance the Postbiotication of Gluten-Free Sourdough

Fermented products are permanently under the attention of scientists and consumers, both due to nutritional importance and health promoting effects. The fermented functional foods contribute to a more balanced diet and increase the immune responses (among many other health effects) with positive implications for quality of life. In this sense, improving the sourdough’s fermentation to boost the biotic (postbiotic and paraprobiotic) properties of the sourdough-based products has positive impacts on the nutritional and functional properties of the final baked products. These enhanced sourdoughs can be obtained in controlled fermentation conditions and used as sourdough bread improvers or novel bioingredients. In this context, our work aimed to optimize, using statistical tools, a gluten-free sourdough based on chickpea, quinoa, and buckwheat fermentation with selected lactic acid bacteria (LAB) to enhance its postbiotic properties. The most important biotechnological parameters were selected by Plackett–Burman Design (PBD) and then Response Surface Methodology (RSM) was applied to evaluate the interactions between the selected factors to maximize the gluten-free sourdough’s properties. As a result, the optimized fermented sourdough had antimicrobial activity with inhibition ratios between 71 and 100% against the Aspergillus niger, Aspergillus flavus, Penicillium spp. molds and against the Bacillus spp endospore-forming Gram-positive rods. The optimized variant showed a total titratable acidity (TTA) of 40.2 mL NaOH 0.1N. Finally, the high-performance liquid chromatography (HPLC) analysis highlighted a heterofermentative profile for the organic acids from the optimized sourdough. Among flavonoids and polyphenols, the level of caffeic and vanillic acids increased after lactic acid fermentation. The comparison between the optimized sourdough and the control evidenced significant differences in the metabolite profiles, thus highlighting its potential postbiotication effect.