Assessment of Ready-to-Use Freeze-dried Immobilized Biocatalysts as Innovative Starter Cultures in Sourdough Bread Making

In the present study the effect of innovative biocatalysts as starter cultures in sourdough bread making was explored. The biocatalysts consisted of Lactobacillus paracasei K5 and Lactobacillus bulgaricus ATCC 11842 (in single and mixed form), immobilized on deligniﬁed wheat bran (DWB), and freeze dried without cryoprotectants. The parameters monitored were physicochemical characteristics, mold and rope spoilage appearance, volatile composition, and organoleptic characteristics. Results obtained showed that both biocatalysts exhibit good fermentative activity. However, the best results were achieved when freeze-dried immobilized L. paracasei K5 was applied as a single culture. In particular, the produced bread had a higher acidity (8.67 mL 0.1 N NaOH) and higher organic load (2.90 g/kg lactic acid and 1.11 g/kg acetic acid). This outcome was the main reason why this bread was preserved more regarding mold spoilage (14 days) and rope spoilage (12 days), respectively. In addition, the employment of freeze-dried immobilized L. paracasei K5 led to bread with better aromatic profile in terms of concentrations and number of volatile compounds produced as gas chromatography/mass spectrometry (GC/MS) analysis proved. Finally, no significant differences were observed through sensorial tests. Last but not least, it should be highlighted that the used microorganisms were cultured in cheese whey, minimizing the cost of the proposed biotechnological procedure.

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Evaluation of Pediococcus pentosaceus SP2 as Starter Culture on Sourdough Bread Making

Foods ◽

10.3390/foods9010077 ◽

2020 ◽

Vol 9 (1) ◽

pp. 77 ◽

Cited By ~ 3

Author(s):

Stavros Plessas ◽

Ioanna Mantzourani ◽

Argyro Bekatorou

Keyword(s):

Organic Acids ◽

Solid Phase ◽

Immobilized Cells ◽

Starter Culture ◽

Gas Chromatography Mass Spectrometry ◽

Bread Making ◽

Pediococcus Pentosaceus ◽

Sourdough Bread ◽

Fresh Freeze ◽

Freeze Dried

In the present study, a novel Pediococcus pentosaceus SP2 strain, recently isolated from kefir grains, was evaluated as a starter culture in sourdough bread making. The novel starter was applied in fresh, freeze-dried, and freeze-dried immobilized (on wheat bran) form. The type of culture (fresh, freeze-dried, immobilized cells) influenced the bread characteristics. Specifically, the application of freeze-dried immobilized cells led to higher total titratable acidity (TTA) values (9.81 mL NaOH N/10), and the produced bread presented higher resistance to mold and rope spoilage. Moreover, the produced sourdough breads were significantly better in terms of pH, TTA, organic acids content, and resistance to mold and rope spoilage, compared to breads made with a commercial, wild microbiota, sourdough. The organic acids content was also significantly higher than the commercial sourdough sample (2.93 g/kg lactic acid; 1.01 g/kg acetic acid). Determination of volatile compounds through solid-phase microextraction (SPME) gas chromatography/mass spectrometry (GC/MS) analysis and sensorial assessments indicated no significant differences between the tested sourdough breads.

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Evaluation of Volatile Compounds in Milks Fermented Using Traditional Starter Cultures and Probiotics Based on Odor Activity Value and Chemometric Techniques

Molecules ◽

10.3390/molecules25051129 ◽

2020 ◽

Vol 25 (5) ◽

pp. 1129

Author(s):

Li Zhang ◽

Si Mi ◽

Ruobing Liu ◽

Yaxin Sang ◽

Xianghong Wang

Keyword(s):

Volatile Compounds ◽

Starter Culture ◽

Principal Component ◽

Streptococcus Thermophilus ◽

Starter Cultures ◽

Lactobacillus Bulgaricus ◽

Gas Chromatography Mass Spectrometry ◽

Volatile Components ◽

Odor Quality ◽

Odor Activity Value

The volatile components of milks fermented using traditional starter cultures (Streptococcus thermophilus and Lactobacillus bulgaricus) and probiotics (Lactobacillus lactis, Lactobacillus bifidus, Lactobacillus casei, and Lactobacillus plantarum) were investigated by means of gas chromatography-mass spectrometry (GC-MS) combined with simultaneous distillation extraction (SDE). A total of 53 volatile compounds were detected, being 10 aldehydes, 11 ketones, 10 acids, 11 hydrocarbons, 7 benzene derivatives, and 4 other compounds. The starter culture was found to significantly affect the composition of volatile components in the fermented milks. Ketones and hydrocarbons were the dominant compounds in milk before fermentation, while acids were dominant compounds in the fermented samples. Compared with probiotics, there was greater abundance of volatile components in fermented milks with traditional strains. The importance of each volatile compound was assessed on the basis of odor, thresholds, and odor activity values (OAVs). Of the volatile compounds, 31 of them were found to be odor-active compounds (OAV > 1). The component with the highest OAVs in most samples was (E,E)-2,4-decadienal. Heatmap analysis and principal component analysis were employed to characterize the volatile profiles of milks fermented by different starter cultures. The results could help to better understand the influence of starter cultures on the odor quality of milks.

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Assessment of Freeze-Dried Immobilized Lactobacillus casei as Probiotic Adjunct Culture in Yogurts

Foods ◽

10.3390/foods8090374 ◽

2019 ◽

Vol 8 (9) ◽

pp. 374 ◽

Cited By ~ 4

Author(s):

Dimitra Dimitrellou ◽

Panagiotis Kandylis ◽

Yiannis Kourkoutas

Keyword(s):

Lactic Acid ◽

Lactobacillus Casei ◽

Polymerase Chain Reaction Analysis ◽

Physicochemical Characteristics ◽

Mass Spectrometry Analysis ◽

Gas Chromatography Mass Spectrometry ◽

Spectrometry Analysis ◽

Freeze Dried ◽

Polymerase Chain ◽

Adjunct Culture

Freeze-dried immobilized Lactobacillus casei ATCC 393 on casein and apple pieces were assessed as a probiotic adjunct culture for novel probiotic yogurt production. The effect of probiotic culture on physicochemical characteristics, probiotic cell survival, volatile aroma compounds, and sensory quality were evaluated during 28 days of storage at 4 °C. The use of L. casei resulted in lower pH values (3.92–4.12), higher acidity (0.88–1.10 g lactic acid/100 g of yogurt), and lower syneresis (40.8%–42.6%) compared to traditionally produced yogurt (pH 4.29; acidity 0.83 g lactic acid/100 g of yogurt; syneresis 44.1%). Microbiological and strain-specific multiplex PCR (Polymerase Chain Reaction) analysis confirmed that immobilized L. casei ATCC 393 cells were detected in yogurts at levels >7 log cfu g−1 after 28 days. In addition, probiotic supplementation significantly affected the concentrations of key volatile compounds, like acetic and other organic acids, 2-ethyl-1-hexanol, acetoin, and 2-butanone, as revealed by GC-MS (Gas Chromatography–Mass Spectrometry) analysis. Finally, the sensory evaluation demonstrated that the new products exhibited improved characteristics compared to traditionally produced yogurts.

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Effect of natural starters used for sourdough bread in Morocco on phytate biodegradation

Eastern Mediterranean Health Journal ◽

10.26719/2003.9.1-2.141 ◽

2003 ◽

Vol 9 (1-2) ◽

pp. 141-147

Author(s):

A. Chaoui ◽

M. Faid ◽

R. Belhcen

Keyword(s):

Saccharomyces Cerevisiae ◽

Lactic Acid ◽

Lactic Acid Bacteria ◽

Acid Hydrolysis ◽

Phytic Acid ◽

Leuconostoc Mesenteroides ◽

Physicochemical Characteristics ◽

Phytase Activity ◽

Starter Cultures ◽

Sourdough Bread

Phytase activity was studied in natural sourdough bread starters to determine physicochemical characteristics [phytic acid hydrolysis, dough rising capacity and pH] in the flour and during sourdough fermentation. Fermentation microorganisms [yeasts and lactic acid bacteria] were also characterized. Results showed a decrease of phytic acid in sourdoughs started with traditional starters, and wide variation in phytase activity. Microorganism counts were high at the end of fermentation, indicating higher fermenting activity of the starters. Yeast populations showed wide variation and lactic acid bacteria had high counts in the fermentation. Phytase activity was demonstrated in starter cultures made of lactic acid bacteria and yeast isolates, the most interesting of which were Saccharomyces cerevisiae combined with Lactobacillus plantarum and Leuconostoc mesenteroides

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Innovations in Sourdough Bread Making

Fermentation ◽

10.3390/fermentation7010029 ◽

2021 ◽

Vol 7 (1) ◽

pp. 29

Author(s):

Stavros Plessas

Keyword(s):

Shelf Life ◽

Nutritional Value ◽

Starter Cultures ◽

Gluten Free ◽

Special Issue ◽

Bread Making ◽

High Quality ◽

Proper Selection ◽

Sourdough Bread ◽

Selection Of

The application of sourdough is considered to be a key tool for the production of high-quality bread. Several advantages have been presented through the application of sourdough in bread making, such as increased shelf life, improved aromatic profiles and sensory characteristics, increased nutritional value, and health benefits. Technological benefits have also been recorded, such as the successful application of sourdough in gluten-free breads. Likewise, an upsurge of interest in sourdough applications in bread making as well as in other foodstuffs (pasta) has been witnessed in recent years. Many factors are considered important for sourdough preparations; however, the proper selection of the starter cultures is considered the most central. This Special Issue of Fermentation aims to disseminate recent innovative research regarding sourdough bread making, as well as authoritative reviews that compile information from previously published material.

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Technological properties, shelf life and consumer preference of spelt-based sourdough bread using novel, selected starter cultures

LWT ◽

10.1016/j.lwt.2021.112097 ◽

2021 ◽

pp. 112097

Author(s):

Dea Korcari ◽

Riccardo Secchiero ◽

Monica Laureati ◽

Alessandra Marti ◽

Gaetano Cardone ◽

...

Keyword(s):

Shelf Life ◽

Consumer Preference ◽

Starter Cultures ◽

Technological Properties ◽

Sourdough Bread

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Compound Identification and In Vitro Cytotoxicity of the Supercritical Carbon Dioxide Extract of Papaya Freeze-Dried Leaf Juice

Processes ◽

10.3390/pr8050610 ◽

2020 ◽

Vol 8 (5) ◽

pp. 610

Author(s):

Kooi-Yeong Khaw ◽

Paul Nicholas Shaw ◽

Marie-Odile Parat ◽

Saurabh Pandey ◽

James Robert Falconer

Keyword(s):

Mass Spectrometry ◽

Carbon Dioxide ◽

Supercritical Carbon Dioxide ◽

Chemical Constituents ◽

Gas Chromatography Mass Spectrometry ◽

Cytotoxic Activities ◽

Compound Identification ◽

Freeze Dried ◽

Leaf Juice ◽

Supercritical Carbon

Carica papaya leaves are used as a remedy for the management of cancer. Freeze-dried C. papaya leaf juice was extracted using a supercritical fluid extraction system. Compound identification was carried out using analytical techniques including liquid chromatography coupled to high-resolution quadrupole time-of-flight mass spectrometry (LC–QToF-MS) and gas chromatography–mass spectrometry (GC–MS). The cytotoxic activities of the scCO2 extract and its chemical constituents were determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on squamous cell carcinoma (SCC25) and human keratinocyte (HaCaT) cell lines. The chemical constituents were quantified by QToF-MS. The supercritical carbon dioxide (scCO2) extract of papaya freeze-dried leaf juice showed cytotoxic activity against SCC25. Three phytosterols, namely, β-sitosterol, campesterol, and stigmasterol, together with α-tocopherol, were confirmed to be present in the scCO2 extract. Quantitative analysis showed that β-sitosterol was the major phytosterol present followed by α-tocopherol, campesterol, and stigmasterol. β-Sitosterol and campesterol were active against SCC25 (half maximal inhibitory concentration (IC50) ≈ 1 µM), while stigmasterol was less active (~33 µM) but was biologically more selective against SCC25. Interestingly, an equimolar mixture of phytosterols was not more effective (no synergistic effect was observed) but was more selective than the individual compounds. The compounds identified are likely accountable for at least part of the cytotoxicity and selectivity effects of C. papaya.

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A high-throughput and sensitive methodology for the quantification of urinary 8-hydroxy-2′-deoxyguanosine: measurement with gas chromatography-mass spectrometry after single solid-phase extraction

Biochemical Journal ◽

10.1042/bj20040004 ◽

2004 ◽

Vol 380 (2) ◽

pp. 541-548 ◽

Cited By ~ 78

Author(s):

Hai-Shu LIN ◽

Andrew M. JENNER ◽

Choon Nam ONG ◽

Shan Hong HUANG ◽

Matthew WHITEMAN ◽

...

Keyword(s):

Gas Chromatography ◽

Solid Phase Extraction ◽

Healthy Subjects ◽

Solid Phase ◽

Large Population ◽

Urine Samples ◽

Gas Chromatography Mass Spectrometry ◽

Phase Extraction ◽

Freeze Dried ◽

Wide Range

8-Hydroxy-2´-deoxyguanosine (8OHdG) is a widely used biomarker for the measurement of endogenous oxidative DNA damage. A sensitive method for the quantification of 8OHdG in urine by single solid-phase extraction and GC-MS (gas chromatography with MS detection) using selective ion monitoring is described in the present study. After solid-phase extraction, samples are freeze-dried, derivatized by trimethylsilylation and analysed by GC-MS. The urinary 8OHdG was quantified using heavy isotope dilution with [18O]8OHdG. The recovery of 8OHdG after the solid-phase extraction ranged from 70 to 80% for a wide range of urinary 8OHdG levels. Using 1 ml of urine, the limit of quantification was >2.5 nM (2.5 pmol/ml) and the calibration curve was linear in the range 2.5–200 nM. This method was applied to measure 8OHdG in urine samples from 12 healthy subjects. The intra- and inter-day variations were <9%. Urinary 8OHdG levels in spot urine samples from four healthy subjects were also measured for 1 week and, again, the variation was small. The presence of H2O2 in urine did not cause artifactual formation of 8OHdG. Since this assay is simple, rapid, sensitive and reproducible, it seems suitable to be used as a routine methodology for the measurement of urinary excretion of 8OHdG in large population studies.

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Core Fluxome and Metafluxome of Lactic Acid Bacteria under Simulated Cocoa Pulp Fermentation Conditions

Applied and Environmental Microbiology ◽

10.1128/aem.01483-13 ◽

2013 ◽

Vol 79 (18) ◽

pp. 5670-5681 ◽

Cited By ~ 36

Author(s):

Philipp Adler ◽

Christoph Josef Bolten ◽

Katrin Dohnt ◽

Carl Erik Hansen ◽

Christoph Wittmann

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Starter Cultures ◽

Superior Performance ◽

Gas Chromatography Mass Spectrometry ◽

Glycolytic Flux ◽

Content Type ◽

Phosphoketolase Pathway ◽

Labeling Approach ◽

Cocoa Fermentation

ABSTRACTIn the present work, simulated cocoa fermentation was investigated at the level of metabolic pathway fluxes (fluxome) of lactic acid bacteria (LAB), which are typically found in the microbial consortium known to convert nutrients from the cocoa pulp into organic acids. A comprehensive13C labeling approach allowed to quantify carbon fluxes during simulated cocoa fermentation by (i) parallel13C studies with [13C6]glucose, [1,2-13C2]glucose, and [13C6]fructose, respectively, (ii) gas chromatography-mass spectrometry (GC/MS) analysis of secreted acetate and lactate, (iii) stoichiometric profiling, and (iv) isotopomer modeling for flux calculation. The study of several strains ofL. fermentumandL. plantarumrevealed major differences in their fluxes. TheL. fermentumstrains channeled only a small amount (4 to 6%) of fructose into central metabolism, i.e., the phosphoketolase pathway, whereas onlyL. fermentumNCC 575 used fructose to form mannitol. In contrast,L. plantarumstrains exhibited a high glycolytic flux. All strains differed in acetate flux, which originated from fractions of citrate (25 to 80%) and corresponding amounts of glucose and fructose. Subsequent, metafluxome studies with consortia of differentL. fermentumandL. plantarumstrains indicated a dominant (96%) contribution ofL. fermentumNCC 575 to the overall flux in the microbial community, a scenario that was not observed for the other strains. This highlights the idea that individual LAB strains vary in their metabolic contribution to the overall fermentation process and opens up new routes toward streamlined starter cultures.L. fermentumNCC 575 might be one candidate due to its superior performance in flux activity.

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From Cheese-Making to Consumption: Exploring the Microbial Safety of Cheeses through Predictive Microbiology Models

Foods ◽

10.3390/foods10020355 ◽

2021 ◽

Vol 10 (2) ◽

pp. 355

Author(s):

Arícia Possas ◽

Olga María Bonilla-Luque ◽

Antonio Valero

Keyword(s):

Production Process ◽

Physicochemical Characteristics ◽

Storage Conditions ◽

Starter Cultures ◽

Predictive Microbiology ◽

Factors Affecting ◽

Modeling Approaches ◽

Modelling Studies ◽

Foodborne Outbreaks ◽

User Friendly

Cheeses are traditional products widely consumed throughout the world that have been frequently implicated in foodborne outbreaks. Predictive microbiology models are relevant tools to estimate microbial behavior in these products. The objective of this study was to conduct a review on the available modeling approaches developed in cheeses, and to identify the main microbial targets of concern and the factors affecting microbial behavior in these products. Listeria monocytogenes has been identified as the main hazard evaluated in modelling studies. The pH, aw, lactic acid concentration and temperature have been the main factors contemplated as independent variables in models. Other aspects such as the use of raw or pasteurized milk, starter cultures, and factors inherent to the contaminating pathogen have also been evaluated. In general, depending on the production process, storage conditions, and physicochemical characteristics, microorganisms can grow or die-off in cheeses. The classical two-step modeling has been the most common approach performed to develop predictive models. Other modeling approaches, including microbial interaction, growth boundary, response surface methodology, and neural networks, have also been performed. Validated models have been integrated into user-friendly software tools to be used to obtain estimates of microbial behavior in a quick and easy manner. Future studies should investigate the fate of other target bacterial pathogens, such as spore-forming bacteria, and the dynamic character of the production process of cheeses, among other aspects. The information compiled in this study helps to deepen the knowledge on the predictive microbiology field in the context of cheese production and storage.

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