Preferment Research Articles

Improvement of the freezing resistance characteristics of yeast in dough starter

Improving the freezing resistance of yeast in dough starters is one of the most effective methods to promote the healthy development of frozen dough technology. When the dough starter was composed of yeast, lactic acid bacteria and acetic acid bacteria, the microbial proportion was 10:1:5, and the ratio of wheat flour to corn flour was 1:1. The proline contents of the starters and the survival rates and fermentation capacity of yeast significantly increased compared with those of the starter composed of yeast and wheat flour only (P < 0.05). Laser confocal microscopy observation showed that the cell membrane damage of yeast obviously decreased. Low-field nuclear magnetic resonance method revealed that the water distribution state of starters changed. Adding corn flour and acetic acid bacteria to dough starter in appropriate proportions improves yeast freezing resistance.

Fermentation properties and functional stability of dough starter Jiaozi and Laomian after frozen storage.

This study aims to investigate the effects of frozen storage on the stability of traditional dough starters in China. The microbial community structure and abundance of related metabolic genes in different fermented sourdough prepared by Jiaozi (JZ) and Laomian (LM) starters before and after frozen storage at -20°C for half a year were analyzed using the shotgun metagenomic sequencing method, and differences in characteristics of texture in steamed bread were also compared by formal methods. The fermentation ability (FA) and metabolic activities of yeast in the JZH sourdough (started by JZ which was stored at -20°C for half a year) were better than those of LMH sourdough (started by LM which was stored at -20°C for half a year). The dominant genera of Acetobacter were found to be increased in the JZH0 sourdough (started by JZH and fermented for 0 h) and those of Lactobacillus were found to be decreased. Lactobacillus (98.72%), Pediococcus (0.37%), Saccharomyces (0.27%), and Acetobacter (0.01%), were dominant in sourdough LMH0 (started by LMH and fermented for 0 h). The abundances of "oxidative phosphorylation-related enzymes" and the "biosynthesis of glutamate"-related enzymes and genes related to "biosynthesis of glutamate" and "unsaturated fatty acid" were higher in JZH0 than in the JZ0 sourdough (started by JZ without being frozen and fermented for 0 h). The good FA of yeast, the acid production capacity of bacteria in the sourdough, and the quality of the JZH steamed bread (made by the JZH starter) indicated the better freezing tolerance of the microorganisms in JZ than in LM. The conclusion of this study suggests the better application potential of the JZ as the fermentation starter in actual production.

Research of the Impact of Full Fat Flax Meal from Oilseed Flax Seeds on the Rye Bread Quality

Bakery products can act as a convenient object for modification and development of qualitatively new products with programmable properties on its basis. A flaxseeds processing product – flaxseed flour can be one of the possible sources of dietary fiber and polyunsaturated fatty acids. The research aim is to study the flaxseed flour impact on the rye bread quality. The thesis presents the impact results of non-fat flaxseed flour obtained from the new seeds varieties of oilseed flax of VNIIMK on the organoleptic and physico-chemical quality indicators of rye bread. A man prepared the dough starter culture from the Livendo® LV4 starting culture. The best flavor was in bread containing 15% flaxseed flour of dark-colored flax seeds of the VNIIMK 620 FN variety. The decrease in porosity of bread crumb with dark flaxseed flour was 1; 3 and 5% in variants with 5; 10 and 15% flour, whereas there was a decrease of 6; 7 and 9% in variants with flour from light-colored seeds, respectively, compared with the control. The authors revealed that adding flour from light-colored seeds reduced porosity more significantly than in bread variants with the flour from dark-colored flax seeds added. The volume of bread weighing 100 g varied from 143 to 170 cm3 . Calculations of nutritional and energy value demonstrated that the carbohydrates amount in bread with flaxseed flour is lower compared to the control (without flaxseed flour). Considering the lack of protein, polyunsaturated fatty acids, dietary fiber in the Russians diet, the bread with non-fat flaxseed flour has prospects for the market introduction.

Physicochemical and microbiological properties of Arabic flatbread produced from wild natural sour starters

Background and objectivesExtensive research studies worldwide have discussed and analyzed the sourdough nutritional, chemical, and biotechnological aspects of western types of bread. However, the literature on sourdough usage in Arabic bread processing is very limited. The present study aimed to come up with a new fermentation technique at the bakery level. The new technique is hoped to reveal the traditional nostalgic characteristic flavor of Arabic bread produced using natural sourdough instead of the traditional yeasted dough and study its effect on the resulting bread. Three types of flour (straight grade, whole wheat, and rye) that are ordinarily used in Jordan were used to prepare three natural sour starters using the backslopping technique. FindingsDominant yeast species isolated from the traditional sour starter of the local Jordanian whole wheat were Saccharomyces cerevisiae, Candida glabrata, and Zygosaccharomyces spp., while rye and straight-grade starters showed different domination patterns. The dominant species of lactic acid bacteria (LAB) isolated from the traditional sour starter of the local Jordanian whole wheat (Horani cultivar) were Lactiplantibacillus plantarum2, Lactobacillus delbrueckii ssp bulgaricus, and the Lacticaseibacillus paracasei ssp paracasei3, while mixed strains of LAB isolates were obtained for the rye and straight-grade flour starters on day 7 of preparation.The pH results showed no significant differences (P > 0.05) between the three types of sour starters, while the total titratable acidity (TTA) results showed a significant increase (P ≤ 0.05) in whole wheat sour starters with a TTA value of 11.17 ± 0.11 ml 0.1 N NaOH/10g dough. The 20% and 30% straight-grade sour bread samples and the control exhibited the highest scores in terms of acceptability and total quality scores. ConclusionsThe incorporation of sourdough in Arabic flatbread processing showed remarkable results in extending the shelf life by using natural ingredients, improving the quality, and providing tastier and more convenient bread.

바나나 사워종을 첨가한 sourdough bread의 품질 특성

This study aimed to investigate the quality characteristics of sourdough produced using a banana starter. The contents of sugar and alcohol of the banana fermented broth increased significantly as the fermentation date increased (p&lt;0.05), and the pH tended to decrease. The titratable acidity of the fermentation broth increased significantly from the 2nd day of fermentation and remained high until the 4th day (p&lt;0.05). The pH of dough and bread decreased as the amount of sour starter added increased (p&lt;0.05), and there was no significant difference in titratable acidity of dough and bread as well as the amount of starter. According to the added amount of banana sour, the moisture content of the bread increased, the crude fat and crude flour content decreased, and the crude protein content hardly changed. The height of bread increased in proportion to the increase in the amount of sour starter added. As for the internal color of the bread, the brightness and yellowness decreased as the addition amount increased, and the redness increased. It was found that the volume, specific volume and baking loss rate of bread increased as the amount of sour starter added increased. In the texture of bread, elasticity and adhesion increased as the amount added increased, but gumminess, brittleness and hardness decreased as the amount added increased. From the above results, it is expected that the banana starter will be used as a useful ingredient in the development of sourdough bread products.

Microbial community diversity of traditional dough starter (Jiaozi) from two provinces in northwest China

PurposeMicrobial community composition is crucial for the flavor and quality of fermented foods. However, the microbiota of Chinese traditional dough starter (Jiaozi) from different origins has scarcely been studied. The aim of this study was to determine the composition of bacterial and fungal communities in six Jiaozi collected from two provinces in northwest China.MethodsOur study determined the composition of bacterial and fungal communities in six Jiaozi through Illumina MiSeq sequencing of the 16S rRNA gene and the ITS regions.ResultA total of 234 operational taxonomic units (OTUs) for bacteria and 490 OTUs for fungi were identified. Furthermore, Lactobacillus, Weissella, Acetobacter, Sphingomonas, and Serratia were identified as the predominant bacterial genera in Jiaozi samples, while Saccharomyces, Candida, Alternaria, unclassified Filobasidiales, and Mycosphaerella were the most abundant fungal genera. The results revealed that the six samples could be grouped into two groups based on their province of origin. In the results of PCA and HCA analysis, the first three principal components which were chosen could explain 99.93% and 90.99% of the total bacterial and fungal communities, respectively.ConclusionThe results indicated high levels of bacteria and fungi in traditional Jiaozi and highlighted the possible influence of geographic areas on microbial diversity.

Exploiting heterozygosity in industrial yeasts to create new and improved baker's yeasts.

The main aim of the work was to utilize heterozygosity of industrial yeast strains to construct new baker's yeast strains. Commercial baker's yeast strain ALKO 743, its more ethanol tolerant descendant ALKO 554 selected initially for growth over 300 generations in increasing ethanol concentrations in a glucose medium, and ALKO 3460 from an old domestic sour dough starter were used as starting strains. Isolated meiotic segregants of the strains were characterized genetically for sporulation ability and mating type, and the ploidy was determined physically. Heterozygosity of the segregant strains was estimated by a variety of molecular characterizations and fermentation and growth assays. The results showed wide heterozygosity and that the segregants were clustered into subgroups. This clustering was used for choosing distantly or closely related partners for strain construction crosses. Intrastrain hybrids made with segregants of ALKO 743 showed 16-24% hybrid vigour or heterosis. Interstrain hybrids with segregants of ALKO 743 and ALKO 3460 showed a wide variety of characteristics but also clear heterosis of 27-31% effects as assayed by lean and sugar dough raising. Distiller's yeast ALKO 554 turned out to be a diploid genetic segregant and not just a more ethanol tolerant mutant of the tetraploid parent strain ALKO 743.

Bacterial diversity in traditional Jiaozi and sourdough revealed by high-throughput sequencing of 16S rRNA amplicons

The bacterial communities of 4 dough fermentation starter samples, including Jiaozi A and D and sourdough B4 and B5 selected from Henan, Jiangsu, and Liaoning province of China were compared by high-throughput sequencing of 16S rRNA genes. The highest number of operational taxonomic units (OTUs) was found for the genus Acetobacter in Jiaozi A, but only OTUs adapted to dough conditions after 8 h (A8) and 24 h (A24) of fermentation using Jiaozi A as dough starter. Members belonging to the genus Pediococcus appeared to dominate in Jiaozi D, especially in the dough (D24) fermented for 24 h started by Jiaozi D. The genus Lactobacillus dominated in sourdough B5, A8, and A24. Weissella was the predominant genus in sourdough B4, and members of the genera Leuconostoc and Lactococcus were also identified.

Quality Characteristics of Sourdough Bread made with Kamut Sour Starter

Quality Characteristics of Sourdough Bread made with Kamut Sour Starter

Quality Characteristics of Sourdough Bread made with Kamut Sour Starter

Quality Characteristics of Sourdough Bread made with Kamut Sour Starter

Conspiracy, Kinship, and Preferment in the Interregnum and Restoration; the Brunsells and Holders of Nottinghamshire

Conspiracy, Kinship, and Preferment in the Interregnum and Restoration; the Brunsells and Holders of Nottinghamshire

醸造微生物利用による製パン試験 (第2報)

醸造微生物利用による製パン試験 (第2報)

The antimicrobial effect of organic acids, sour dough and nisin against Bacillus subtilis and B. licheniformis isolated from wheat bread

Prevention of growth in wheat bread for more than 6 d of approximately 106 rope-producing Bacillus subtilis spores per gram of dough was achieved by addition of propionic or acetic acids at levels of 0·10% v/w (based on flour weight), or by addition of 15% sour dough fermented with Lactobacillus plantarum C11, Lact. brevis L62, Lact. plantarum (‘vege-start 60’), Lact. plantarum (ch 20), Lact. maltaromicus (ch 15), or the commercial sour dough starter culture, Lact. sanfrancisco L99. These cultures resulted in an amount of total titratable acids above 10 in the sour dough and a pH value below 4·8 in the final bread. Bacteriocin-producing lactic acid bacteria added as starter cultures in wheat dough and nisin (Nisaplin) at levels up to 100 p.p.m. g−1 flour had no effect against B. subtilis and B. licheniformis strains, despite the fact that nisin-producing strains of Lactococcus lactis ssp. lactis among 186 strains of lactic acid bacteria had demonstrated inhibitory activity against B. subtilis and B. licheniformis in an agar spot assay.

Contribution of the microbial mass to the nitrogen profile of wheat bread doughs started with pure and mixed cultures of yeast and lactic acid bacteria

This paper describes work investigating the contribution of low-molecular-mass nitrogen metabolites (free amino acids and peptides) to the microbial mass of pure strains of fermentation microorganisms (Saccharomyces cerevisiae, P38;Lactobacillus brevis, B33;L. plantarum, B23 andEnterococcus faecium, B12) when they are incorporated as starters individually and in mixed cultures to wheat bread doughs. Under the experimental conditions used, the microbial mass of P38 releases mainly γ-aminobutyric acid, proline, valine, lysine, isoleucine, glycine and alanine, which account together for less than 5% of the amino acid content of the corresponding bread dough; amino acids in the microbial mass of lactic acid bacteria, mainly glycine and alanine, amount to 1–2% of the dough. The peptide contribution of microbial mass to bread dough is higher and dependent on the strain. Mixing ingredients induces an increase of 65% in the total amino acid content of dough started with P38, particularly of glutamic acid, glutamine, isoleucine, ornithine, lysine, histidine and tyrosine, and a significant rise in peptide levels of all individual doughs with respect to the values obtained for mixtures of flour, water and salt. Starting bread dough with mixtures of yeast and lactic acid does not increase low-molecular-mass nitrogen levels, the amount of peptides being similar to those of dough containing yeast P38 alone. Addition of B33 induces a remarkable increase in the amino acid content of bread dough, mainly of dicarboxylic acids and their amides, and proline, similar to the composition of free amino acids of dough starter with B33.

Effects of lactic acid bacteria on the properties of sour dough bread

The effects of 13 different sour dough bacteria and a commercial sour dough starter from West Germany on the properties of sour dough bread were studied. As reference, a rye bread with lactic acid as souring additive was used. An expert taste panel, trained specifically for bread, was used to judge the bread. All organisms produced acids adequate for a good bread quality. However, the sour doughs fermented with the heterofermentative Lactobacillus spp. had higher acid equivalents, lower pH-values and also gave bread with stronger taste of acidity and acetic acid than those fermented with the homofermentative organisms. Correlation coefficients between taste values and analyses data also show that acetic acid has a great influence on the bread taste, whereas lactic acid seems to be of less importance. Two breads were judged to be somewhat different in taste compared to the others, namely those with sour doughs fermented with Lactobacillus alimentarius and Leuconostoc dextranicum. On comparison with the reference bread, the sour dough bread was judged to have a stronger taste of acidity and also a more aromatic and crispy crust. The bread baked with sour doughs fermented with the heterofermentative organisms, and thus containing the highest amounts of acetic acid, showed the best ability to prevent growth of the mould Eurotium rubrum.

Acidification properties of lactic acid bacteria in rye sour doughs

The acidification properties of 33 different sour dough bacteria and starter cultures, one spontaneously generated sour dough and one commercial sour dough starter, a ‘Reinzuchtsauer’ from West Germany, were characterized. The bacteria were tested in three different sour dough processes, the Berliner short-sour-process, the Detmolder one-stage-process and the recently developed Lönner one-stage-process. The Lönner one-stage-process showed a number of advantages in comparison with the other processes. The organisms produced their lowest pH-values and their highest acid equivalents in this process. The rates of pH-decrease were also higher as well as the fermentation quotients. Some of the organisms previously isolated from sour doughs, showed very good properties of acidification. Among the homofermentative organisms, Lactobacillus acidophilus, L. alimentarius, L. plantarum and the unidentified organisms Lactobacillus spp. I and f showed the best properties. Among the heterofermentative organisms the best properties were displayed by L. brevis ssp. lindneri I and II and the unidentified Lactobacillus spp. e, g, h, k and n.

Effect of Soda Leavening on Phytic Acid Content and Physical Characteristics of Middle Eastern Breads

ABSTRACTThe effect of soda (sodium bicarbonate) as a leavening agent on pH, phytic acid hydrolysis and physical quality of a fermentation model system and two popular Middle Eastern breads, Iranian taftoon and Pakistani naan (Arabic) were studied. Supplementing 0.2 and 0.4% soda invariably decreased phytic acid hydrolysis. In sour starter supplemented dough, phytic acid was reduced by 82% after 3 hr. However, when 0.4% soda and sour starter were added loss of phytic acid did not exceed 29%. Supplementing soda in taftoon and naan bread formula significantly lowered phytic acid hydrolysis during fermentation. Soda had no apparent improvement on physical quality of breads but increased the dough water absorption and lengthened the mixing time.

Shirley's "Preferment" and the Court of Charles I

Shirley's "Preferment" and the Court of Charles I

A Study of the Plays of Thomas D'Urfey, with a Reprint of 'A Fool's Preferment'

A Study of the Plays of Thomas D'Urfey, with a Reprint of 'A Fool's Preferment'

Preferment by Affection

Preferment by Affection