Ability Of Dough Research Articles

Study of the protein-carbohydrate mix effect on the technological properties of short yeast-leavened dough

The possibility of increasing the nutritional and biological value of bakery products through the use of a protein-carbohydrate mix (PCM) is considered. The main purpose of the research was to substantiate the effective concentration of PCM in terms of the technological properties of yeast-leavened dough. The study was conducted on the model systems of short yeast-leavened dough by preactivation of yeast (Saccharomycescerevisia) in a culture medium consisting of water and dry additives produced from potato secondary products. Investigations to determine the chemical and amino acid composition of PCM were carried out, high biological value of the mix was proved. The PCM effect on the gas-forming ability of dough, as well as indicators of active and titratable acidity of the yeast-leavened dough was examined. Improvement of the properties of flour protein-proteinase complex in the presence of PCM was revealed. It is proved that the use of PCM in a concentration of 15% by weight of flour improves the technological properties of yeast-leavened dough. The results can be used in the baking industry to intensify the production of yeast-leavened baked products, as well as increase the biological value of the finished products.

The influence of additional fluors on the retention ability of dough and the technological quality of bakery products

The work monitored rheofermentation properties of dough prepared from composite flours formed by 70% of wheat flour T650 and the addition of 30%. Three kinds of additions were used, namely spelt flour, amaranth flour and buckwheat flour. To determine rheofermentation properties Rheofermentometer Rhea F4 was used, by means of which the dough development, the production of fermentation gases, retention ability of dough and the activity of used baking yeast were analysed. The best ability to retain formed fermentation gas had wheat flour (control) and composite flour with the addition of spelt flour. The composite flour with addition of amaranth flour showed a retention coefficient compared to the control lower by 13%, and the composite flour with addition of buckwheat flour showed a retention coefficient compared to the control reduced by 20%. Control flour and composite flours were then processed in the baking experiment. Based on its results it was possible to evaluate the effect of the addition and retention capacity of dough on the quality of the final products (experimental loaves). The biggest loaf volume (200 cm3) and the optimal vaulting (0.65) were found in the control and a loaf made of composite flour with addition of spelt. Loaf volume, produced from composite flours with the addition of amaranth, and buckwheat was compared to control lower by 18.7%, and 16.3% respectively. The value of vaulting of these products (0.40) can be evaluated as unsatisfactory. Based on the evaluation of results observed by measuring on the rheofermentometer and baking experiment results it can be concluded that a better ability to retain the formed fermentation gas, thus ensuring high volume, had loaves made from wheat flour T650 and composite flour with addition of spelt flour. Based on the findings, it is possible to state that the results of rheofermentometric measurements predict the volume and vaulting of bakery products. By means of Rheofermentometer valuable information has been gained concerning the quality of bakery ingredients, especially flour and yeast.

産学官連携による製パン用「とかち野酵母」の開発

Eight yeast strains were isolated from samples collected in Hokkaido after enrichment culture with a high concentration of sucrose. Among them, strain AK 46, which was derived from dough containing fermented cherry fruits was identified as Saccharomyces cerevisiae. The nucleotide sequence of the rDNA spacer region from this strain was identical to those from yeasts used for the production of whisky, wine, and bread. Strain S. cerevisiae AK 46 carried only only SUC2, which is one of multiple genes that encodes invertase, in contrast to the other baking strains, and its sequences were diverged from those of the corresponding gene found in the other strains. In a comparison of six baking strains, strain AK 46 showed lower leavening ability in dough with and without the addition of 5% sucrose by weight of flour but showed high leavening ability in sweet dough containing 30% sucrose. The activities of enzymes α-glucosidase and invertase, which are related to dough fermentation, were lower than those in the other strains. A baking test showed that strain AK 46 was suitable for breadmaking by various methods. Cells of strain AK 46 were propagated industrially and used for the commercial production of dry yeast called “Tokachino”, which is named for the region from which it was isolated.

Baking Properties of Saccharomyces cerevisiae Strains Derived from Brem, a Traditional Rice Wine from Bali

Twenty-two strains of Saccharomyces cerevisiae isolated from tape-mash for the production of brem, a traditional rice wine from Bali, Indonesia, were divided into three groups (I, II, and III) based on the se- quences of the rDNA spacer region and SUC2 gene. DNA analyses suggested that the seventeen strains in groups II and III were taxonomically closer to baking strains than the five strains in group I. These differ - ences were reflected in their leavening ability in dough with and without addition of 5% sucrose, and their α-glucosidase activity, although most of the strains did not leaven dough with addition of 30% sucrose. Strain S-10 in group II showed a high rate of CO2 production from sponge dough without addition of sugar and consumed fermentable sugar within 2.5 h. When baking tests were conducted, strain S-10 and commercial baking strain HP 216 yielded comparable products by the straight-dough and sponge-dough methods.

Characterization of an Alternative Baking Strain of Saccharomyces cerevisiae Isolated from Fermented Cherry Fruits by the Analysis of SUC2 Gene

The yeast strain AK 46 was isolated from dough containing fermented cherry fruits and identified as Saccharomyces cerevisiae. The nucleotide sequence of the rDNA spacer region from this strain coincided with those from the yeasts used for the production of whisky, wine, and bread. In a comparison with six baking strains, strain AK 46 possessed less leavening ability in dough with and without addition of 5% sucrose (based on the weight of flour) but a high ability in sweet dough containing 30% sucrose. The activities of the two enzymes α-glucosidase and invertase, which are related to dough fermentation, were lower than those in the other strains. A baking test showed that strain AK 46 was applicable for breadmaking using the straight dough and sponge dough methods. Strain AK 46 carried only SUC2, which is one of multiple genes encoding invertase, in contrast to the other baking strains, and its sequences diverged from those of the corresponding gene from a representative laboratory strain. Southern hybridization of genomic DNA, using the SUC2 gene as the probe, readily discriminated strain AK 46 and other strains. These observations indicate that strain AK 46 is a wild strain possessing breadmaking properties.

Improvement of tolerance to freeze–thaw stress of baker’s yeast by cultivation with soy peptides

The tolerance to freeze-thaw stress of yeast cells is critical for frozen-dough technology in the baking industry. In this study, we examined the effects of soy peptides on the freeze-thaw stress tolerance of yeast cells. We found that the cells cultured with soy peptides acquired improved tolerance to freeze-thaw stress and retained high leavening ability in dough after frozen storage for 7 days. The final quality of bread regarding its volume and texture was also improved by using yeast cells cultured with soy peptides. These findings promote the utilization of soy peptides as ingredients of culture media to improve the quality of baker's yeast.

Cooperation of phosphatidylcholine with endogenous lipids of wheat flour for an increase in dough volume

Phosphatidylcholine (PC) increases the gas-retaining ability of dough, the dough volume on fermentation and the loaf volume of bread. The cooperation of wheat flour endogenous lipids with PC was examined. More than 90% of the total wheat flour lipids were extracted with chloroform, the extracted lipids comprising glycolipids (33 wt%), non-polar lipids (56 wt%), and phospholipids (11 wt%). The increase in the specific volume of dough with delipidated wheat flour by the addition of PC was smaller than the increase in the specific volume of dough with native wheat flour. The addition of the extracted lipids to delipidated wheat flour restored the increase in dough volume by the addition of PC. The glycolipid fraction of the extracted lipids was most effective for enhancing the action of PC. The results suggest that interaction of PC with wheat flour glycolipids may synergistically increase foam stability to enhance the gas-retaining stability of dough.

Deficiency in the glycerol channel Fps1p confers increased freeze tolerance to yeast cells: application of the fps1delta mutant to frozen dough technology.

Intracellular glycerol content affects the freeze-thaw stress tolerance of Saccharomyces cerevisiae. We have recently reported that intracellular-glycerol-enriched cells cultured in glycerol medium acquire tolerance to freeze stress and retain high leavening ability even in dough after frozen storage [Izawa et al. (2004) Appl Microbiol Biotechnol http://dx.doi.org/10.1007/s00253-004-1624-4]. A deletion mutant of the FPS1 gene, which encodes a glycerol channel, accumulates glycerol inside the cell without an exogenous supply of glycerol into the medium. We found that the fps1delta cells acquired tolerance to freeze stress and retained high leavening ability in dough after frozen storage for 7 days. These results suggest that the fps1delta mutant is a useful strain for developing better frozen-dough with a commercial advantage.

Intracellular glycerol influences resistance to freeze stress in Saccharomyces cerevisiae: analysis of a quadruple mutant in glycerol dehydrogenase genes and glycerol-enriched cells.

Glycerol is well known as a cryoprotectant similar to trehalose. However, there is little information about the effects of intracellular glycerol on the freeze-thaw stress tolerance of yeast. Through analysis of a quadruple-knockout mutant of glycerol dehydrogenase genes (ara1 Delta gcy1 Delta gre3 Delta ypr1 Delta) in Saccharomyces cerevisiae, we revealed that the decrease in glycerol dehydrogenase activity led to increased levels of intracellular glycerol. We also found that this mutant showed higher tolerance to freeze stress than wild type strain W303-1A. Furthermore, we demonstrated that intracellular-glycerol-enriched cells cultured in glycerol medium acquire tolerance to freeze stress and retain high leavening ability in dough even after frozen storage for 7 days. These results suggest the possibility of using intracellular-glycerol-enriched cells to develop better frozen dough.

Leavening ability of baker’s yeast exposed to hyperosmotic media

To develop a simple and rapid method for enhancing the leavening ability of baker’s yeast, we examined the fermentation ability of baker’s yeast exposed to hyperosmotic media. When baker’s yeast cells were incubated at 25°C for 1 h in a hyperosmotic medium containing 0.5% yeast extract, 0.5% peptone and 20% sucrose, the cells showed a higher fermentation ability in the subsequent fermentation test than those untreated. The increased ratios were from 40 to 60% depending on the strains used. Glucose and fructose showed a similar effect to that of sucrose, but sorbitol was less effective. A high correlation between the intracellular glycerol content and fermentation ability after the osmotic treatment suggested that glycerol accumulated during the hyperosmotic treatment was used in the subsequent fermentation as a substrate, lessened the lag time, and consequently enhanced the fermentation ability. Various baker’s yeasts also showed a high leavening ability in dough after the hyperosmotic treatment.

Leavening ability of baker's yeast exposed to hyperosmotic media.

To develop a simple and rapid method for enhancing the leavening ability of baker's yeast, we examined the fermentation ability of baker's yeast exposed to hyperosmotic media. When baker's yeast cells were incubated at 25 degrees C for 1 h in a hyperosmotic medium containing 0.5% yeast extract, 0.5% peptone and 20% sucrose, the cells showed a higher fermentation ability in the subsequent fermentation test than those untreated. The increased ratios were from 40 to 60% depending on the strains used. Glucose and fructose showed a similar effect to that of sucrose, but sorbitol was less effective. A high correlation between the intracellular glycerol content and fermentation ability after the osmotic treatment suggested that glycerol accumulated during the hyperosmotic treatment was used in the subsequent fermentation as a substrate, lessened the lag time, and consequently enhanced the fermentation ability. Various baker's yeasts also showed a high leavening ability in dough after the hyperosmotic treatment.

Role of maltose permease and α-glucosidase in maltose fermentation and dough-leavening of Torulaspora pretoriensis YK-1

The yeast Torulaspora pretoriensis YK-1 possesses both high potential leavening ability and freeze-thaw resistance, but its leavening ability in dough, without the addition of sugar, is much less than commercial baking strains (Oda and Tonomura 1993) Institute for Fermentation, Osaka, Japan (IFO) 0022, another strain of T. pretoriensis , previously found to leaven dough efficiently without the addition of sugar, showed higher activities of both maltose permease and α -glucosidase and fermented maltose in an aqueous medium faster than YK-1. No significant difference was observed between the affinities of maltose permease and α -glucosidase from IFO 0022 and those from YK-1. MAL61 and MAL62 genes of Saccharomyces cerevisiae were expressed in T. pretoriensis YK-1 and elevated the activities of maltose permease and α -glucosidase, respectively, when these genes were introduced on YCp-type plasmids under control of the glyceraldehyde 3-phosphate dehydrogenase promoter. Maltose fermentation by cells harbouring the plasmids carrying either MAL61 or MAL62 genes was slightly stimulated. Introduction of both genes further enhanced the maltose fermentation rate but not leavening ability in dough without the addition of sugar. These results suggest that maltose permease and α -glucosidase determine the overall velocity of maltose fermentation.

Hybridization of Bakers' yeast by the rare-mating method to improve leavening ability in dough

Saccharomyces cerevisiae MA233 is a diploid strain that is available for breadmaking by the frozen-dough method but it has lower leavening ability than commercial Bakers' yeasts in dough with no sugar or a small amount of sugar. To improve baking quality, MA233 was hybridized with YOY34, a haploid derived from a commercial baking strain, by the rare-mating method. The hybrid YOY671 exhibited MAL-constitutive phenotype of α-glucosidase, resulting in an increased rate of CO 2 production from the dough without addition of sugar. YOY671 had a higher leavening ability in the dough containing 5% to 30% sucrose (based on the weight of flour) than MA233. Freeze-thaw resistance of YOY671 in dough was higher than that of YOY34, but less than that of MA233.

Potassium oxide in California : Anon. ( Oil, Paint, and Drug Rep., Sept. 7, 1914)

The yeast Torulaspora pretoriensis YK-1 possesses both high potential leavening ability and freeze-thaw resistance, but its leavening ability in dough, without the addition of sugar, is much less than commercial baking strains (Oda and Tonomura 1993) Institute for Fermentation, Osaka, Japan (IFO) 0022, another strain of T. pretoriensis, previously found to leaven dough efficiently without the addition of sugar, showed higher activities of both maltose permease and α-glucosidase and fermented maltose in an aqueous medium faster than YK-1. No significant difference was observed between the affinities of maltose permease and α-glucosidase from IFO 0022 and those from YK-1. MAL61 and MAL62 genes of Saccharomyces cerevisiae were expressed in T. pretoriensis YK-1 and elevated the activities of maltose permease and α-glucosidase, respectively, when these genes were introduced on YCp-type plasmids under control of the glyceraldehyde 3-phosphate dehydrogenase promoter. Maltose fermentation by cells harbouring the plasmids carrying either MAL61 or MAL62 genes was slightly stimulated. Introduction of both genes further enhanced the maltose fermentation rate but not leavening ability in dough without the addition of sugar. These results suggest that maltose permease and α-glucosidase determine the overall velocity of maltose fermentation.