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Effects of Salt on Wheat Flour Dough Fermentation
Toshiyuki Toyosaki,Yasuhide Sakane
Advance Journal of Food Science and Technology , 2013,
Abstract: Most food chemistry characteristics in the dough fermentation of salt are not solved. Effects of salt on the acceleration process of wheat flour dough fermentation were studied, respectively. The mechanism of dough expansion influenced by salt and yeast was also investigated. The dough expansion rate with no salt reached a maximum of 18% in the 50 min dough fermentation time. In contrast, dough with 2.0% salt reached an expansion rate of 96% in 30 min of fermentation. Furthermore, the maximum dough expansion rate with 8.0% salt was 58% in 20 min. Lipid peroxidation catalyzed by baker’s yeast was observed in the dough fermentation process following the addition of salt. Although the baker’s yeast catalyzed lipid peroxidation salt triggered the reaction. The hydroperoxide produced in the induced lipid peroxidation reaction was found to play an unspecified role in the expansion phenomenon of dough. Based on these findings, we examined how salt is associated with the dough fermentation phenomenon. We hypothesized that the presence of salt would induce the following two chemical phenomena: 1) Salt enhances cross-linkages between gliadin and glutelin, which in turn leads to increased gluten content. 2) While baker’s yeast catalyzes lipid peroxidation, salt potentiates this reaction. We speculated that hydroperoxide, produced in lipid peroxidation, would accelerate the dough fermentation process, thereby resulting in a higher dough expansion rate. These results revealed some new findings in the biochemical effects of salt in bread making, which could break new ground in the bread-making industry.
Effect of Microwave, Infrared and Infrared-assisted Microwave Heating on the Drying Rate of Bread Dough
Suzan Tireki,Gulum Sumnu,Ali Esin
American Journal of Food Technology , 2006,
Abstract: The present study was aimed to determine the contribution of microwave and infrared drying mechanism in infrared-assisted microwave drying. Bread dough samples were dried from 40.9 to 8% moisture content (wet basis) with microwave, infrared and infrared-assisted microwave drying by using halogen lamp-microwave combination oven. Microwave and/or halogen power levels of 30, 50 and 70% were used. It was found that in the infrared-assisted microwave drying, microwave energy was the dominant mechanism with about nine times greater contribution than that of infrared. An estimation for the change in the relative drying rate of infrared-assisted microwave drying was found by using the relative drying rate values and the fractional contributions of both drying mechanisms.
Influence of fermentation and cowpea steaming on some quality characteristics of maize-cowpea blends
S Sefa-Dedeh, Y Kluvitse, EO Afoakwa
African Journal of Science and Technology , 2001,
Abstract: Fermentation and cowpea steaming can be used to improve the protein quality and quantity of fermented maize dough. In the production of maize-cowpea blends, it is important that the quality characteristics are evaluated to determine their functionality in the products. A 5x4x2x2 factorial experiment with cowpea level, fermentation time, cowpea steaming time and fermentation method as the variable was performed. The cowpeas were dehulled, steamed, dried at 65EC for 24 hours and milled into flours. Maize was soaked in water (18 hours), drained and milled into flour. The maize-cowpea blends were made into a 50% moisture dough, fermented for the specified periods, dried at 65EC and milled into flour. Samples were evaluated for pH, titratable acidity, water absorption and sugars. The pH and titratable acidity of the samples were affected by fermentation time, steaming time, and the levels of cowpeas in the blend. Cowpeas was the main source of glucose/galactose. Fermentation caused a reduction in stacchyose and glucose/galactose. The mixing of cowpea flour with fermented maize dough prior to drying (single component fermentation) gave similar effects on sugar concentrations as detected in the co-fermented samples (multi-component fermentation). Fermentation and steamed cowpea fortification can be used to produce high protein fermented cereal foods with reduced anti-nutritional factors.
Influence of Fermentation and Drying Materials on the Contamination of Cocoa Beans by Ochratoxin A  [PDF]
Sébastien Djédjé Dano,Pierre Manda,Ardjourma Dembélé,Ange Marie-Joseph Kouassi Abla,Joel Henri Bibaud,Julien Zroh Gouet,Charles Bruno Ze Maria Sika
Toxins , 2013, DOI: 10.3390/toxins5122310
Abstract: Ochratoxin A (OTA) is a mycotoxin produced mainly by species of Aspergillus and Penicillium. Contamination of food with OTA is a major consumer health hazard. In Cote D’Ivoire, preventing OTA contamination has been the subject of extensive study. The current study was conducted to evaluate the influence of fermentation and drying materials on the OTA content in cocoa. For each test, 7000 intact cocoa pods were collected, split open to remove the beans, fermented using 1 of 3 different materials, sun-dried on 1 of 3 different platform types and stored for 30 days. A total of 22 samples were collected at each stage of post-harvesting operations. The OTA content in the extracted samples was then quantified by high-performance liquid chromatography. OTA was detected in beans at all stages of post-harvesting operations at varying levels: pod-opening (0.025 ± 0.02 mg/kg), fermentation (0.275 ± 0.2 mg/kg), drying (0.569 ± 0.015 mg/kg), and storage (0.558 ± 0.04 mg/kg). No significant relationships between the detected OTA level and the materials used in the fermentation and drying of cocoa were observed.
Production of fungal protein by solid substrate fermentation of cactus Cereus peruvianus and Opuntia ficus indica
Oliveira, Moises A.;Rodrigues, Claudenice;Reis, Edson Marques dos;Nozaki, Jorge;
Química Nova , 2001, DOI: 10.1590/S0100-40422001000300004
Abstract: agricultural wastes from cactus cereus peruvianus and opuntia ficus indica were investigated for protein production by solid substrate fermentation. firstly, the polyelectrolytes were extracted and used in water cleaning as auxiliary of flocculation and coagulation. the remaining fibrous material and peels were used as substrate for fermentation with aspergillus niger. glucoamylase and cellulase were the main enzymes produced. amino acids were determined by hplc and protein by lowry's method. after 120 hours of fermentation the protein increased by 12.8%. aspartic acid (1.27%), threonine (0.97%), glutamic acid (0.88%), valine (0.70%), serine (0.68%), arginine (0.82%), and phenylalanine (0.51%) were the principal amino acids produced.
Production of fungal protein by solid substrate fermentation of cactus Cereus peruvianus and Opuntia ficus indica  [cached]
Oliveira Moises A.,Rodrigues Claudenice,Reis Edson Marques dos,Nozaki Jorge
Química Nova , 2001,
Abstract: Agricultural wastes from cactus Cereus peruvianus and Opuntia ficus indica were investigated for protein production by solid substrate fermentation. Firstly, the polyelectrolytes were extracted and used in water cleaning as auxiliary of flocculation and coagulation. The remaining fibrous material and peels were used as substrate for fermentation with Aspergillus niger. Glucoamylase and cellulase were the main enzymes produced. Amino acids were determined by HPLC and protein by Lowry's method. After 120 hours of fermentation the protein increased by 12.8%. Aspartic acid (1.27%), threonine (0.97%), glutamic acid (0.88%), valine (0.70%), serine (0.68%), arginine (0.82%), and phenylalanine (0.51%) were the principal amino acids produced.
Biochemical, Microbial and Processing Study of Dèguè a Fermented Food From Pearl millet dough) from Burkina Faso  [PDF]
Fatoumata Hama,Aly Savadogo,Cheik A.T. Ouattara,Alfred S. Traore
Pakistan Journal of Nutrition , 2009,
Abstract: Dèguè was a traditional fermented food (pearl millet dough) which consumed in Burkina Faso. In this work, the traditional processing of pearl millet into dèguè was investigated in 18 traditional production units. This study was followed in Ouagadougou and Bobo-Dioulasso. The main steps of diagram of production were dehulling, winnowing, washing, drying, milling, sieving, kneading, cooking, pounding, shaping and fermentation. Before fermentation, crude protein, crude fat, ash, starch and carbohydrates content were respectively 5.43; 3.00; 1.13; 33.37 and 41.81 %. After 72 hours of fermentation only protein content (6.12 %) was increased; starch content was(23.6 %) decreased. pH and titratable acidity were respectively 6.75 and 0.12 before the fermentation and after 72 hours pH (4.49) was decreased and titratable acidity (0.57 g of 100 grams of lactic acid) was increased. Microbiology analyses indicated that the number of lactic acid bacteria, yeasts and moulds increased during the course of fermentation. The number of coliforms was decreased slightly after 72 hours of fermentation.
Incidence and distribution of filamentous fungi during fermentation, drying and storage of coffee (Coffea arabica L.) beans
Silva, Cristina Ferreira;Batista, Luis Roberto;Schwan, Rosane Freitas;
Brazilian Journal of Microbiology , 2008, DOI: 10.1590/S1517-83822008000300022
Abstract: the objective of this work was to isolate and characterize filamentous fungi present in different stages of harvest, fermentation, drying and storage of coffee beans processed by natural method. the cherries were hand-picked and then placed on a cement drying platform where they remained until reached 11% of humidity. microbial counts were found in all samples during fermentation and drying of the coffee beans. counts of fungi in the coffee cherries collected from the tree (time 0) were around 1.5 x 103 cfu/g. this number increased slowly during the fermentation and drying reaching values of 2 x 105 cfu/g within 22 days of processing. two hundred and sixty three isolates of filamentous fungi were identified. the distribution of species during fermentation and drying was very varied while there was a predominance of aspergillus species during storage period. the genera found were pestalotia (4), paecelomyces (4), cladosporium (26), fusarium (34), penicillium (81) and aspergillus (112) and comprised 38 different species.
Influence of addition of amylase preparation to dough on fermentative activity of baker's yeast  [PDF]
Dodi? Jelena M.,Pejin Du?anka J.,Popov Stevan D.,Dodi? Sini?a N.
Zbornik Matice Srpske za Prirodne Nauke , 2005, DOI: 10.2298/zmspn0508217d
Abstract: Dough samples with different content of amylases were investigated immediately after mixing and after 7, 14 and 30 days of frozen storage. The obtained results show that the fermentation time is shorter, both in fresh and frozen samples, when amylase sample 1 was added, compared to dough without enzymes. The addition of amylase 2 to dough resulted in minimal decrease of "rising" time, both is frozen and fresh dough samples. The rising time of fresh samples was shorter when amylase 3 was added to dough. The specific fermentative activity of fresh dough samples is increasing by about 10% compared to the control sample, for all amounts of amylase 1 and 2 added to the do- ugh. The fermentative activity of yeast in frozen samples increased by 5-10%, after keeping of dough with the addition of amylase 1 for 14 days. The specific fermentative activity of fresh dough samples increased compared to the control, for all amounts of added amylase 3 to the dough. In frozen dough samples the fermentative activity of yeast decreased by 10% for all added amounts of amylase 3. Baked goods made of fresh and frozen dough, prepared with the addition of amylase 1, are better than the ones made of control dough sample, considering all evaluated parameters.
Influence of dough freezing on Saccharomyces cerevisiae metabolism  [PDF]
Pejin Du?anka J.,Do?anovi? Irena S.,Popov Stevan D.,Suturovi? Zvonimir J.
Zbornik Matice Srpske za Prirodne Nauke , 2007, DOI: 10.2298/zmspn0713293p
Abstract: The need to freeze dough is increasing in bakery production. Frozen dough can be stored for a long time without quality change. The capacity of bakery production can be increased in this way, and in the same time, the night shifts can be decreased. Yeast cells can be damaged by freezing process resulting in poor technological quality of dough after defrostation (longer fermentation of dough). The influence of frozen storage time of dough on survival percentage of Saccharomyces cerevisiae was investigated. Dough samples were taken after 1, 7, 14 and 28 days of frozen storage at -20°C. After defrosting, at room temperature, samples were taken from the surface and the middle part of dough (under aseptic conditions), and the percentage of living S. cerevisiae cells was determined. During frozen storage of dough, the number of living S. cerevisiae decreased. After 28 days of frozen storage, the percentage of live cells on the surface and inside the dough was 53,1% and 54,95%, respectively. The addition of k-carragenan to dough increased the percentage of living cells in the middle part of dough up to 64,63%. Pure cultures, isolated from survived S. cerevisia cells in frozen dough by agar plates method (Koch's method), were multiplied in optimal liquid medium for yeasts. The content of cytochromes in S. cerevisiae cells was determined by spectrophotometric method. The obtained results showed that the content of cytochromes in survived S. cerevisiae cells was not affected by dough freezing process. Growth rate and fermentative activity (Einchor's method) were determined in multiplied cells.
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