共查询到20条相似文献,搜索用时 203 毫秒
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低糖适应性耐冻面包酵母菌种的性能及应用 总被引:1,自引:0,他引:1
对已筛选出的2株低糖适应性耐冻面包酵母BY-03和FY-03进行了发酵力、存活率、麦芽糖酶活力和耐糖性的测定以及面包制作应用实验。实验结果表明,-20℃下冷冻4周后BY-03和FY-03的发酵力保持在40%以上,存活率在60%以上,明显高于市售普通酵母;其麦芽糖酶活力分别为10.12和15.10u/g,高于普通低糖酵母和普通高糖酵母;且在蔗糖质量分数为0%~40%的条件下生长良好。应用实验表明,含BY-03和FY-03的低糖面团在冷冻4周后其面包制品的感官综合评价结果均好于普通酵母制品。 相似文献
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Hernández-López MJ Pallotti C Andreu P Aguilera J Prieto JA Randez-Gil F 《International journal of food microbiology》2007,116(1):103-110
Torulaspora delbrueckii is a baker's yeast that is highly tolerant to freeze-thaw stress, making it suitable for frozen dough technology. The T. delbrueckii strain PYCC5321, isolated from traditional bread dough, combines this tolerance with a high degree of ionic and osmotic stress resistance. However, the industrial use of this strain for frozen and sweet frozen baking is hampered by its small cell size, which causes clogging problems at the filtering stage. Here, we report the construction of a stable diploid strain of T. delbrueckii PYCC5321, which we named Td21-2n. The new strain was more than 2.7-fold bigger than their haploid counterpart, whereas biomass yield, stress resistance and sweet dough leavening ability were found to be similar in both strains. Moreover, the gassing power of the diploid after dough freezing also remained unaltered. Thus, Td21-2n meets the requirements necessary for industrial production and is suitable for application in frozen sweet baking products. 相似文献
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Among five strains of Zymomonas mobilis strain Z6C had the highest leavening ability in doughs containing either glucose or sucrose. Z6C most efficiently leavened the dough when it contained 5% sucrose, and this leavening ability was twice as much as that of commercial compressed yeast. At the same concentrations of NaCl, the leavening ability of Z6C was reduced more than that of baker's yeast. When comparing baked goods made with yeast, those made with Z6C had similar specific volumes, but Z6C baked goods had slight acidic flavor. Chromatographic analysis of head-space gas of yeast-leavened bread showed that two chemicals appearing in Z6C leavened bread were missing. 相似文献
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A method based on microbial re-inoculation, or the so-called backslopping and subsequent proofing of rye bread dough simulating commercial one-stage sourdough process, was used for the screening of the leavening capacity of sourdough yeast strains. Two yeast strains were initially tested with seven Lactobacillus strains. Thereafter, 17 yeast strains, mostly of sourdough origin, were tested with a backslopping procedure with heterofermentative Lactobacillus brevis as an acidifying lactic acid bacteria (LAB). The highest leavening capacity was found in sourdoughs containing Candida milleri, in particular when it was accompanied by obligately homofermentative Lactobacillus acidophilus or facultatively heterofermentative Lactobacillus plantarum when it acted homofermentatively. The leavening capacity of the reference strain Saccharomyces cerevisiae was about half that of C. milleri in all sourdoughs tested. The re-inoculation procedure increased the differences found in the leavening capacity of the tested yeast strains during final proofing of rye bread dough. The backslopped sourdoughs containing a heterofermentative Lactobacillus strain were more suppressive than those containing a homofermentative strain. The highest leavening capacity was found in C. milleri strains. The use of one backslopping cycle before assaying the leavening capacity of a laboratory sourdough is recommended since it helps to differentiate between yeast strains to be tested for their leavening power in the final bread dough. 相似文献
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本文研究了面包酵母高糖耐性与蔗糖酶活性的关系。通过对八株酵母菌株的蔗糖酶活性和高糖面团发酵力比较分析,其中ADY2蔗糖酶酶活最大,BY-6最小,分别为128.70 U/g干酵母和30.55 U/g干酵母,而在高糖面团中发酵力却是BY-6最大,ADY2最小,CO2的产生量分别为850 ccm和225 ccm,证实了较低蔗糖酶活性的面包酵母菌株具有在高糖面团中发酵力较高的特性。通过测定蔗糖酶酶活相差较大的株菌BY-6和ADY2在蔗糖模拟面团中的蔗糖消耗和葡萄糖积累曲线,结果表明ADY2不仅蔗糖消耗速度比BY-6快,且其积累葡萄糖的速度比BY-6快,同时所积累的最高葡萄糖量也比BY-6高,分别为5.89?10-2和4.50?10-2 g/mL。此外,即便是蔗糖酶酶活低且高糖面团发酵力大菌株BY-6在蔗糖模拟面团培养基中仍有较多葡萄糖积累,因此选育蔗糖酶水解生成葡萄糖速度与其利用葡萄糖速度一致或相差不大的菌株是我们选育耐高糖面包酵母菌株的一个控制靶点。 相似文献
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Nore Struyf Eva Van der Maelen Sami Hemdane Joran Verspreet Kevin J. Verstrepen Christophe M. Courtin 《Comprehensive Reviews in Food Science and Food Safety》2017,16(5):850-867
Yeast‐mediated dough fermentation is an important phase in the bread making process. The fermentative performance of yeast cells during fermentation is of critical importance for final bread quality, since yeast cells produce CO2 and other metabolites that have an influence on dough rheology and bread texture, volume, and taste. Different factors affect the fermentative performance of yeast cells during dough fermentation, including dough ingredients, fermentation conditions, the type of yeast strain used and yeast pregrowth conditions. Bread dough is a complex matrix that contains several ingredients that can affect the fermentation rate of yeast cells. Although the individual effects of sugar availability and salt level on the leavening ability of yeast have been studied extensively, a comprehensive overview of the relationship between bread dough constituents, fermentation conditions and yeast functionality is still lacking. Moreover, the dough environment is highly variable as several types of dough like lean, sweet or frozen doughs are currently produced by commercial bread producers. For optimal fermentation rates in different types of dough, the use of appropriate yeast strains with specific phenotypic traits is required. Therefore, many researchers have focused on the improvement of yeast strains for optimal fermentation in different types of dough like lean, sweet or frozen dough. Against this background, this review summarizes the current knowledge on the interaction between bread dough and baker's yeast and how to improve this interaction, thereby providing a useful background for further research concerning the functionality of yeast in bread dough. 相似文献
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Influence of yeast and frozen storage on rheological, structural and microbial quality of frozen sweet dough 总被引:2,自引:0,他引:2
Smail Meziani Jordane JasniewskiPablo Ribotta Elmira Arab-TehranyJean-Marc Muller Mohamed GhoulStéphane Desobry 《Journal of food engineering》2012,109(3):538-544
The aim of the present study was to investigate the effect of yeast content and frozen storage (9 weeks at −40 °C) on the structural and rheological parameters, and fermentative activity of frozen sweet dough. Two types of dough were studied (to estimate dough shelf life): simple yeasted dough (SY) and double yeasted dough (DY). Fermentative activity (yeast viability, gassing power, and dough volume), rheological and textural parameters were assessed for frozen sweet doughs.These effects were explored by different and complementary methods: Fourier transform infrared (FTIR), dynamic rheology, texture profile analysis (TPA) and differential scanning calorimetry (DSC).The data showed that the longer the frozen storage time at −40 °C, the higher the decreased of frozen sweet dough quality. The rheological attributes such as hardness, ΔS, springiness, tan δ and yeast activity declined significantly during frozen storage. This modification led to lower specific volume of frozen sweet dough during proofing.The observed changes of the frozen sweet doughs rheological properties after thawing may be attributed to the damage on the gluten cross-linking, mainly produced by the ice crystallization during frozen storage. The storage effect was particularly concentrated in the first 27 days of storage. 相似文献
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We examined the effect of poly-gamma-glutamate (PGA) on the freeze-tolerance of four types of commercial bakers' yeast (freeze-tolerant, osmotic-tolerant, low-temperature-sensitive, and ordinary bakers' yeasts). The survival ratio of ordinary bakers' yeast cells frozen at -30 degrees C for 3 d in a medium (0.5% yeast extract, 0.5% peptone, and 2% glucose: YPD medium) was improved by adding more than 1% PGA to the medium; the survival ratio increased from about 10% to more than 70%. All PGA preparations, which differed in average molecular mass (50, 2,000, 4,000, 6,000, 8,000, and 10,000 kDa), showed a similar cryoprotecive effect on the cells. Similar results were also obtained with other types of bakers' yeast, sake yeast and beer yeast. When the four types of bakers' yeast cell were frozen at -30 degrees C for 3 d in dough supplemented with more than 1% PGA, the cells (after freezing and thawing) showed higher leavening ability than those frozen in dough without PGA, irrespective of the molecular mass of PGA. Thus, PGA appears to protect bakers' yeast from lethal freeze injury, leading to a high leavening ability after freezing and thawing. PGA did not decrease the original leavening ability of the bakers' yeast, and was not decomposed by the yeast cells. PGA suppressed the decrease in leavening ability during a prolonged fermentation time, probably because PGA adsorbed inhibitory metabolites accumulated in the dough. PGA could prove useful for improving the freeze-tolerance of bakers' yeast by its addition to dough. 相似文献
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