Comparison of active dry yeast (Saccharomyces cerevisiae) and yeast culture for growth performance, carcass traits, meat quality and blood indexes in finishing bulls

2015 ◽  
Vol 87 (8) ◽  
pp. 982-988 ◽  
Author(s):  
Chun-Yin Geng ◽  
Li-Ping Ren ◽  
Zhen-Ming Zhou ◽  
Ying Chang ◽  
Qing-Xiang Meng
2015 ◽  
Vol 14 (3) ◽  
pp. 575-582 ◽  
Author(s):  
Pedro A Hernández-García ◽  
Alejandro Lara-Bueno ◽  
Germán D Mendoza-Martínez ◽  
José R Bárcena-Gama ◽  
Fernando X Plata-Pérez ◽  
...  

Fermentation ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 31
Author(s):  
Pilar Blanco ◽  
María Vázquez-Alén ◽  
Teresa Garde-Cerdán ◽  
Mar Vilanova

Yeast plays an essential role in winemaking. Saccharomyces cerevisiae strains involved in fermentation determine the chemical and sensory characteristics of wines. S. cerevisiae XG3, isolated in Galicia (NW Spain), has desirable oenological potential, which has been proved at a pilot scale to produce quality wines. This study applies XG3 as active dry yeast at an industrial scale for Treixadura wine elaboration, and compares it with commercial yeast and spontaneous fermentation within three wineries included in Denomination of Origin Ribeiro over two vintages. Fermentations are monitored using conventional methods, and microbiological implantation controls are carried out by mtDNA-RFLPs analysis. Wine basic chemical parameters are determined using OIV official methodology, and volatile aroma compounds are determined by GC-MS. Finally, wine sensory analysis is also performed. S. cerevisiae XG3 shows an acceptable implantation ability—as compared to commercial control strains. The wines from XG3 have a higher total acidity and lower alcohol content. Their volatile composition differs from control wines, since XG3 produces significantly higher concentrations of acetates, volatile acids, esters and volatile phenols, depending on the vintage and winery. However, lower differences are perceived at the sensory level, where fruity and floral descriptors are perceived by the panellists in XG3 wines. Therefore, XG3 constitutes an alternative to differentiate Treixadura wines.


Author(s):  
А.А. АЛЕКСЕЕВА ◽  
Н.М. АГЕЕВА ◽  
В.Е. СТРУКОВА ◽  
Ю.Ф. ЯКУБА ◽  
Л.И. СТРИБИЖЕВА

Рассмотрено влияние способа технологической обработки белого столового виноматериала на состав и концентрацию компонентов ароматобразующего комплекса и органических кислот. В качестве объекта исследований был белый столовый виноматериал Пино Блан урожая 2018 г. Виноматериал получен по следующей схеме: переработка винограда в мягком режиме путем пневмопрессования, отделение сусла первой фракции, осветление сусла с предварительным охлаждением, внесение подкормки для дрожжей АF1 в количестве 0,9 г/дм3, сбраживание сусла активными сухими дрожжами Saccharomyces cerevisiae раса WT1 (Германия). Установлено, что выдержка виноматериала на дрожжевом осадке привела к снижению концентрации винной и янтарной кислот, количество яблочной и лимонной кислот не изменилось. Отмечено увеличение количества молочной, уксусной, валериановой и изовалериановой кислот. В результате обработки бентонитом снизились концентрации валериановой и изовалериановой кислот. В результате брожения виноградного сусла в присутствии сухих дрожжей образуется большое количество эфиров, определяющих специфические оттенки и формирующих аромат виноматериала. Выдержка виноматериала на дрожжевом осадке способствовала повышению концентрации ацетальдегида, метилацетата, ацеталей, высших спиртов, эфира этилвалериата. Количество других эфиров и терпеновых соединений значительно уменьшилось. Обработка виноматериала бентонитом привела к уменьшению количества ароматобразующих компонентов на 8 16. The influence of the method of technological processing of white table wine material on the composition and concentration of components of the aromatic complex and organic acids is considered. White table wine material Pinot Blanc harvest 2018 was as an object of research. Wine material is obtained according to the following scheme: processing of grapes in the soft mode by pneumomassage, the separation of the wort of the first fraction, wort clarification with preliminary cooling to fertilize for yeast AF1 in an amount of 0,9 g/dm3, the fermentation wort active dry yeast Saccharomyces cerevisiae, race, WT1 (Germany). It was found that the aging of wine material on yeast sediment led to a decrease in the concentration of tartaric and succinic acids, the amount of malic and citric acids has not changed. An increase in the amount of lactic, acetic, valerian and isovaleric acids was noted. Concentrations of valerian and isovaleric acids decreased as a result of treatment by bentonite. A large number of esters, which determine the specific shades and form the aroma of wine material, is formed as a result of fermentation of grape must in the presence of dry yeast. The wine material aging on yeast sediment has contributed to increasing concentration in wine acetaldehyde, and methyl acetate, acetals, higher alcohols, ether of ethylmalonate, a number of other esters and terpenic compounds is significantly reduced. Treatment of wine material by bentonite led to a decrease in the number of aromatic components by 8 16.


1978 ◽  
Vol 24 (6) ◽  
pp. 637-642 ◽  
Author(s):  
K. C. Thomas ◽  
Mary Spencer

Effects of the carbon source and oxygen on ethylene production by the yeast Saccharomyces cerevisiae have been studied. The amounts of ethylene evolved by the yeast culture were less than those detected in the blank (an equal volume of uninoculated medium), suggesting a net absorption of ethylene by the yeast cells. Addition of glucose to the lactate-grown yeast culture induced ethylene production. This glucose-induced stimulation of ethylene production was inhibited to a great extent by cycloheximide. Results suggested that the yeast cells in the presence of glucose synthesized an ethylene precursor and passed it into the medium. The conversion of this precursor to ethylene might be stimulated by oxygen. The fact that ethylene was produced by the yeast growing anaerobically and also by respiration-deficient mutants isolated from the wild-type yeast suggested that mitochondrial ATP synthesis was not an absolute requirement for ethylene biogenesis.


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