scholarly journals EFFECTS OF HIGH PITCHING RATE AND NUTRITIONAL SUPPLEMENTION ON YEAST FERMENTATION PERFORMANCE IN VERY HIGH GRAVITY BREWING

2011 ◽  
Vol 14 (4) ◽  
pp. 5-15
Author(s):  
Nguyet Dang Minh Vo ◽  
Man Van Viet Le
Keyword(s):  
Ethanol Yield ◽  
Yeast Fermentation ◽  
High Gravity ◽  
Fermentation Performance ◽  
Fermentation Time ◽  
Very High Gravity ◽  
Pitching Rate ◽  
Maltose Syrup ◽  
Very High ◽  
High Gravity Brewing

In this study, the 30oBx wort with 30% maltose syrup adjunct was used for very high gravity brewing. Increase in pitching rate from 25×106 cells/mL to 125×106 cells/mL shortened the primary fermentation time and augmented the level of ethanol and diacetyl in the green beer. The suitable pitching rate was 75×106 cells/mL. Under this condition, the fermentation time reduced 44.2% and the ethanol concentration in the green beer increased 13.7% in comparison with those in the culture with conventional pitching rate; the ethanol yield achieved maximum of 44.1%. Combination of high pitching rate and nutritional supplementation to 30oBx wort reduced the fermentation time 8.7% and maintained the similar ethanol content in the green beer and the similar ethanol yield in comparison with the high pitching rate culture.

scholarly journals Wheat Gluten Hydrolysates Promotes Fermentation Performance of Brewer’s Yeast in Very High Gravity Worts

2020 ◽  
Author(s):  
Huirong Yang ◽  
Teodora Emilia Coldea ◽  
Yingjie Zeng ◽  
Haifeng Zhao
Keyword(s):  
Ethanol Yield ◽  
Wheat Gluten ◽  
Membrane Integrity ◽  
High Gravity ◽  
Brewer’S Yeast ◽  
Fermentation Performance ◽  
Brewer's Yeast ◽  
Very High Gravity ◽  
Very High ◽  
Ethanol Fraction

Abstract The effects of wheat gluten hydrolysates (WGH) and their ethanol elution fractions obtained on XAD-16 resin on physiological activity and fermentation performance of brewer’s yeast during very-high-gravity (VHG) worts fermentation were investigated. The results showed that the addition of WGH and their elution fractions in VHG worts significantly enhanced yeast biomass and viability, and further increased the fermentability, ethanol yield and productivity of yeast. Supplementation with 40% ethanol fraction exhibited the highest biomass (6.9 g/L dry cell), cell viability, fermentability (82.05%), ethanol titer (12.19%, v/v) and ethanol productivity during VHG worts fermentation. In addition, 40% ethanol fraction supplementation also caused the most consumption of amino acid and the highest accumulation of intracellular glycerol and trehalose, 15.39% of increase in cell-membrane integrity, 39.61% of enhancement in mitochondrial membrane potential (MMP), and 18.94% of reduction in intracellular reactive oxygen species (ROS) level in yeast under VHG conditions. Therefore, WGH supplementation was an efficient method to improve fermentation performance of brewer’s yeast during VHG worts.

scholarly journals Wheat gluten hydrolysates promotes fermentation performance of brewer’s yeast in very high gravity worts

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Huirong Yang ◽  
Teodora Emilia Coldea ◽  
Yingjie Zeng ◽  
Haifeng Zhao
Keyword(s):  
Ethanol Yield ◽  
Wheat Gluten ◽  
Membrane Integrity ◽  
High Gravity ◽  
Brewer’S Yeast ◽  
Fermentation Performance ◽  
Brewer's Yeast ◽  
Very High Gravity ◽  
Very High ◽  
Ethanol Fraction

AbstractThe effects of wheat gluten hydrolysates (WGH) and their ethanol elution fractions obtained on XAD-16 resin on physiological activity and fermentation performance of brewer’s yeast during very-high-gravity (VHG) worts fermentation were investigated. The results showed that the addition of WGH and their elution fractions in VHG worts significantly enhanced yeast biomass and viability, and further increased the fermentability, ethanol yield and productivity of yeast. Supplementation with 40% ethanol fraction exhibited the highest biomass (6.9 g/L dry cell), cell viability, fermentability (82.05%), ethanol titer (12.19%, v/v) and ethanol productivity during VHG worts fermentation. In addition, 40% ethanol fraction supplementation also caused the most consumption of amino acid and the highest accumulation of intracellular glycerol and trehalose, 15.39% of increase in cell-membrane integrity, 39.61% of enhancement in mitochondrial membrane potential (MMP), and 18.94% of reduction in intracellular reactive oxygen species (ROS) level in yeast under VHG conditions. Therefore, WGH supplementation was an efficient method to improve fermentation performance of brewer’s yeast during VHG worts.

scholarly journals Selection from Industrial Lager Yeast Strains of Variants with Improved Fermentation Performance in Very-High-Gravity Worts

2010 ◽  
Vol 76 (5) ◽  
pp. 1563-1573 ◽  
Author(s):  
Anne Huuskonen ◽  
Tuomas Markkula ◽  
Virve Vidgren ◽  
Luis Lima ◽  
Linda Mulder ◽  
...  
Keyword(s):  
Survival Rates ◽  
High Gravity ◽  
Fermentation Performance ◽  
Lager Yeast ◽  
Very High Gravity ◽  
Sedimentation Behavior ◽  
Yeast Strains ◽  
Industrial Strains ◽  
Improved Performance ◽  
Very High

ABSTRACT There are economic and other advantages if the fermentable sugar concentration in industrial brewery fermentations can be increased from that of currently used high-gravity (ca. 14 to 17�P [degrees Plato]) worts into the very-high-gravity (VHG; 18 to 25�P) range. Many industrial strains of brewer's yeast perform poorly in VHG worts, exhibiting decreased growth, slow and incomplete fermentations, and low viability of the yeast cropped for recycling into subsequent fermentations. A new and efficient method for selecting variant cells with improved performance in VHG worts is described. In this new method, mutagenized industrial yeast was put through a VHG wort fermentation and then incubated anaerobically in the resulting beer while maintaining the α-glucoside concentration at about 10 to 20 g�liter−1 by slowly feeding the yeast maltose or maltotriose until most of the cells had died. When survival rates fell to 1 to 10 cells per 106 original cells, a high proportion (up to 30%) of survivors fermented VHG worts 10 to 30% faster and more completely (residual sugars lower by 2 to 8 g�liter−1) than the parent strains, but the sedimentation behavior and profiles of yeast-derived flavor compounds of the survivors were similar to those of the parent strains.

Relationship of low lysine and high arginine concentrations to efficient ethanolic fermentation of wheat mash

1992 ◽  
Vol 38 (7) ◽  
pp. 626-634 ◽  
Author(s):  
Kolothumannil C. Thomas ◽  
W. M. Ingledew
Keyword(s):  
Cell Viability ◽  
Amino Nitrogen ◽  
Nitrogen Sources ◽  
Inhibitory Effect ◽  
High Gravity ◽  
Yeast Growth ◽  
Fermentation Time ◽  
Very High Gravity ◽  
Assimilable Nitrogen ◽  
Very High

Very high gravity wheat mashes containing 20 or more grams of carbohydrates per 100 mL were fermented completely by Saccharomyces cerevisiae, even though these mashes contained low amounts of assimilable nitrogen. Supplementation of wheat mashes with various amino acids or with yeast extract, urea, or ammonium sulfate reduced the fermentation time. However, lysine or glycine added as single supplements, inhibited yeast growth and fermentation. With lysine, yeast growth was severely inhibited, and a loss of cell viability as high as 80% was seen. Partial or complete reversal of lysine-induced inhibition was achieved by the addition of a number of nitrogen sources. All nitrogen sources that relieved lysine-induced inhibition of yeast growth also promoted uptake of lysine and restored cell viability to the level observed in the control. They also increased the rate of fermentation. Experiments with minimal media showed that for lysine to be inhibitory to yeast growth, assimilable nitrogen in the medium must be in growth-limiting concentrations or totally absent. In the presence of excess nitrogen, lysine stimulated yeast growth and fermentation. Results indicate that supplementing wheat mash with other nitrogen sources increases the rate of fermentation not only by providing extra nitrogen but also by reducing or eliminating the inhibitory effect of lysine on yeast growth. Key words: very high gravity, lysine inhibition, fuel alcohol, free amino nitrogen.

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