Fermentation activators

The fermentative activity of the yeasts is almost the same in aH industries. Differences in fermentation times arise mainly from differences in temperature. For the baking industry, temperature is high, therefore fermentation time is short, with Htde time for ceU multiplication and very high ceU counts at the start. 

Compressed yeast is also sold in supermarkets in 18-g and 56-g packages. Since this product contains approximately 10% added starch to increase its shelf life, it has a lower protein content and fermentative activity than the compressed yeast sold to bakeries. 

The production of ethanol from cooked rice starch (Moebus and Teuber, 1985) differs from the normal process of spraying the carbon source into the bed since all of the carbon source is made available at the start of the run, subject only to the breakdown of starch to glucose (and maltose) by amylases. The starch (0.3 mm particles), amylases and yeast pellets were mixed in the bed and water sprayed in to maintain the fermentative activity of the yeast. The fermentation was carried out at 31.5°C. 

The chemical changes that take place in detached fruit are directly, or indirectly, related to the oxidative and fermentative activities collectively referred to as biological oxidations. Once the fruit is harvested, respiration, the process concerned with the oxidation of predominantly organic substances by the cell, assumes the dominant role, and the fruit no longer depends on absorption of water and minerals by the root, on conduction by vascular tissues, and on the photosynthetic activity of the leaves. After harvest, the fruit lives an independent life by utilizing substrates accumulated during maturation.385... 

S. cerevisiae can produce H2S and SO2 in the presence of sulfur-containing insecticides such as chlorpyrifos-methyl, fenitrothion, and methidathion (Cabras et al., 1995b Eschenbruch, 1974). These insecticides did not affect fermentative activity. Quinoxyfen, belonging to the family of quinolines, showed no effect on the alcoholic fermentation using three strains of yeasts (Cabras et al., 2000 Lopez et al., 2004). 

However, in a successive study, Domizio et al. (2008) showed the positive influence of Vin Santo madre on yeasts growth and their persistence during fermentation, as well as on the fermentative activities of the... 

Since the discovery of fermentative activity of microorganisms in the eighteenth century and its proof by the French scientist Louis Pasteur, fermentative production of alcohols, amino acids, enzymes (biocatalysts), organic... 

The yeasts used in the second fermentation should also present a series of characteristics such as fermentative activity at low temperature, resistance to ethanol and to CO2 pressure, flocculation potential etc. (Bidan et al. 1986 Martfnez-Rodrfguez et al. 2001a). 

Mauricio, J.C., Guijo, S., Ortega, J.M. (1991). Relationship between phospholipid and sterol contents in Saccharomyces cerevisiae and Torulaspora delbrueckii and their fermentation activity in grape musts. Am. J. Enol. Vitic., 42, 301-308. 

The effect of complex commercial fermentation activators on biogenic amine production was tested by Marques et al. (2008). On the whole, it does not seem that complex nutrient preparations produced for the use with fermentation starter cultures pose a serious threat to biogenic amine production in wines. 

Agenbach W.A. (1977). A study of must nitrogen content in relation to incomplete fermentations, yeast production and fermentation activity. South Afr. Society Enol. Vitic., 1, 66-87. 

The fermentation activity of grapes or musts, which for example may start during transport from the vineyard to the cellar, may be determined by an index that measures the organic compounds metabolised during fermentation. 

Mustroph A., Albrecht G. Tolerance of crop plants to oxygen deficiency stress fermentative activity and photosynthetic capacity of entire seedlings under hypoxia and anoxia. Physiologia Plantarum 2003 117(4) 508-520. 

Reed, G. and Chen, S.L. 1978. Evaluating commercial active dry wine yeasts by fermentation activity. Am. J. Enol. Vitic. 29, 165-168. 

Most microorganisms cannot grow at temperatures below zero, although their fermentation activity may slowly proceed at some degrees below zero. 

Unsamrated long-chain fatty acids (C18, C20) are related to the sterol family. These compounds are fermentation activators, mainly under anaerobic conditions. The most important of these are oleic (C18 with one double bond) and linoleic acids (C18 with two double bonds). They are active in... 

Low-alcohol wines are affected by flor and a bloom develops on the wine s surface that is in contact with air. This bloom consists of a strain of yeast (Candida mycoderma) with a high respiratory capacity, but practically no fermentation activity, so it does not affect sugars. The main transformation caused by Candida mycoderma is the oxidation of ethanol into ethanal. This reaction may continue until the ethanol has... 

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