0000000000046629
AUTHOR
Letitia Oprean
THE INFLUENCE OF THIAMINE IN THE FERMENTATION OF THE WINE YEASTS
Due to the enzymatic equipment, the yeast cell produces alcoholic fermentation by the meaning of a zimazic complex which catalyzes in different stages the redox processes of the carbohydrates, which are able to ferment, ultimately leading to ethanol. The fermentation rate is an exponential function being influenced by the cells concentration in the development environment and the starter cultures of micro-organisms. Most of the yeast strains do ferment some substrates rich in hexosanes and oligoglucides: sucrose, maltose, raffinose, lactose and celobiose. The biomass quantity may be increased in various ways. An important aspect in the increasing of the multiplication rate of the yeast cell…
Basic Physical-Chemical and Sensorial Evaluation of Some Fermented Mashes Produced from Wheat, Husked Millet, Barley Malt and Oat
Abstract Fermented mashes based on different cereal grist are a healthy and nutritious beverage, a source for new functional products with beneficial effects on human health. These mashes are a thick consistency and sour-sweet taste, different colors depending on the ingredients and method of preparation. In this study were determined the main physical and chemical characteristics (pH, volatile and total acidity, total and soluble dry substances, alcohol concentration, dynamic viscosity) and was made sensorial analysis of some boiled aqueous mashes obtained from wheat, husked millet, barley malt and oat. Mashes were fermented at 30 °C with a mixed culture of mesophilic cheese lactic acid ba…
Physiological properties of some yeast strains
Twenty yeast strains have recently been isolated in pure cultures from natural and industrial sources and identified based mainly on physiological properties. The majority of the strains (15) are alcohologenic belonging to the genus Saccharomyces and comprise two brewer's (beer) yeast strains (S. carlsbergensis= S. uvarum A and B), two baker's yeast strains (S. cerevisiae CA and CP), one spirit yeast strain (S. cerevisiae CF) and ten wine yeast strains (S. cerevisiae var. ellipsoideus = S. ellipsoideus 1, 3, 4, 6, 8 and 9; S. oviformis 2, 5 and 7; and S. uvarum 10). The other 5 yeast strains belong to different species: Kloeckera apiculate, Candida mycoderma (Mycoderma vini), Pichia membran…
Introduction to environmental security
The term "Environmental Security" refers to a range of concerns that can be organized into three general categories: (1) concerns about the adverse impact of human activities on the environment, seen as an asset to be inherited by the next generations; (2) concerns about the direct and indirect effects of various forms of environmental change (especially scarcity and degradation), which may be natural or human-generated on national and regional security; (3) concerns about the loss of security individuals and groups (from small communities to humankind) experience due to environmental change such as water scarcity, air pollution, global warming, and so on. In order to provide sustainability…
Evaluation of Two Method to Measure Xylanase Activity in Relation with Rheological Effects of Xylanases on White Flour
Many methods are available to measure the xylanase activity of enzymatic preparation. Most of method uses different substrates from those that will be hydrolyzed in various applications in food industry. This fact will lead to a deformed image about how evaluated xylanases will really act in a specific application. The aim of this study is to evaluate the activity of seven xylanase preparation with two method, a colorimetric method with birch insoluble xylan as substrate and a viscometric method with wheat soluble arabinoxylan as substrate.
Steady and oscillatory shear behaviour of semi-concentrated starch suspensions
The viscoelastic moduli G’ and G” of aqueous suspensions with 40% (w/v) normal corn starch (NCS) and waxy corn starch (WCS) were determined by oscillation rheometry. The oscillatory shear flow experiments at heating from 30° to 75 °C and maintaining at this temperature showed changes from a behaviour predominant viscous (G”>>G’) to predominant elastic (G’>G”) for both starches at 60.5 °C for WCS, respectively 70,85 °C for NCS, WCS having higher values of G’ and G” as NCS. After the gelatinisation temperature was attired, NCS showed no significant changes, both moduli remaining relatively constant. Peaks of both moduli G’ and G” were obtained for WCS at its maintaining at 75oC, these changes…
The Influence of The Degree of Grinding to Obtain of Some Fermented Mashes Based on Whole Wheat and Husked Millet
The purpose of this article was to study the influence of degree of milling whole wheat (was ground in 4 variants of grain) and husked millet (was finely ground) to obtain fermented mashes type Braga. There have been 4 mashes of grist of whole wheat, grist husked millet, hop pellets and water and were boiled under continuous stirring and then cooled. Their content has diluted with water and then strainer by pressed through a sieve. Each mash-filtrate has divided in two and added white sugar 7%, resulting two series of sweet mashes. One has inoculated with a mixed culture of yeast and lactic bacteria and the other only with yeast culture. After fermentation were analyzed fermented mashes (pH…