Yeast powder and yeast extract are important medium ingredients in biological fermentation industry.
Yeast powder is to point to inactivated yeast commonly, product composition basically is the yeast body that loses activity, nutrient composition includes the crude protein that still encases in bacterium body interior, cyst wall polysaccharide and rich vitamin, growth element, microelement to wait.The use cost of yeast powder is relatively low, but the utilization rate of nutrients and utilization rate of yeast powder by microorganisms is low, and the residue (crude protein and cell wall of bacteria body) that cannot be used after fermentation is more, which is difficult to deal with.
Yeast powder is divided into bread yeast powder and beer yeast powder. The former is produced by fermentation and drying. Molasses is the main raw material.The latter is made of the waste beer-waste beer yeast putty as raw material, which is generally dried in rollers, with low cost, but more impurities, aging yeast cells, difficult absorption and utilization of microorganisms, and unstable quality.
Yeast extract is the customary name of some varieties of yeast extract used in the bio-fermentation industry.
Yeast extract is a product with amino acids, peptides, polypeptides and water-soluble components of yeast cells, which is made from yeast by means of autolysis or enzymatic hydrolysis, and by separation, decolorization (or refining, concentration, spray drying).Contains products in powder and paste form.
The main components of yeast extract powder are degraded protein, amino acid and nucleotide.The content of vitamins, auxin, trace elements and other nutrients is also relatively rich, and most in line with the microbial production of nutrients required ratio.
The high bioavailability of yeast extract powder and the fast utilization rate of microorganism are especially beneficial to the absorption and utilization of nutrition-deficient and genetically recombinant engineering bacteria which are picky about the fermentation medium, which is helpful to shorten the fermentation cycle and improve the fermentation titer of microorganism.At the same time, the fermentation residue is very small, which is beneficial to the environmental protection of the fermentation waste liquor.
Yeast extract can also be produced from molasses fermented bread yeast and waste beer yeast puree.
The yeast extract produced by bread yeast is generally of high quality. On the one hand, the quality of raw materials is relatively high due to the professional production control of bread yeast fermentation; on the other hand, molasses as raw materials is also conducive to the accumulation of more abundant natural nutrients in bread yeast.On the other hand, the production scale of yeast extract powder with bread yeast as raw material can be very large. Manufacturers can fully adopt advanced production equipment and technology to ensure the high quality of yeast extract powder products from the perspective of production technology.
The quality of yeast extract from waste beer yeast paste is generally much worse than that of bread yeast extract.On the other hand is the waste beer yeast mud can't long-distance transportation, manufacturers can only rely on surrounding breweries limited supply, difficult to expand production scale and therefore limit the investment scale of manufacturer, normally only horse method, it is difficult to put the production technology and equipment, and can take the technology to the ideal state, leading to deeper color products, insoluble impurities is more, the content of vitamins, hormones and other micronutrients is lacking.
Yeast extract is a paste of yeast extract.