Yeast, dried tablets

The most widely available yeast biomass is a by-product of the brewing industry, where the multiplication of yeast during brewing results in a surplus of ceUs. Eor every barrel (117 L) of beer brewed, 0.2—0.3 kg of yeast soHds may be recovered. In the U.S., a substantial fraction is recovered and made available about 40 x 10 kg of brewers yeast aimually. The yeast is recovered from beer by centrifuging and dried on roUer dmms or spray dryers and sold as animal feed or a pet-food supplement. It can be debittered by alkaline extraction to remove the bitter hop residues, and is then sold mainly by the health-food industry. It is available as tablets, powder, or flakes and is often fortified with additional vitamins. Distillers yeast caimot be readily separated from the fermented mash and the mixture is sold as an animal feed supplement. 

The inactive brewery yeast suspension as the by-product of the beer production contains vitamin B and trace elements in relatively high concentration therefore the dried powder, after tabletting can be circulated as roborant. It was very important to preserve its vitamin content whereas the moisture content of the dried product should be less than 5% m/m moreover, the particle size of 90% of the product should be smaller than 0.4 mm and the size of remains should not exceed 1 mm. 

A suitable daily portion of the dried yeast—for people who are not prone to either hyperuricemia or gout—is 1 or 2 tablespoons (75 or 30 ml). It may be mixed in vegetable drinks like tomato juice, cooked cereals, flavored instant breakfast drinks, gravies, meat loaves, or various sauces. If there is a choice of product, one that is debittered should be selected. Tablets are also available for those who prefer a more convenient form of the product. 

Dried torula yeast is an excellent source of high-quality protein (50 to 62% crude protein), minerals, B vitamins (including vitamin B-12), unidentified factors, and of vitamin D if irradiated. Unlike the bitter-tasting brewers yeast, torula yeast is tasteless, thereby facilitating its use as a palatable foodstuff. Torula yeast is available in powder and tablets. 

Dried Yeast, B.P.C., and Tablets of Yeast, B.P.C, (containing 5 grains of dried yeast), are assayed for nicotinic acid by the microbiological method given above. 

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