Debittered dried

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. 

Effects on human health reflecting neurological, cardiovascular, or gastrointestinal symptoms can be observed either if lupin seeds are eaten unripe or not debittered. Symptoms of intoxication after ingestion of lupin seeds with high alkaloids content appear 1-14 h after consumption and include dry mouth, muscular weakness, disturbed balance, sweating, palpitation, blurred vision, mydriasis (i.e., dilated pupils), urine retention, gastric and intestinal troubles, and abtmdant ventricular extrasystoles [45]. 

A few poisoning cases have been reported in literature, all related to the consumption of raw lupin seeds [46, 47]. There are some cases of acute toxicity in humans who ate lupin beans, which had not been previously debittered. These subjects suffered from blurry vision, dry mouth, facial flushing, and confusion [46,47]. 

The fat content of lupine is relatively small, except for the South American species L. mutabilis, which contains about 22-24% of oil in dry matter). In the technological production of oil from this lupine, about 60% of alkaloids present in bitter varieties are removed during extraction with hexane. Subsequent refining decreases their concentration in the oil down to 0.0005%. Meals are debittered by extraction with ethanol containing hydrochloric acid, which decreases the alkaloid content from the original amount of 3.2% to 0.1-0.2%. 

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. 

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