Increasing the protein content of starchy prod. - esp. maize and manioc, by fermentation with yeast having no hydrolytic activity

摘要

The protein content of starch-rich products such as maize kernels or manioc slices is increased fermenting a suspension of the communited prod. (particle size 1 mm) to which has been added mineral salts, an N-source, trace elements and growth factors to give a complete medium. Fermentation is continuous or batchwise using a strain of yeast which causes no chemical or enzymatic hydrolysis of the starch e.g. a strain of Candida tropicalis grown on soluble starch. The fermentation is at pH 4-6 and 30-39 degrees C with vigorous stirring and aeration, then the biomass is centrifuged off, dried and the enriched product is suitable for immediate use. Masize and manioc flour enriched to =15 wt. % protein prepd. by this method are claimed. The prod. is suitable for human or animal consumption. The yeast used has higher protein content and grows more rapidly than the mycelial fungi previously used.