Abstract: This invention relates to a process for debittering spent brewer's yeast, aiming at maximal efficiency with minimal impact on yeasts for their further use as live cells. The process consists in bringing a yeast suspension in contact with a surfactant containing unsaturated fatty acids, like Tween 80.RTM. (0.2% to 20% v/v), adjusting pH to 10.0 with NaOH 2N and agitating during 5 minutes at 50 rpm and 50.degree. C. A bitterness reduction of 98% is obtained, without affecting yeast viability or protein content. Furthermore, the debittered yeasts treated with 20% Tween 80.RTM. can be reactivated (viability of 100% and increased production of CO.sub.2) by growing them in a suitable medium for a sufficient time (about two to six hours). These reactivated yeasts have restored biological properties which are expected to allow the use of these spent yeasts in complete or partial replacement of new yeasts in bakery industry and in spirit and beer fabrication.

Abstract: The present invention relates to a method for the hydrolysis of sweetpotato starch which comprises the steps of: a) separating outer and starchy inner tissues of sweetpotato roots; b) heating the separated starchy inner tissues of step a) for a time sufficient for obtaining a suitable slurry; c) preparing an amylase crude extract from sweetpotato roots outer tissues of step a); and d) incubating the slurry of step b) with the extract of step c) for a time sufficient for the complete hydrolysis of starch.