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dc.contributor.authorBechman, Allison Rae
dc.date.accessioned2014-03-04T21:05:05Z
dc.date.available2014-03-04T21:05:05Z
dc.date.issued2013-08
dc.identifier.otherbechman_allison_r_201308_phd
dc.identifier.urihttp://purl.galileo.usg.edu/uga_etd/bechman_allison_r_201308_phd
dc.identifier.urihttp://hdl.handle.net/10724/28970
dc.description.abstractKoji are solid-state fermentation products made by inoculating steamed grains with the spores of fungi, particularly Aspergillus spp. This research was undertaken to identify the fermentation and storage conditions optimal for the production and maintenance of selected hydrolytic enzymes, such as α-amylase and protease, in koji. Steamed rice and barley were inoculated with 2 X 10 11 Aspergillus oryzae spores per kg of grains and fermented for 118 h in a growth chamber at 28-32° C with controlled relative humidities. Samples were drawn periodically during fermentation and storage at -20, 4, or 32 °C, and α-amylase and protease activity, mold counts, aw, moisture contents, and pH of collected samples were determined. It was observed that the aw, moisture contents, and pH of the koji were influenced by the duration of fermentation and temperature of storage. The α-amylase activity of both koji increased as the populations of A. oryzae increased during the exponential growth phase. The enzyme activity of barley koji was significantly higher than that of rice koji, reaching a peak activity of 211.87 or 116.57 U at 46 and 58 h, respectively, into the fermentation process. The enzyme activity in both products started to decrease once the mold culture entered the stationary growth phase. The protease activities of both koji were low and remained relatively stable during fermentation and storage. These results suggest that rice and barley koji can be used as sources of α-amylase and desired enzyme activity can be achieved by controlling the fermentation and storage conditions.
dc.languageeng
dc.publisheruga
dc.rightspublic
dc.subjectAspergillus oryzae
dc.subjectkoji
dc.subjectfermentation
dc.subjectα-amylase
dc.subjectprotease
dc.titleFormulation and development of peanut-based ready-to-use therapeutic foods for malnourished pregnant women in Mali
dc.typeDissertation
dc.description.degreePhD
dc.description.departmentFood Science and Technology
dc.description.majorFood Science
dc.description.advisorJinru Chen
dc.description.committeeJinru Chen
dc.description.committeeRobert Shewfelt
dc.description.committeeRobert Dixon Phillips
dc.description.committeeWilliam L. Kerr
dc.description.committeeYao-wen Huang


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