The conversion of soybeans to tempe is achieved through fermentation by Rhizopus. This fermentation process leads to hydrolysis of both proteins and lipids. The present work investigated certain biochemical changes which accompany the conversion of soybeans to tempe. The contents of non-protein nitrogen and free $ alpha$-amino nitrogen increased from 2.34 to 15.14%, and 2.03 to 5.22%, respectively after 48 h fermentation. SDS electrophoresis showed that a substantial quantity of the proteins in raw soybeans were hydrolysed by the Rhizopus to low molecular species (molecular weight $<$13,000 Daltons). Trypsin inhibitor activity found in tempe was lower than that of soybean and soaked soybean (an intermediate step in tempe preparation). The protein digestibilities of tempe and soaked soybean were higher than that of soybean. Reversed phase HPLC showed that the peptide separation profile of tempe was different from that of soybean and soaked soybean. The ESI/MS of the RP-HPLC fractions gave molecular weight of soybean peptides ranging from 1962 Da to 22,699 Da and tempe peptides ranging from 569 Da to 16,688 Da. The fatty acid compositions of tempe, soybean and soaked soybean were similar; relatively high levels of linoleic acid followed by oleic, linolenic and stearic acids were found. The acid values increased from 1.49 to 11.42 during the fermentation of soybeans. The total soluble carbohydrate contents of soybean, tempe and soaked soybean as well as the types and quantities of individual sugars were similar. The fermentation of soybean by Rhizopus had only a minor effect on the proximate composition of soybean; however, the soybean and fungal enzymes contributed primarily to changes in protein composition.

Thesis (Ph. D.)--Victoria University (Melbourne, Vic.), 2007. / Includes bibliographical references.

Thesis (M.S.P.H.)--University of Michigan, 1940.

Thesis (M.S.P.H.)--University of Michigan, 1940.

The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on October 2, 2009). Thesis advisor: Dr. Azlin Mustapha and Dr. Fu-Hung Hsieh. Includes bibliographical references.

No description available.

No description available.

Typescript. / Digitized by Kansas Correctional Industries

The factors determining the generation of aroma in starch extrudates containing added ingredients with aroma precursors were elucidated. Analyses were performed using headspace analysis of raw materials and extrudates and subsequent analysis by Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography-Olfactometry (GC-O. Study I described the volatile, amino acid and fatty acid profiles of Hydrolised vegetable protein (HVP)and Soy protein isolate (SPI). Studies II, III and IV descibed the volatiles developed from extrusion of different feedstocks under mild and extreme processing conditions. Wheat starch was chosen as the carrier.A comparison of the influence of the three different ingredients HVP, SPI and glucose, added to the starch feed, showed the formation of Strecker aldehydes and Maillard-type compounds were significantly affected by the addition of these ingredients. The work in this thesis demonstrated that the addition of ingredients such as HVP, SPI, glucose, cysteine, cysteine-HCI, modifies the aroma of wheat starch extrudates. Furthermore, it showed the changes in conditions of extrusion and pH will greatly influence the aroma profile of the products. / Doctor of Philosophy (PhD)

Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 96-113).