http://hdl.handle.net/1957/18479 2013-05-18T19:16:38Z 2013-05-18T19:16:38Z Wells, A. Osborne, J. P. http://hdl.handle.net/1957/38289 2013-04-22T21:26:30Z 2011-01-01T00:00:00Z

Production of SO₂ Binding Compounds and SO₂ by Saccharomyces during Alcoholic Fermentation and the Impact on Malolactic Fermentation Wells, A.; Osborne, J. P. The objective of this study was to investigate the production of SO₂ and SO₂ binding compounds by wine yeast and the impact of the production of these compounds on the MLF at various time points during alcoholic fermentation. Fermentations were observed for a number of commercial wine yeasts in a synthetic grape juice and Pinot gris juice and SO₂, acetaldehyde, pyruvic acid and α-ketoglutarate. Measurements were taken at multiple time points during the fermentation. Samples were taken from the fermentations at weekly intervals, sterile filtered, and inoculated with 0. oeni strain VFO to induce MLF. Significant differences between the amount of SO₂, acetaldehyde and pyruvic acid produced by the various yeast strains were noted. Some yeast strains such as FX10, CK S102, F15 and M69, produced significantly higher SO₂ concentrations than other yeast strains and MLF was inhibited in these wines. Insignificant free SO₂ was measured, indicating that bound SO₂ rather than free SO₂ was responsible for inhibition. At almost all time points of the alcoholic fermentation, acetaldehyde bound SO₂ was determined to be the dominant species of bound SO₂ present, suggesting that MLF inhibition by bound SO₂ was due to acetaldehyde bound SO₂. This is the publisher’s final pdf. The published article is copyrighted by South African Society for Enology & Viticulture and can be found at: http://www.sasev.org/journal/?id=8.

2011-01-01T00:00:00Z Smith, Mark R. Boenzli, Matthew G. Hindagolla, Vihangi Ding, Jun Miller, John M. Hutchison, James E. Greenwood, Jeffrey A. Abeliovich, Hagai Bakalinsky, Alan T. http://hdl.handle.net/1957/37911 2013-03-30T00:37:40Z 2013-01-01T00:00:00Z

Identification of gold nanoparticle-resistant mutants of Saccharomyces cerevisiae suggests a role for respiratory metabolism in mediating toxicity Smith, Mark R.; Boenzli, Matthew G.; Hindagolla, Vihangi; Ding, Jun; Miller, John M.; Hutchison, James E.; Greenwood, Jeffrey A.; Abeliovich, Hagai; Bakalinsky, Alan T. Positively-charged gold nanoparticles (0.8 nm core diameter) reduced yeast survival, but not growth, at a concentration of 10-100 μg/ml. Among 17 resistant deletion mutants isolated in a genome-wide screen, highly significant enrichment was observed for respiration-deficient mutants lacking genes encoding proteins associated with the mitochondrion. This is the author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by the American Society for Microbiology and can be found at: http://aem.asm.org/.

2013-01-01T00:00:00Z Zhang, Hongcai Jin, Yafang Deng, Yun Wang, Danfeng Zhao, Yanyun http://hdl.handle.net/1957/37874 2013-03-25T21:43:33Z 2012-11-15T00:00:00Z

Production of chitin from shrimp shell powders using Serratia marcescens B742 and Lactobacillus plantarum ATCC 8014 successive two-step fermentation Zhang, Hongcai; Jin, Yafang; Deng, Yun; Wang, Danfeng; Zhao, Yanyun Shrimp shell powders (SSP) were fermented by successive two-step fermentation of Serratia marcescens B742 and Lactobacillus plantarum ATCC 8014 to extract chitin. Taguchi experimental design with orthogonal array was employed to investigate the most contributing factors on each of the one-step fermentation first. The identified optimal fermentation conditions for extracting chitin from SSP using S. marcescens B742 were 2% SSP, 2 h of sonication time, 10% incubation level and 4 d of culture time, while that of using L. plantarum ATCC 8014 fermentation was 2% SSP, 15% glucose, 10% incubation level and 2 d of culture time. Successive two-step fermentation using identified optimal fermentation conditions resulted in chitin yield of 18.9% with the final deproteinization (DP) and demineralization (DM) rate of 94.5% and 93.0%, respectively. The obtained chitin was compared with the commercial chitin from SSP using scanning electron microscopy (SEM), Fourier transform infrared spectrometer (FT-IR) and X-ray diffraction (XRD). Results showed that the chitin prepared by the successive two-step fermentation exhibited similar physicochemical and structural properties to those of the commercial one, while significantly less use of chemical reagents. This is the author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/carbohydrate-research/.

2012-11-15T00:00:00Z Martinez-Monteagudo, Sergio I. Saldana, Marleny D. A. Torres, J. Antonio Kennelly, John J. http://hdl.handle.net/1957/37392 2013-03-08T23:41:20Z 2012-10-01T00:00:00Z

Effect of pressure-assisted thermal sterilization on conjugated linoleic acid (CLA) content in CLA-enriched milk Martinez-Monteagudo, Sergio I.; Saldana, Marleny D. A.; Torres, J. Antonio; Kennelly, John J. Conjugated linoleic acid (CLA) has been recently studied for its health-promoting and disease-preventing properties. The objective of this study was to evaluate the effect of pressure (100-600 MPa), temperature (60-120˚C) and treatment time (0-14 min) on CLA content in milk and anhydrous milk fat (AMF) rich in CLA. In milk treated up to 14 min at 100 MPa, CLA was stable (> 80 % of retention), regardless of the temperature. In contrast, only 3.4 ± 2 % of CLA was retained at 600 MPa and 120°C. For AMF, CLA retention was considerably higher (40.2 ± 2 %) than that obtained for milk. The presence of free metal ions in milk might catalyze CLA degradation. When the antioxidant catechin (1 g/kg) was used, CLA retention increased significantly (> 90%) in milk and AMF, regardless of the experimental conditions. This is the author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/innovative-food-science-and-emerging-technologies/.

2012-10-01T00:00:00Z