Concentration of sulfamethazine in spray dried milk
| dc.contributor.author | Malik, Shahana | en |
| dc.contributor.committeechair | Duncan, Susan E. | en |
| dc.contributor.committeemember | Bishop, J. Russell | en |
| dc.contributor.committeemember | Taylor, Larry T. | en |
| dc.contributor.department | Food Science and Technology | en |
| dc.date.accessioned | 2014-03-14T21:47:59Z | en |
| dc.date.adate | 2009-10-22 | en |
| dc.date.available | 2014-03-14T21:47:59Z | en |
| dc.date.issued | 1991 | en |
| dc.date.rdate | 2009-10-22 | en |
| dc.date.sdate | 2009-10-22 | en |
| dc.description.abstract | A study was conducted to investigate the effect ofspray drying on concentration of sulfamethazine (SMZ) in fluid milk dried to powder «10% moisture). Antibiotic-free skim and whole (homogenized) milk were spiked at 5, 10, 50 and 100 ppb sulfamethazine levels, pasteurized and stored at 4°C till further processed. All samples were spray dried at an inlet temperature of 180 ± 2°C and outlet temperature of 100 ± 2°C and stored at -20°C until analyzed. Sulfamethazine concentration was determined quantitatively by HPLC, a microbial receptor assay (Charm-II®) and an ELISA assay (LacTek®) and qualitatively by an ELISA method (Cite®) in milk samples before and after spray drying. Dry milk samples were reconstituted (10% w/w) for all analyses. statistical determination of significant differences (p = 0.05) between fluid and dry milk samples and whole and skim milk sample~was completed by paired t-tests. Sulfamethazine concentrations increased 81.4% and 84.1% in skim and whole milk respectively at 100 ppb spiked level but were lower than expected increase of 88-91% based on their total solids for whole and skim milk as obtained by modified FDA HPLC method. At lower levels of 5 and 10 ppb, the HPLC method was not sensitive enough to provide usable data. Increase in sulfamethazine concentration from fluid to dry milk was also determined by· Charm-II® and LacTek® techniques. Poor recoveries and variability in data were evident due to binding of sulfamethazine to undetermined milk components as a result of processing and storage also due to break-down of sulfamethazine (mp = 176°C) at 1S00C during spray drying. Sulfamethazine 163 ppb by LacTek® and 94.6 ppb by Charm-II® (at a spiked level of 10 ppb fluid milk) was successfully removed from dried milk after 120 min using supercritical CO₂ (pressure = 5500 psi, 50 0 C | en |
| dc.description.degree | Master of Science | en |
| dc.format.extent | ix, 68 leaves | en |
| dc.format.medium | BTD | en |
| dc.format.mimetype | application/pdf | en |
| dc.identifier.other | etd-10222009-125009 | en |
| dc.identifier.sourceurl | http://scholar.lib.vt.edu/theses/available/etd-10222009-125009/ | en |
| dc.identifier.uri | http://hdl.handle.net/10919/45244 | en |
| dc.language.iso | en | en |
| dc.publisher | Virginia Tech | en |
| dc.relation.haspart | LD5655.V855_1991.M3585.pdf | en |
| dc.relation.isformatof | OCLC# 25070356 | en |
| dc.rights | In Copyright | en |
| dc.rights.uri | http://rightsstatements.org/vocab/InC/1.0/ | en |
| dc.subject.lcc | LD5655.V855 1991.M3585 | en |
| dc.subject.lcsh | Dried milk | en |
| dc.subject.lcsh | Sulfamethazine | en |
| dc.title | Concentration of sulfamethazine in spray dried milk | en |
| dc.type | Thesis | en |
| dc.type.dcmitype | Text | en |
| thesis.degree.discipline | Food Science and Technology | en |
| thesis.degree.grantor | Virginia Polytechnic Institute and State University | en |
| thesis.degree.level | masters | en |
| thesis.degree.name | Master of Science | en |
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