Aboard the International Space Station, potable water will likely be produced from recycled wastewater. The National Aeronautic and Space Administration (NASA) plans to use iodine as a disinfectant, and, consequently, the formation of iodinated disinfection by-products (IDBPs) requires investigation. Objectives of this research were to determine possible precursors of IDBPs, identify IDBPs formed, and apply flavor profile analysis (FPA) as a tool to evaluate water qaulity. Experiments were performed by separately reacting iodine with each of the following organic compounds: methanol, ethanol, 1-propanol, 2-propanol, 1-methoxy-2-propanol, acetone, and formaldehyde. NASA previously identified all of these compounds in wastewater sources under consideration for recycling into potable water. Experiments were performed at pH 5.5 and 8, iodine concentrations of 10 and 50 mg/L, and organic concentrations of 5 and 50 mg/L. Gas chromatography/mass spectrometry was used to identify and monitor the concentrations of organic species. Spectrophotometry was used to monitor the iodine concentration. Acetone was the only compound identified as an IDBP precursor and it reacted to produce iodoacetone and iodoform. Concentrations of iodoform from 0.34 mg/L to 8.637 mg/L were produced at conditions that included each pH level, iodine concentration, and acetone concentration. The greatest iodoform concentration was produced at pH 8 from 50 mg/L of iodine and acetone. FPA indicated that the odor threshold concentration (OTC) of iodoform was 1.5 ug/L, and the OTC of iodine was 500 ug/L. Both iodine and iodoform have medicinal odors, making it difficult to distinguish each compound when present in a mixture. / Master of Science

This study determined how quality grade and degree of doneness influence the development of beef flavor compounds among whole muscle and ground patties. Proximate composition, pH, cooking duration, neutral and polar lipid fatty acids, free and total amino acids, total reducing sugars, and volatile compounds were evaluated in beef strip steaks and ground patties of Longissimus lumborum from three USDA quality grades (Prime, Low Choice, and Standard; n=8 per quality grade) and six degrees of doneness (4, 25, 55, 60, 71, and 77°C). In the split-plot experiment, quality grade was the whole-plot, product-type was a sub-plot, and degree of doneness was the sub-sub-plot. The 3-way interaction of quality grade, degree of doneness, and product type impacted moisture (P = 0.004) and protein content (P = 0.006); pH (P < 0.001); neutral and polar lipid fatty acids (P ≤ 0.048); free and total amino acids (P ≤ 0.044); total reducing sugars (P < 0.001); and volatile compounds (P ≤ 0.029). The 2-way interaction of quality grade and degree of doneness impacted free amino acids (P ≤ 0.036); PUFA within the neutral lipid fraction (P ≤ 0.033); fatty acids within the polar lipid fraction (P ≤ 0.043); volatile compounds (P ≤ 0.038); and the total fat percentage (P = 0.046). The 2-way interaction of quality grade and product type impacted fatty acids within the neutral lipid fraction (P ≤ 0.042); fatty acids within the polar lipid fraction (P ≤ 0.015); and volatile compounds (P ≤ 0.047). The 2-way interaction of product type and degree of doneness affected fatty acids within the neutral lipid fraction (P ≤ 0.046); fatty acids within the polar lipid fraction (P ≤ 0.035); free amino acids (P ≤ 0.005) and total amino acids (P ≤ 0.004); volatile compounds (P ≤ 0.029); and cooking duration (P < 0.001). Overall the results of this study indicated that quality grade, grinding, and cooking have interacting effects on flavor related compounds. Thus, each factor must be considered during any model development which aims to predict beef flavor.

Millions of pounds of venison are harvested each year in the United States. Over 12,000,000 pounds of dressed venison are harvested during the regular season each year in the State of Utah. The hunters of venison contribute approximately 10 1/2 billion dollars to the economy of the state for licenses, lodging, transportation, and other expense of hunting. In many cases this source of meat is a significant part of the household meat supply. Venison is often wasted, however, because of its undesirable flavor. The lack of knowledge as to the causes of variation in venison flavor has prompted this study. Research into tho causes of variation in venison flavor can contribute significantly to the problems of undesirable flavors and waste by determining the cause and distribution of factors which are responsible for these variations. This primary basic information may aid the hunter in his selection of animals to harvest. Suggestions as to age, sex, season of harvest, and physical condition of the animal may be applicable.

Swiss cheese has been rightly called "king of the cheeses." It has been prized the world over for its stately appearance and sweet "hazelnut" flavor. In grading Swiss cheese, these two things,appearance and flavor, are important considerations in determining the cheese score. Appearance is judges according to the number, type, and size of eyes present in the cheese, with color and body and texture also considered. Flavor is judges according to the degree of sweetness and the amount and kinds of off flavors present. In the past, there has been considerable variation in the quality of the Swiss cheese produces. Causes of this variation were little understood, since wide ranges in grades of cheese were obtained from seemingly similar milk and manufacturing precedures. Technique has been greatly improved by research conducted in both private industry and experiment stations. Much has been done to produce beneficial effects in the cheese, and to reduce detrimental effects. One question, still debated, is the amount of eye forming bacteria necessary to produce the best eye formation. Propionibacterium shermanii, by its production of carbon dioxide, is thought to be the most important bacteria in producing the eyes. Some Swiss cheese makers see no necessity in adding prepared culture of E. shermanii to their milk. They allow the milk to become "seeded" from organisms already present in the vets and on the equipment. Other cheese makers add small amounts of prepared cultures of T. shermanii, whil still others add rather large quantities. Procedure varies from plant to plant. Propionic acid and acetic acid are also produced in the life processes of P. shermanii. These two acids are important factors in the development of flavor in Swiss cheese. Therefore, a change in the amount of P. shermanii in the Swiss cheese, and the subsequent effect on eye formation and flavor. It is the purpose of this experiment to determine the general effects that variations in the size of the inoculation of P. shermanii will produce on eye formation and flavor development. The effects, if any, of the three milk treatments mentioned above will also be noted.

Liver off-flavor is a sporadic problem that limits the consumer acceptance of several beef chuck muscles, including the infraspinatus (flat iron steak). Residual blood hemoglobin is known to contribute to liver off-flavor development. This study was conducted to evaluate factors affecting development of liver off-flavor after cooking of beef chuck (shoulder) muscles. The study was conducted in three parts. The objective of part 1 was to determine effects of muscle (infraspinatus, longissimus dorsi, serratus ventralis, supraspinatus, teres major) and processing (with or w/o carcass electrical stimulation) on residual blood hemoglobin content and total pigment content of raw muscle and sensory characteristics after cooking to 71 or 82?C. The objective of part 2 was to evaluate the effect of antioxidant treatment and anaerobic packaging to possibly reduce the incidence of liver and other off-flavors of beef infraspinatus (IF) steaks. The objective of part 3 was to determine the effect of animal age (commercial grade; >42 months, compared to select grade; <30>months), antioxidant treatment, and anaerobic packaging on sensory characteristics of beef IF steaks. Among beef chuck muscles, the infraspinatus had highest mean liver flavor score of 2.08±1.00 where 2=slightly intense liver flavor. Other muscles (longissimus dorsi, serratus ventralis, supraspinatus, teres major) had mean liver flavor scores less than 2. Liver flavor score, myoglobin, hemoglobin, and total pigment content were higher (p<0.05) for infraspinatus muscle from older animals. Among select grade muscles, carcass electrical stimulation had no significant effect on liver flavor score. Rancid flavor scores were significantly increased from 1.34±0.65 to 1.58±0.84 as internal cook temperature increased from 71 to 82°C but mean TBA values as a measure of rancidity (0.25±0.15 and 0.29±0.13, respectively) were not affected by cook temperature. Antioxidant treatment significantly reduced TBA values, rancid, and liver flavor scores for aerobically packaged steaks (PVC or 80% O2-MAP) but had little effect on scores of steaks in anaerobic packaging (0.4% CO-MAP). Results of this study indicate that infraspinatus steaks from older animals are most likely to have objectionable liver, sour/grassy, or rancid flavors. Objectionable flavor scores were lower in steaks receiving antioxidant injection or packaged anaerobically in 0.4% CO-MAP.

No description available.

High gravity (HG) brewing has become the most used strategy for maximizing fermenter productivity in commercial brewing. While HG brewing has many benefits, the additional stress placed on the yeast due to the higher concentration of fermentable sugars in the wort can negatively impact fermentation performance and flavor compound formation. A proper dissolved oxygen (DO) level is vital to guarantee adequate yeast performance during HG fermentations. Dissolved oxygen is vital to yeast viability throughout the fermentation process, as yeast requires oxygen to synthesize vital cell membrane components needed for continued anaerobic growth and cell division. Previous research has demonstrated the importance of DO in wort for regular gravity fermentation and flavor compound production. However, the impact of dissolved oxygen during HG brewing on fermentation performance and how this will impact the production of flavor compounds have not been fully researched. The objectives of this research were to analyze the impact of wort aeration timing and concentration on fermentation performance, flavor stability, and the formation of volatile flavor compounds, determined using gas chromatography. Gas chromatography analysis was modeled after the ASBC Method Beer-48. Flavor stability and staling was analyzed during aging under normal and accelerated conditions utilizing TBA analysis. Pre-pitch oxygen treatments at levels greater than 8 ppm dissolved oxygen significantly increased attenuation when compared to the unoxygenated controls. Post-pitch oxygenation significantly increased attenuation, with DO treatments at levels of 8 ppm showed the most significant decrease in wort specific gravity. Aldehyde, ester, and higher alcohol production were all significantly affected by DO concentration. Aldehyde production decreased with increased DO concentration. Ester production increased from 0 to 8 ppm DO treatment and decreased at DO treatments greater than 8 ppm. Higher alcohol production increased from 0 to 10 ppm and decreased with DO treatments greater than 10 ppm. Greater concentrations v of DO resulted in greater TBA index values after normal and accelerated aging, with accelerated aging producing greater TBA index values than normal aging.

The purpose of this study was to screen the effect of some food-grade ingredients on the off-odors caused by geosmin and 2-methylisoborneol (MIB) compounds in catfish fillets by sensory evaluation. The study revealed that geosmin and MIB odor intensity were reduced to different degrees when fillets were dipped in lime flavor (94% and 67%, respectively), 0.5% acetic acid (AA) (70% and 16%, respectively), hardwood liquid smoke (98% and 86%, respectively), or hickory liquid smoke (98% and 100% respectively) in cooked products. A 0.5% AA proved to be effective in decreasing odor intensity of geosmin (70%) in cooked products, whereas lime flavor (94%), hardwood liquid smoke (98%), and hickory liquid smoke (98%) were very effective in decreasing odor intensity of geosmin in cooked products. These agents added desirable flavors as well, except for AA by panelists? comments. These flavors could be added to a marinade or incorporated in an injection/tumbling solution when catfish fillets are processed.

No description available.

No description available.