Matching Items (3)
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- All Subjects: Non-native
- Creators: Sweat, Ken
Description
Capsaicin and dihydrocapsaicin account for 90% of capsaicinoids when it comes to the pungency of peppers. Capsaicin stability was investigated through a cooking and storage parameter where three different tests were done; cooking duration, cooking temperature, and storage stability. The concentration of capsaicinoids was quantified through gas chromatography-mass spectrometry where those values were then used to determine the total Scoville heat units (SHU). Furthermore, half-life was determined by finding the decay rate during cooking and storage. Results showed that there was an increase in degradation of capsaicinoids concentration when peppers were cooked for a long period of time. Degradation rate increases with increasing temperatures as would be expected by the Arrhenius equation. Hence, if a maximum pungency is wanted, it is best to cook the least time as possible or add the peppers towards the end of the culinary technique. This would help by cooking the peppers for a short period of time while not being exposed to the high temperature long enough before significant degradation occurs. Lastly, the storage stability results interpreted that a maximum potency of the peppers can be retained in a freezer or refrigerator opposed to an open room temperature environment or exposure from the sun. Furthermore, the stability of peppers has a long shelf life with even that the worse storage condition's half-life value was 113.5 months (9.5 years). Thus, peppers do not need to be bought frequently because its potency will last for several years.
ContributorsBustamante, Krista Gisselle (Author) / Cahill, Thomas (Thesis director) / Sweat, Ken (Committee member) / Armendariz Guajardo, Jose (Committee member) / School of Mathematical and Natural Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
Through the months September-November of 2017 a study was conducted to determine if bees prefer the sunflower, Helianthus annuus, native to Arizona, or a cultivar Helianthus sunflower in an urban environment. The study was executed in a small, controlled urban environment on Arizona State University West campus. Seven identified bee species and forty-nine specimens were collected, of the forty-nine specimens, two bees were reported on the Helianthus cultivar supporting native floral host preferences of native species. Variables such as nectar, pollen, floral color, and floral height were not measured, however, when the floral host genus was maintained wild bees visited the native Helianthus host significantly more yielding a supportive two-tailed p-value of 2.97x10-5. Three trends were identified in correlation with the experiment: 1) Bees foraged on native Helianthus annuus over the Helianthus cultivar, 2) Generalist species were more abundant than specialists on the Helianthus annuus, 3) Honey bees (Apis mellifera) were the most abundant species present. While not considered a trend, low floral diversity and abundance may explain the low diversity of bee species observed on the Helianthus. Floral host and pollinator desynchronization may also have affected bee diversity and abundance. Analysis of bee abundance and diversity support that wild bees may prefer native floral hosts over cultivar floral hosts when the floral genus, temperature, and time was controlled for in an urban environment.
ContributorsDunham, Jocelen Michaela (Author) / Foltz-Sweat, Jennifer (Thesis director) / Sweat, Ken (Committee member) / School of Mathematical and Natural Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-12
Description
One can argue that bees are the most unique insects in the animal kingdom due to their invaluable services they provide on a global level. Their importance goes beyond their capability of pollination; it is shown in their environmental impact and maintenance of the world's food supply. It is evident that the bee population is experiencing a serious and rapid decline that has resulted in changes to ecosystems in the past couple of decades. In order to resolve these issues, further research must be conducted to understand what humans can do to benefit their species' longevity. It is necessary for knowledge regarding bees, specifically their foraging behavior, to improve so humans can understand their essentiality to not only them, but the world. The focus of this study is to address any differences in foraging behavior between Apis mellifera, the honey bee, and native bee species. Other questions were answered including: do native and non-native bees have floral host preferences? Do native and non-native bees visit a variety of floral hosts? Experimental procedures were conducted to address these questions, which involved netting bees at differing times in four varying garden locations at the Desert Botanical Garden in Phoenix, Arizona. Then, the preparation of bee pollen and plant pollen slides along with bee mounting was performed. After the completion of data analysis, it was discovered that the preliminary data showed different foraging behavior between native and non-native bee species. Further studies are pertinent in obtaining statistically significant data due to an insufficient sample proportion. This is crucial in understanding the true differences in behaviors between both bee species.
ContributorsPerez, Czarinabelle Eunice (Author) / Foltz-Sweat, Jennifer (Thesis director) / Sweat, Ken (Committee member) / School of Social and Behavioral Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-12