Date of Award
Summer 8-5-2024
Degree Type
Dissertation/Thesis
Degree Name
Masters in Integrative Biology
Department
Molecular and Cellular Biology
Committee Chair/First Advisor
Dr. Christopher Cornelison
Second Advisor
Dr. Mario Bretfeld
Third Advisor
Dr. Carol Chrestensen
Abstract
Postharvest loss of agricultural products impacts consumers, producers, natural resources, and commercial vendors. Mushrooms, particularly vulnerable to postharvest losses, have garnered increasing interest recently. This study uses the culinary mushroom Pleurotus ostreatus (oyster mushroom) as a model species. Postharvest degradation of P. ostreatus begins rapidly due to microbial activity, and continued respiration. Continued respiration postharvest leads to the build-up of reactive oxygen species, and other radicals are responsible for enzymatic browning that occurs postharvest. This study aims to enhance understanding of the application of essential oils (EOs) to limit the degradation of P. ostreatus. Past research has shown that introducing EOs to produce can prolong degradation by limiting browning, microbial damage, and water loss. Limited research exists on the effects of EOs on mushrooms, particularly P. ostreatus. We seek to bridge this gap by examining changes in color and weight loss as metrics for consumer acceptability. We hypothesize that EO-modified packaging can prolong shelf life. The present study showed that the EOs Cinnamomum zeylanicum Bark & Leaf, Syzygium aromaticum, Origanum vulgare, and T. vulgaris caused significant inhibition of the growth of Bacillus cereus, Enterobacter cloacae, and Staphylococcus aureus in direct contact assays. The vapor phase of C. zeylanicum Bark, O. vulgare, and T. vulgaris inhibited these bacteria. Furthermore, over eight days, P. ostreatus exposed to volatilized O. vulgare significantly reduced weight loss values. These results indicate that EOs contain compounds that have antimicrobial and preservative effects that could be used to prevent postharvest loss.