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 Katrina  Kelly

Katrina Kelly

Katrina Kelly

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Advisor : Cecilia Nunes

Program

MS

Strawberries are an important source of bioactive compounds (i.e., vitamin C and polyphenolic compounds) in the human diet. The production of polyphenolic compounds is mediated by the enzyme Phenylalanine Ammonia-Lyase (PAL) while the breakdown is mediated by Polyphenol Oxidase (PPO). Previous studies have shown that the activity of PAL increases while the strawberry ripens on the plant, but there have been few studies on how its activity is affected by postharvest abiotic stresses. PPO oxidizes polyphenolic compounds into quinones, which polymerize with other quinones or phenolics, resulting into browning of strawberry fruit. This process is normally accelerated as the fruit senesces, but abiotic stresses such exposure to high temperatures and low humidity and/or physical damage may also contribute to this enzymatic browning. I am currently investigating the effect of post-harvest storage of these two enzymes in different strawberry cultivars.