Dissertation defence (Food Development): MSc Liz Gutiérrez Quequezana
Time
18.12.2023 at 12.00 - 16.00
MSc Liz Gutiérrez Quequezana defends the dissertation in Food Development titled “Effect of Cultivar, Growth Environment and Developmental Stage on Phenolic Compounds and Ascorbic Acid in Potato Tubers Grown in Finland” at the University of Turku on 18 December 2023 at 12.00 (University of Turku, Medisiina C, Osmo Järvi lecture hall, Turku).
The audience can participate in the defence by remote access: https://utu.zoom.us/j/65531749123
Opponent: Professor Agnieszka Kita (Wroclaw University of Environmental and Life Sciences, Poland)
Custos: Professor Baoru Yang (University of Turku)
Doctoral Dissertation at UTUPub: https://urn.fi/URN:ISBN:978-951-29-9569-1
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Summary of the Doctoral Dissertation:
The annual value of potato (Solanum tuberosum L.) consumed worldwide exceeds USD 10 000 million. Only corn, rice and wheat of the staple crops exceed the volume of potato. It provides us essential carbohydrates, proteins, fiber, vitamins, minerals, and antioxidants such as carotenoids, and phenolic compounds. Purple-fleshed potatoes, naturally occurring in the Andes, are particularly rich in anthocyanins, antioxidants known to combat oxidative stress for potential health benefits.
This study focused on developing reliable methods for extracting the target compounds from potatoes. Freeze-drying was proved to be crucial in enhancing the extraction efficiency of anthocyanins and vitamin C. This study also identified suitable solvents and reducing agents to optimize the recovery of the analytes.
The greenhouse and field experiments showed that the content of anthocyanins, phenolic acids, and vitamin C in the tubers primarily depends on the cultivar type. The highest concentrations of these compounds were observed between 70 and 80 days after planting, declining with tuber maturity.
Cold temperatures generally increase phenolic compounds in the upper plant organs, but little is known about their impact on underground organs like potato tubers. When grown under controlled temperatures (13 and 18 °C) no significant differences were found in the content of anthocyanins, phenolic acids, and vitamin C in the purple-fleshed tubers.
Field studies performed at different latitudes (61 and 64° N) over two years (2014 and 2015) revealed significant variations in tuber composition. Warmer and drier weather conditions led to lower levels of anthocyanins, phenolic acids, and vitamin C in potato tubers. Conversely, moderate temperatures (13-18 °C) with good precipitation resulted in tubers with the highest content of phenolic compounds and vitamin C. Thus, the hot and dry weather conditions produced tubers with lower nutritional value.
The audience can participate in the defence by remote access: https://utu.zoom.us/j/65531749123
Opponent: Professor Agnieszka Kita (Wroclaw University of Environmental and Life Sciences, Poland)
Custos: Professor Baoru Yang (University of Turku)
Doctoral Dissertation at UTUPub: https://urn.fi/URN:ISBN:978-951-29-9569-1
***
Summary of the Doctoral Dissertation:
The annual value of potato (Solanum tuberosum L.) consumed worldwide exceeds USD 10 000 million. Only corn, rice and wheat of the staple crops exceed the volume of potato. It provides us essential carbohydrates, proteins, fiber, vitamins, minerals, and antioxidants such as carotenoids, and phenolic compounds. Purple-fleshed potatoes, naturally occurring in the Andes, are particularly rich in anthocyanins, antioxidants known to combat oxidative stress for potential health benefits.
This study focused on developing reliable methods for extracting the target compounds from potatoes. Freeze-drying was proved to be crucial in enhancing the extraction efficiency of anthocyanins and vitamin C. This study also identified suitable solvents and reducing agents to optimize the recovery of the analytes.
The greenhouse and field experiments showed that the content of anthocyanins, phenolic acids, and vitamin C in the tubers primarily depends on the cultivar type. The highest concentrations of these compounds were observed between 70 and 80 days after planting, declining with tuber maturity.
Cold temperatures generally increase phenolic compounds in the upper plant organs, but little is known about their impact on underground organs like potato tubers. When grown under controlled temperatures (13 and 18 °C) no significant differences were found in the content of anthocyanins, phenolic acids, and vitamin C in the purple-fleshed tubers.
Field studies performed at different latitudes (61 and 64° N) over two years (2014 and 2015) revealed significant variations in tuber composition. Warmer and drier weather conditions led to lower levels of anthocyanins, phenolic acids, and vitamin C in potato tubers. Conversely, moderate temperatures (13-18 °C) with good precipitation resulted in tubers with the highest content of phenolic compounds and vitamin C. Thus, the hot and dry weather conditions produced tubers with lower nutritional value.
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