Sadržaj polifenolnih spojeva i antioksidacijska aktivnost koprive uzgojene u sustavu plutajućih ploča

master's thesis

• Title (english): Content of polyphenol compounds and antioxidant activity of stinging nettle grown in a floating hydroponics
• Author: Martina Hapač
• Mentor: Jana Šic Žlabur (mentor)
• Committee member: Jana Šic Žlabur (predsjednik povjerenstva)
• Committee member: Sanja Radman (član povjerenstva)
• Committee member: Sandra Voća (član povjerenstva)
• Committee member: Nevena Opačić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Agriculture; (Sustainable Technologies and Renewable Energy Sources); Zagreb
• Defense date and country: 2021-09-27, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Agronomy

Abstract

Kopriva (Urtica dioica L.) je ljekovita, jestiva, često zanemarena biljna vrsta s visokim sadržajem brojnih fitokemikalija, posebice polifenolnih spojeva, a time i visokim potencijalom za ljudsko zdravlje. Cilj ovog diplomskog rada bio je utvrditi učinak hranive otopine i višekratne košnje na sadržaj ukupnih fenola, flavonoida i neflavonoida te antioksidacijski kapacitet lista koprive iz plutajućeg hidropona. Dvofaktorijalni pokus s koprivom postavljen je po metodi slučajnog bloknog rasporeda u tri ponavljanja u plutajućem hidroponu u zaštićenom prostoru Zavoda za povrćarstvo. Praćen je sadržaj polifenolnih spojeva (ukupnih fenola, flavonoida i neflavonoida) i antioksidacijski kapacitet u svježem listu koprive uzgajane u dvije hranive otopine različitog sastava nutrijenata, tijekom tri roka košnje. Rezultati istraživanja su pokazali kako višekratna košnja i sastav hranive otopine značajno utječu na sadržaj polifenolnih spojeva i antioksidacijski kapacitet. Utvrđeno je da su vrijednosti sadržaja ukupnih fenola, flavonoida, neflavonoida te vrijednosti antioksidacijskog kapaciteta najveće u trećem roku košnje (ukupni fenoli 419,22 mg GAE/100 g svježe tvari, flavonoidi 214,06 mg GAE/100 g svježe tvari, neflavonoida 205,16 mg GAE/100 g svježe tvari, antioksidacijski kapacitet 2475,76 μmol TE/L). Najviši sadržaj ukupnih polifenolnih spojeva te antioksidacijskog kapaciteta, ovisno o sastavu hranive otopine, utvrđen je prilikom uzgoja u otopini po Johnson recepturi, a koja kumulativno sadrži manji udio dušika u usporedbi s otopinom po Larson recepturi. Temeljem svega navedenog, može se zaključiti kako su sastav hranive otopine kao i rok košnje značajni čimbenici u uzgoju koprive u plutajućem hidroponu te da se optimalnim balansiranjem istih može i značajno utjecati na nutritivnu kvalitetu gotovog proizvoda.

Abstract (english)

Stinging nettle (Urtica dioica L.) is a medicinal, edible, often neglected plant species with a high content of numerous phytochemicals, especially polyphenolic compounds, thus the high potential for human health. The aim of this thesis was to determine the effects of nutrient solution and harvest (mowing) time on total phenolic, flavonoid, and non-flavonoid content, and antioxidant capacity of stinging nettle leaves from floating hydroponics. A two-factor experiment with stinging nettle was set up according to a randomized block design in three replicates in a floating hydroponics in a greenhouse. The content of polyphenolic compounds (total phenols, flavonoids, non-flavonoids) and antioxidant capacity in fresh nettle leaf cultivated in two different nutrient solutions were monitored, during three mowing periods. The content of polyphenolic compounds (total phenols, flavonoids and neflavonoids) and antioxidant capacity in fresh nettle leaf grown in two feed solutions of different nutrient composition, over three mowing periods were monitored. The results of the study showed that repeated mowing and the composition of the feed solution significantly affect the content of polyphenolic compounds and antioxidant capacity. The values of the content of total phenols, flavonoids, neflavonoids and antioxidant capacity values were found to be highest in the third mowing period (total phenols 419.22 mg GAE/100 g fresh matter, flavonoids 214.06 mg GAE/100 g fresh matter, neflavonoids 205.16 mg GAE/100 g fresh matter, antioxidant capacity 2475.76 μmol TE/L). The highest content of total polyphenole compounds and antioxidant capacity, depending on the composition of the feed solution, was established when growing in a solution according to the Johnson recipe, which cumulatively contains a lower nitrogen content compared to the solution according to the Larson recipe. Based on all of the above, it can be concluded that the composition of the feed solution as well as the mowing period are significant factors in the cultivation of nettle in floating hydroponics and that optimal balancing of them can also significantly affect the nutritional quality as a final product.

• Keywords: ukupni fenoli; kopriva; plutajući hidropon; rok košnje; antioksidacijski kapacitet
• Keywords (english): total phenols; stinging nettle; floating hydropon; mowing period; antioxidant capacity
• Language: croatian
• URN:NBN: urn:nbn:hr:204:469403
• Study programme: Title: Horticulture; Study programme type: university; Study level: graduate; Academic / professional title: magistar/ magistra inženjer/inženjerka hortikulture (magistar/ magistra inženjer/inženjerka hortikulture)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to authenticated users
• Created on: 2021-12-01 08:29:12