Primerjava vsebnosti antioksidantov v plodovih aronije glede na njihovo izpostavljenost soncu

Topler, Eva (author), Kreft, Samo (mentor)

Aronija je rastlina, ki ji prepisujejo mnoge zdravilne lastnosti, saj ima veliko vsebnost antioksidantov, ki so za človekovo zdravje nepogrešljivi. Začetek njene uporabe sega že v čase Indijancev, ki so jo uporabljali za zdravljenje najrazličnejših bolezni, pa tudi za konzerviranje mesa in sadja. Največji delež antioksidantov v aroniji predstavljajo polifenoli in sicer antocianini, ki so odgovorni za barvo, ter proantocianidini in tanini, ki dajejo rastlini značilen trpek okus. Zadnje študije kažejo, da ima aronija pozitivne učinke pri zaviranju procesa staranja, razrasti rakavih celic, kardiovaskularnih bolezni ter sladkorne bolezni. V diplomski nalogi smo iz zamrznjenih plodov aronije izdelali etanolne izvlečke ter preverjali celokupno vsebnost polifenolov in antocianinov glede na osojno oziroma prisojno stran grma. Vsebnost celokupnih polifenolov smo preverjali s pomočjo Folin-Ciocâlteujevega reagenta in merjenja absorbance vzorcev ter standarda, ki je bil v našem primeru galna kislina. Za metodo celokupne vsebnosti antocianinov pa smo potrebovali 0,1 M raztopino HCl. Tudi v tem primeru smo merili absorbance in rezultat preračunali tako, da smo dobili vsebnost antocianinov v mg/g plodu. Rezultati meritev so tako za polifenole kot tudi za antocianine pokazali, da prevladujejo na osojni strani, vendar pa so razlike zelo majhne. Nekoliko večje razlike med prisojno in osojno stranjo smo opazili pri vsebnosti celokupnih antocianinov pri grmih dva in tri. Na drugem grmu je vsebnost antocianinov skoraj za polovico večja na osojni strani kot na prisojni, medtem ko na grmu tri antocianini prevladujejo na prisojni strani. Pri izračunu standardnih deviacij opazimo, da so razlike med plodovi dokaj velike in tudi T– testi nam povejo, da rezultati niso statistično značilni, zato trditve, da osojna in prisojna lega vplivata na vsebnost antioksidantov, ne moremo ne potrditi in ne zavreči.

• Language: Slovenian
• Keywords: aronija, antioksidanti, polifenoli, antocianini, FC reagent, absorbanca, osojna stran, prisojna stran
• Work type: Bachelor thesis/paper
• Organization: FFA - Faculty of Pharmacy
• Year: 2020
• PID: 20.500.12556/RUL-119633
• Publication date in RUL: 10.09.2020

Secondary language

• Language: English
• Title: Analysis of antioxidants content in aronia berries according to their sun exposure

Abstract

Aronia (also known as the chokeberry) is a plant that is characterised with many health benefits, on account of its high content of antioxidants, which are vital to human health. The origin of its use can be traced back to native Americans who used it as a remedy for many illnesses, as well as for the preservation of meats and fruits. The highest levels of antioxidants in the plant consist of polyphenols, more specifically anthocyanins, which give it its signature colour along with proanthocyanin and tannin, responsible for the characteristic bitter taste. The latest studies show that the chokeberry has also beneficial effects on the aging process, decrease of cancer cells, cardiovascular diseases, and diabetes. In the diploma work we used frozen berries of the aronia to produce ethanol extracts and checked the total inclusion of polyphenols and anthocyanins based on the plant’s growth location facing the sun. We confirmed the presence of polyphenols with a Folin-Ciocalteu reagent and by measuring the absorbance of the samples and the standard, in our case we used gallic acid. As the confirmation method for the presence of anthocyanins, we used 0,1 M HCl solution. Even in this instance we measured the absorbance and calculated the results by gaining the presence of anthocyanins in mg/g. The results revealed that both polyphenols and anthocyanins dominate in berries in the shady side, but the difference is very slight. We noticed bigger differences between shady and suuny side in content of total anthocyanins in bushes two and three. The bush number two had a content of anthocyanins that was almost a half increased in berries in the shady side than in sunny, but in the bush number three the higher levels were found in the fruits growing in the sunny side. When calculating the standard deviations, we can observe that the differences between the fruits are significant and also the T-tests show that the results are insignificant. Therefore, the claim that growth position (facing sun or shade) influences the levels of antioxidants in the plant cannot be confirmed nor rejected.

• Keywords: aronia (chokeberry), antioxidants, polyphenols, anthocyanins, FC reagent, absorbance, shady side, sunny side