Antioxidant activity of raspberry (Rubus fruticosus) leaves extract and its effect on oxidative stability of sunflower oil

Abstract

Efficacy of R. fruticosus leaves extract in stabilizing sunflower oil during accelerated storage has been studied. Extracts of R. fruticosus were prepared in different solvents which methanolic extract yield with 15.43 % was higher than water and acetone ones (11.87 and 6.62 %, respectively). Methanolic extract was chosen to evaluate its thermal stability at 70°C in sunflower oil, due to the highest yield, antioxidant and antiradical potential and also high content of phenolic compounds campared to other solvents. So, different concentrations of methanolic extract (200, 400, 600, 800 and 1,000 ppm) were added to sunflower oil. BHA and BHT at 200 ppm served as standards besides the control. Peroxide value (PV) and thiobarbituric acid (TBA) were taken as parameters for evaluation of effectiveness of R. fruticosus leaves extract in stabilization of sunflower oil. Moreover, antioxidant activity index (AAI) of the extract at 120°C at rancimat were conducted. Results from different parameters were in agreement with each other, suggesting the highest efficiency of 1,000 ppm of the extract followed by BHT, BHA and other concentrations of the extract. Results reveal the R. fruticosus leaves extract to be a potent antioxidant for stabilization of sunflower oil.

Antioxidant activities of Thai pigmented rice cultivars and application in sunflower oil

“…Asnaashari et al . () also found that the AAI values of the treated samples with 200, 400, 600, 800 and 1000 ppm of R. fruticosus extract were 1.013, 1.07, 1.187, 1.47 and 2.09, respectively, suggesting its remarkable effectiveness on oxidative stability of sunflower oil.…”

“…After the 6th day, there was a sharp rise in PV of control sample from 8.35 to 75.74 meqO 2 kg −1 oil. However, PV s of the samples with 1000 ppm of the methanolic extract changed from 1.8 (at day 6) to 18.8 meqO 2 kg −1 oil (at day 12) (Asnaashari et al ., ).…”

Prediction of oxidation parameters of purified Kilka fish oil including gallic acid and methyl gallate by adaptive neuro‐fuzzy inference system (ANFIS) and artificial neural network

“…In the propagation stage, the peroxide value increased rapidly and the amount of lipid hydroperoxides accumulated to an extremely high level. After the peroxide content reached a maximum level in the Kilka oil, the rate of peroxide decomposition actually exceeded the rate of formation, resulting in deceasing peroxide value . The level of hydroperoxides in the Kilka oil samples increased relatively slowly towards the end of induction period (the PV IP values ranged from 9 meqO 2 kg) −1 to 31meqO 2 (kg) −1 for gallic acid and to 40 meqO 2 (kg) −1 for methyl gallate) and then increased sharply in the propagation stage of lipid oxidation.…”

Ocena właściwości antyoksydacyjnych liści Ginkgo biloba L. po zakończeniu wegetacji

“…Na taką ich zdolność wskazują również bada nia innych autorów z wykorzystaniem liści miłorzębu [13,14,15,23,24], a także badania przeprowadzone na liściach innych roślin, w tym np. winorośli właściwej [25], aronii czarnej [26], akki sellowej [27], bielunia surmikwiatu [28] czy jeżyny euro pejskiej [29].…”