Antioxidant Capacity of Rapeseed Extracts Obtained by Conventional and Ultrasound‐Assisted Extraction

Abstract

Ultrasound-assisted extraction (UAE) and conventional solid–liquid extraction were applied to extract total antioxidants from two rapeseed varieties. The antioxidant capacities (AC) of winter and spring rapeseed cultivars were determined by four different analytical methods: ferric reducing antioxidant power (FRAP), cupric reducing antioxidant capacity (CUPRAC), 2,2′-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS). The average AC of the studied rapeseed cultivars ranged between 4.21–10.03 mmol Trolox (TE)/100 g, 7.82–10.61 mmol TE/100 g, 8.11–51.59 mmol TE/100 g, 22.48–43.13 mmol TE/100 g for FRAP, CUPRAC, DPPH and ABTS methods, respectively. There are positive correlations between total phenolics (TPC = 804–1625 mg sinapic acid (SA)/100 g) and AC of the studied rapeseed extracts (r = 0.2650–0.9931). Results of the principal component analysis (PCA) indicate that there are differences between the total amounts of antioxidants in rapeseed samples extracted by different extraction techniques. Rapeseed extracts obtained after 18 min of ultrasonication revealed the highest content of total antioxidants. The UAE is a very useful, efficient and rapid technique of oilseed samples preparation for determination of AC by different analytical methods.

Optimization of ultrasound‐assisted extraction of cold‐brewed black tea using response surface methodology

“…Similar to the work done by (Annegowda et al, 2010) shows a significant decrease in %ABTS activity with increased sonication time. The probable reason for decreased activity during prolonged sonication might be the cause of a decreased area of diffusion which aligns with this study (Annegowda et al, 2010; Szydłowska‐Czerniak & Tułodziecka, 2014). With continuous extraction of bioactives from tea leaves, it is possible for the diffusion process to move more towards the inner portion of the black tea leaves.…”

Potential use of Lentinus squarrosulus mushroom as fermenting agent and source of natural antioxidant additive in livestock feed

“…On the other hand, there was no significant correlation between TPC and their ability to reduce cupric ions. It has been suggested that not all of the phenolic compounds are active cupric ion reductor . Therefore, the type of phenolic compounds present in the extract is more influential to the CUPRAC activity than their total content.…”

“…It is noteworthy that there are significant ( P < 0.01) correlations between DPPH‐RPA ( r = 0.980) and DPPH‐CUPRAC ( r = 0.977) methods used to determine the antioxidant capacity of the studied LSMB and LSFM samples. Similar correlation coefficients ( r = 0.8199–0.9999) between the three antioxidant assays were found in the rapeseed samples …”

“…It has been suggested that not all of the phenolic compounds are active cupric ion reductor. 38 Therefore, the type of phenolic compounds present in the extract is more influential to the CUPRAC activity than their total content. It is noteworthy that there are Similar correlation coefficients (r = 0.8199-0.9999) between the three antioxidant assays were found in the rapeseed samples.…”

“…It is noteworthy that there are Similar correlation coefficients (r = 0.8199-0.9999) between the three antioxidant assays were found in the rapeseed samples. 38 The results of the LSMB and LSFM extracts were subjected to PCA using SPSS 22.0 package. Principal component analysis revealed the presence of two components with eigenvalues exceeding 1, which explained a total of 87.39% of the variance, with Component 1 contributing 65.59% and Component 2 contributing 21.78% (Fig.…”