Evaluation of antioxidant activity of nano‐ and microencapsulated rosemary (Rosmarinus officinalis L.) leaves extract in cress (Lepidium sativum) and basil (Ocimum basilicum) seed gums for enhancing oxidative stability of sunflower oil

Abstract

There has been interest in the use of plant extract as a natural preservative agent for improving the oxidative stability of vegetable oils. However, plant extracts have low stability against heat and environmental stress. In this study, the antioxidant potential of nano‐ and microencapsulated Rosmarinus officinalis L. extract (RE) obtained using the ultrasonication method was measured. The total phenolic and flavonoid content of the extract was 174.4 ± 25.9 mg gallic acid/g extract and 78.30 ± 3.2 mg rutin/g extract, respectively. Antioxidant activity of 50, 100, 200, and 400 ppm of RE was measured by DPPH free radical scavenging methods, ferric reduction assay, and β‐carotene/linoleic acid assay, and then compared to the 100 ppm of TBHQ as a common synthetic antioxidant. The results showed that the antioxidant activity increased with increasing the concentration of the extract in all evaluating methods. The antioxidant activity of 200 ppm of the free and encapsulated extract in cress (Lepidium sativum) and basil (Ocimum basilicum) seed gums at different ratios (1:0, 1:1, and 0:1) was compared to sunflower oil without antioxidants, and oil‐containing TBHQ which was stored at 60°C for 24 days. The oxidation indexes of oil samples include peroxide value, thiobarbituric acid value, and p‐anisidine value measured at 4‐day intervals. A lower oil oxidation was observed in oil‐containing nanoencapsulated extract followed by microencapsulated extract, free extract, and TBHQ. Since producing nanoencapsulated RE requires a higher time and speed of homogenization and due to no statistically significant difference between the antioxidant properties of nanocapsules and microcapsules in oil, the use of microcapsules of RE in basil seed gum to increase the shelf life of sunflower oil is recommended.

The effect of antioxidant properties of free and encapsulated rosemary extract in liposome on the oxidation process of canola oil

“…The amount of TBA increased rapidly after 4 days, similar to results reported by Chen et al (2014). Jafari et al (2022) detailed a diminished TBA in sunflower oil following expanded concentration of rosemary extract.…”

“…Jafari et al . (2022) detailed a diminished TBA in sunflower oil following expanded concentration of rosemary extract.…”

“…The number of polyphenol compounds of rosemary extract, in different studies, was 174.25 AE 4.9 mg gallic acid gˉ1 (Jafari et al, 2022), 136.66 AE 7.41 mg gallic acid gˉ1 (Saini et al, 2020) and 128.97 mg GAE gˉ1 (Teruel et al, 2015). Free radical scavenging activities of free and liposomal rosemary extract were obtained to be 84.57% and 92.5%, respectively.…”

Evaluation of antioxidant properties of nanoencapsulated sage (Salvia officinalis L.) extract in biopolymer coating based on whey protein isolate and Qodumeh Shahri (Lepidium perfoliatum) seed gum to increase the oxidative stability of sunflower oil

“…Antioxidant properties of plants are effective in delaying oxidation and rancidity in fats and oils and they have similar activity as chemically synthetic antioxidants (Aly et al, 2021; Wang et al, 2020). Natural extracts from different herbs, such as Heracleum persicum (Kenari et al, 2020), Fumaria parviflora L. (Razavi & Kenari, 2021), sesame (Esmaeilzadeh Kenari & Razavi, 2022), and Rosmarinus officinalis L. (Jafari et al, 2022), are stable for oxidation which is related to the presence of natural phenolic compounds.…”

“…Natural extracts from different herbs, such as Heracleum persicum (Kenari et al, 2020), Fumaria parviflora L. , sesame (Esmaeilzadeh , and Rosmarinus officinalis L. (Jafari et al, 2022), are stable for oxidation which is related to the presence of natural phenolic compounds. Sage (Salvia officinalis L.), an evergreen shrub, belongs to the mint family (Labiatae).…”