Development and Validation of an Analytical Method for Carnosol, Carnosic Acid and Rosmarinic Acid in Food Matrices and Evaluation of the Antioxidant Activity of Rosemary Extract as a Food Additive

Abstract

Antioxidants are used to prevent the oxidation of foods. When used for food additive purposes, the dosage should be regulated and the functionality evaluated to ensure stability. In this study, we performed a method validation for the quantitative analysis of rosemary extract residues and evaluated the antioxidant activity of rosemary extract in food matrices. The validated method was able to determine rosemary extract under the optimized high-performance liquid chromatography-photodiode array (HPLC-PDA) conditions. Furthermore, the antioxidant activity was evaluated by peroxide value, acid value, and in terms of the residual antioxidant levels in lard oil. For HPLC-PDA analysis, the limit of detection and quantification of rosemary extracts was ranged from 0.22 to 1.73 μg/mL, 0.66 to 5.23 μg/mL and the recoveries of the rosemary extracts ranged from 70.6 to 114.0%, with relative standard deviations of between 0.2% and 3.8%. In terms of antioxidant activity, carnosic acid performed better than carnosol. Furthermore, by evaluation of the residual antioxidant level using HPLC, we found that carnosic acid is more stable in lard oil than carnosol. These results indicate that rosemary extract can be used as an antioxidant and that the analytical method is suitable for the determination of rosemary extract in various food samples.

Antioxidant Activity of Polyphenolic Plant Extracts

“…The dosage of antioxidant compounds used as food preservatives should be regulated and the functionality should be evaluated to ensure stability [34]. For example, polyphenolic extracts from Rosmarinus officinalis L. (rosemary) has been widely used in food industry as antioxidant additive [35]. In some countries, the addition of rosemary extract as food additive is permitted, while in other countries it is not allowed [35].…”

“…For example, polyphenolic extracts from Rosmarinus officinalis L. (rosemary) has been widely used in food industry as antioxidant additive [35]. In some countries, the addition of rosemary extract as food additive is permitted, while in other countries it is not allowed [35]. Thus, Choi et al [35] developed a quantitative high-performance liquid chromatography-photodiode array (HPLC-PDA) method for the determination of the amount of rosemary extract in various food products (e.g., edible oils, processed meat products and dressings).…”

“…In some countries, the addition of rosemary extract as food additive is permitted, while in other countries it is not allowed [35]. Thus, Choi et al [35] developed a quantitative high-performance liquid chromatography-photodiode array (HPLC-PDA) method for the determination of the amount of rosemary extract in various food products (e.g., edible oils, processed meat products and dressings). Moreover, the method could evaluate the antioxidant activity of rosemary extract in foods, and consequently its functional stability [35].…”

“…Thus, Choi et al [35] developed a quantitative high-performance liquid chromatography-photodiode array (HPLC-PDA) method for the determination of the amount of rosemary extract in various food products (e.g., edible oils, processed meat products and dressings). Moreover, the method could evaluate the antioxidant activity of rosemary extract in foods, and consequently its functional stability [35]. Thus, they found that in terms of antioxidant activity carnosic acid of rosemary extract is more stable than carnosol [35].…”

“…Moreover, the method could evaluate the antioxidant activity of rosemary extract in foods, and consequently its functional stability [35]. Thus, they found that in terms of antioxidant activity carnosic acid of rosemary extract is more stable than carnosol [35]. Fruit vinegars containing polyphenolic antioxidants are also used widely in food industry as condiments [36].…”