Revista de Processamento e Tecnologia de Alimentos

Abstrato

Measurement of Phenolic Content and Antioxidant Capacity of Pennyroyal (Mentha pulegium L.) and Microalgae Spirulina platensis Extracted by Steeping, Ultrasonic and Microwave Methods

Delfan P, Mortazavi A, Rad AHE and Zenoozian MS

Now-a-days more attention is drawn to the use of natural compounds over synthetic ones in the production of food dyes and pharmaceutical additives. Among the most important and effective components in diets are antioxidants which protect the body from oxidative stress caused by free radicals. In this study, extracts of microalgae Spirulina platensis: and pennyroyal were prepared via steeping, microwave and ultrasonic methods using two solvents, water and ethanol under controlled conditions. Six treatments including water-steeping, water-microwave, water- ultrasound, ethanol-steeping, ethanol-microwave and ethanol-ultrasound, were prepared and triplicate experiments were performed to determine the following components: flavonoid, total phenols content as well as antioxidant capacity (IC₅₀) of the extracts based on Alcl, follin-ciocaltuea and absorption of radical DPPH (2,2-diphenyl -1-ipicryl hydrasil). The data was analyzed by SPSS version 24 and the means were compared using a multi-range Duncan test at 5% level (p<0.05). The results showed that the ultrasound method had the best efficacy for the extraction of phenolic and antioxidant compounds. The use of the water-ultrasound treatment in the extraction of microalgae resulted in the highest amounts of flavonoids and total phenols and the lowest amounts of IC₅₀ (the greatest radical scavenging activity) compared to the five other treatments. The use of the ethanol-ultrasound treatment in the extraction of pennyroyal produced similar results to the waterultrasound extracted microalgae, showing high amounts of flavonoid, total phenol, and radical scavenging activity. These results revealed that a combination of different extraction methods and different solvents is needed to obtain the best results.