Abstract
The effect of microwave pretreatment on the levels of total phenolic compounds, flavonoids, proanthocyanidins, and individual major compounds as well as the total antioxidant activity of the dried lemon pomace was investigated. The results showed that microwave pretreatment significantly affected all the examined parameters. The total phenolic content, total flavonoids, proanthocyanidins, as well as the total antioxidant activity significantly increased as the microwave radiation time and power increased (e.g., 2.5-fold for phenolics, 1.4-fold for flavonoids, and 5.5-fold for proanthocyanidins); however, irradiation of more than 480W for 5min resulted in the decrease of these parameters. These findings indicate that microwave irradiation time and power may enhance higher levels of the phenolic compounds as well as the antioxidant capacity of the dried lemon pomace powder. However, higher and longer irradiation may lead to a degradation of phenolic compounds and lower the antioxidant capacity of the dried lemon pomace.
Practical applicationsLemon pomace could be a good source of bioactive compounds and antioxidants. Microwave irradiation could be applied for the enhancement of the total phenolic compounds and antioxidants of the lemon pomace-dried powder. The findings of this study can be applied for enhancing the bioactive compounds and the antioxidant activity of the dried lemon pomace for further extraction, isolation, and utilisation.
