| Abstrakt: |
In this study, the effect of infrared drying process condition (drying temperature and time) on weight loss, total phenolic compounds and antioxidant properties of mint leaf was investigated and optimized by response surface methodology. The results showed that with increasing drying temperature, the weight loss of mint samples decreased, but with increasing drying time up to 176 minutes, the weight loss of the samples increased and then decreased. Drying time had a greater effect on weight loss changes in samples compared to drying temperature. The trend of changes in total phenolic compounds of samples with drying time was similar to the weight loss of samples, but with increasing drying temperature, the amount of total phenolic compounds of samples increased. The DPPH radical scavenging ability of the samples decreased with increasing drying time (up to 238 minutes) and then increased with increasing drying time. The results showed that applying drying temperatures up to 55°C increased DPPH radical scavenging ability of samples but applying higher drying temperatures led to a decrease in DPPH radical inhibition ability of the samples. Increasing the drying temperature increased the total antioxidant capacity and reduced the ferric reducing activity of the samples. Also, increasing the infrared drying time led to a decrease in the total antioxidant capacity of the samples. The best conditions for infrared drying of mint leaves are using drying temprature of 56.58 °C for 52 minutes and by applying the optimal conditions, the amount of weight loss (moisture loss), total phenolic compounds, and DPPH inhibition percentage of produced dry mint were 76.62%, 8.722 mg/gram of dry weight, 91.97% respectively and the desirability of this optimal condition was 0.727. [ABSTRACT FROM AUTHOR] |
