Effects of hibiscetin pretreatment on the color and anthocyanin level of microwave vacuum dried edible roses

Abstract

Pretreatments may reduce the degradation of color and anthocyanin during drying of rose flowers. To better preserve the color and anthocyanin content of rose flower during drying process and storage period, rose flowers were pretreated by dipping in three solutions including, 0.1% hibiscetin, 0.3% CaCl2, and the mixture of 0.3% CaCl2 and 0.5% Vitamin C. Then, the effects of these three pretreatments on the drying characteristics, color, anthocyanin content, and odor of dried rose flowers were investigated. In addition, the change of color and anthocyanin content of three different treated rose flowers during storage were determined. Results showed that all pretreatment caused no significant difference on drying time of rose flowers. Little flavor change was observed among rose flower samples treated with 0.1% hibiscetin compared to other pretreatments. Dried roses were less bright than fresh ones with L* values decreasing from 60.31 to almost half. Samples pretreated by hibiscetin revealed the maximum value of a* (37.95 ± 0.76) and the most stable anthocyanin level during storage. Therefore, hibiscetin pretreatment may be considered as a potential technique for improving the stability of natural color of roses during its processing and storage.