अमूर्त

Impacts of different drying methods on phenols contents and antioxidant activity of Russian Olive (Elaeagnus angustifolia L) fruit.

Soussene Boudraa*, Driss Elothmani, Sara Zidani

In the present study, the effects of two drying methods (freeze-drying and microwave at different power) on antioxidant properties of Russain olive (Elaeagnus angustifolia) fruits were investigated. For the rate of drying, results showed that sample weight stability was reached faster in microwave (300 W/270 s) than in freeze-drying (5 µba/68 h). Concerning antioxidants, results showed that the highest total polyphenols ,total flavonoids, Flavan-3-ols , ascorbic acid and tocopherols contents were recorded by fruits dried in microwave at 300 W (127.50 mg GAE/g dw, 70.75±5.89 mg EQ/L dw ,0.23 mg catechin/g extract dw ,6.39 mg /100 mg dw and 1.10 mg /100 g dw, respectively) than those dried in other power of microwave oven . At the end, the assessment of radical scavenging activity against stable Diphenylpicrylhydrazyl Assay (DPPH), the ferric reducing antioxidant power (FRAP) and the oxygen radical absorbance capacity (ORAC)) of Russain olive (Elaeagnus angustifolia L.) showed an increase in scavenging effect particularly when microwave drying at 300 W technology was used. The selection of a particular drying method is important for Russain olives fruits desired characteristics of the dried products, as well as onthe operating conditions and costs. This work demonstrates that Russain olive (indigenous cultivars) can be a good of different nutrients for the local population.