Study on the Antioxidant and Antifungal Activities of Extract and Pulp of Date (Phoenix dactylifera L.) by-Products

Iran is considered as one of the most important suppliers of date all over the word. Since date is a rich source of polyphenolic compounds, the aim of this study is to investigation of the antioxidant and antifungal properties of dates pulp and its methanolic extract.
Methanolic extract of date pulp was extracted by Soxhlet and evaluated by colorimetric method. In addition, antioxidant properties of the extracts were measured by DPPH radical scavenging method. The effect of different levels of date extract and pulp on acidic, peroxide and thiobarbituric acid values of sunflower oil during 15 days of storage at 70 °C were investigated. Antifungal effect of date extract and pulp against Aspergillus niger was evaluated according to the disc diffusion method.
Total phenolic (mg gallic acid/ 100 g sample) and flavonoid (mg catechin/100 g sample) compounds of extract and pulp were 414.72, 304.18, 28.62 and 20.72, respectively. DPPH radical scavenging activity of TBHQ, date pulp and extract showed the results as follows: TBHQ date extract ˃date pulp. Based on the results, addition of date pulp and its extract decreased peroxide and TBA values of sunflower oil compared to the control sample. The results of antifungal test indicated antifungal effects of date extract against Aspergillus niger.
According to the obtained results, date pulp and its extract can be introduced as a cost-effective source of antioxidant as well as antifungal compound in food technology.