Investigation of the effect of flower and leaf ethanolic extract of Humulus lupulus plant on the shelf life and quality attributes of strawberry fruits

This study was conducted to determine the effects of flower and leaf extract of Humulus lupulus plant on the shelf life and quality attributes of strawberry fruits. Different treatments were applied in this research including: flower and leaf ethanolic extract of Humulus lupulus plant at concentration of 25, 50 and 100 percent, diazinon fungicide at concentration of 100 and 200 ppm and blank samples (0 ppm). Different quality attributes including: total soluble solids, fruit juice pH, titratable acidity, flavor index of fruit, sensory attributes and total microbial counts of fruits were measured during storage periods. The results showed that application of the flower and leaf extract of Humulus lupulus plant and diazinon fungicide had no significant effect on the pH value of strawberry fruits but maintained the titratable acidity during storage periods compared to the blank samples (p>0.05). Total soluble solid content of strawberry fruits was decreased with increase of the storage time but increased with increase of the flower and leaf extract of Humulus lupulus plant concentration and compared to applied concentration of diazinon fungicide (tow concentration) lead to better brix content maintenances. Treated strawberry samples with the flower and leaf extract of Humulus lupulus plant compared to other samples obtained the higher score in case of appearance, color and texture during sensory evaluation. Microbial evaluation results, showed the ability of the flower and leaf extract of Humulus lupulus plant in microbial spoilage inhibition compared to the diazinon fungicide. According to the obtained results from different chemical, microbial and sensory evaluations, the flower and leaf extract of Humulus lupulus plant can be introduced as replacer of the common fungicide applied in strawberry preservation.