Evaluation of Oregano essential oil effects on quality and biochemical attributes of sweet cherry (Prunus avium L. cv. ‘Takdaneh Mashhad’)

Fruits and vegetables contain antioxidants, among which sweet cherries has the highest antioxidants and plays a major role in preventing diseases and protecting human health. In addition, consumption and demand of fruits with high-quality, healthy and chemical free is increasing. The present study was carried out to evaluate the effect of postharvest spray with marjoram essential oil with 5 levels (0, 250, 500, 750 and 1000 μL.L-1) on harvested ‘Takdaneh Mashhad’ sweet cherry fruits. The fruits were kept at 1 ±0.5 °C with 90 to 95% RH. The fruits were removed from the cold chamber every 15 days in a 30-day period. Different physiological indices such as total soluble solids (TSS), titratable acidity (TA), pH, fruit firmness, total antioxidants based on the DPPH-free radical scavenger capacity, phenols and total flavonoid content were evaluated. The results showed that marjoram essential oil at 750 μL.L-1 had a significant effect on pH, TSS, TA, firmness, antioxidant activity, and at 1000 μL.L-1 affected total phenols and flavonoid contents. The essential oil treatment increased the storage time and maintained pH and TSS at a lower level than control. The treatment reduced the rate of TA and firmness reduction. In addition, the higher levels of essential oil, enhanced antioxidant activity and phenolic compounds. The results showed that postharvest use of marjoram essential oil increased the quality and antioxidant properties of the sweet cherry fruits, and can be used as a safe method for increasing the shelf life of sweet cherries.