The effect of different packaging methods on quantitative and qualitative characteristics of Dragonhead (Dracocephalum moldavica L.)

In this research, in order to study the effect of different packaging on essential oil content, antioxidant activity, phenolic compounds, total flavonoid, flavone and flavonol content, microbial load and color characteristics of Dracocephalum moldavica L., an experiment in a randomized complete design (RCD) with nine treatments and three replications was carried out. The packaging treatments were P1: control (without definite packaging), P2: polyethylene packaging with ambient gas combination exposed in light conditions P3: Polyethylene-polyamide package with ambient gas combination exposed in light conditions, P4: polyethylene-polyamide packaging with ambient gas combination exposed in dark conditions, P5: polyethylene-polyamide packaging with 5% O2 and 95% N2 gas combination exposed in light conditions, P6: polyethylene-polyamide packaging with 5% O2 and 95% N2 gas combination exposed in dark conditions, P7: polyethylene-polyamide packaging and vacuum gas combination exposed in light conditions, P8: polyethylene-polyamide packaging and vacuum gas combination exposed in dark conditions, P9: dried material before of packaging. All packages were stored at room temperature for three months. Results showed that packaging treatments had significant effects on some factors. The maximum essential oil content (0.73 and 0.72%, respectively v/w) was related to pre-packaged sample and P8 treatments and minimum essential oil content belonged to control, P2 and P5 treatments (0.28, 0.37 and 0.39%, respectively). Maximum antioxidant activity was obtained in pre-packaged, P1 and P5 treatments while P2 and P4 treatments showed minimum antioxidant activity. The highest (188.8) and the lowest (72/8) content of phenolic compounds (mg Quercitin/g DW) were measured in P9 and P2 treatments respectively. The maximum (78.6) and the minimum (14.1) content of flavonoids (mg Quercitin/g DW) were detected in P9 and P7 treatments, respectively. Fungal colony in P9 treatment (4× 103 Cfu) was higher than other packaging methods while the quantity of this contamination was not significantly different among other packaging treatments.