Eco-friendly control of licorice aqueous extract to increase quality and resistance to postharvest decay in apple and tangerine fruits

Abstract

Postharvest diseases in fruits and vegetables are one of the major problems in storing them as a fresh agri-product. This study aimed to investigate the antifungal activity of licorice (Glycyrrhiza glabra) aqueous extract against the Penicillium expansum and the Penicillium digitatum in apple and tangerine fruits as well as their postharvest decay during storage time. The minimum inhibitory concentration (MIC) of the molds, and the decay inhibition percentage (%DI) with the P.expansum for apple and P.digitatum for tangerine after treatment with licorice aqueous extract were measured. Additionally, the lesion diameter, titratable acidity (TA), total soluble solids (TSS), pH, and organoleptic properties were determined. The growth of molds was almost inhibited at the concentration of 62.5 mg/mL. The ability of licorice aqueous extract to significantly control and reduce the growth of P. expansum in apple by 60 and 20\u2009% after 7 days and 21 days of storage time was proved, respectively. Furthermore, significant differences in pH and TSS (p\u2009<\u20090.05) were observed in apples. Also, the growth of P. digitatum in the tangerine reduced by 33.3\u2009% after 7 days, while there was no significant difference between the control and treatment groups in pH and TSS for apples, and similarly, there was no significant difference in TA for tangerine samples. Therefore, the licorice aqueous extract treatment could postpone the blue mold decay in apple fruits and green mold decay in tangerine without any significant effect on fruit quality characteristics. It can be considered as a new eco-friendly control in fruit preservation, while it did not result in any significant adverse effect on the quality.