Application of Amine Salts of Glycyrrhizinic Acid for Prevention of Grape Rot during Storage Period

Abstract

Rots of various origins account for a significant part of the losses of grapes both during the growing season and during long-term storage. Along with traditional methods, to prevent damage to grapes during storage, environmentally friendly preparations were tested, the raw materials for which were licorice roots (Glycyrrhiza). The corresponding salts of glycyrrhizic acid were synthesized by the interaction of glycyrrhizic acid with o-phenylenediamine and methyl ester of p-aminobenzoic acid in a medium of dry acetone. The universal grape variety Moldova was chosen as the object of the study, and the storage was carried out in a refrigerator at a temperature of 5°C for 4 months. To prevent the development of pathogenic microflora, granules of sodium metabisulfite (Na2S2O5) were used at the rate of  20 g per 7–8 kg of grapes and in the same dose granules of o-phenylenediamine glycyrrhizic acid and methyl ether of p-aminobenzoic acid, as well as granules of dried crushed licorice root. It was revealed that when using Na2S2O5, to protect against the effects of harmful microflora, there were no losses either from rotting or from tearing the berries from the crest of the bunch, the color and consistency of the berries remained the same as during storage. The effectiveness of the tested drugs with the same method of application was somewhat less: in the variant with licorice root granules, losses amounted to more than half, with o-phenylenediamine glycyrrhizic acid (compound 2) – about half of the product, with methyl ester of p-aminobenzoic acid (compound 3), the yield of standard products was slightly more than 70% of the batch stored.