The plum (Prunus domestica) cuticle, its components and their impact on the drying process

Abstract

The Main aim of this research is understanding how to carried our drying process for the two varieties of plum: ‘‘Shavkliava’’ (local) and ‘’Stanley’’ (introduced) according of cuticle performance. The four fractions was take out from the isolated cuticle: epicuticular wax, intracuticular wax, triterpene acids, and cutin. All these have been analyzed. Obtained data according to the varieties is folowing: ‘Shavkliava’ - 370-478-594-980 μg /cm² and ‘Stanley’ is 625-440-770-1100 μg /cm^2. The optimal parameters of the blanching was established: ‘Shavkliava’ NaOH concentration 0.5%, 20-30 seconds of exposure, temperature 90⁰C; ‘Stanley’ 0.5 % - 30 seconds 95⁰C respectively. In such conditions only epicuticular wax is moved off. When there is a high concentration – 1 % NaOH, the intracutic- ular wax, the total number of phenols and terpene acids decreased, which significantly reduces the dry product’s quality parameters. Treatment involves stopping the oxidation process temporarely. In connection with this, it dete-rmined that the phenol compounds in the initial samples and after drying.With the impact of optimal conditions for treatment, the total number of common phenols is signifi- cantly more and consists 35.5% for ‘Shavkliava’, 30 % for ‘Stanley’. Drying was carried out in three temperature conditions gradually 40-45⁰C, 60-65⁰C, 75-85⁰C.