Concentration of apricot juice using complex membrane technology

Abstract

In this study, pressed apricot (Prunus armeniaca L.) juice was concentrated using complex membrane technology with different module combinations: UF-RO-OD, UF-RO-MD, UF-NF-OD and UF-NF-MD. In case of the best combination a cross-fl ow polyethylene ultrafi ltration membrane (UF) was applied for clarifi cation, after which preconcentration was done using reverse osmosis (RO) with a polyamide membrane, and the fi nal concentration was completed by osmotic distillation (OD) using a polypropylene module. The UF-RO-OD procedure resulted in a fi nal concentrate with a 65-70 °Brix dry solid content and an excellent quality juice with high polyphenol content and high antioxidant capacity.Nanofi ltration (NF) and membrane distillation (MD) were not proper economic solutions. In addition, experiments were performed for apricot juice concentration by evaporation, which technique is widely applied in the industry using vacuum and low temperature.For description the UF fi ltration, a dynamic model and regression by SPSS 14.0 statistics software were applied.Keywords: apricot juice, ultrafi ltration, reverse osmosis, osmotic distillation, evaporation, economic evaluation Apricot (Prunus armeniaca L.) is the third most commonly produced stone fruit. The main areas of production are the Mediterranean countries, which contribute 40% of the world's supply (VERSARI et al., 2008). Hungary also occupies a respectable place among producer countries. The apricot is used for consumption as fresh fruit, jams and preserves, juice, conserve, and for making alcoholic spirits. The nature of apricot means that it is only available for fresh consumption during the ripening period of 4-5 weeks. It is a delicate fruit that tends to go bad quickly. The harvested fruit endures only a short storage time of 2-3 d at room temperature. The food industry often produces a concentrated apricot juice that contains the fi bres of the fruit. With membrane technology the apricot liquor is concentrated without fi bres, but after the concentration the sterilized squeezed fi bre can be added to the juice.