Determination of chemical composition of some currantvarieties and investigation of availability in food industry

Scientific interest has been focused on fruits and their derived products with high antioxidant capacity and high content of phenolic compounds that are important for human health. In this study, the physico-chemical (moisture, soluble solids, pH, color, protein, acidity, sugar fractions, dietary fiber, ascorbic acid, minerals), functional (polyphenol, total anthocyanin (TAC), total (TPC) and bioavailable phenolic matter (BPM), antioxidant capacity (DPPH ve CUPRAC)), aroma and sensory properties of currant varieties (Ribes L.) (Rosenthal, Boskoop Giant, Goliath, Red Lake, Jostaberry) having high phytochemical content were determined. Then, the extract was obtained at optimum conditions from the 'Boskoop Giant' variety having the best properties. This extracts were used to produce concentrated currant extract and microencapsulated powder product by coating at different concentrations of maltodextrin (MD) (70, 80 and 90%, w/w) by spray dryer. In powder products; drying yield, moisture, water activity, color, solubility, higroscopicity, glass transition temperature and functional properties were evaluated, then the stability of bioactive properties for concentrated extract and powders at +4 OC during 12 months storage period were assessed. According to the results, 'Goliath' was the most liked berry in terms of sensory properties and principal component analysis demonstrated that 'Rosenthal' and 'Goliath' showed big differences in the volatile fraction that they can be differentiated from each other. The minerals K, Ca and Mg presented higher in all currant varieties. 'Rosenthal' variety had the highest amounts of TPC and antioxidant capacity, whereas 'Boskoop Giant' characterised with the best content of TAC, polyphenols and in-vitro BPM. Increased levels of MD caused to decrease in drying yield, glass transition temperature, solubility and anthocyanin recovery, whereas the functional properties were found to increase. According to results, it was considered that currants offer opportunities for development of value–added products because of high content of bioactive compounds, and extracts could be used in various food products as a natural colorant and food additive.