FOOD. Science. Technology. Quality

Food. SCIENCE. Technology. Quality

Food. Science. TECHNOLOGY. Quality

Food. Science. Technology. QUALITY




Osmotic dehydration of apples in sucrose and ascorbic acid solution


The aim of this study was to investigate quality of cold-pressed oils coming from Warsaw market. In each oil sensory and physicochemical quality were examined: spectrofotometric colour, acid value, peroxide value, anisidine value, Totox index, oxidative stability in Rancimat test and content of following elements such as: Fe, Cu, Cd, Pb, As, Hg and Zn. The aim of this work was to investigate the effect of presence of ascorbic acid (C-vitamin) on kinetics of osmodehydration of apples. Apple cubes (10x10x10 mm) were osmotically dehydrated in 20, 40 and 61,5% sucrose solution either containing or not ascorbic acid at temperature 50 and 70°C. Treatment time ranged from 0 to 1200 minutes. Water content, weight loss, solids gain, water activity, ascorbic acid uptake, sugar uptake and apple acid content were analyzed. The results showed that mass transfer was the highest after 180 minutes of processing time. Higher temperature, acid ascorbic addition into osmotic solution and applying higher sucrose solution caused decrease of water content and water activity, but increase weight loss and solid gain in osmodehydrated apples. The higher temperature and concentration of solution caused increase apple acid content in apples. Higher sucrose concentration in solution and higher temperature, but less effect of ascorbic acid addition influenced higher sugar content (total and direct reduction sugar) in analized apples.


apples, sucrose, sugar and ascorbic acid content, osmodehydration, weight loss, total acid