Effect of osmotic dehydration in fructose, sucrose and fructooligosaccharide solutions on the content of saccharides in plums and apples and their energy value

Plums (Najbolia and Stanley) and apples (Idared) were subjected to osmotic dehydration in 50% solutions of fructose, sucrose and fructooligosaccharides (FOS) at 22, 40 and 60 °C for 24 hours. The content of fructooligosaccharides, sucrose and monosaccharides in dried material was determined. Plums osmosed in fructose contained from 22.3% w/w to 29.6%w/w of this saccharide depending on the process temperature. The content of sucrose in plums and apples varied from 18.6% w/w to 30.4% w/w after using sucrose as osmotic agent. Material processed at 40 °C was characterised by the highest content of FOS: 22.6 24.7% w/w in plums (nystose as osmotic agent) and 13.7% w/w in apples (FOS preparation as osmotic agent). The partial replacement of sucrose and monosaccharides by fructooligosaccharides reduced the energy value of carbohydrates in dried material by 12 37% depending on the process conditions.