Anthocyanins from blackberry (Rubus fructicosus L.) impregnated in yam bean (Pachyrhizus erosus (L.) Urb.) by osmotic dehydration

Yam bean (Pachyrhizus erosus (L.) Urb.) tuber has a low carbohydrate content and contains several aminoacids, but contains few active compounds, such as vitamins and antioxidants. Anthocyanins are antioxidants found in Rubus fructicosus L. The osmotic drying is a technique that can be used to impregnate antioxidants in a matrix, so the objective of this study was to impregnate yam bean tuber slices with anthocyanin. The effect of temperature (40, 50 and 60 degrees C), sucrose content (40, 50 and 60 degrees Brix) and vacuum pulse (0, 300 and 600 mbar) on water loss (WL), solid gain (SG), color changes (Delta E) and anthocyanin concentration (.A) during osmotic drying of yam bean slices was determined. Polynomial equations were used to determine changes in WL, SG, Delta E and Delta A of yam bean slices after 6 h of osmotic drying. An osmotic solution at 60 degrees C with a SC of 40 degrees Brix, applying a vacuum pulse of 12 mbar maximized anthocyanin impregnation (6.67 mg anthocyanin per g initial dry matter) in tuber slices. The Page equation predicted optimum WL, SG and Delta A of yam bean tuber slices during osmotic drying. No relation was found between temperature, sucrose content and vacuum pulse with K and n parameters in the Page equation.