Dietary fibre concentrate from carrot pomace: Process optimization, antioxidative and functional properties

Dietary fibre concentrate from carrot pomace was prepared and characterized for its physicochemical, antioxidative and functional properties. Optimization of process was done for three independent process variables i.e temperature (30–90°C) of solvent,treatment time (5-15min) and water to sample ratio (5–10) and four responses viz.total dietary fibre (TDF), Ferric ion reducing antioxidant power (FRAP), water holding capacity (WHC) and oil holding capacity (OHC) using Box-Behnken design of response surface methodology. The results revealed that temperature witnessed most significant effect on all the responses of developed carrot fibre concentrate followed by time. The optimum process parameters for preparation of fibre concentrate were: temperature 90°C, time 15 min and water to sample ratio 8.94. These conditions yielded fibre concentrate having 73.56% of TDF, 22.57mg/g of FRAP, 7.89 g/g of WHC and 2.50 g/g of OHC. Further characterization of fibre concentrate prepared under optimized conditions revealed that it has IDF to SDF ratio 2.87 and antioxidative activities viz. ABTS 49.22±0.21% and DPPH 55.26±0.32% respectively. The results recommended that carrot pomace fibre concentrate have considerable antioxidant activity and functional properties and can be used as source of dietary fibre in formulation of functional foods.