Although freeze-drying preserved deep-orange color of fresh
pumpkin, metabisulfite caused color loss. Freeze-drying also
improved some techno-functional properties (WHC, OBC, ES and
EC) of pumpkin flours. However, the cost of freeze drying application
is very high. Phenolics, bioaccessible phenolics, antioxidant
activities and phenolic acid concentrations of hot-air oven dried
pumpkin flours were higher than those of freeze-dried pumpkin
flour samples. Metabisulfite application also caused an increase in
phenolic contents, bioaccessible phenolics, antioxidant capacities
and phenolic acid levels of pumpkin flour. As consumers tend to
avoid SO2 for its allergenic effect, it is suggested that hot-air oven
dried pumpkin flour without metabisulfite pre-treatment may be
more appropriate in terms of phenolics, bioavailable phenolics,