Physicochemical property of pumpkin slices dehydrated with red algae extract

Abstract

Pumpkin (Cucurbita maxima) slices dehydrated with red algae extract (RAE) at 40% (w/w), and the dried samples were compared with freeze-and hot-air-dried samples for functional qualities. Rehydration ratios of freeze-and hot-air-dried, and RAE-treated samples were 5.79, 5.25, and 11.09 g/g, respectively. The RAE-treated samples had better results than those of freeze-dried or hot-air dried samples in terms of color and sensory evaluation. Total carotenoid content of the RAE-treated samples (574.54 μg/g) was lower than that of the freeze-dried samples (636.62 μg/g), but higher than that of the hot-air dried samples (235.27 μg/g). These results suggest that pumpkin slices can be dehydrated with RAE to preserve quality during storage.

Supercritical Carbon Dioxide Extraction of Carotenoids from Pumpkin (Cucurbita spp.): A Review

“…Hot air- [ 43 ], oven- [ 44 – 46 ], freeze- [ 44 , 47 , 48 ], convective- [ 44 , 49 – 51 ], microwave- [ 52 , 53 ], and osmotic- [ 54 – 56 ] drying methods, as well as combined treatments such as microwave-air [ 53 ] and vacuum-microwave [ 44 ], have been assessed for pumpkin flesh dehydration, and their effects on drying kinetics, chemical properties (moisture, ash, total and reducing sugars, fibers, proteins, lipids, and isoprenoids), texture and color of the final products have been investigated [ 7 , 16 , 47 ].…”

“…It is known that high temperature may alter the chemical composition, the color, the nutritional value and the organoleptic quality of the dried product. Color changes have been related to carotenoids degradation during pumpkin heat processing [ 43 , 57 ]. Nevertheless, only a few papers report data on the carotenoid composition of dehydrated pumpkin flesh ( Table 1 ).…”

“…Using conventional solvent extraction techniques, Wang et al . [ 43 ] found that hot-air treatment (70 °C) of pumpkin flesh slices ( C. maxima ), with 9.3% residual moisture, determined a strong reduction (65%) of total carotenoid content with respect to raw pumpkin (67.6 mg/100 g). In order to overcome these limitations, oven-drying is generally carried out under vacuum, at moderate temperature (40–60 °C) [ 44 , 45 ] or replaced by freeze-drying [ 45 , 48 ] which preserves, almost unaltered, the physico-chemical characteristics and quality of the raw plant material [ 45 ].…”

“…An approximately 6% reduction of total carotenoids, with respect to raw pumpkin, was reported by Wang et al . [ 43 ] in freeze-dried pumpkin slices with a residual moisture of 10.9%. Nawirska et al .…”

“…Wang et al . [ 43 ] proposed a dehydration method based on treatment of pumpkin slices with a red algae extract (RAE) at 40% ( w / w ), a promising new dehydrating agent. They found that RAE-treated samples had a residual moisture of 7.8% and a total carotenoid content approximately 15% lower than that measured in raw pumpkin and considerably higher than in hot air-dried pumpkin slices.…”