Abstract
An efficient and effective drying method is desired by food processors to preserve fresh carrots. The present study evaluated the impact of combining oven drying (OD) with freeze-drying (FD) on the drying behaviour, energy requirements, cost implications and physicochemical properties of dried carrots. The drying conditions were as follows: 36 h of FD, 1 h of OD + 21 h of FD, 2 h of OD + 18 h of FD, 3 h of OD + 15 h of FD, and 9 h of OD. Although the OD had the shortest (9 h) drying time, the dried carrot slices were of poor quality. Compared to FD only, the combination of OD and FD (OD-FD) reduced the drying time by 39-50%. When compared to OD and OD-FD combinations, FD carrot slices showed significantly (p<0.05) higher β-carotene (0.30-0.72 mg g-1 DM), lycopene (0.36-0.87 mg g-1 DM), total phenolic content (7.12-10.36 mg GAE 100 g-1 DM), and DPPH antioxidant capacity (6.54-9.88 mM AAE 100 g-1 DM). However, OD-FD significantly decreased energy consumption and cost by 40-56% compared to only FD. Overall, drying at 1 h OD+ 21 h FD produced better β-carotene, total phenolic content and radical scavenging activity retention while reducing energy consumption and costs; therefore, this could be an energy-efficient and time saving drying method to produce good quality and nutrient-rich dried carrot slices.
Original language | English |
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Pages (from-to) | 75-82 |
Number of pages | 8 |
Journal | Acta Horticulturae |
Issue number | 1387 |
DOIs | |
Publication status | Published - 2024 |
Keywords
- bioactive compounds
- carrot slices
- energy requirements
- freeze drying
- oven drying
ASJC Scopus subject areas
- Horticulture