Table 3 Different drying methods applied to commercial species with interest in evaluating quality characteristics
Species | Drying methods | Drying conditions | Quality assessment | Conclusions | References |
|---|---|---|---|---|---|
Arthrospira sp. | Convective drying | Temperature: 70 °C; Time: 8 h | • Total protein analysis • Phycobiliprotein analysis | • Convection may be the most appropriate way to have food grade feedstock • The phycobiliprotein fractions are greatly affected by the drying method | [98] |
Freeze drying | Primary drying at − 30 °C for 6 h; secondary drying at − 52 °C for 48 h | ||||
Spray drying | Inlet air temperature: 180 °C; feed rate: 2.16 kg h−1 | ||||
Chlorella sp. | Convective drying | Temperature: 40–140 °C | • Chemical composition • Colour characterization • Surface structure analysis | • Chlorella should be dried at 60–80 °C • The dominant mechanism in Chlorella drying is diffusion | [99] |
Freeze drying | Temperature: − 50 °C; time: 24 h | • Protein analysis • Elemental composition • Lipid content analysis • Total chlorophylls analysis | • Freeze drying biomass provide the highest lipid content (10.7%) and total chlorophylls (204.6 µg mL−1) • The free fatty acids in the extract from solar drying biomass were highest | [100] | |
Solar drying | Temperature: 25–58 °C; time: 72 h | ||||
Spray drying | Inlet air temperature: 170–190 °C; outlet air temperature: 95.0 °C; feed rate: 7.00–9.00 mL min−1; encapsulants: maltodextrin | • Total carotenoid analysis • Moisture content and water activity • Colour properties • Drying efficiencies | • The moisture, total carotenoid, and chlorophyll-a contents were modelled significantly • The use of encapsulants in spray drying for food applications is essential | [101] | |
D. salina | Spray drying | Inlet air temperature: 120 °C and 140 °C; outlet air temperature: 95.0 °C; Feed rate: 400 mL min−1 and 600 mL min−1; encapsulants: maltodextrin, gum Arabic, gelatin | • Chlorophyll a content analysis • β-Carotene content analysis | • Microcapsules composed of maltodextrin: gum Arabic (90:10) exhibited the highest capability (93.22%) to preserve the β-carotene | [102] |
H. pluvialis | Freeze drying | Temperature: − 40 °C; time: 16 h | • Astaxanthin content analysis • Moisture content analysis | • Freeze–drying led to 41% higher astaxanthin recovery • Freeze–drying followed by vacuum-packed storage at − 20 °C can generate AUD$ 600 higher profit | [94] |
Spray drying | Inlet air temperature: 180 °C; outlet air temperature: 110 °C | ||||
Spray drying | Inlet air temperature: 180 °C; Outlet air temperature: 80 °C; Encapsulants: maltodextrin and gelatin (2.1:1) | • Astaxanthin content analysis • Microcapsule powder analysis | • Microencapsulation yield reached 38.02% and the highest encapsulation efficiency was 71.76% • Astaxanthin microcapsules could be applied in the food industry | [103] | |
E. gracilis | Spray drying | Inlet air temperature: 155 °C; Outlet air temperature: 95 °C | – | • The dried powder could be used directly in many Euglena powder products | [24] |
N. sphaeroides | Pulse-spouted microwave freeze drying | Temperature: − 45 °C; pulse frequency: 3 times h−1; pulse time: 0.3 s | • Colour properties • Texture • Flavour analysis • Ascorbic acid analysis • Antioxidant capacity | • Biomass by pulse-spouted microwave freeze drying has higher antioxidant activity, and has the advantages of short drying time and low energy consumption than freeze drying and convective drying | [104] |
Freeze drying | Temperature: − 45 °C | ||||
Convective drying | Temperature: − 60 °C |