In this study, the potential of infrared assisted freeze-drying (IRAFD) was
tested for the production of shelf-stable edible insects:
Protaetia
brevitarsis
larva (larva of white-spotted flower chafer). The IRAFD
system was customized using an infrared lamp, K-type thermocouple, controller,
and data acquisition system. The infrared lamp provided the sublimation energy
for rapid freeze-drying (FD). The IRAFD conditions were continuous IRAFD-5.0
kW/m
2
and IRAFD-5.0 kW/m
2
at different weight
reduction (WR) (10%, 20%, and 30%). The continuous IRAFD
reduced the drying time to 247 min compared to the 2,833 min duration of FD
(p<0.05). The electrical energy could be reduced by more than 90%
through infrared radiation during FD (p<0.05). The Page model resulted in
the best prediction among the tested drying kinetic models. In terms of quality,
IRAFD showed significantly lower hardness, chewiness, and higher protein levels
than hot air drying and FD (p<0.05). IRAFD better preserved the glutamic
acid (6.30–7.29 g/100 g) and proline (3.84–5.54 g/100 g). The
external product appearance after IRAFD exhibited more air pockets and volume
expansion, which might result in a good consumer appeal. In conclusion, this
study reports the potential of IRAFD in producing shelf-stable and value-added
edible insects.