Microwave Freeze Drying of Type I Collagen from Bovine Bone

Bovine bone wastes can be used to produce high-quality collagen products. Freeze drying (FD) can yield the best quality of dried collagen but at the cost of long drying time, high energy consumption, and also the overall cost. A microwave-freeze-drying (MFD) technique was developed to dry collagens extracted from bovine bone. The relationship between corona discharge and microwave power at various pressures and moisture content conditions was studied to avoid the possibility of corona discharge during MFD collagens. A microwave loading scheme was optimized to avoid the corona discharge and resulted in high product quality with greatly reduced drying time. The results suggested that MFD has the potential to substitute for traditional FD in drying of high-value products.