Motivated by the urgent need to address environmental concerns associated with traditional food packaging, this review explores the shift towards sustainable, bio-based packaging solutions.
Hempseed protein has gained increasing attention for its sustainability and nourishment. This study aimed to investigate the effects of spray drying and freeze drying on the physicochemical properties, functionality, and digestibility of hempseed protein isolate (HPI). Compared to undried-HPI, both drying techniques altered physicochemical and structural properties. Particularly, protein denaturation temperature increased in freeze-dried HPI (FD-HPI) and spray-dried HPI (SD-HPI) samples (∼90 °C) than in undried-HPI (82.5 °C). Lysine content decreased from 38.26 mg/g in undried-HPI to 35.03 and 33.18 mg/g in FD-HPI and SD-HPI, respectively. Results revealed the loss of 26 and 17 kDa bands after drying. Notably, FD-HPI exhibited higher emulsifying stability and oil-holding capacity than SD-HPI. While both FD-HPI and SD-HPI had higher digestibility than undried-HPI, a 50% reduction in the liberation of free α-amino groups after digestion was found. This study provided information regarding changes in HPI after drying, offering insights for HPI production and application in the food industry.
Drying is an extremely energy-intensive process. Superheated steam as a drying medium can improve the energy efficiency of the drying processes. In superheated steam drying, waste heat can be recovered by condensing the exhaust steam or raising its specific enthalpy. Spray drying is widely used in industry, even though its energy efficiency is often low. Substitution of air by superheated steam as a drying medium in a spray dryer may reduce the energy consumption of the drying process by 20–30%; moreover, if excess steam generated by moisture evaporation is upgraded to a higher temperature level and reused for drying, the energy demand could be decreased by even 80%. A literature review showed that superheated steam spray drying was successfully applied for both thermally resistant and a wide range of thermally sensitive materials. Superheated steam drying gives a number of advantages in terms of product properties, i.e., higher particle porosity due to rapid moisture evaporation results in improved powder rehydration properties. Additionally, steam drying may be applied for in situ particle crystallization. Taking into account the advantages of superheated steam drying and the potential application of this technology in spray drying systems, there is a great need for further research in this field. This literature review aimed to present an energy-saving solution, i.e., superheated steam spray drying process, showing its advantages and potential applications, followed by drying kinetics, providing analysis of the research papers on experimental studies as well as mathematical modeling of this drying technique.