Effect of Solid-State Osmotic Pretreatment on Emission Reduction, Resource Consumption and Product Quality in the Processing of Freeze-Dried Mango

Abstract

Consumption and emission reduction has become an inevitable trend in the development the food processing industry. While liquid-state osmotic pretreatment can save energy effectively in freeze-dried fruit processing, there is still a need to explore the effect of solid-state osmotic pretreatment. The effects of solid- and liquid-state osmotic pretreatment on waste liquid, resource consumption and product quality in the processing of freeze-dried mango were compared in this study. Results showed that compared with liquid-state infiltration (sucrose concentration of 60%, and solid-to-liquid ratio of 1:1; designated as L60), solid-state infiltration with sucrose concentration of 30% and 40% (designated as S30 and S40, respectively) significantly reduced the waste liquid discharge by 61.00% and 51.71%, the consumption of sucrose by 50.01% and 33.24%, and the total chemical oxygen demand of waste liquid by 60.13% and 41.83%, respectively. Compared with non-osmosed samples, the carbon emission of S30, S40 and L60 during processing was reduced by 10.59%, 12.21% and 8.80%, respectively. Compared with the liquid-state osmosis group, the solid-state osmosis group had lower nutrient retention (total phenolics and VC) during osmosis, but higher nutrient retention during lyophilization. After freeze-drying, the structure of the solid-state osmosis group was shrunk without collapse. In the trend of sustainable development, solid-state osmosis is superior to liquid-state osmosis in energy conservation and emission reduction, which is worthy of further research and exploration.

Keywords

• sustainable development; emission reduction; solid-state osmosis; freeze-drying; mango