Maple syrup production from sap preconcentrated to ultra high °Brix by membrane technology: Composition and properties

Maple syrup is produced typically from maple sap concentrated by nanofiltration or reverse osmosis at a moderate degrees Brix level ranging from 6 to 16 degrees Brix followed by heat evaporation. Recently, new membrane processes have been developed to concentrate maple sap to ultra-high degrees Brix reaching up to 40 degrees Brix. The aim of this study is to evaluate the effect of this ultra-high concentration of sap on the composition, the properties and the cost of corresponding maple syrup. Results showed some differences in chemical composition and properties between syrups produced from low and ultra-high concentration of sap. Syrups produced from ultra-high degrees Brix concentrated sap had lower concentrations of potassium and polyphenols, a lighter color and distinctive flavor. This was mainly observed when no modification were applied to the heating pattern in the evaporator pans. However, syrups produced by modulation of the heating pattern in the evaporator had color, flavor and taste similar to control syrups. These results demonstrate that syrups with comparable sensory properties can be obtained from low and ultra-high concentrated sap by adjusting the heating time depending on the initial degrees Brix. The concentration process to ultra high degrees Brix allows for a concomitant reduction of the production costs and a modulation of syrup quality.