Assessment of the Flavor of Syrup Produced with High-Brix RO Systems
Concentrating sap with reverse osmosis (RO) substantially increases the efficiency and profitability of processing maple sap into syrup by reducing the amount of fuel and time required to complete concentration to syrup density in the evaporator, with gains proportional to the level of sap pre-concentration. Because most flavor development in maple syrup occurs through nonenzymatic browning reactions as sap is processed with heat in the evaporator, it has often been speculated that reduced evaporator processing time resulting from the use of RO might also result in perceptible impacts on syrup flavor. However, a series of controlled experiments conducted at the University of Vermont Proctor Maple Research Center using the same sap processed to different levels with RO determined that concentrating sap up to 21.5% prior to boiling in standard maple evaporators had no substantive effects on syrup composition or flavor.