Hey! I guesse you CAN use it if you must.... this from the book:
The maple syrup is a balanced form of positive and negative Sugar and must be used, not some "substitute". There are three grades of maple syrup. Grade A is the first run—mild in taste, sweet and with less minerals than the other grades. It is more expensive and less desirable but it may be used. Grade B is the second run with more minerals plus more maple taste. It is more suitable for the diet and is less expensive. Grade C is the third run with even more minerals and still stronger taste of maple and slightly less pleasant for most people, although acceptable in the diet. It is lower in price. As Grade C is less expensive it can be used as an excellent sweetening agent in preparing foods. The strong maple flavor blends very well.