Patenting "flavors" is almost impossible and definitely not something you typically see. Look at every name brand of every food item in your local grocery store and then look next to the item for the "store brand" item which is virtually the same. If the big boys aren't able to protect their IP, I wouldn't worry about it... legally. I'm not talking ethically.
The original author of your starter recipe may have a copyright protection because it is in the book and the book has a copyright. However, they intend for you to MAKE it and USE it. Look at your book and see if there is anything there that says that these recipes cannot be used commercially. Most likely there isn't. The author and publisher likely doesn't care, or they wouldn't have published their prized recipe. Even if they did, they'd find it fairly impossible to come back and protect the intellectual property.
Legally... don't sweat it one bit.
Ethically... don't sweat it. You are modifying what you learned from a source made available to the general public.
Pork Pullin Plowboys
(and Smoke on Wheels
Save a hog, ride a plowboy!
Todd Johns (me); Blue Springs, MO
Randy Hinck (PigBoy); Concordia, MO
Andy Groneman (Hodedo); KC, KS (Cameo Appearances)
FEC-500SS; FEC-100 (Right handed); FEC-100 (Left handed); Country Smoker Tailgater; Big Green Egg (2-large, small, mini); Cookshack Pellet Fired Charbroiler