Sugar is neutral in PH, but can be used to help balance out overly acidic food. I would be worried that in this case it would just bolster the flavor of the lemon if it is strong enough that you can detect it in the sauce.
Baking soda should work fine and just turns the acid into CO2 and salt, but if it has a flavor of lemon, it sounds like you are dealing with lemon oils in the sauce.
You could try cutting it with some fat (milk, cream or butter), and I would try adding more onion and/or garlic to complement/mask the lemon.
You should probably consider buying a different base tomato sauce in the future.
Sugar is neutral in PH, but can be used to help balance out overly acidic food. I would be worried that in this case it would just bolster the flavor of the lemon if it is strong enough that you can detect it in the sauce.
Baking soda should work fine and just turns the acid into CO2 and salt, but if it has a flavor of lemon, it sounds like you are dealing with lemon oils in the sauce.
You could try cutting it with some fat (milk, cream or butter), and I would try adding more onion and/or garlic to complement/mask the lemon.
You should probably consider buying a different base tomato sauce in the future.