Does adding lemon juice in the dough extents its shelf life time? As I notice adding lemon juice can delay the appearances of black spots. But it also turned out weirdly bland, without any flavor. And I think it is the issues of adding lemon juice. Also, the roti tastes fresh and without the complex taste (sweetness) that brought by the long period of resting, as the longer you rest, the more flavor it creates. The results also came out less crisper than usual. I also tried to use vinegar and it came out the same. So does asorbic acid (vitamin C) would do the same "side effect" as I know this is a very common preservative when it comes to bread making, and it taste sour also. How much ascorbic acid need to be added in 1000g of flour?