During the conversion of fresh milk to curd, the vitamin B12 content increases. This is because the bacteria involved in the fermentation process of turning milk into curd, such as Lactobacillus, produce vitamin B12.
Vitamin B12 is not significantly present in fresh milk but is synthesized by the bacteria during the fermentation process of curd, thus making curd a good source of this vitamin.
Hereβs a breakdown of the other options:
(1) B2 (Riboflavin): This vitamin is present in milk, but its concentration does not significantly increase during the conversion to curd.
(2) B5 (Pantothenic acid): While milk contains vitamin B5, its levels do not increase during the conversion process.
(4) B1 (Thiamine): Vitamin B1 is also present in milk, but the fermentation process does not increase its levels.
Thus, the correct answer is (3) B12.