I shower daily and maintain hygiene strictly. but lately, my armpits smell very pungent, salty more like semen. why is that? there are no pimples.

Armpits: Can be many things. See your doctor for a complete check up to make sure that there are not any systemic or body causes

Body odor: Body odor is very much affected by our diet. Medications and stress can also change it. Staying well hydrated with pure water. eating a 'clean' diet (avoid fast foods, pre-packaged products, preservatives, excessive red meat) and regularly exercising will help reduce unnatural body odor.