Exercise cannot tighten your loose skin, but you can minimize the amount of loose skin you have. If you have excess skin, patience is key as you wait for your skin to adjust to your new size.
A Pepsi takes between 30 and 45 minutes to freeze solid, depending on the temperature it was at before putting it in a typical home freezer. Be aware that most (but not all) Pepsi containers will burst if you keep them frozen for more than 2 hours.
For general digestion of proteins, suggested conditions are a 0.4% solution of pepsin in 10 mM HCl, and digestion for 30-90 minutes at 37 Â°C. Pepsin has optimal activity with native proteins at approximately pH 1.0, but with some denatured proteins the optimal activity is at approximately pH 1.5-3.5.9,10.