Acai Goji

Is necessary to put preservatives in in a supplement health drink if it is bottled in plastic?
I have been told that supplement juices ie; noni goji acai bottled in plastic containers have to contain preservatives and glass bottles don’t. This is supposedly to make sure no air seeps through the pores in the plastic bottles and creates bacteria, therefore causing the need for preservatives to keep the juice from spoiling. Any thoughts or facts?
No, that’s not true because I take a vitamin and Mineral Supplement called Vemma and it doesn’t have it in their’s, (they used to but they took it out and I’m glad they did) and they have it in plastic bottles. I thought that the reason why they put preservatives in it such as sodium benzoate to keep it longer. I didn’t think it mattered what type of bottle it was in. Xango used to have sodium benzoate in their supplement and they use glass bottles. I don’t know if they still do or not though.
Acai, Goji, Noni & Mangosteen: the Super Fruits!