A: wikipedia says it "It is used as a preservative and antioxidant in food and is also known as E223"
There's so many coconut milk brands on the market I don;t know which one to go for. I've being buying young coconuts online from Thai Foods Market for 600 yen a pop and I thought I'd get some other items to get up to 10,000 and get free delivery. Their Chaokoh coconut milk is 400 yen, so I checked in the local supermarket and their Chef's Choice coconut milk was much cheaper. So then I started thinking that some coconut milks are better than others. Some coconut milks like Chef's choice contain sodium metabisulfite, other's contain other antioxidants, preservatives and thickeners. Coconut milk can separate in the can into oily cream and water so most brands put in a thickener like guar gum. It's harmless apparently.
So which coconut milk is better? Well, none of the above.