A person I known recently created a Centella asiatica vegetable juice.
She states that we should add some sugar (e.g. 2 tea-spoons for 1.5 liter of vegetable water) to reduce the spoil rate of the juice.
I disagree because I feel that the concentration rate is too low for that - it would increase the spoil rate instead. However, it bases on just my feeling.
I think water, sugar and honey can be stored almost forever, but syrup has relatively short storage time.
There has to be some figure of sugar concentration (e.g.
X gram of sugar per 1 liter of water) that make the spoilage rate maximum (parabola?), right?
How is the relation between sugar concentration and spoil rate?
How much it can be applied to vegetable juice?
Please also provide some graph/reference/research to support your answer.